Battery cell, battery and electric device

Abstract

The present application relates to a battery cell, a battery and an electric device. The battery cell comprises a casing having an accommodating cavity, wherein the accommodating 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 supporting the electrode assembly, wherein the fixing member is provided with a liquid passage channel penetrating along the thickness of the first wall. The fixing member comprises a supporting surface in contact with the electrode assembly; the area of the supporting surface accounts for at least 50% of the surface area of the electrode assembly with which the supporting surface is in contact. In the present application, the provision of the fixing member that provides support between the electrode assembly and the first wall not only limits expansion deformation of the electrode assembly, but also reduces the probability of the electrode assembly wobbling inside the casing. In addition, the liquid passage channel on the fixing member enables smooth flow-through of an electrolyte, providing sufficient accommodating space for the electrolyte, and reducing the probability of problems such as excessive hydraulic pressure inside the casing or electrolyte overflow.

Description

Battery monomer, battery and electric device Related applications

[0001] The present application claims priority to the Chinese patent application No. 2024222887172, filed on September 19, 2024, and entitled "Battery monomer, battery and electric device", the contents of which are hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery monomer, a battery and an electric device. BACKGROUND

[0003] In the structure of the battery monomer, the electrode assembly is placed inside the shell, and the electrolyte is filled inside the shell, so that the electrolyte can be fully soaked in the electrode assembly, and the electrode assembly can smoothly undergo electrochemical reaction.

[0004] The electrode assembly will swell and deform during the electrochemical reaction, which not only affects the use performance of the electrode assembly itself, but also squeezes the electrolyte, which is easy to cause problems such as excessive internal pressure of the shell or electrolyte overflow. SUMMARY

[0005] Based on this, the present application provides a battery monomer, a battery and an electric device.

[0006] In a first aspect, the present application provides a battery monomer, comprising a shell, an electrode assembly and a fixing member, the shell has a receiving cavity, the receiving cavity has a first wall; the electrode assembly is arranged in the receiving cavity; the fixing member is arranged between the electrode assembly and the first wall and supports the electrode assembly, and a liquid passing channel is formed on the fixing member and penetrates the fixing member along the thickness direction of the first wall; wherein the fixing member comprises 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 therewith.

[0007] By arranging the fixing member, the swelling and deformation of the electrode assembly can be limited, and the probability of the electrode assembly being damaged by knocking due to shaking in the shell can be reduced. In addition, since the liquid passing channel is formed on the fixing member and penetrates the fixing member, the electrolyte in the receiving cavity can smoothly flow in the receiving cavity through the liquid passing channel, so that more sufficient space can be provided for the electrolyte, the probability of problems such as excessive internal pressure of the shell or electrolyte overflow can be reduced, and the use performance of the battery monomer is more stable.

[0008] In some embodiments, the area of the supporting surface accounts for 70% to 100% of the surface area of the electrode assembly in contact therewith.

[0009] Through the above structure, the contact area between the supporting surface and the surface of the corresponding electrode assembly is increased, and the supporting effect of the fixing member on the electrode assembly is further improved.

[0010] In some embodiments, the liquid-passing channel includes a main flow channel arranged through the first wall in the thickness direction, and the volume of the main flow channel accounts for at least 50% of the volume of the fixing member.

[0011] In some embodiments, the liquid-passing channel further includes a branch flow channel arranged through the fixing member in a direction intersecting the thickness direction of the first wall, and the total volume of the main flow channel and the branch flow channel accounts for at least 80% of the volume of the fixing member.

[0012] In some embodiments, in the direction intersecting the supporting surface, the ratio between the height of the fixing member and the height of the shell ranges from 0.03 to 0.4.

[0013] By setting the ratio between the height of the fixing member and the height of the shell in the above range, the volume energy density of the battery monomer is effectively improved on the premise of improving the flow performance of the electrolyte inside the shell and in the liquid-passing channel.

[0014] In some embodiments, in the direction intersecting the supporting surface, the ratio between the height of the fixing member and the height of the shell ranges from 0.03 to 0.25.

[0015] In this way, the rebound ratio of the metal negative electrode system can be further optimized, the volume energy density advantage of the battery monomer can be further expanded, and the internal structure stability and reliability can be further improved.

[0016] In some embodiments, the ratio between the volume of the fixing member and the volume of the accommodating cavity ranges from 5% to 40%.

[0017] When the ratio between the volume of the fixing member and the volume of the accommodating cavity is set in the above range, not only can the basic electrolyte flow space be met, but also the probability of opening the explosion-proof valve due to excessive hydraulic pressure caused by the full charging process can be reduced. Moreover, the rebound ratio of different metal negative electrode systems can be met, and the volume energy density advantage of the battery monomer can be improved.

[0018] In some embodiments, the ratio between the volume of the fixing member and the volume of the accommodating cavity ranges from 10% to 25%.

[0019] 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 monomer 100.

[0020] In some embodiments, the shell includes a body and a top cover, the top cover is sealed 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 inside of the accommodating cavity.

