Battery monomer, battery device and power utilization device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device, and belongs to the technical field of batteries, an electrode assembly is accommodated in an accommodating cavity in a shell, the side wall of the shell is annular and defines the accommodating cavity, the bottom wall of the shell is fixedly connected to the side wall, the accommodating cavity is blocked by one side of the accommodating cavity, and the bottom wall is used for supporting the electrode assembly; the top wall of the shell is fixedly connected to the side wall and is opposite to the bottom wall. The separator is fixedly connected to the bottom wall and the side wall and divides the accommodating cavity into at least two separation cavities, the electrode assemblies are accommodated in the at least two separation cavities, each separation cavity for accommodating the electrode assemblies at least accommodates one electrode assembly, and the electrode assemblies in different separation cavities are connected in series. Part of electrolyte is contained in each separation cavity for containing the electrode assembly, and the electrolyte in the different separation cavities is isolated from one another through separators. The separator is arranged in the shell to separate the electrolyte, so that the possibility that the electrolyte in the separation cavity is decomposed is reduced, and the service life of the battery monomer is prolonged.

Description

Technical Field

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

[0002] Batteries are increasingly used in daily life and industry. For example, new energy vehicles equipped with batteries are widely used, and batteries are also increasingly being applied in energy storage. However, a key limitation of these technologies is the relatively short lifespan of individual battery cells. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a battery cell, a battery device, and an electrical device to improve the service life of the battery cell.

[0004] This application is achieved through the following technical solution.

[0005] A first aspect of this application provides a battery cell, comprising:

[0006] Electrode assembly;

[0007] The outer shell has an internal cavity for housing the electrode assembly. The outer shell includes a side wall, a bottom wall, and a top wall. The side wall is annular and encloses the cavity. The bottom wall is fixedly connected to the side wall and blocks the cavity from one side. The bottom wall supports the electrode assembly. The top wall is fixedly connected to the side wall and is disposed opposite to the bottom wall.

[0008] A separator is fixedly connected to the bottom wall and the side wall and divides the receiving cavity into at least two partition cavities. The electrode assembly is configured to be at least two, with at least two partition cavities containing the electrode assembly. Each partition cavity containing the electrode assembly contains at least one electrode assembly, and the electrode assemblies in different partition cavities are connected in series.

[0009] The electrolyte is contained in each partition cavity that houses the electrode assembly, and the electrolytes in different partition cavities are isolated from each other by the partition.

[0010] In this embodiment, the electrolyte is separated by a separator, which reduces the voltage that the electrolyte bears, reduces the possibility of electrolyte decomposition, and helps to improve the service life of the battery cell.

[0011] In one embodiment, at least two of the partition cavities are arranged in a first direction, the bottom wall is sealed to the lower side of the partition, and the side wall is sealed to the opposite sides of the partition along a second direction to isolate the electrolyte in the adjacent partition cavities on the corresponding sides of the partition. The second direction is arranged to intersect the first direction and the vertical direction, and the first direction is arranged to intersect the vertical direction.

[0012] In this embodiment of the application, the electrolyte is sealed and isolated by at least the lower side of the separator and both opposite sides of the separator along the second direction being sealed to the outer shell.

[0013] In one embodiment, the potential difference of the electrode assembly within each of the partitioned cavities is less than or equal to 5V.

[0014] In this embodiment, the voltage of the electrolyte in each compartment is within a suitable range, thereby reducing electrolyte decomposition.

[0015] In one embodiment, the potential difference of the electrode assembly within each of the partitioned cavities is less than or equal to 4.5V.

[0016] In this embodiment, the voltage of the electrolyte in each compartment is within a suitable range, thereby reducing electrolyte decomposition.

[0017] In one embodiment, the output or input potential difference of the battery cell is 8V to 50V; and / or, the number of electrode assemblies connected in series is greater than or equal to two.

[0018] In this embodiment, the input or output voltage of the battery cell is within a suitable range, and the current will not be too large when the battery cell can have high input or output power.

[0019] In one embodiment, the separator includes:

[0020] The conductive element is electrically connected to the electrode assembly in the adjacent partition cavity on both sides respectively, so that the electrode assembly on both sides is connected in series;

[0021] An insulating element is provided between the bottom wall and the lower side of the conductive element, and between the side wall and the opposite sides of the separator along the second direction. The bottom wall, the side wall, the lower side of the conductive element, and the opposite sides of the conductive element along the second direction are all sealed to the corresponding insulating element to isolate the electrolyte in the adjacent separator cavities on the corresponding sides of the conductive element.

[0022] In this embodiment, the electrode assembly is connected in series using conductive components.

[0023] In one embodiment, the arrangement direction of at least two of the partition cavities is a first direction. The electrode assembly includes an isolator and at least two electrodes. The electrodes and the isolator are stacked to form a stacked structure. An isolator is disposed between each pair of adjacent electrodes. The electrodes and the isolator are stacked along the first direction. The conductive element is electrically connected to the electrodes of the electrode assembly in the adjacent partition cavities on both sides so that the electrode assemblies corresponding to the adjacent partition cavities on both sides are connected in series.

[0024] In this embodiment, the electrode assembly with a stacked structure is connected in series with the conductive element through the electrode plates.

[0025] In one embodiment, each electrode includes a current collector, and at least one electrode of each electrode assembly further includes an active material layer disposed on the current collector. At least two electrodes in each electrode assembly are preset electrodes. All electrodes in each electrode assembly except the preset electrodes are located between the two preset electrodes along the first direction. The active material layer of the electrode assembly is located between the current collectors of the two preset electrodes. The conductive element is in conductive contact with the current collectors of the corresponding preset electrodes in the electrode assemblies on both sides along the first direction.

[0026] In this embodiment, the active material layer is reduced by electrically connecting the current collector to the conductive component.

[0027] In one embodiment, the polarities of the preset electrodes that are in conductive contact with both sides of the conductive element along the first direction are opposite to those of the conductive element on the side away from the conductive element.

[0028] In this embodiment, the polarity of the side of the preset electrode opposite to that of the conductive element is reversed, so that the electrode assemblies on both sides can be connected in series through the conductive element.

[0029] In one embodiment, each of the insulating elements and the adjacent electrodes on opposite sides of the insulating elements constitute a power conversion unit, and at least two power conversion units are connected in series.

[0030] In this embodiment, the power conversion unit consisting of the electrode and the isolator is connected in series, which can reduce the number of tabs and reduce the space occupied by the electrode assembly.

[0031] In one embodiment, each electrode includes a current collector and an active material layer disposed on the current collector. In each electrode assembly, the current collector, the positively polarized active material layer, the separator, and the negatively polarized active material layer are arranged alternately along the first direction so that at least two energy conversion units are connected in series.

[0032] In this embodiment, the current collector, the positively polarized active material layer, the separator, and the negatively polarized active material layer are arranged alternately along the first direction, so that the power conversion units of the electrode assembly of the non-metallic battery are connected in series.

[0033] In one embodiment, each electrode includes a current collector, and at least one electrode further includes a positively polarized active material layer disposed on the corresponding current collector. In each electrode assembly, the current collector, the positively polarized active material layer, and the separator are arranged alternately along the first direction so that at least two energy conversion units are connected in series.

