Battery cells, battery devices and electrical equipment

Abstract

This application relates to a battery cell, a battery device, and an electrical appliance. The battery cell includes: a casing with an internal cavity; a liquid injection port communicating with the cavity and located on a first wall of the casing along its thickness direction; an electrode assembly disposed within the cavity; a lower plastic layer disposed between the first wall and the electrode assembly; and a flow guide tube disposed between the lower plastic layer and the electrode assembly along its thickness direction. The flow guide tube includes a main channel and at least one branch channel. The main channel communicates with the liquid injection port, and one end of each branch channel communicates with the main channel, while the other end extends in a direction intersecting the thickness direction and communicates with the cavity surrounding the electrode assembly. This application can reduce the impact of electrolyte on the electrode assembly and ensure that the electrolyte always flows directionally into the bottom of the electrode assembly through each branch channel, allowing the electrolyte to wet the electrode assembly from bottom to top. This results in more thorough wetting of the electrode assembly, thereby reducing the probability of lithium plating.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, and electrical equipment. Background Technology

[0002] During the assembly of a battery cell, electrolyte needs to be filled into the casing through an injection port to ensure that the electrode components inside the casing are fully immersed in the electrolyte. However, during the electrolyte injection process, liquid sealing can easily occur in the middle of the electrode components, resulting in uneven lithium intercalation in the middle of the electrode components. This leads to lithium plating during cycling, affecting the performance and lifespan of the battery cell. Utility Model Content

[0003] Therefore, it is necessary to provide a battery cell, battery device, and electrical equipment to address the problem that liquid sealing is prone to occur in the middle of the electrode assembly during liquid injection, resulting in uneven lithium intercalation in the middle of the electrode assembly, leading to lithium plating during cycling, which affects the performance and service life of the battery cell.

[0004] In a first aspect, this application provides a battery cell, including a housing, an electrode assembly, a lower plastic layer, and a flow guide tube. The housing has a receiving cavity inside, and a liquid injection port communicating with the receiving cavity is formed on the first wall of the housing along its thickness direction. The electrode assembly is disposed in the receiving cavity. The lower plastic layer is disposed between the first wall and the electrode assembly. The flow guide tube is disposed between the lower plastic layer and the electrode assembly along its thickness direction. The flow guide tube includes a main channel and at least one branch channel. The main channel is connected to the liquid injection port. One end of each branch channel is connected to the main channel, and the other end extends in a direction intersecting the thickness direction and communicates with the receiving cavity on the periphery of the electrode assembly.

[0005] With the above structure, on the one hand, the electrolyte flows downward from the periphery of the electrode assembly to the bottom of the electrode assembly under the guidance of each branch flow channel, which can reduce the impact of the electrolyte on the electrode assembly; on the other hand, the electrolyte always flows into the bottom of the electrode assembly through each branch flow channel in a directional manner, and then the electrolyte wets the electrode assembly from bottom to top, which can make the electrode assembly more fully wetted, thereby reducing the probability of lithium plating.

[0006] In some embodiments, the guide tube includes at least two branch channels, wherein a portion of the branch channels extends along the length direction of the first wall and the other portion of the branch channels extends along the width direction of the first wall.

[0007] With the above structure, the electrolyte can flow into the bottom of the electrode assembly from the large surface and side surface, which not only improves the injection efficiency, but also makes the electrolyte wetting more thorough.

[0008] In some embodiments, the guide tube includes four branch channels, two of which are connected at one end to the main channel and at the other end extend in opposite directions along the length to the edge of the lower plastic; the other two branch channels are connected at one end to the main channel and at the other end extend in opposite directions along the width to the edge of the lower plastic.

[0009] With the above structure, the electrolyte inside the main channel can be evenly distributed to the two sides and two large surfaces of the electrode assembly, so that the electrolyte is more fully wetted.

[0010] In some embodiments, each branch flow channel is centered relative to the lower plastic in the length direction; and / or, each branch flow channel is centered relative to the lower plastic in the width direction.

[0011] The above structure allows the electrolyte to flow down from the middle of the large or side surface of the electrode assembly, resulting in more uniform electrolyte wetting.

[0012] In some embodiments, in the length direction of the first wall, the length of the guide tube is 2mm to 5mm shorter than the length of the lower plastic.