[0021] Through the above structure, in the assembling process, first, the electrode assembly is arranged in the accommodating cavity, then the fixing member is arranged on the side surface of the electrode assembly facing the opening, and finally the top cover sealing cover is arranged at the opening, so that the assembly of the battery monomer can be realized, which is convenient to operate.

[0022] In some embodiments, the top cover is provided with an electrode terminal, the electrode assembly is formed with a first tab and a second tab, and the first tab and the second tab are arranged towards the top cover and electrically connected with the electrode terminal through the liquid passing channel.

[0023] Through the above structure, the first tab and the second tab are electrically connected with the electrode terminal on the top cover, so that the smooth output and input of the battery monomer energy can be realized. In addition, the liquid passing channel on the fixing member not only realizes the circulation of the electrolyte, but also provides the first tab and the second tab to be smoothly arranged and electrically connected with the electrode terminal.

[0024] In some embodiments, the body has a first side wall and a second side wall oppositely arranged and both intersecting with the top cover, and the first side wall and the second side wall are both provided with an electrode terminal; wherein the opposite ends of the electrode assembly are respectively formed with a first tab and a second tab, the first tab is arranged towards the first side wall and electrically connected with the electrode terminal on the first side wall, and the second tab is arranged towards the second side wall and electrically connected with the electrode terminal on the second side wall.

[0025] Through the above structure, the electrode assembly has tabs on the left and right sides, and the first tab and the second tab can be electrically connected with the electrode terminal through the soft connection. First, when the electrode assembly is arranged in the accommodating cavity, the liquid level of the electrolyte is parallel to the top cover, and the section of the electrode assembly, i.e. the end face formed with the first tab and the second tab, is perpendicular to the liquid level of the electrolyte, so that the electrolyte can better infiltrate into the interior of the electrode assembly through the section, and the electrolyte can be better absorbed. In addition, the first tab and the second tab are arranged towards the first side wall and the second side wall, and the fixing member is supported between the electrode assembly and the top cover, so that the support surface and the electrode assembly can be more stably attached, and the support effect is improved.

[0026] In some embodiments, a gas permeable hole is provided through the top cover and communicates with the accommodating cavity, and a gas permeable assembly is arranged in the gas permeable hole, which is configured to realize one-way gas permeation from the interior to the exterior of the accommodating cavity.

[0027] In some embodiments, the electrode assembly is a negative electrode-free electrode assembly.

[0028] 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 swelling deformation of the electrode assembly. Moreover, the support of the fixing member on the electrode assembly can improve the stability of the electrode assembly in the accommodating cavity and reduce the probability of problems such as deviation or shaking of the electrode assembly during the cyclic use. On the other hand, the liquid passing channel is arranged on the fixing member, which can provide a flow channel for the electrolyte and provide a larger accommodation space for the electrolyte, effectively improving the problem of excessive hydraulic pressure in the accommodating cavity and reducing the probability of electrolyte overflow.

[0029] In a second aspect, the application also provides a battery cell as described above.

[0030] In a third aspect, the application also provides a battery as described above.

[0031] The battery cell, the battery and the electric device described above can be set by the fixing member to 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 can the swelling deformation of the electrode assembly be limited, but also the probability of damage caused by the shaking of the electrode assembly in the shell can be reduced. In addition, the liquid passing channel is arranged on the fixing member, so that the electrolyte in the accommodating cavity can flow smoothly in the accommodating cavity through the liquid passing channel. In this way, the electrolyte can be provided with more sufficient accommodation space, the probability of problems such as excessive hydraulic pressure or electrolyte overflow in the shell can be reduced, and the use performance of the battery cell can be more stable. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments of the application. Obviously, the drawings described below are only some embodiments of the application, and other drawings can be obtained by the drawings without creative labor.

[0033] FIG. 1 is a structural schematic view of a battery cell according to one or more embodiments.

[0034] FIG. 2 is a top view of a fixing member in a battery cell according to one or more embodiments.

[0035] FIG. 3 is a top view of a fixing member in a battery cell according to one or more embodiments.

[0036] FIG. 4 is a front view of a fixing member in a battery cell according to one or more embodiments.

[0037] FIG. 5 is a left view of a fixing member in a battery cell according to one or more embodiments.

[0038] FIG. 6 is a structural schematic diagram of a battery cell according to one or more embodiments.

[0039] Legend: 100, battery cell; 10, shell; 20, electrode assembly; 30, fixing member; 11, accommodating cavity; 12, body; 13, top cover; 14, electrode terminal; 15, first side wall; 16, second side wall; 17, gas permeable hole; 21, first tab; 22, second tab; 31, liquid passing channel; 311, main flow channel; 312, branch flow channel. DETAILED DESCRIPTION

[0040] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described and it is to be understood that the present application is not limited to the specific embodiments described below.