[0034] In this embodiment, the current collector, the positively polarized active material layer, and the separator are arranged alternately along the first direction, so that the power conversion units of the electrode assembly of the metal battery are connected in series.

[0035] In one embodiment, each electrode includes a current collector, the sidewall of the housing includes a preset housing wall arranged opposite to each other along the first direction, the electrode assemblies in at least two partition cavities arranged sequentially along the first direction are connected in series, the battery cell also includes an electrode terminal mounted on the housing, among all the current collectors arranged sequentially along the first direction, the current collectors closest to the preset housing wall on both sides are electrically connected to the corresponding electrode terminal, and the thickness of the current collectors closest to the preset housing wall on both sides is 5μm to 100μm.

[0036] In this embodiment, the thickness of the current collectors closest to the preset shell wall on both sides is appropriate, which not only has good flow capacity, but also can prevent the current collectors from being too thick to a certain extent, thus reducing costs.

[0037] In one embodiment, among all the current collectors arranged sequentially along the first direction, the thickness of the current collectors closest to the preset shell wall on both sides is 10μm to 20μm.

[0038] In this embodiment, the thickness of the current collectors closest to the preset shell wall on both sides is appropriate, which not only has good flow capacity, but also can prevent the current collectors from being too thick to a certain extent, thus reducing costs.

[0039] In one embodiment, each electrode includes a current collector, the sidewall of the housing includes a preset housing wall arranged opposite to each other along the first direction, electrode assemblies in at least two partition cavities arranged sequentially along the first direction are connected in series, the battery cell also includes an electrode terminal mounted on the housing, among all the current collectors arranged sequentially along the first direction, the current collectors closest to the preset housing wall on both sides are electrically connected to the corresponding electrode terminal, the current collectors closest to the preset housing wall on both sides include a main body and a first electrode tab disposed on the main body, the direction in which the first electrode tab protrudes from the main body and the direction intersecting the first direction are respectively a third direction, the ratio of the size of the first electrode tab along the third direction to the size of the main body along the third direction is 20% to 40%.

[0040] In this embodiment, the ratio of the size of the first electrode tab along the third direction to the size of the main body along the third direction is 20% to 40%, which makes the proportion of the size of the first electrode tab along the third direction more appropriate, and the first electrode tab has better current carrying capacity.

[0041] In one embodiment, the ratio of the dimension of the first tab along the third direction to the dimension of the body along the third direction is 30% to 40%.

[0042] In this embodiment, the ratio of the size of the first electrode tab along the third direction to the size of the main body along the third direction is 30% to 40%, which makes the proportion of the size of the first electrode tab along the third direction more appropriate, and the first electrode tab has better current carrying capacity.

[0043] In one embodiment, an insulating member is disposed between the top wall and the upper side of the conductive member, and both the top wall and the upper side of the conductive member are sealed to the corresponding insulating member to isolate the electrolyte in the adjacent partition cavities on both sides of the partition member.

[0044] In this embodiment, the separation of electrolyte in the two-sided partition cavity by the separator is not limited by the arrangement of the battery cells, and can better adapt to various application scenarios of battery cell arrangement, thus having wide adaptability.

[0045] In one embodiment, the electrode assembly includes an isolator and at least two electrodes, the electrodes and the isolator being wound together to form a wound structure, the isolator being disposed between each two adjacent electrodes, and a second tab being formed at at least one end of the electrode assembly along the winding axis of the electrode assembly, and electrode assemblies with different partition cavities being connected in series through the second tab.

[0046] In this embodiment of the application, for wound electrode assemblies, the second tab of the electrode assembly can be used to easily connect two electrode assemblies in series.

[0047] In one embodiment, at least two of the partition cavities are arranged in a first direction, and the winding axis of the electrode assembly is arranged to intersect the first direction.

[0048] In this embodiment, the second tabs of different polarities at at least one end of the winding axis of the electrode assembly can be separated to both sides of the electrode assembly along the first direction, so as to be connected in series with the electrode assembly of the adjacent partition cavity along the first direction.

[0049] In one embodiment, the second tab of each electrode assembly is located at one end of the corresponding electrode assembly along the winding axis, and in each electrode assembly, the second tabs with positive polarity and the second tabs with negative polarity are arranged alternately in directions that intersect the winding axis and the first direction, respectively.

[0050] In this embodiment, the positive and negative polarity second electrodes are arranged alternately in directions that intersect the winding shaft and the first direction, respectively. This facilitates the connection of the second electrodes of different electrode assemblies 4 to achieve series connection, and the spacing between the second electrodes with different polarities reduces the possibility of short circuits between them.

[0051] In one embodiment, in two adjacent partition cavities along the first direction, one partition cavity corresponds to the direction in which the positive polarity of the second electrode tab of the electrode assembly points to the direction in which the negative polarity of the second electrode tab is pointed, which is opposite to the direction in which the positive polarity of the second electrode tab of the electrode assembly points to the direction in which the negative polarity of the second electrode tab is pointed in the other partition cavity.

[0052] In this embodiment, the second tabs of the electrode assemblies with opposite polarities on both sides of the separator are positioned close together, which facilitates the electrical connection of the electrode assemblies of the adjacent separator assemblies on both sides to form a series connection.

[0053] In one embodiment, the battery cell further includes electrode terminals, and electrode assemblies corresponding to the partition cavities arranged sequentially along the first direction are connected in series. The sidewall of the housing includes a preset housing wall arranged opposite to each other along the first direction. The second tabs of the electrode assemblies closest to the preset housing wall on both sides of the sequentially connected electrode assemblies are electrically connected to the corresponding electrode terminals. The number of partition cavities arranged sequentially along the first direction is odd.

[0054] In this embodiment, the second tab of the electrode assembly closest to the preset shell wall on one side along the first direction for electrical connection with the corresponding electrode terminal is spaced as far apart as possible from the second tab of the electrode assembly closest to the preset shell wall on the other side for electrical connection with the corresponding electrode terminal. The corresponding electrode terminals with opposite polarities are also spaced as far apart as possible, reducing the possibility of short circuit of the electrode terminals.

[0055] In one embodiment, the separator is made of insulating plastic.

[0056] In the embodiments of this application, it is beneficial to reduce weight.

[0057] In one embodiment, the upper end of the separator is spaced apart from the top wall. In two adjacent separator cavities, the second electrode tab of the electrode assembly in at least one separator cavity passes through the gap between the upper end of the separator and the top wall to be electrically connected to the second electrode tab of the electrode assembly in the other separator cavity.

[0058] In this embodiment, a space is left between the upper end of the separator and the outer shell for the second tab of the electrode assembly corresponding to one side of the separator cavity to extend to the separator cavity on the other side, so that the electrode assemblies corresponding to adjacent separator cavities on both sides of the separator cavity can be electrically connected through the second tab to achieve series connection.

[0059] In one embodiment, the battery cell is a sodium-ion battery cell.

[0060] In this embodiment of the application, when sodium crystals are deposited in the battery cell to form sodium branches, the sodium branches are relatively round, which reduces the possibility of the separator being punctured.