[0013] In this way, the outlet of the branch flow channel is formed at the edge of the lower plastic and extends to the outer surface of the electrode assembly, which allows the electrolyte to flow better from the outer periphery of the electrode assembly to the bottom of the electrode assembly, reducing the probability of the electrolyte prematurely contacting the top electrode of the electrode assembly.

[0014] In some embodiments, in the width direction of the first wall, the width of the guide tube is 1mm to 3mm smaller than the width of the lower plastic.

[0015] In this way, the outlet of the branch flow channel is formed at the edge of the lower plastic and extends to the outer surface of the electrode assembly, which allows the electrolyte to flow better from the outer periphery of the electrode assembly to the bottom of the electrode assembly, reducing the probability of the electrolyte prematurely contacting the top electrode of the electrode assembly.

[0016] In some embodiments, the lower plastic includes a body and a plurality of protrusions, each protrusion being disposed on a side surface of the body facing the electrode assembly, the body being used to connect with the first wall; wherein, in the thickness direction, the thickness of the guide tube is less than the thickness of the protrusion.

[0017] In this way, firstly, the flow guide will not affect the tab space of the electrode assembly; secondly, it can minimize the space occupied by the flow guide in the thickness direction, thereby improving the overall volumetric energy density of the battery cell.

[0018] In some embodiments, the guide tube is provided with waterproof and venting holes. By providing waterproof and venting holes, the exhaust channels during formation and aging can be effectively increased, and the exhaust efficiency can be improved. In addition, when the electrode assembly experiences thermal runaway, the waterproof and venting holes can also provide more channels for gas to be discharged more smoothly through the explosion-proof valve.

[0019] In some embodiments, the waterproof vent extends along the thickness direction of the first wall; and / or, the waterproof vent extends along the length direction of the first wall; and / or, the waterproof vent extends along the width direction of the first wall.

[0020] In this way, the waterproof and breathable pores can provide more flow directions for the gas, which can further improve the exhaust efficiency.

[0021] Secondly, this application also provides a battery device, including the battery cell as described above.

[0022] Thirdly, this application also provides an electrical device, including the battery device described above.

[0023] In the aforementioned battery cell, battery device, and electrical equipment, the electrolyte injection port is located on the first wall of the casing along the thickness direction. During the electrolyte injection process, the electrolyte is first injected from the injection port into the main channel of the guide tube, and then flows from the main channel to each branch channel, flowing into the receiving cavity through each branch channel. During this process, each branch channel extends in a direction intersecting with the thickness direction of the first wall. Thus, when the electrolyte is injected from the injection port, it flows along the thickness direction. Guided by the branch channels, the electrolyte flows towards the electrode assembly in a direction intersecting with the thickness direction. In this way, on the one hand, the impact of the electrolyte on the electrode assembly can be reduced, and on the other hand, the electrolyte always flows into the bottom of the electrode assembly through each branch channel in a directional manner. Then, the electrolyte wets the electrode assembly from bottom to top, which can make the electrode assembly more fully wetted, thereby reducing the probability of lithium plating. Attached Figure Description

[0024] Figure 1 This is a structural schematic diagram of a vehicle according to one or more embodiments.

[0025] Figure 2 This is an exploded structural diagram of a battery according to one or more embodiments.

[0026] Figure 3 This is an exploded structural diagram of a battery cell according to one or more embodiments.

[0027] Figure 4 This is a three-dimensional structural diagram of the top cover in a battery cell according to one or more embodiments.

[0028] Figure 5This is a plan view of the top cover in a battery cell according to one or more embodiments.

[0029] Figure 6 This is a side view of the top cover in a battery cell according to one or more embodiments.

[0030] Figure 7 This is a side view of the top cover in a battery cell according to one or more embodiments.

[0031] Explanation of reference numerals in the attached drawings: 1000, vehicle; 100, battery device; 200, controller; 300, motor; 10, housing; 20, battery cell; 11, first part; 12, second part; 21, top cover; 22, shell body; 23, electrode assembly; 24, lower plastic; 25, guide tube; 26, liquid inlet; 27, branch channel; 28, waterproof and ventilated hole; 241, body; 242, protrusion; a, thickness direction; b, length direction; c, width direction. Detailed Implementation

[0032] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0033] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0034] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0035] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, 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 possible implementation.

[0038] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as other fields. With the continuous expansion of the application areas of power batteries, the market demand is also constantly increasing.