[0041] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0042] In addition, if the terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "multiple" appears, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0043] In the present application, unless specifically defined otherwise, if there is an appearance of the terms "installation", "connection", "connection", "fixation" and the like, these terms should be broadly understood. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] In the present application, unless specifically defined otherwise, if there is a similar description of the first feature "on" or "under" the second feature, it can mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0045] It should be noted that if an element is referred to as "fixed to" or "provided on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are for illustrative purposes only and are not the only embodiment.

[0046] At present, from the development of market situation, the application of power battery is more and more widely. Power battery is not only applied to energy storage power supply system of water power, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment and aerospace and other fields. With the continuous expansion of the application field of power battery, the demand of its market is also increasing.

[0047] In the battery structure, it usually includes a box body and a battery monomer, and the battery monomer is placed in the box body, so as to provide a containing space for the battery monomer through the box body, and the battery monomer is well protected.

[0048] The battery cell is the smallest unit of a battery. For the battery cell, a shell and an electrode assembly contained in the shell are usually included. The shell is filled with electrolyte, which fully wets the electrode assembly, so that the electrode assembly can smoothly undergo electrochemical reactions.

[0049] During the electrochemical reaction of the electrode assembly, the electrode assembly will swell and deform. After swelling, the electrode assembly will not only affect its own performance, but also squeeze the electrolyte in the shell, causing excessive internal pressure in the shell or causing the electrolyte to overflow.

[0050] In addition, the change in swelling and deformation of different types of battery cells is also different. For example, in a negative electrode-free battery system, the negative electrode current collector cannot lock the electrolyte because no negative active material is provided on the negative electrode current collector. The negative electrode current collector itself has poor liquid retention capacity, and the volume change rate is also larger.

[0051] Therefore, the negative electrode-free battery system is more likely to cause the electrolyte to be squeezed out of the shell, and therefore more space is needed to accommodate the change in the liquid level of the electrolyte.

[0052] Based on the above considerations, in order to solve the problem that the swelling and deformation of the electrode assembly not only affect the performance of the electrode assembly itself, but also squeeze the electrolyte, which easily causes excessive internal pressure in the shell or electrolyte overflow, one or more embodiments of the present application provide a battery cell. By providing a fixing member, a supporting effect is provided between the electrode assembly and the inner wall of the corresponding accommodation cavity, so that the electrode assembly can be more stably arranged in the accommodation cavity. In this way, the swelling and deformation of the electrode assembly can be limited, and the probability of damage to the electrode assembly caused by the shaking of the electrode assembly in the shell can be reduced. In addition, the electrolyte in the accommodation cavity can flow smoothly in the accommodation cavity through the liquid passage provided on the fixing member. In this way, more sufficient accommodation space can be provided for the electrolyte, the probability of problems such as excessive internal pressure in the shell or electrolyte overflow can be reduced, and the performance of the battery cell can be more stable.

[0053] It should be noted that the battery (Battery Apparatus) mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly (Battery Cell Assembly) can include a plurality of battery cells connected in series, parallel or mixed connection through a busbar component.

[0054] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells. As an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells into a single module. As an example, the battery module can be formed by bundling a plurality of battery cells by a cable tie.

[0055] In some embodiments, the battery can be a battery pack, which includes a case and one or more battery cell assemblies housed in the case.

[0056] As an example, the battery cell assembly can be a battery module, which can be housed in the case by fixing the battery module in the case.

[0057] As an example, the battery cell assembly can also be housed in the case by directly fixing a plurality of battery cells in the case.

[0058] Referring to FIGS. 1 and 2, one embodiment of the present application provides a battery cell 100, which includes a housing 10, an electrode assembly 20, and a fixing member 30. The housing 10 has a receiving cavity 11 with a first wall (not shown in the figure), and the electrode assembly 20 is disposed in the receiving cavity 11. The fixing member 30 is disposed between the electrode assembly 20 and the first wall and supports the electrode assembly 20, and the fixing member 30 has a liquid passage 31 that penetrates the fixing member 30 along the thickness direction of the first wall. The fixing member 30 includes a support surface that contacts the electrode assembly 20, and the area of the support surface accounts for at least 50% of the surface area of the electrode assembly 20 that contacts the support surface.

[0059] It should be noted that the housing 10 refers to a structure for housing the electrode assembly 20, electrolyte, and other functional structures, and providing protection for the electrode assembly 20 and other structures. The housing 10 is designed to be hollow inside, forming the receiving cavity 11, and the electrode assembly 20 is placed in the receiving cavity 11, and the receiving cavity 11 is filled with electrolyte, so that the electrolyte can fully soak the electrode assembly 20, and the electrode assembly 20 can smoothly perform electrochemical reactions.

[0060] The electrode assembly 20 refers to a component in which an electrochemical reaction actually occurs in the battery cell 100, and is generally formed by stacking or winding a positive electrode sheet, a separator, and a negative electrode sheet in this order. Among them, the positive electrode sheet and the negative electrode sheet generally include a current collector, and the current collector is mainly a metal foil. An active material can be coated on the current collector, for example, a positive electrode active material is coated on the current collector to form a main part of the positive electrode sheet, and a portion in which the active material is not coated is formed as a positive electrode tab. Similarly, a negative electrode active material is coated on the current collector to form a main part of the negative electrode sheet, and a portion in which the active material is not coated is formed as a negative electrode tab.