[0061] In one embodiment, the electrode assembly includes an isolator and at least two electrodes, with the isolator disposed between each pair of adjacent electrodes, and each electrode includes a current collector made of aluminum.

[0062] In this embodiment, sodium ions do not form an alloy with aluminum, which helps to better maintain the capacity of the battery cell. Aluminum is less expensive than copper, and using aluminum as the current collector helps to reduce costs.

[0063] In one embodiment, at least two of the partition cavities are arranged in a first direction, and the outer shell includes:

[0064] A housing, wherein the sidewalls are formed in the housing;

[0065] An end cap is disposed on the housing, and a separator is connected within the space enclosed by the housing and the end cap to divide the space enclosed by the end cap and the housing into at least two partition cavities. The end cap and the housing are arranged in an intersecting direction with the first direction, and the top wall and / or the side wall are formed on the end cap.

[0066] In this embodiment, since the end cap and the housing are arranged in a cross direction with the first direction, the end cap covers most of the openings of the partition cavities arranged along the first direction. Before the end cap is placed on the housing, most of the partition cavities arranged along the first direction are in an open state, which makes it easier to place the electrode assembly into each partition cavity, making the installation of the electrode assembly more convenient.

[0067] In one embodiment, the electrode assembly includes an isolator and at least two electrodes, with the isolator disposed between each pair of adjacent electrodes. Each electrode includes a current collector, and at least one electrode of each electrode assembly further includes an active material layer disposed on the current collector. The active material layer, which is positively polar, is made of sodium.

[0068] In this embodiment, the active material layer with positive polarity contains sodium. Sodium ions reciprocate through the separator, enabling the charging and discharging of the battery cell. When sodium crystals are deposited in the battery cell, forming sodium branches, the rounded shape of these crystals reduces the likelihood of the separator being punctured.

[0069] In one embodiment, the material of the positively polar active material layer is a sodium-containing oxide, a sodium-containing Prussian compound, or a sodium-containing polyanionic compound.

[0070] A second aspect of this application provides a battery device comprising any of the aforementioned battery cells.

[0071] A third aspect of this application provides an electrical device, including any of the above-described battery cells or battery devices, wherein the battery cells or battery devices are used to store or provide electrical energy.

[0072] Invention Effects

[0073] In the embodiments of this application, the series connection of electrode assemblies allows the battery cells to have higher input or output voltages, i.e., higher charging voltages. While increasing the charging power of the battery cells, this can suppress charging current to a certain extent, reduce battery cell heating, and lower energy loss. By providing a separator within the housing to divide the internal cavity into at least two compartments, the electrolytes in the compartments are isolated from each other. The electrolytes in the compartments do not bear the overall potential difference of the series connection of the electrode assemblies. The potential difference borne by the electrolyte in any compartment is equal to the potential difference of the corresponding electrode assembly within that compartment. Therefore, the smaller potential difference borne by the electrolyte in the compartments helps reduce the possibility of electrolyte decomposition, thereby improving the lifespan of the battery cells. Attached Figure Description

[0074] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0075] Figure 1This is a schematic diagram of the structure of a battery cell according to an embodiment of this application. The end cap is not shown in the figure, and the electrode assembly is a stacked electrode assembly.

[0076] Figure 2 This is an assembly diagram of the housing, separator, and electrode assembly according to an embodiment of this application, showing three electrode assemblies arranged along a first direction;

[0077] Figure 3 for Figure 2 A magnified view at position A in the middle;

[0078] Figure 4 for Figure 2 A magnified view at position B in the middle;

[0079] Figure 5 This is a schematic diagram of the stacking of conductive components and stacked electrode assemblies. A negative electrode active material layer is provided on one side of the current collector.

[0080] Figure 6 This is a schematic diagram of the stacking of conductive components and stacked electrode assemblies. The current collector in the diagram does not have a negative electrode active material layer.

[0081] Figure 7 This is a schematic diagram of the current collector closest to the preset shell wall in an embodiment of this application;

[0082] Figure 8 This is an assembly diagram of the housing, separator, and wound electrode assembly according to an embodiment of this application;

[0083] Figure 9 This is an assembly drawing of the housing and partition components according to an embodiment of this application;

[0084] Figure 10 This is a schematic diagram of the structure of the wound electrode assembly according to an embodiment of this application;

[0085] Figure 11 This is a schematic diagram of the structure of a battery cell according to an embodiment of the application, showing the end cap and electrode terminals.

[0086] Explanation of reference numerals in the attached figures

[0087] 1. Outer shell; 11. Pre-set shell wall; 12. Shell; 13. End cap; 14. Side wall; 15. Bottom wall; 16. Top wall; 2. Separator; 21. Conductive component; 22. Insulating component; 3. Separating cavity; 4. Electrode assembly; 41. Electrode sheet; 411. Current collector; 4111. Main body; 4112. First electrode tab; 412. Positive electrode active material layer; 413. Negative electrode active material layer; 42. Isolator; 441. Positive electrode tab; 442. Negative electrode tab; 45. Straight area; 46. Corner area; 5. Electrode terminal. Detailed Implementation

[0088] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0089] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having”, and any variations thereof, in the specification and the foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0090] In the description of the embodiments of this application, technical terms such as "first," "second," and "third" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0091] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0092] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0093] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0094] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0095] In related technologies, a battery cell includes a casing and electrode assemblies disposed within the casing. The casing contains an electrolyte, and the electrode assemblies are immersed in the electrolyte. Increasing charging power allows for faster charging and discharging of the battery cell, battery device, or electrical device. There are various ways to increase charging power, including by increasing the charging voltage or charging current. Increasing the charging voltage allows for a smaller charging current, reducing battery cell heating and energy loss. However, the solvent in the electrolyte cannot withstand high voltages and will decompose at high voltages. In cases where at least two electrode assemblies are connected in series within the casing, the electrolyte is not separated. The electrolyte in the casing bears the overall potential difference of the at least two electrode assemblies connected in series. A high overall potential difference causes solvent decomposition in the electrolyte, resulting in a shorter battery cell lifespan.

[0096] For example, the voltage of a single electrode assembly can be 4.5V. The overall potential difference between two electrode assemblies connected in series is 9V.

[0097] This application separates multiple electrode assemblies connected in series into different compartments, thereby reducing the voltage across the electrolyte in each compartment, which in turn reduces the likelihood of electrolyte decomposition in the battery cell and improves the battery cell's lifespan.

[0098] The solutions in this application can be used not only for individual battery cells, but also for battery devices and electrical devices.

[0099] Electrical devices are devices that use electrical energy as their energy source to perform corresponding functions by consuming electrical energy. Examples include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, and ships. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.

[0100] The electrical device in the embodiments of this application may include a device body.

[0101] The main body of a device refers to the main structure that consumes electrical energy to perform its corresponding functions. For example, an electrical device can be a mobile phone, where the main body is the part that enables communication and other functions, powered by individual battery cells or battery packs. Similarly, an electrical device can be a car, where the main body is the part that provides seating and allows the vehicle to move on the road, powered by individual battery cells or battery packs.

[0102] Electrical devices also include individual battery cells or battery packs, which supply power to the main body of the device through individual battery cells or battery packs.

[0103] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0104] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0105] 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 an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0106] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0107] 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.