[0039] The battery cell is the smallest unit that makes up a battery device. A battery cell typically includes a casing, electrode components housed inside the casing, and an electrolyte. Ensuring the electrode components are fully immersed in the electrolyte inside the casing allows lithium ions to better intercalate into the electrode plates during charging, resulting in more uniform lithium intercalation. Conversely, insufficient immersion of the electrode components hinders lithium ion intercalation, leading to lithium plating and affecting the battery cell's performance.

[0040] During the assembly of a battery cell, an injection port needs to be opened on the casing. The injection port is connected to the receiving cavity, so that electrolyte can be injected into the receiving cavity through the injection port.

[0041] It should be noted that the electrode assembly is typically formed by stacking or winding a positive electrode, a separator, and a negative electrode. When the electrode assembly is placed in the receiving cavity, the winding axis of the electrode assembly is parallel to the opening direction of the injection port, or the stacking direction of the electrode assembly is perpendicular to the opening direction of the injection port. Therefore, during the injection process, the electrolyte flows directly into the receiving cavity from the injection port. On the one hand, the electrolyte, under the influence of gravity, directly impacts the layered structure of the electrode assembly, which can easily affect the multilayer structure between the positive electrode, separator, and negative electrode.

[0042] On the other hand, a portion of the initially injected electrolyte flows to the bottom of the electrode assembly and then wets it from the bottom up. At the same time, the remaining electrolyte continues to be injected from top to bottom through the injection port. As a result, the electrolyte wets both ends of the electrode assembly at the same time, which can easily lead to a liquid seal phenomenon in the middle of the electrode assembly. If the middle of the electrode assembly is not wetted with electrolyte or is not wetted sufficiently, the lithium ion insertion will be affected during charging due to poor wetting in the thickness direction of the electrode sheet, resulting in lithium plating, which affects the performance and lifespan of the battery cell.

[0043] Based on the above considerations, to address the problem of liquid sealing easily occurring in the middle of the electrode assembly during electrolyte injection, leading to uneven lithium intercalation and lithium plating during cycling, thus affecting the lifespan of the battery cell, one or more embodiments of this application provide a battery cell with an injection port located on the first wall of the casing along the thickness direction. During the electrolyte injection process, the electrolyte is first injected from the injection port into the main channel of the guide tube, and then flows from the main channel to various branch channels, flowing into the receiving cavity through each branch channel. During this process, each branch channel extends in a direction intersecting the thickness direction of the first wall. Thus, when the electrolyte is injected from the injection port, it flows along the thickness direction, and guided by the branch channels, the electrolyte flows towards the electrode assembly in a direction intersecting the thickness direction. This reduces the impact of the electrolyte on the electrode assembly and ensures that the electrolyte always flows directionally into the bottom of the electrode assembly through each branch channel, allowing the electrolyte to thoroughly wet the electrode assembly from bottom to top, thereby reducing the probability of lithium plating.

[0044] It should be noted that the battery device 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 mixed connections via a busbar.

[0045] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0046] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0047] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0048] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0049] The battery devices disclosed in this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft.

[0050] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0051] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0052] Please refer to Figure 1 The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0053] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0054] Please refer to Figure 2 The battery device 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, collectively defining a space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 together define the space. Alternatively, both the first portion 11 and the second portion 12 may be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0055] In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel connections. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is also housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0056] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0057] Please refer to Figure 3A battery cell 20 refers to the smallest unit that makes up a battery. A battery cell 20 typically includes a top cover 21, a housing body 22, an electrode assembly 23, and other functional components. The top cover 21 is a component that closes onto the opening of the housing body 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the top cover 21 may be adapted to the shape of the housing body 22 to fit it. Functional components such as electrode terminals may be provided on the top cover 21; electrode terminals may also be called terminals. The electrode terminals can be used to electrically connect to the electrode assembly 23 for outputting or inputting electrical energy into the battery cell 20. In some embodiments, the top cover 21 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. In some embodiments, an insulating member may also be provided inside the top cover 21. The insulating member can be used to isolate the electrical connection components within the housing 22 from the top cover 21 to reduce the risk of short circuits. Exemplarily, the insulating member may be made of plastic, rubber, etc.