[0061] When the active material is coated on the current collector, when the electrolyte is filled in the case 10, the positive electrode active material and the negative electrode active material are infiltrated with the electrolyte, and a liquid retention function for the electrolyte is achieved, so that the electrolyte can sufficiently infiltrate the electrode assembly 20, and the electrode assembly 20 can smoothly undergo an electrochemical reaction.

[0062] When the electrode assembly 20 undergoes an electrochemical reaction, the electrode assembly 20 will be deformed by swelling. At present, in order to improve the energy density of the battery cell 100, the space reserved inside the case 10 is usually small, so that the electrode assembly 20 can be more fully filled inside the case 10. However, in this way, when the electrode assembly 20 is deformed by swelling, firstly, the structure of the electrode assembly 20 after swelling deformation changes, which will affect the use performance of the electrode assembly 20 itself. Secondly, after the electrode assembly 20 swells, it will squeeze the electrolyte inside the case 10, which is easy to cause the internal hydraulic pressure of the case 10 to be too large, and even cause the electrolyte to overflow, which will affect the use performance of the battery cell 100.

[0063] Based on this, the electrode assembly 20 is arranged in the accommodation cavity 11, a mounting position is formed between the electrode assembly 20 and the first wall of the accommodation cavity 11, and the fixing member 30 is arranged in the mounting position. The fixing member 30 can support the electrode assembly 20 and the first wall in the mounting position, so that the electrode assembly 20 can be more stably arranged in the accommodation cavity 11.

[0064] Specifically, the first wall can be one of the cavity inner walls of the accommodation cavity 11, that is, the fixing member 30 can be supported between the electrode assembly 20 and one of the cavity inner walls of the accommodation cavity 11, and at this time, the number of the fixing member 30 is one. Of course, the first wall can also be two or more cavity inner walls of the accommodation cavity 11, that is, the fixing member 30 can also be supported between the electrode assembly 20 and two or more cavity inner walls of the accommodation cavity 11 at the same time, and at this time, the fixing member 30 is correspondingly provided as two or more.

[0065] As a specific embodiment, the fixing member 30 is provided as one, and is supported between the electrode assembly 20 and the inner wall of one of the cavities. The electrode assembly 20 is stably arranged in the accommodation cavity 11 by the support of the fixing member 30. In addition, the fixing member 30 also functions as a limiting member for the electrode assembly 20, and can effectively limit the expansion deformation of the electrode assembly 20.

[0066] Further, the liquid passage 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 arranged in the accommodation cavity 11, and the electrolyte is filled into the accommodation cavity 11. The electrolyte can flow smoothly in the accommodation cavity 11 through the liquid passage 31 formed through the fixing member 30, on the one hand, the electrolyte can more evenly soak the electrode assembly 20, on the other hand, when the liquid level of the electrolyte changes, the electrolyte in the accommodation cavity 11 can be more evenly distributed.

[0067] When the fixing member 30 is supported between the electrode assembly 20 and the inner wall of the corresponding accommodation cavity 11, the surface of the fixing member 30 in contact with the electrode assembly 20 is a support surface, and the area of the support surface accounts for at least 50% of the surface area of the electrode assembly 20 in contact therewith. That is, the area of the support surface is not less than 50% of the surface area of the electrode assembly 20 in contact therewith.

[0068] In this way, the contact area of the support surface with the electrode assembly 20 is larger, and a larger area of the electrode assembly 20 can be supported, so that the support effect of the fixing member 30 on the electrode assembly 20 is more stable.

[0069] Therefore, by arranging the fixing member 30, not only can the expansion deformation of the electrode assembly 20 be limited, but also the probability of the electrode assembly 20 being damaged due to bumping caused by shaking of the electrode assembly 20 inside the shell 10 can be reduced. In addition, since the liquid passage 31 is formed through the fixing member 30, the electrolyte in the accommodation cavity 11 can flow smoothly in the accommodation cavity 11 through the liquid passage 31, so that more sufficient accommodation space can be provided for the electrolyte, the probability of problems such as excessive liquid pressure or electrolyte overflow inside the shell 10 can be reduced, and the use performance of the battery monomer 100 is more stable.

[0070] 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 therewith.

[0071] Further, the area of the support surface is not less than 70% of the surface area of the electrode assembly 20 in contact therewith, and is not greater than 100% of the surface area of the electrode assembly 20 in contact therewith. For example, the support surface can be made to completely cover the surface of the electrode assembly 20 in contact therewith, i.e., the area of the support surface is equal to 100% of the surface area of the electrode assembly 20 in contact therewith. In this way, the support surface can completely 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 accommodation cavity 11, further improving the support effect.