[0108] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0109] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0110] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0111] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0112] In some embodiments, the battery device may be an energy storage device.

[0113] The following description will be based on an embodiment of the electrical device in this application, which is a vehicle.

[0114] One embodiment of this application provides a vehicle that can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery pack is installed inside the vehicle, and the battery pack can be located at the bottom, front, or rear of the vehicle. The battery pack can be used to power the vehicle; for example, the battery pack can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor, and the controller can be used to control the battery pack to power the motor. For example, the battery pack can be used to meet the vehicle's power needs during starting, navigation, and driving.

[0115] In some embodiments of this application, the battery pack can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0116] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0117] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0118] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the positive and negative electrodes. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0119] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0120] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0121] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0122] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0123] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, a positive electrode active material is filled and / or deposited within the foamed metal.

[0124] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0125] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0126] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0127] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0128] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0129] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0130] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0131] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0132] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0133] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0134] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0135] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0136] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0137] Liquid electrolytes include electrolyte salts and solvents.

[0138] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0139] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0140] In some embodiments, lipid electrolytes are also called ester electrolytes, mainly including two categories: carboxylic acid esters and carbonates. Common ester solvents include ethylene carbonate (EC) and propylene carbonate (PC). To improve electrolyte performance, researchers have developed various ester solvents, such as propyl acetate (PA) and methyl acetate (MA). These solvents have lower melting points and viscosities, which helps to improve the low-temperature conductivity of the electrolyte. However, these electrolytes are difficult to withstand high voltages; when the potential difference is greater than approximately 5V, the solvent may decompose.

[0141] In some embodiments, ether electrolytes in lithium batteries are mainly classified into two types: linear ethers and cyclic ethers. Linear ether solvents include 1,2-dimethoxypropane (DMP), dimethoxymethane (DMM), and dimethyl glycol ether (DME), while cyclic ether solvents include tetrahydrofuran (THF) and 2-methyltetrahydrofuran (2-Me-THF). Dimethyl glycol ether (DME) can form stable chelates with lithium salts, exhibiting strong dissolving power for lithium salts and thus improving the electrolyte's conductivity. However, this type of electrolyte is difficult to withstand high voltages; when the potential difference exceeds approximately 5V, the solvent may decompose.

[0142] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0143] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0144] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0145] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0146] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium-germanium-phosphorus-sulfur, sulfosilium-germanium), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0147] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0148] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0149] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0150] The battery device in this application embodiment includes a single battery cell.

[0151] For the battery cell in this application embodiment, please refer to [link / reference]. Figure 1 and Figure 2The battery cell includes a casing 1, a separator 2, an electrode assembly 4, and an electrolyte. The casing 1 forms an internal cavity in which the electrode assembly 4 is housed. The casing 1 includes a side wall 14, a bottom wall 15, and a top wall 16. The side wall 14 is annular and encloses the cavity. The bottom wall 15 is fixedly connected to the side wall 14 and seals the cavity from one side, supporting the electrode assembly 4. The top wall 16 is fixedly connected to the side wall 14 and is positioned opposite to the bottom wall 15. The separator 2 is fixedly connected to the bottom wall 15 and the side wall 14, dividing the cavity into at least two partition cavities 3. At least two electrode assemblies 4 are provided, with at least two partition cavities 3 containing one electrode assembly 4. The electrode assemblies 4 in different partition cavities 3 are connected in series. Each partition cavity 3 that houses the electrode assembly 4 contains a portion of the electrolyte, and the electrolytes in different partition cavities 3 are isolated from each other by the partition 2.

[0152] The outer shell 1 is a shell-like structure outside the electrode assembly 4, mainly used to protect the electrode assembly 4.

[0153] For example, the bottom wall 15 and side wall 14 of the outer casing 1 can be integrally formed structures.

[0154] For example, the bottom wall 15 and side wall 14 of the outer casing 1 can be formed independently and then connected by welding.

[0155] For example, the sidewall 14 can be a one-piece structure.

[0156] For example, the sidewall 14 can be formed by bending a single plate and welding it end to end.

[0157] For example, the sidewall 14 can be formed by welding together multiple plates.

[0158] The bottom wall 15 is used to support the electrode assembly 4. Here, "support" means that, under normal working conditions, the bottom wall 15 supports the electrode assembly 4 so that the electrode assembly 4 overcomes the effect of gravity and keeps its position fixed relative to the bottom wall 15.

[0159] The separator 2 is a structure that separates the electrolyte in each separator cavity 3.

[0160] For example, the separator 2 is plate-shaped.

[0161] For example, please refer to the figure. The arrangement direction of at least two partition cavities 3 is a first direction. The outer shell 1 includes a shell 12 and an end cap 13. The end cap 13 covers the shell 12. The partition 2 is connected in the space enclosed by the shell 12 and the end cap 13 to divide the space enclosed by the end cap 13 and the shell 12 into at least two partition cavities 3. The partition 2 can be integrally formed with the shell 12.

[0162] As exemplarily, referring to the figure, the partition 2 can be integrally formed with the sidewall 14. The sidewall 14 is formed in the housing 12, and the sidewall 14 of the outer shell 1 is the same as the sidewall 14 of the housing 12.

[0163] For example, the partition 2 is welded to the bottom wall 15.

[0164] For example, the partition 2 is welded to the side wall 14.

[0165] For example, one of the bottom wall 15, top wall 16 and side wall 14 is welded to the partition 2, and the remaining structures of the bottom wall 15, top wall 16 and side wall 14, except for those welded to the partition 2, can be snapped or interference-fitted to the partition 2.

[0166] For example, the side wall 14 is welded to the partition 2, the top wall 16 is snap-fitted or interference-fitted to the partition 2, and the bottom wall 15 is snap-fitted or interference-fitted to the partition 2.

[0167] It should be explained that welding can be between metals, between insulating materials and metals, or between insulating materials. For example, it can be welded between plastic and metal. For example, it can be welded between plastics.

[0168] The separator 2 is a structure inside the outer casing 1 used to separate the electrolyte. The separator 2 divides the space inside the outer casing 1 into at least two partition cavities 3, and at least one electrode assembly 4 is located in each partition cavity 3. The separated electrolyte is subjected to the potential difference of the electrode assembly 4 in the corresponding partition cavity 3.

[0169] For example, an electrode assembly 4 is provided in each partition cavity 3, and the potential difference borne by the electrolyte in each partition cavity 3 is the potential difference of the corresponding electrode assembly 4.

[0170] For example, the number of partition cavities 3 can be two, three, five, or eight.

[0171] For example, please refer to Figure 1 , Figure 2 , Figure 8 and Figure 9 There are three partition cavities 3 and two partition elements 2.

[0172] For example, please refer to Figure 1 , Figure 2 , Figure 8 and Figure 9 Each compartment 3 contains one electrode assembly 4, and the number of electrode assemblies 4 is three.

[0173] For example, the electrode assemblies 4 of each partition cavity 3 are connected in series.

[0174] For example, the electrode assemblies 4 of some partition cavities 3 are connected in parallel, and the parallel electrode assemblies 4 of different partition cavities 3 are connected in series.

[0175] For example, the electrode assembly 4 is insulated from the housing 1.