[0058] The casing body 22 is a component used to cooperate with the top cover 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 23, electrolyte, and other components. The casing body 22 and the top cover 21 can be independent components. An opening can be provided on the casing body 22, and the top cover 21 can close the opening to form the internal environment of the battery cell 20. Alternatively, the top cover 21 and the casing body 22 can be integrated. Specifically, the top cover 21 and the casing body 22 can form a common connecting surface before other components are inserted into the casing. When it is necessary to encapsulate the interior of the casing body 22, the top cover 21 closes the casing body 22. The casing body 22 can have various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. Specifically, the shape of the casing body 22 can be determined according to the specific shape and size of the electrode assembly 23.

[0059] Electrode assembly 23 is the component in the battery cell 20 where electrochemical reactions occur. The casing 22 may contain one or more electrode assemblies 23. Electrode assembly 23 mainly consists of a positive electrode, a separator, and a negative electrode. Specifically, positive and negative active materials are coated onto the current collector to form the positive and negative electrode, respectively. The positive and negative electrode are wound or stacked, with the separator positioned between them, thus forming electrode assembly 23. The portions of the positive and negative electrode with active material constitute the main body of electrode assembly 23, while the portions without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or at opposite ends. During charging and discharging, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0060] Please refer to the following: Figure 3 , Figure 4 as well as Figure 5 One embodiment of this application provides a battery cell 20, including a housing, an electrode assembly 23, a lower plastic 24, and a flow guide 25. The housing has an internal cavity (not shown in the figure), and a liquid injection port 26 communicating with the cavity is formed on the first wall of the housing along its thickness direction a. The electrode assembly 23 is disposed in the cavity, and the lower plastic 24 is disposed between the first wall and the electrode assembly 23. The flow guide 25 is disposed between the lower plastic 24 and the electrode assembly 23 along the thickness direction a. The flow guide 25 includes a main channel (not shown in the figure) and at least one branch channel 27. The main channel communicates with the liquid injection port 26, and one end of each branch channel 27 communicates with the main channel, while the other end extends in a direction intersecting the thickness direction a and communicates with the cavity around the electrode assembly 23.

[0061] It should be noted that the housing refers to a structure that forms an internal cavity for accommodating the electrode assembly 23 and other functional components, and that protects the electrode assembly 23 inside. The housing may include a housing body 22 and a top cover 21. One side of the housing body 22 is open, and the top cover 21 is sealed at the opening, so that the top cover 21 and the housing body 22 together enclose and form the accommodating cavity.

[0062] The first wall of the casing may be, but is not limited to, a top cover 21. That is, an injection port 26 is formed on the top cover 21 along the thickness direction a, through which electrolyte can be injected into the cavity. In addition, after the injection is completed, the injection port 26 can be sealed with a sealing pin to form a closed environment inside the casing.

[0063] The lower plastic 24 refers to a component used to isolate the electrical connection parts within the housing from the top cover 21 to reduce the risk of short circuits. That is, the lower plastic 24 is an insulating component and may be, but is not limited to, plastic, rubber, etc. The lower plastic 24 is disposed between the first wall and the electrode assembly 23; that is, the lower plastic 24 is connected to the lower surface of the top cover 21 and is located above the electrode assembly 23.

[0064] The guide tube 25 is also disposed within the receiving cavity and is located between the lower plastic 24 and the electrode assembly 23 along the thickness direction a of the top cover 21. Specifically, the guide tube 25 can be connected to the top cover 21 by means of heat fusion, spiral connection, etc., and the guide tube 25 can be connected to the lower surface of the top cover 21.

[0065] An opening can be formed on the surface of the guide tube 25, which is connected to the injection port 26. This allows the main flow channel of the guide tube 25 to be connected to the injection port 26, and the main flow channel is connected below the injection port 26. In this way, when electrolyte is injected through the injection port 26, the electrolyte can flow smoothly from the injection port 26 into the main flow channel. That is to say, the main flow channel can receive the electrolyte flowing out of the injection port 26.

[0066] After the electrolyte enters the main channel, it flows along each branch channel 27 under the guidance of the branch channels 27, and flows into the receiving cavity through each branch channel 27. Each branch channel 27 extends in a direction intersecting the thickness direction a. Specifically, each branch channel 27 can extend in a direction perpendicular to the thickness direction a, meaning that each branch channel 27 is parallel to the top cover 21.