[0072] In this way, through the above structure, the contact area between the support surface and the surface of the corresponding electrode assembly 20 is increased, and the support effect of the fixing member 30 on the electrode assembly 20 is further improved.

[0073] In some embodiments, the liquid passage 31 includes a main flow passage 311 disposed through the thickness direction of the first wall, and the volume of the main flow passage 311 accounts for at least 50% of the volume of the fixing member 30.

[0074] Specifically, the main flow passage 311 is disposed through the thickness direction of the first wall, i.e., one end of the main flow passage 311 communicates with the first wall, and the other end communicates with the electrode assembly 20, so that the electrolyte or other fluid in the accommodation cavity 11 can smoothly pass through the main flow passage 311.

[0075] Further, the volume of the main flow passage 311 accounts for at least 50% of the volume of the fixing member 30, specifically, the fixing member 30 can be divided into a through-hole part and a solid part, wherein the through-hole part is the part of the main flow passage 311, and the solid part is the other part of the fixing member 30 which is not provided with a through hole.

[0076] When the main flow passage 311 is provided as one, the volume of the main flow passage 311 accounts for greater than or equal to 50% of the total volume of the fixing member 30. When the main flow passage 311 is provided as two or more, the total volume of all the main flow passages 311 accounts for greater than or equal to 50% of the total volume of the fixing member 30.

[0077] In this way, on the basis of ensuring the support effect of the fixing member 30, the smooth flow of the electrolyte or other fluid in the accommodation cavity 11 can be realized.

[0078] In addition, the shape of the main flow passage 311 can be, but is not limited to, rectangular, cylindrical, conical or other shapes, which will not be described here.

[0079] 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 the main flow channel 311 formed on the fixing member 30 can also realize smooth flow of the electrolyte or other fluids in the accommodation cavity 11, thereby providing more accommodation space for the electrolyte or other fluids.

[0080] As shown in FIGS. 3, 4 and 5, in some embodiments, the liquid passing channel 31 further includes a branch flow channel 312 in communication with the main flow channel 311, the branch flow channel 312 is arranged through the fixing member 30 in a direction intersecting the thickness direction of the first wall, and the total volume of the main flow channel 311 and the branch flow channel 312 accounts for at least 80% of the volume of the fixing member 30.

[0081] Specifically, the branch flow channel 312 can be arranged through in a direction intersecting the thickness direction of the first wall, or arranged through in a direction perpendicular to the thickness direction of the first wall. The branch flow channel 312 is in communication with the main flow channel 311, so that the liquid passing channel 31 in the fixing member 30 can pass through in different directions up, down, left and right, respectively, to make the electrolyte flow more smoothly.

[0082] Further, the branch flow channel 312 can be provided as one or more, when the branch flow channel 312 is provided as one, the volume of the branch flow channel 312 and the total volume of all main flow channels 311 account for more than or equal to 80% of the total volume of the fixing member 30. When the branch flow channel 312 is provided as multiple, the total volume of all branch flow channels 312 and the total volume of all main flow channels 311 account for more than or equal to 80% of the total volume of the fixing member 30.

[0083] In this way, the electrolyte in the accommodation cavity 11 can flow in all directions through the main flow channel 311 and the branch flow channel 312, making the electrolyte flow more smoothly.

[0084] It can be understood that the shape of the branch flow channel 312 can be but not limited to rectangular, cylindrical, conical or other shapes, which will not be described here.

[0085] Through the above structure, the electrolyte in the accommodation cavity 11 can flow in all directions through the main flow channel 311 and the branch flow channel 312, further increasing the accommodation space of the electrolyte.

[0086] As shown in FIG. 6, in some embodiments, in the direction intersecting the support surface, the ratio between the height H1 of the fixing member 30 and the height H2 of the shell 10 is in the range of 0.03-0.4.

[0087] Specifically, the height of the fixing member 30 needs to consider the machinability of the fixing member 30 itself and the height capability bottleneck of the shell 10 to ensure that the basic electrolyte flow space can be met, and to ensure that the explosion-proof valve will not be opened due to excessive hydraulic pressure caused by the full charging process of the electrolyte.

[0088] Further, under the condition of meeting the rebound ratio of different metal negative electrode systems, it is necessary to ensure that the battery monomer 100 has the advantage of volume energy density, and the limitation in the height direction is the key to meet the support of mechanical parts and the stability of the internal structure.

[0089] Based on this, the ratio between the height H1 of the fixing member 30 and the height H2 of the shell 10 is set to the above range, which effectively improves the volume energy density of the battery monomer 100 under the premise of improving the flow performance of the electrolyte inside the shell 10 and the liquid passage 31.

[0090] In some embodiments, the ratio between the height H1 of the fixing member 30 and the height H2 of the shell 10 in the direction intersecting the support surface is in the range of 0.03-0.25.

[0091] As a specific implementation, 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, more greatly expand the volume energy density advantage of the battery monomer 100, and further improve the internal structure stability and reliability.