[0176] In this embodiment, the series connection of electrode assemblies 4 allows the battery cell to have a higher input or output voltage, i.e., a higher charging voltage. This increases the charging power of the battery cell while suppressing the charging current to some extent, reducing battery cell heating and energy loss. By providing a separator 2 within the housing 1, the accommodating cavity within the housing 1 is divided into at least two separate cavities 3. Since the electrolytes in the separate cavities 3 are isolated from each other, the electrolytes in the separate cavities 3 do not bear the overall potential difference of the series connection of the electrode assemblies 4. The potential difference borne by the electrolyte in any separate cavity 3 is equal to the potential difference of the corresponding electrode assembly 4 within that separate cavity 3. Therefore, the potential difference borne by the electrolyte in the separate cavity 3 is smaller, which helps reduce the possibility of electrolyte decomposition within the separate cavity 3, thereby improving the service life of the battery cell.

[0177] In some embodiments, please refer to Figure 2 At least two partition cavities 3 are arranged in the first direction. The bottom wall 15 is sealed to the lower side of the partition 2, and the side wall 14 is sealed to the opposite sides of the partition 2 along the second direction to isolate the electrolyte in the adjacent partition cavities 3 on the corresponding sides of the partition 2. The second direction is arranged to intersect with the first direction and the up and down direction, and the first direction is arranged to intersect with the up and down direction.

[0178] For example, please refer to Figure 1 , Figure 2 , Figure 5 and Figure 6 ,as well as Figures 8-10 The direction indicated by arrow R1 in the diagram is the first direction.

[0179] For example, please refer to Figure 1 ,as well as Figures 7-11 The direction indicated by arrow R2 in the diagram is the second direction.

[0180] For example, please refer to Figure 1 and Figure 2 , Figures 7-9 ,as well as Figure 11 The direction indicated by arrow R3 in the diagram is the up and down direction.

[0181] For example, the separator 2 can be sealed to the housing 1 by a contact seal.

[0182] For example, sealing is achieved by pressing the spacer 2 against the housing 1.

[0183] For example, a seal is provided between the separator 2 and the housing 1.

[0184] For example, the separator 2 can be integrally formed with the housing 1.

[0185] For example, the upper side of the separator 2 may be spaced apart from the outer casing 1, and the electrolyte accumulates below the top surface of the separator 2 due to gravity.

[0186] For example, the upper side of the separator 2 can be sealed to the housing 1.

[0187] The second direction intersects with the first direction and the up / down direction respectively. The first direction intersects with the up / down direction. The first direction, the second direction, and the up / down direction intersect each other but are not coplanar.

[0188] For example, the first direction is perpendicular to the second direction, the first direction is perpendicular to the up and down direction, and the second direction is perpendicular to the up and down direction.

[0189] In this embodiment, the lower side of the separator 2 is sealed to the bottom wall 15 to prevent the battery fluid in the adjacent compartments 3 on both sides of the separator 2 from flowing or communicating with each other through the lower side of the separator 2. The two adjacent compartments 3 on both sides of the separator 2 are sealed to the side wall 14 along the second direction to prevent the two adjacent compartments 3 on both sides of the separator 2 from flowing or communicating with each other through the two sides of the separator 2 along the second direction. Since the first direction and the vertical direction are arranged in a cross pattern, the electrolyte accumulates below the top surface of the separator 2 under the action of gravity. The sealing connection between the lower side of the separator 2 and the bottom wall 15 and the sealing connection between the two adjacent compartments 3 along the second direction and the side wall 14 allows the electrolyte in the adjacent compartments 3 on both sides to be well isolated by the separator 2.

[0190] It is understood that the specific arrangement of the separator 2 is not limited. For example, there may be local gaps between the opposite sides of the separator 2 along the second direction and the corresponding sidewall 14, as long as these local gaps are located above the electrolyte to separate the electrolyte and prevent the electrolyte from communicating through these local gaps.

[0191] In some embodiments, please refer to Figure 2 and Figure 8 The potential difference of the electrode assembly 4 in each partition cavity 3 is less than or equal to 5V.

[0192] For example, lipid electrolytes, also known as ester electrolytes, mainly include two categories: carboxylic acid esters and carbonates. Common ester solvents include ethylene carbonate (EC) and propylene carbonate (PC). To improve electrolyte performance, researchers have developed various ester solvents, such as propyl acetate (PA) and methyl acetate (MA). These solvents have lower melting points and viscosities, which helps to improve the low-temperature conductivity of the electrolyte. However, these electrolytes are difficult to withstand high voltages; when the potential difference is greater than approximately 5V, the solvent may decompose.

[0193] For example, ether electrolytes in lithium batteries are mainly divided into two types: linear ethers and cyclic ethers. Linear ether solvents include 1,2-dimethoxypropane (DMP), dimethoxymethane (DMM), and dimethyl glycol ether (DME), while cyclic ether solvents include tetrahydrofuran (THF) and 2-methyltetrahydrofuran (2-Me-THF). Dimethyl glycol ether (DME) can form stable chelates with lithium salts, exhibiting strong dissolving power for lithium salts and thus improving the electrolyte's conductivity. However, this type of electrolyte is difficult to withstand high voltages; when the potential difference exceeds approximately 5V, the solvent may decompose.

[0194] For example, the potential difference of the electrode assembly 4 in each partition cavity 3 can be 1V, 2V, 3V, 4V or 5V.

[0195] In this embodiment, the solvent of most electrolytes can withstand a voltage of around 5V, and the potential difference of the electrode assembly 4 in each partition cavity 3 is less than or equal to 5V, which can reduce the possibility of most electrolytes decomposing.

[0196] It is understood that the potential difference of the electrode assembly 4 within each partition chamber 3 is not limited. For example, the solvent of a portion of the electrolyte can withstand a higher voltage, and the potential difference of the electrode assembly 4 within each partition chamber 3 can be greater than 5V as appropriate.

[0197] In some embodiments, please refer to Figure 2 and Figure 8 The potential difference of the electrode assembly 4 in each partition cavity 3 is less than or equal to 4.5V.

[0198] For example, the potential difference of the electrode assembly 4 in each partition cavity 3 can be 1V, 1.5V, 2V, 2.5V, 3V, 4V or 4.5V.

[0199] In this embodiment, the potential difference of the electrode assembly 4 in each partition cavity 3 is less than or equal to 4.5V, so that the electrolyte in each partition cavity 3 is subjected to a small potential difference, which can reduce the possibility of most electrolyte decomposition.

[0200] In some embodiments, the output or input potential difference of a single battery cell is 8V to 50V.

[0201] The input potential difference of a battery cell is the charging voltage of that battery cell.

[0202] The potential difference output by a single battery cell is the discharge voltage of that single battery cell.

[0203] The input potential difference of a single battery cell is 8V to 50V. Under the condition that it basically meets the input power of the single battery cell, it can suppress the input current of the single battery cell to a certain extent.

[0204] The potential difference of the battery cell output is 8V to 50V. Under the condition that it basically matches the output power of the battery cell, it can suppress the output current of the battery cell to a certain extent.