[0067] Thus, when the electrolyte is injected into the receiving cavity from the injection port 26, it flows from top to bottom. After reaching the main flow channel, under the guidance of the branch flow channels 27, the flow direction of the electrolyte changes, becoming horizontal, flowing into the receiving cavity from all sides of the electrode assembly 23. In this way, the electrolyte can climb from the bottom of the electrode assembly 23 under capillary action, gradually wetting the electrode assembly 23.

[0068] With the above structure, on the one hand, the electrolyte flows downward from the periphery of the electrode assembly 23 to the bottom of the electrode assembly 23 under the guidance of each branch flow channel 27, which can reduce the impact of the electrolyte on the electrode assembly 23; on the other hand, the electrolyte always flows into the bottom of the electrode assembly 23 through each branch flow channel 27 in a directional manner, and then the electrolyte wets the electrode assembly 23 from bottom to top, which can make the electrode assembly 23 more fully wetted, thereby reducing the probability of lithium plating.

[0069] In some embodiments, the guide tube 25 includes at least two branch channels 27, wherein a portion of the branch channels 27 extends along the length direction b of the first wall, and the other portion of the branch channels 27 extends along the width direction c of the first wall.

[0070] It should be noted that the electrode assembly 23 is typically designed as a rectangular structure, and has two large, parallel surfaces, two parallel side surfaces, and a top and bottom surface that are parallel to each other. The large surface refers to the outer surface of the electrode assembly 23 with the largest area.

[0071] Furthermore, the long side of the top cover 21 corresponds to the large surface of the electrode assembly 23, and the short side of the top cover 21 corresponds to the side surface of the electrode assembly 23. That is, the length direction b of the top cover 21 is parallel to the large surface of the electrode assembly 23, and the width direction c of the top cover 21 is parallel to the side surface of the electrode assembly 23.

[0072] Thus, a portion of the branch flow channel 27 extends along the length direction b of the top cover 21, which can guide the electrolyte inside to the side of the electrode assembly 23, and flow from the side of the electrode assembly 23 into the bottom of the electrode assembly 23, and then wet upward from the bottom of the electrode assembly 23.

[0073] The other branch channel 27 extends along the width direction c of the top cover 21, which can guide the electrolyte inside to the large surface of the electrode assembly 23, and flow from the large surface of the electrode assembly 23 into the bottom of the electrode assembly 23, and then wet upward from the bottom of the electrode assembly 23.

[0074] With the above structure, the electrolyte can flow into the bottom of the electrode assembly 23 from the large surface and the side surface, which can not only improve the injection efficiency, but also make the electrolyte wetting more thorough.

[0075] In some embodiments, the guide tube 25 includes four branch channels 27, two of which are connected at one end to the main channel and at the other end extend in opposite directions along the length direction b to the edge of the lower plastic 24. The other two branch channels 27 are connected at one end to the main channel and at the other end extend in opposite directions along the width direction c to the edge of the lower plastic 24.

[0076] As a specific embodiment, the branch channels 27 can be configured as four, of which two branch channels 27 extend along the length direction b of the top cover 21 and are respectively connected to the opposite ends of the main channel. These two branch channels 27 can guide the electrolyte in the main channel to the edge of the lower plastic 24, and then flow from the side of the electrode assembly 23 into the bottom of the electrode assembly 23.

[0077] Two additional branch channels 27 extend along the width direction c of the top cover 21 and are respectively connected to the opposite ends of the main channel. In this way, these two branch channels 27 can guide the electrolyte in the main channel to the edge of the lower plastic 24, and then flow from the large surface of the electrode assembly 23 into the bottom of the electrode assembly 23.

[0078] With the above structure, the electrolyte inside the main channel can be evenly distributed to the two sides and two large surfaces of the electrode assembly 23, so that the electrolyte is more fully wetted.

[0079] Understandably, the number of branch channels 27 can also be adjusted according to actual needs. For example, it can be set to three, with two branch channels 27 extending along the width direction c of the top cover 21 and the other branch channel 27 extending along the length direction b of the top cover 21. Of course, branch channels 27 can also be set to five or more, and the specific number can be adjusted according to actual production needs, which will not be elaborated here.

[0080] In some embodiments, in the length direction b, each branch flow channel 27 is centered relative to the lower plastic 24. And / or, in the width direction c, each branch flow channel 27 is centered relative to the lower plastic 24.

[0081] It should be noted that "center setting" means that the branch flow channel 27 is located in the middle area of ​​the lower plastic 24, and not necessarily that all branch flow channels 27 are located on the center line of the lower plastic 24.