[0092] In some embodiments, the ratio between the volume of the fixing member 30 and the volume of the accommodating cavity 11 is in the range of 5%-40%.

[0093] Specifically, the volume ratio of the fixing member 30 in the accommodating cavity 11 will affect the size of the electrolyte flow space in the accommodating cavity 11 and the volume energy density of the battery monomer 100 as a whole.

[0094] When the ratio between the volume of the fixing member 30 and the volume of the accommodating cavity 11 is set to the above range, not only can the basic electrolyte flow space be met, but also the probability of the explosion-proof valve being opened due to excessive hydraulic pressure caused by the full charging process can be reduced. Moreover, the rebound ratio of different metal negative electrode systems can be met, and the advantage of the volume energy density of the battery monomer 100 can be improved.

[0095] In some embodiments, the ratio between the volume of the fixing member 30 and the volume of the accommodating cavity 11 is in the range of 10%-25%.

[0096] As a specific embodiment, the ratio between the volume of the fixing member 30 and the volume of the accommodating cavity 11 is set to the above range, which can further reserve the space requirement of the gas generated in the circulation process of the electrode assembly 20 and improve the life cycle of the battery monomer 100 on the premise of meeting the basic electrolyte flow space.

[0097] Further, 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 monomer 100.

[0098] Please refer to FIG. 1 and FIG. 6, in some embodiments, the shell 10 includes a body 12 and a top cover 13, the top cover 13 is sealed and covers the opening of the body 12, and the two together enclose the accommodating cavity 11. Among them, the first wall is a side surface of the top cover 13 facing the inside of the accommodating cavity 11.

[0099] Specifically, the shell 10 includes a body 12 and a top cover 13, the body 12 is provided as a hollow structure with one end open, and the top cover 13 is sealed and covers the opening of the body 12, and the two can enclose the accommodating cavity 11. Among them, first, the electrode assembly 20 and the fixing member 30 are placed in the accommodating cavity 11 in sequence, so that the fixing member 30 is supported between the electrode assembly 20 and the inner wall of the corresponding accommodating cavity 11, and then the top cover 13 is sealed and covers the opening of the body 12.

[0100] Further, the electrolyte is filled into the inside of the accommodating cavity 11 from the liquid injection hole on the top cover 13, and after the filling is completed, the liquid injection hole is sealed, and the assembly of the battery monomer 100 can be completed.

[0101] Among them, the first wall is a side surface of the top cover 13 facing the inside of the accommodating cavity 11, that is, the mounting position is arranged between the electrode assembly 20 and the top cover 13. That is, the electrode assembly 20 and the top cover 13 are arranged with a spacing therebetween to form a mounting position between them. Then, the fixing member 30 is arranged in the mounting position, so that the fixing member 30 is supported between the electrode assembly 20 and the top cover 13.

[0102] Through the above structure, in the assembly process, first, the electrode assembly 20 is arranged in the accommodating cavity 11, then the fixing member 30 is arranged on the side surface of the electrode assembly 20 facing the opening, and finally the top cover 13 is sealed and covers the opening, so that the assembly of the battery monomer 100 can be realized, which is convenient to operate.

[0103] In some embodiments, the top cover 13 is provided with an electrode terminal 14, and the electrode assembly 20 is formed with a first tab 21 and a second tab 22, both of which are arranged towards the top cover 13 and electrically connected with the electrode terminal 14 through the liquid passage 31.

[0104] Specifically, the electrode terminal 14 refers to a structure for electrically connecting with the electrode assembly 20 and realizing the 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, and the electrode assembly 20 has a first tab 21 and a second tab 22, wherein the first tab 21 and the second tab 22 are positive and negative tabs respectively, the positive tab is electrically connected with the positive electrode terminal 14, and the negative tab is electrically connected with the negative electrode terminal 14.

[0105] The first tab 21 and the second tab 22 are arranged upward and towards the top cover 13. The first tab 21 and the second tab 22 pass through the liquid passage 31 and are electrically connected with the corresponding electrode terminal 14. In this way, the liquid passage 31 not only realizes the flow of electrolyte, but also enables the first tab 21 and the second tab 22 to pass through and be electrically connected with the electrode terminal 14.

[0106] Through the above structure, the first tab 21 and the second tab 22 are electrically connected with the electrode terminal 14 on the top cover 13, which can realize the smooth output and input of the energy of the battery cell 100. In addition, the liquid passage 31 on the fixing member 30 not only realizes the flow of electrolyte, but also enables the first tab 21 and the second tab 22 to pass through and be electrically connected with the electrode terminal 14.

[0107] In some embodiments, the body 12 has a first side wall 15 and a second side wall 16 arranged oppositely and both intersecting with the top cover 13, and the electrode terminal 14 is arranged on each of the first side wall 15 and the second side wall 16. Wherein, the opposite ends of the electrode assembly 20 form the first tab 21 and the second tab 22 respectively, the first tab 21 is arranged towards the first side wall 15 and electrically connected with the electrode terminal 14 on the first side wall 15, and the second tab 22 is arranged towards the second side wall 16 and electrically connected with the electrode terminal 14 on the second side wall 16.