[0205] For example, the input potential difference of a single battery cell can be 8V, 9V, 10V, 11V, 12V, 13V, 14V, 15V, 20V, 25V, 30V, 35V, 40V, 45V or 50V.

[0206] For example, the output potential difference of a single battery cell can be 8V, 9V, 10V, 11V, 12V, 13V, 14V, 15V, 20V, 25V, 30V, 35V, 40V, 45V or 50V.

[0207] In this embodiment, the output or input potential difference of the battery cell is 8V to 50V. The input or output potential difference of the battery cell is relatively large. Under the condition that it basically meets the output or output power of the battery cell, it can suppress the input or output current of the battery cell to a certain extent and reduce the heat generation and energy loss of the battery cell.

[0208] It is understood that the input or output potential difference of a single battery cell is not limited. For example, the input or output potential difference of a single battery cell can be 4.5V to 8V, or 5V to 8V.

[0209] In some embodiments, the number of electrode assemblies 4 connected in series is greater than or equal to two.

[0210] For example, the output or input potential difference of a single battery cell is 8V to 50V; and / or, the number of electrode assemblies 4 connected in series is greater than or equal to two.

[0211] In this embodiment of the application, connecting at least two electrode components 4 in series within a single battery cell is beneficial for increasing the input or output potential difference of the battery cell.

[0212] In some embodiments, please refer to Figure 1 and Figure 9The separator 2 includes a conductive element 21 and an insulating element 22. The conductive element 21 is electrically connected to the electrode assemblies 4 in the adjacent separator cavities 3 on both sides, so that the electrode assemblies 4 on both sides are connected in series. The insulating element 22 is provided between the bottom wall 15 and the conductive element 21, and between the side wall 14 and the conductive element 21. The bottom wall 15, the side wall 14, the side of the conductive element 21 facing the bottom wall 15, and the opposite sides of the conductive element 21 facing the corresponding side wall 14 are all sealed to the corresponding insulating element to isolate the electrolyte in the adjacent separator cavities 3 on both sides of the conductive element 21.

[0213] For example, the insulating element 22 can be insulating plastic or insulating rubber, etc.

[0214] For example, the insulating element 22 can be an injection molded part.

[0215] For example, the conductive element 21 can be made of metal.

[0216] For example, the conductive element 21 can be made of aluminum or copper.

[0217] For example, the insulating element 22 is connected to the conductive element 21 by heat fusion to seal the insulating element 22 and the conductive element 21 as much as possible, and the insulating element 22 is connected to the outer shell 1 by heat fusion to seal the insulating element 22 and the outer shell 1 as much as possible.

[0218] For example, the electrode assembly 4 corresponding to each partition cavity 3 is completely located within the corresponding partition cavity 3, and the tabs of the electrode assembly 4 do not extend into another partition cavity 3.

[0219] For example, an insulating member 22 is provided between the bottom wall 15 and the conductive member 21, and the insulating member 22 is respectively sealed to the bottom wall 15 and the conductive member 21.

[0220] For example, an insulating member 22 is provided between the sidewall 14 and the conductive member 21. The insulating member 22 between the conductive member 21 and the sidewall 14, as well as the arrangement direction of the conductive member 21, are arranged intersecting with the arrangement direction of at least two partition cavities 3. That is, the insulating member 22 between the conductive member 21 and the sidewall 14, as well as the arrangement direction of the conductive member 21, are arranged intersecting with the first direction. The insulating member 22 between the sidewall 14 and the conductive member 21 is sealed to both the sidewall 14 and the conductive member 21.

[0221] For example, an insulating element 22 is provided between the conductive element 21 and the sidewall 14 on opposite sides along the second direction.

[0222] In this embodiment, the electrode assemblies 4 in adjacent partition cavities 3 on both sides can be electrically connected to the conductive element 21 to achieve series connection between the electrode assemblies 4, which can facilitate the series connection of electrode assemblies 4 in two adjacent partition cavities 3. The insulating element 22 can insulate the conductive element 21 from the bottom wall 15 and the side wall 14 respectively, reducing the possibility of different conductive elements 21 forming equipotential through the outer shell 1, so that the electrode assemblies 4 in different partition cavities 3 can be better connected in series.

[0223] It is understood that the structure of the separator 2 is not limited. Exemplarily, the conductive element 21 is sealed to the housing 1, and the insulating element 22 is at least partially disposed between the conductive element 21 and the electrode assembly 4 to insulate the conductive element 21 from the electrode assembly 4. The electrode assemblies 4 in adjacent partition cavities 3 are electrically connected through tabs of the electrode assemblies 4. Exemplarily, the conductive element 21 can be integrally formed with the housing 1. Exemplarily, the insulating element 22 can be a Mylar membrane.

[0224] In some embodiments, please refer to Figures 1 to 7 At least two of the partition cavities 3 are arranged in a first direction. The electrode assembly 4 includes an isolator 42 and at least two electrode plates 41. The electrode plates 41 and the isolator 42 are stacked to form a stacked structure. An isolator 42 is provided between each two adjacent electrode plates 41. The electrode plates 41 and the isolator 42 are stacked along the first direction. The conductive member 21 is electrically connected to the electrode plates 41 of the electrode assembly 4 in the adjacent partition cavities 3 on both sides so that the electrode assemblies 4 corresponding to the adjacent partition cavities 3 on both sides are connected in series.

[0225] The electrode 41 and the separator 42 are stacked to form a stacked structure, and the electrode assembly 4 is a stacked electrode assembly 4.

[0226] For example, the separator 42 can be a separator membrane.

[0227] In this embodiment, the electrode 41 and the separator 42 are stacked along the first direction, which facilitates the electrical connection between the electrode 41 at one end of the electrode assembly 4 along the first direction and the conductive member 21, thereby better realizing the series connection of the electrode assemblies 4 corresponding to the adjacent partition cavities 3 on both sides.

[0228] It is understood that the stacking method of the electrode 41 and the spacer 42 is not limited. Exemplarily, the stacking direction of the electrode 41 and the spacer 42 is intersected with the first direction. Exemplarily, the stacking direction of the electrode 41 and the spacer 42 is perpendicular to the first direction.

[0229] In some embodiments, please refer to Figure 5 and Figure 6Each electrode 41 includes a current collector 411, and at least one electrode 41 of each electrode assembly 4 also includes an active material layer disposed on the current collector 411. At least two of the electrode 41 in each electrode assembly 4 are preset electrode 41s. All electrode 41s in each electrode assembly 4 except the preset electrode 41s are located between two preset electrode 41s along a first direction. The active material layer of the electrode assembly 4 is located between the current collectors 411 of the two preset electrode 41s. The conductive element 21 makes conductive contact with the current collectors 411 of the corresponding preset electrode 41s in the two electrode assemblies 4 along the first direction.

[0230] The active material layer of the electrode assembly 4 is located between the current collectors 411 of the two preset electrode sheets 41, and the conductive element 21 is in conductive contact with the current collectors 411 of the corresponding preset electrode sheets 41 in the electrode assemblies 4 on both sides along the first direction. The side of the current collectors 411 of the preset electrode sheets 41 facing the conductive element 21 does not have an active material layer.