[0082] Specifically, along the length direction b of the top cover 21, each branch flow channel 27 is centrally located relative to the lower plastic 24. In this way, the branch flow channel 27 can guide the electrolyte to the middle area of ​​the side of the electrode assembly 23 and flow from the middle position of the side of the electrode assembly 23 to the bottom of the electrode assembly 23, making the electrolyte wetting more uniform.

[0083] Furthermore, in the width direction c of the top cover 21, each branch flow channel 27 is centrally located relative to the lower plastic 24. In this way, the branch flow channel 27 can guide the electrolyte to the middle area of ​​the large surface of the electrode assembly 23, and flow from the middle position of the large surface of the electrode assembly 23 to the bottom of the electrode assembly 23, so that the electrolyte wetting is more uniform.

[0084] The above structure allows the electrolyte to flow down from the middle area of ​​the large surface or side surface of the electrode assembly 23, making the electrolyte wetting more uniform.

[0085] In some embodiments, in the longitudinal direction b of the first wall, the length of the guide tube 25 is 2mm to 5mm shorter than the length of the lower plastic 24.

[0086] Specifically, in the longitudinal direction b of the top cover 21, the length of the guide tube 25 is 2mm to 5mm shorter than the length of the lower plastic 24.

[0087] In this way, the outlet of the branch flow channel 27 is formed at the edge of the lower plastic 24 and extends to the outer surface of the electrode assembly 23, which allows the electrolyte to flow better from the outer periphery of the electrode assembly 23 to the bottom of the electrode assembly 23, reducing the probability that the electrolyte will prematurely contact the top electrode of the electrode assembly 23.

[0088] In some embodiments, in the width direction c of the first wall, the width of the guide tube 25 is 1mm to 3mm smaller than the width L4 of the lower plastic.

[0089] Specifically, in the width direction c of the top cover 21, the width of the guide tube 25 is 1mm to 3mm smaller than the width of the lower plastic 24.

[0090] In this way, the outlet of the branch flow channel 27 is formed at the edge of the lower plastic 24 and extends to the outer surface of the electrode assembly 23, which allows the electrolyte to flow better from the outer periphery of the electrode assembly 23 to the bottom of the electrode assembly 23, reducing the probability that the electrolyte will prematurely contact the top electrode of the electrode assembly 23.

[0091] like Figure 6 and Figure 7In some embodiments, the lower plastic 24 includes a body 241 and a plurality of protrusions 242, each protruding from one side surface of the electrode assembly 23 on the body 241. The body 241 is used to connect with the first wall. In the thickness direction a, the thickness L1 of the guide tube 25 is less than the thickness L2 of the protrusion 242.

[0092] Specifically, the body 241 of the lower plastic 24 is constructed as a flat plate structure, with the lower surface of the body 241 facing the electrode assembly 23, and each protrusion 242 protruding from the lower surface of the body 241 and surrounding the body 241 at intervals.

[0093] When the body 241 is connected to the lower surface of the top cover 21, the space formed by each protrusion 242 in the thickness direction a can be used as the tab space of the electrode assembly 23.

[0094] Furthermore, in the thickness direction a, the thickness of the guide tube 25 is less than the thickness of the protrusion 242. That is, the guide tube 25 is accommodated in the recess formed by the protrusions 242.

[0095] In this way, firstly, the guide tube 25 will not affect the tab space of the electrode assembly 23, and secondly, the space occupied by the guide tube 25 in the thickness direction a can be minimized as much as possible, thereby improving the overall volumetric energy density of the battery cell 20.

[0096] like Figure 5 As shown, in some embodiments, the guide tube 25 is provided with waterproof and breathable holes 28.

[0097] Specifically, the waterproof and breathable pore 28 refers to a microporous structure that allows only gas molecules to pass through, but not polymer electrolytes.

[0098] By setting waterproof and breathable holes 28, the exhaust channels during formation and aging can be effectively increased, and the exhaust efficiency can be improved. In addition, when the electrode assembly 23 experiences thermal runaway, the waterproof and breathable holes 28 can provide more channels so that the gas can be discharged more smoothly through the explosion-proof valve.

[0099] In some embodiments, the waterproof vent 28 extends along the thickness direction a of the first wall. And / or, the waterproof vent 28 extends along the length direction b of the first wall. And / or, the waterproof vent 28 extends along the width direction c of the first wall.