[0108] Specifically, the body 12 has a bottom wall and a plurality of side walls, each side wall is perpendicular to the bottom wall, and each side wall surrounds the outer periphery of the bottom wall. Wherein, the first side wall 15 and the second side wall 16 are arranged oppositely and parallel to each other, and both the first side wall 15 and the second side wall 16 are perpendicular to the top cover 13 when the top cover 13 is sealed on the opening of the body 12.

[0109] The positive electrode terminal 14 and the negative electrode terminal 14 are arranged on the first side wall 15 and the second side wall 16 respectively, and the opposite ends of the electrode assembly 20 form the first tab 21 and the second tab 22 respectively. When the electrode assembly 20 is placed in the accommodating cavity 11, the first tab 21 is arranged towards the first side wall 15 so that the first tab 21 can be electrically connected with the electrode terminal 14 on the first side wall 15. The second tab 22 is arranged towards the second side wall 16 so that the second tab 22 can be electrically connected with the electrode terminal 14 on the second side wall 16.

[0110] Through the above structure, the electrode assembly 20 is provided with the left and right side tabs, and the first tab 21 and the second tab 22 can be electrically connected to the electrode terminal 14 through the flexible connection. First, when the electrode assembly 20 is arranged in the accommodation cavity 11, the liquid level of the electrolyte is parallel to the top cover 13, and the cross section of the electrode assembly 20, i.e., the end face where the first tab 21 and the second tab 22 are formed, is perpendicular to the liquid level of the electrolyte. In this way, the electrolyte can better infiltrate 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 towards 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, which can make the support surface and the electrode assembly 20 more stably adhere to each other, and improve the support effect.

[0111] In addition, the explosion-proof valve or other exhaust structure of the battery monomer 100 is usually arranged on the top cover 13. Through the above structure of the left and right side tabs, the gas-electric separation of the battery monomer 100 can be achieved, and the safety performance of the battery monomer is further improved.

[0112] In some embodiments, the top cover 13 is provided with a gas permeable hole 17 communicating with the accommodation cavity 11, and a gas permeable assembly (not shown in the figure) is arranged in the gas permeable hole 17. The gas permeable assembly is configured to achieve one-way gas permeation from the interior of the accommodation cavity 11 to the outside.

[0113] Specifically, the gas permeable assembly can include a gas permeable film. The gas permeable film can achieve the exhaust of the gas in the accommodation cavity 11 to the outside, so as to maintain an acceptable internal pressure in the interior of the accommodation cavity 11, and improve the stability of the battery monomer 100. At the same time, the gas permeable film can also block the liquid or other impurities from the outside. That is, the gas permeable film can achieve one-way exhaust from the interior of the accommodation cavity 11 to the outside. The structure and material of the gas permeable film can be designed according to the prior art, and will not be described here.

[0114] Further, the gas permeable assembly can also include a one-way valve. The one-way valve is arranged in the gas permeable hole 17, and the one-way valve can be opened in one direction to achieve the exhaust of the gas from the interior of the accommodation cavity 11 to the outside, and can block the gas, liquid or other impurities from the outside of the accommodation cavity 11.

[0115] Through the above structure, one-way exhaust from the interior of the accommodation cavity 11 to the outside can be achieved, the internal pressure of the accommodation cavity 11 can be kept stable, and the stability performance of the battery monomer 100 is improved.

[0116] In some embodiments, the electrode assembly 20 is a negative electrode-free electrode assembly.

[0117] It should be noted that the negative electrode assembly refers to the electrode assembly 20 which is not actively provided with negative active material on the negative side. For example, no negative active material is provided on the current collector of the negative electrode. During the first charging, ions obtain electrons on the negative side and deposit on the surface of the negative current collector to form a metal phase. During discharging, the metal can be converted into metal ions to return to the positive electrode to realize cyclic charging and discharging. Compared with other electrode assemblies, the negative electrode assembly is applied to the battery monomer 100. Since there is no negative active material, the battery monomer 100 can obtain higher energy density.

[0118] Wherein, the metal can be sodium or other metals. When metal sodium is used, the battery monomer 100 formed is a negative electrode-free sodium secondary battery.

[0119] When the negative electrode assembly is used, since there is no negative active material coated on the negative current collector, the liquid retention capacity of the electrolyte is weak, and the deformation amount of the electrode assembly 20 during the cycle process is larger. In this way, not only the use performance of the electrode assembly 20 is affected, but also the liquid level change amount of the electrolyte in the containing cavity 11 is larger.