[0231] For example, please refer to Figure 5 and Figure 6 The active material layer with positive polarity is the positive electrode active material layer 412, and the active material layer with negative polarity is the negative electrode active material layer 413.

[0232] It should be noted that both metal batteries and non-metal batteries require a positively polarized active material layer as the positive electrode. Metal batteries can use the current collector 411 itself as the negative electrode and do not require a negatively polarized active material layer. Non-metal batteries require a negatively polarized active material layer as the negative electrode.

[0233] For metal batteries, the current collector 411 itself can serve as the negative electrode, and there is no need to provide a negative electrode active material layer 413 on the current collector 411. The preset electrode 41, which serves as the negative electrode at one end of the electrode assembly 4 along the first direction, may include the current collector 411, but no active material layer is provided on the current collector 411, that is, neither a positively polarized active material layer nor a positively polarized active material layer is provided on the current collector 411.

[0234] For example, please refer to Figure 5 and Figure 6The figure shows three electrode assemblies 4. One electrode assembly 4 is located between two separators 2. Another electrode assembly 4 is located to the left of the left separator 2, and the third electrode assembly 4 is located to the right of the right separator 2. The leftmost electrode 41 of the electrode assembly 4 between the two separators 2 and the rightmost electrode 41 of the electrode assembly 4 between the two separators 2 are both preset electrode 41s. The electrode assembly 4 between the two separators 2 shows the complete arrangement of the electrode 41s and spacers 42. The electrode assembly 4 on the left side of the left separator 2 shows a portion of the electrode 41s. The electrode assembly 4 on the left side of the left separator 2 does not show all the electrode 41s and spacers 42s of this electrode assembly 4. The electrode assembly 4 on the right side of the right separator 2 shows a portion of the electrode 41s. The electrode assembly 4 on the right side of the right separator 2 does not show all the electrode 41s and spacers 42s of this electrode assembly 4.

[0235] For example, the current collector 411 is attached to the conductive element 21 to make the current collector 411 electrically connected to the conductive element 21.

[0236] For example, please refer to Figure 5 and Figure 6 The figure shows the complete arrangement of electrode plates 41 and isolation members 42 of the electrode assembly 4 between two conductive members 21. The preset electrode plates 41 on both sides of the electrode assembly 4 between the two conductive members 21 along the first direction are electrically connected to the corresponding conductive members 21. Except for the preset electrode plates 41 on both sides, the other electrode plates 41 of the electrode assembly 4 between the two conductive members 21 are located between the corresponding preset electrode plates 41 on both sides.

[0237] In this embodiment, the active material layer of the electrode assembly 4 is disposed between the current collectors 411 of the two preset electrode sheets 41. The side of the current collectors 411 of the preset electrode sheets 41 facing the conductive element 21 is not provided with an active material layer, so that the current collectors 411 of the preset electrode sheets 41 can make good conductive contact with the conductive element 21, thereby increasing the contact area between the current collectors 411 and the conductive element 21 and achieving better electrical connection between the current collectors 411 and the conductive element 21.

[0238] It is understood that the arrangement of the active material layer of the electrode assembly 4 is not limited. For example, the active material layer can be provided on the side of the current collector 411 of the preset electrode 41 facing the conductive member 21 as appropriate.

[0239] In some embodiments, please refer to Figure 5 and Figure 6 The polarity of the preset electrode 41, which is in conductive contact with both sides of the conductive element 21 along the first direction, is opposite to that of the side away from the conductive element 21.

[0240] Please see Figure 5 and Figure 6The preset electrode 41 is in conductive contact with both sides of the conductive member 21 along the first direction, namely the preset electrode 41 of the electrode assembly 4 corresponding to the partition cavity 3 on one side of the conductive member 21 along the first direction, and the preset electrode 41 of the electrode assembly 4 corresponding to the adjacent partition cavity 3 on the other side of the conductive member 21 along the first direction.

[0241] The polarity of the side of the preset electrode 41 away from the conductive element 21 is determined as follows: when the polarity of the active material layer on the side of the preset electrode 41 away from the conductive element 21 is positive, the polarity of the side of the preset electrode 41 away from the conductive element 21 is positive; when the polarity of the active material layer on the side of the preset electrode 41 away from the conductive element 21 is negative or no active material layer is provided, the polarity of the side of the preset electrode 41 away from the conductive element 21 is negative.

[0242] For example, please refer to Figure 6 When the preset electrode plates 41 at both ends of the electrode assembly 4 of the metal battery between the two separators 2 in the figure are electrically connected to the corresponding conductive parts 21, the polarity of the leftmost preset electrode plate 41 of the electrode assembly 4 between the two separators 2 in the figure is positive, and the polarity of the rightmost preset electrode plate 41 is negative.

[0243] For example, please refer to Figure 5 When the preset electrode plates 41 at the left and right ends of the electrode assembly 4 of the non-metallic battery between the two separators 2 in the figure are electrically connected to the corresponding conductive parts 21, the polarity of the preset electrode plate 41 at the leftmost end between the two separators 2 in the figure is positive, and the polarity of the preset electrode plate 41 at the rightmost end is negative.

[0244] For example, please refer to Figure 5 In the diagram, the polarity of the active material layer on the side of the current collector 411 of the adjacent preset electrode 41 on the left side of the conductive element 21, which is opposite to the conductive element 21, is negative, i.e., negative electrode active material layer 413. In the diagram, the polarity of the active material layer on the side of the current collector 411 of the adjacent preset electrode 41 on the right side of the conductive element 21, which is opposite to the conductive element 21, is positive, i.e., positive electrode active material layer 412.

[0245] For example, please refer to Figure 6 In the diagram, the current collector 411 of the adjacent preset electrode 41 on the left side of the conductive element 21 does not have an active material layer on the side facing away from the conductive element 21; that is, the adjacent preset electrode 41 on the left side of the conductive element 21 is the current collector 411. The active material layer of the current collector 411 of the adjacent preset electrode 41 on the right side of the conductive element 21 has a positive polarity, that is, the positive electrode active material layer 412.

[0246] In this embodiment, by having the polarity of the preset electrode 41, which is in conductive contact with both sides of the conductive element 21 along the first direction, opposite to that of the conductive element 21, the electrode assemblies 4 of the adjacent partition cavities 3 on both sides of the conductive element 21 can be connected in series.

[0247] In one embodiment, please refer to Figure 5 and Figure 6 Each isolation element 42 and the adjacent electrode plates 41 on both sides of the isolation element 42 constitute a power conversion unit, and at least two power conversion units are connected in series.

[0248] Each separator 42 and the adjacent electrode plates 41 on both sides of the separator 42 constitute an energy conversion unit, which is used to convert chemical energy and electrical energy into each other.