[0100] Specifically, the waterproof and breathable hole 28 can be provided through and extending along the thickness direction a, or through and extending along the length direction b, or through and extending along the width direction c.

[0101] Understandably, the waterproof vent 28 can be set along the two directions mentioned above at the same time, or it can be set along the three directions at the same time. That is, the waterproof vent 28 can be set along the thickness direction a, the length direction b, and the width direction c respectively.

[0102] Thus, the waterproof and breathable pores 28 can provide more flow direction for gas, which can further improve exhaust efficiency.

[0103] Based on the same concept as the battery cell 20 described above, this application also provides a battery device 100, including the battery cell 20 as described above.

[0104] Based on the same concept as the battery device 100 described above, this application also provides an electrical device including the battery device 100 as described above.

[0105] According to one or more embodiments, in actual use, the body 241 of the lower plastic 24 is first fixed on the lower surface of the top cover 21, then the guide tube 25 is fixed on the lower surface of the body 241, and an opening communicating with the main channel is opened on the body 241, and the main channel is communicated with the injection port 26 on the top cover 21 through the opening.

[0106] Each branch channel 27 of the guide pipe 25 is connected to the main channel and extends along the length direction b or the width direction c of the top cover 21 to the edge of the lower plastic 24.

[0107] Thus, electrolyte is injected into the receiving cavity through the injection port 26. The electrolyte first enters the main channel, and then, guided by the branch channels 27, flows along the large surface and / or side surface of the electrode assembly 23 to the bottom of the electrode assembly 23, and then gradually wets the bottom of the electrode assembly 23.

[0108] In addition, during the formation and aging tests of the battery cell 20, or when thermal runaway occurs inside the battery cell 20, the gas can be quickly discharged through the waterproof and breathable hole 28 on the guide pipe 25, thereby improving the exhaust efficiency and further improving the performance of the battery cell 20.

[0109] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0110] The embodiments described above are merely illustrative of several implementation methods of this application, and 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 those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell, characterized by, include: The shell has an internal cavity, and an injection port communicating with the cavity is formed on the first wall of the shell along its thickness direction; The electrode assembly is disposed within the receiving cavity; The lower plastic layer is disposed between the first wall and the electrode assembly; and A flow guide tube is disposed between the lower plastic and the electrode assembly along the thickness direction. The flow guide tube includes a main channel and at least one branch channel. The main channel is connected to the injection port. One end of each branch channel is connected to the main channel, and the other end extends along a direction intersecting the thickness direction and is connected to the receiving cavity on the outer periphery of the electrode assembly.

2. The battery cell of claim 1, wherein, The guide pipe includes at least two branch channels, one portion of which extends along the length of the first wall, and the other portion extends along the width of the first wall.

3. The battery cell of claim 2, wherein, The guide tube includes four branch channels, two of which are connected at one end to the main channel and at the other end to the edge of the lower plastic along the length direction in opposite directions; the other two branch channels are connected at one end to the main channel and at the other end to the edge of the lower plastic along the width direction in opposite directions.

4. The battery cell of claim 2, wherein, In the length direction, each of the branch channels is centered relative to the lower plastic; and / or, in the width direction, each of the branch channels is centered relative to the lower plastic.

5. The battery cell of claim 1, wherein, Along the length of the first wall, the length of the guide tube is 2mm to 5mm shorter than the length of the lower plastic.

6. The battery cell according to claim 1 or 5, characterized in that, In the width direction of the first wall, the width of the guide tube is 1mm to 3mm smaller than the width of the lower plastic.

7. The battery cell of claim 1, wherein, The lower plastic includes a body and a plurality of protrusions, each of the protrusions being disposed on the side surface of the body facing the electrode assembly, and the body being used to connect with the first wall; In the thickness direction, the thickness of the guide tube is less than the thickness of the protrusion.

8. The battery cell of claim 1, wherein, The guide tube is provided with waterproof and breathable holes.

9. The battery cell of claim 8, wherein, The waterproof and breathable holes extend along the thickness direction of the first wall; and / or, the waterproof and breathable holes extend along the length direction of the first wall; and / or, the waterproof and breathable holes extend along the width direction of the first wall.

10. A battery device characterized by comprising: Includes the battery cell as described in any one of claims 1-9.

11. An electrical device, characterized by Includes the battery device as described in claim 10.

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