[0120] In this way, by using the above structure, the fixing member 30 can provide stable support to the electrode assembly 20, play a certain limiting role, and reduce the probability of swelling deformation of the electrode assembly 20. Moreover, the fixing member 30 supports the electrode assembly 20, which can improve the stability of the electrode assembly 20 in the containing cavity 11 and reduce the probability of problems such as deviation or shaking of the electrode assembly 20 during the cycle use process. On the other hand, the fixing member 30 is provided with the liquid passing channel 31, which can provide a flow channel for the electrolyte, provide a larger containing space for the electrolyte, effectively improve the problem of excessive liquid pressure in the containing cavity 11, and reduce the probability of electrolyte overflow.

[0121] Based on the same concept as the above battery monomer 100, the application also provides a battery comprising the battery monomer 100 as described above.

[0122] Based on the same concept as the above battery, the application also provides a power utilization device comprising the battery as described above.

[0123] According to one or more embodiments, during the assembly of the battery monomer 100, the electrode assembly 20 can be first placed in the containing cavity 11. Wherein, the first and second tabs 21 and 22 are respectively formed on the opposite sides of the electrode assembly 20, so that the first tab 21 is arranged opposite to the first side wall 15 of the body 12, and the first tab 21 is electrically connected with the electrode terminal 14 on the first side wall 15. The second tab 22 is arranged opposite to the second side wall 16 of the body 12, and the second tab 22 is electrically connected with the electrode terminal 14 on the second side wall 16.

[0124] Further, the fixing member 30 is arranged on the surface of the electrode assembly 20 towards the opening of the accommodating cavity 11, and then the top cover 13 is sealed to 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. In this way, the electrode assembly 20 is more stable in the accommodating cavity 11, and the probability of the electrode assembly 20 being offset or shaken is reduced. Moreover, the fixing member 30 limits the electrode assembly 20, and can effectively inhibit the expansion deformation of the electrode assembly 20.

[0125] In addition, when the liquid level of the electrolyte changes, the electrolyte can flow through the liquid passage 31 on the fixing member 30, more electrolyte can be accommodated, and the distribution of the electrolyte in the accommodating cavity 11 is more uniform.

[0126] The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0127] The above embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A battery cell, comprising: a housing having a receiving cavity, the receiving cavity having a first wall; an electrode assembly disposed in the receiving cavity; and a fixing member disposed between the electrode assembly and the first wall and supporting the electrode assembly, the fixing member having a liquid passage penetrating the fixing member along a thickness direction of the first wall; wherein the fixing member comprises 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 supporting surface. 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.

2. The battery cell of claim 1, wherein, The liquid passage comprises a main flow passage penetrating the fixing member along the thickness direction of the first wall, and a volume of the main flow passage accounts for at least 50% of a volume of the fixing member.

3. The battery cell of claim 1 or 2, wherein, The liquid passage further comprises a branch flow passage in communication with the main flow passage, the branch flow passage penetrating the fixing member along a direction intersecting the thickness direction of the first wall, and a total volume of the main flow passage and the branch flow passage accounts for at least 80% of the volume of the fixing member.

4. The battery cell of claim 3, wherein, In a direction intersecting the supporting surface, a ratio between a height of the fixing member and a height of the housing ranges from 0.03 to 0.

4.

5. The battery cell of any one of claims 1-4, wherein, In the direction intersecting the supporting surface, the ratio between the height of the fixing member and the height of the housing ranges from 0.03 to 0.

25.

6. The battery cell of claim 5, wherein, A ratio between a volume of the fixing member and a volume of the receiving cavity ranges from 5% to 40%.

7. The battery cell of any one of claims 1-6, wherein, The ratio between the volume of the fixing member and the volume of the receiving cavity ranges from 10% to 25%.

8. The battery cell of claim 7, wherein, The housing comprises a body and a top cover, the top cover being sealed to an opening of the body and together enclosing the receiving cavity; 9. The battery cell of any one of claims 1-8, wherein, wherein the first wall is a side surface of the top cover facing an inside of the receiving cavity. The top cover is provided with an electrode terminal, the electrode assembly is formed with a first tab and a second tab, and the first tab and the second tab are both arranged towards the top cover and electrically connected with the electrode terminal through the liquid passage.

10. The battery cell of claim 9, wherein, The body has a first side wall and a second side wall oppositely arranged and both intersecting the top cover, and the first side wall and the second side wall are both provided with an electrode terminal; 11. The battery cell of claim 9 or 10, wherein, wherein opposite ends of the electrode assembly are respectively formed with a first tab and a second tab, the first tab is arranged towards the first side wall and electrically connected with the electrode terminal on the first side wall, and the second tab is arranged towards the second side wall and electrically connected with the electrode terminal on the second side wall. The top cover is provided with a gas permeable hole penetrating the top cover and in communication with the receiving cavity, and a gas permeable assembly is disposed in the gas permeable hole, the gas permeable assembly being configured to enable one-way gas permeation from the inside of the receiving cavity to the outside.

12. The battery cell of any one of claims 9-11, wherein, The electrode assembly is a negative electrode-free electrode assembly.

13. The battery cell of any one of claims 1-12, wherein, 14.A battery comprising the battery cell according to any one of claims 1 to 13. 15.An electric device comprising the battery according to claim 14. ​

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