[0249] In this embodiment, since the electrode plates 41 and the insulating members 42 of the electrode assembly 4 are stacked along the first direction, at least two power conversion units formed by at least two insulating members 42 and their corresponding electrode plates 41 arranged along the first direction are connected in series. The at least two power conversion units are arranged approximately along the first direction. The positive electrode of the at least two power conversion units connected in series is on one side of the electrode assembly 4 along the first direction, and the negative electrode of the at least two power conversion units connected in series is on the other side of the electrode assembly 4 along the first direction. That is, the positive electrode of the entire electrode assembly 4 is located on one side of the electrode assembly 4 along the first direction, and the negative electrode of the entire electrode assembly 4 is located on the other side of the electrode assembly 4 along the first direction. Each electrode plate 41 of the electrode assembly 4 can be provided with tabs to lead out the positive or negative electrode. The conductive member 21 is electrically connected to the electrode plates 41 of the electrode assembly 4 of the adjacent partition cavities 3 on both sides to realize the series connection of the electrode assembly 4, or the tabs are not required to lead out the positive or negative electrode. By connecting at least two power conversion units in series and connecting the electrode plates 41 of adjacent electrode assemblies 4 on both sides in series with the conductive element 21, the number of electrode tabs of the electrode assembly 4 can be reduced, thereby reducing the space occupied by the electrode assembly 4.

[0250] In some embodiments, please refer to Figure 5 Each electrode 41 includes a current collector 411 and an active material layer disposed on the current collector 411. In each electrode assembly 4, the current collector 411, the positively polarized active material layer, the separator 42, and the negatively polarized active material layer are arranged alternately along a first direction so that at least two energy conversion units are connected in series.

[0251] For example, please refer to Figure 5 The active material layer with positive polarity is the positive electrode active material layer 412, and the active material layer with negative polarity is the negative electrode active material layer 413.

[0252] The current collector 411, the positively polarized active material layer, the separator 42, and the negatively polarized active material layer are arranged alternately along the first direction, and the battery cell is a non-metallic battery.

[0253] For example, please refer to Figure 5The electrode assembly 4 between the two conductive elements 21 shown in the figure consists of, from left to right, a current collector 411, a positively polarized active material layer, an isolator 42, a negatively polarized active material layer, another current collector 411, a positively polarized active material layer, an isolator 42, and another negatively polarized active material layer, etc. These layers are arranged periodically in a sequence of "current collector 411, positively polarized active material layer, isolator 42, negatively polarized active material layer". In the electrode assembly 4 between the two conductive elements 21 shown in the figure, besides the pre-set electrode plates 41 at the left and right ends between the two conductive elements 21, one side of the current collector 411 of the remaining electrode plates 41 between the two conductive elements 21 is coated with a positively polarized active material layer, and the other side is coated with a negatively polarized active material layer.

[0254] For example, please refer to Figure 5 The electrode assembly 4 shown in the figure has an isolator 42, a current collector 411 corresponding to one of the adjacent electrodes 41 and a positively polarized active material layer on the side of the current collector 411 facing the isolator 42, and a current collector 411 corresponding to the other adjacent electrode 41 and a negatively polarized active material layer on the side of the current collector 411 facing the isolator 42, which constitute a power conversion unit. The electrode assembly 4 between the two conductive elements 21 shown in the figure includes four isolators 42. Each isolator 42 and the corresponding adjacent electrodes 41 on both sides constitute a power conversion unit. The four power conversion units are connected in series.

[0255] For example, the material of the negatively polar active material layer can be hard carbon, soft carbon, or graphite, or a mixture of two materials.

[0256] In this embodiment, the current collector 411, the positively polarized active material layer, the separator 42, and the negatively polarized active material layer are arranged alternately along the first direction, so that at least two power conversion units of the electrode assembly 4 are connected in series. The electrode 41 and the separator 42 of the electrode assembly 4 can obtain the required voltage with fewer stacked layers.

[0257] In some embodiments, please refer to Figure 6 Each electrode 41 includes a current collector 411, and at least one electrode 41 also includes a positively polarized active material layer disposed on the corresponding current collector 411. In each electrode assembly 4, the current collector 411, the positively polarized active material layer, and the separator 42 are arranged alternately along a first direction.

[0258] For example, please refer to Figure 6 The active material layer with positive polarity is the positive electrode active material layer 412, and the active material layer with negative polarity is the negative electrode active material layer 413.

[0259] The current collector 411, the positively polarized active material layer, and the separator 42 are arranged alternately along the first direction, with the current collector 411 itself serving as the negative electrode, and the battery cell being a metal battery.

[0260] For example, please refer to Figure 6 The electrode assembly 4 between the two conductive elements 21 shown in the figure consists of, from left to right, a current collector 411, a positively polarized active material layer, an isolator 42, another current collector 411, another positively polarized active material layer, and another isolator 42, etc. These elements are arranged periodically, with "current collector 411, positively polarized active material layer, and isolator 42" forming a cycle. In the electrode assembly 4 between the two conductive elements 21, except for the rightmost pre-set electrode 41 between the two conductive elements 21, which is the current collector 411 and has no active material layer on either side, the other electrodes 41 between the two conductive elements 21 have a positive active material layer 412 on one side of the current collector 411 and no active material layer on the other side.

[0261] For example, please refer to Figure 6 In the figure, an isolator 42 of the electrode assembly 4, a current collector 411 corresponding to one of the adjacent electrodes 41, a positively polarized active material layer on the side of the current collector 411 facing the isolator 42, and the side of the current collector 411 corresponding to the other adjacent electrode 41 facing the isolator 42 without an active material layer constitutes a power conversion unit. The electrode assembly 4 between the two conductive members 21 in the figure includes four isolators 42. Each isolator 42 and the corresponding adjacent electrodes 41 on both sides constitute a power conversion unit. The four power conversion units are connected in series.

[0262] In this embodiment, the current collector 411, the positively polarized active material layer, and the separator 42 are arranged alternately along the first direction, so that the power conversion units of the electrode assembly 4 are connected in series. The electrode 41 and the separator 42 of the electrode assembly 4 obtain the required voltage with fewer layers. The electrode assembly 4 uses the current collector 411 as the negative electrode, and there is no need to set a negatively polarized active material layer, which helps to reduce the space occupied by the electrode assembly 4.

[0263] In some embodiments, please refer to Figures 2-4 Each electrode 41 includes a current collector 411. The sidewall 14 of the housing 1 includes a preset housing wall 11 arranged opposite to each other along a first direction. The electrode assemblies 4 in at least two partition cavities 3 arranged sequentially along the first direction are connected in series. The battery cell also includes an electrode terminal 5 installed on the housing 1. Among all the current collectors 411 arranged sequentially along the first direction, the current collectors 411 closest to the preset housing wall 11 on both sides are electrically connected to the corresponding electrode terminal 5. The thickness of the current collectors 411 closest to the preset housing wall 11 on both sides is 5μm to 100μm.

[0264] For example, please refer to Figures 2-4 The thickness of the current collector 411 closest to the preset shell wall 11 on both sides is D1, 5μm≤D1≤100μm.

[0265] Among all the current collectors 411 arranged sequentially along the first direction, the current collectors 411 that are closest to the preset shell wall 11 on both sides include the current collector 411 that is closest to the preset shell wall 11 on one side along the first direction and the current collector 411 that is closest to the preset shell wall 11 on the other side along the first direction.

[0266] For example, please refer to Figures 2-4 Among all the current collectors 411 arranged sequentially along the first direction, the current collectors 411 closest to the preset shell wall 11 on both sides include the current collector 411 closest to the preset shell wall 11 on the left side of the figure and the current collector 411 closest to the preset shell wall 11 on the right side of the figure.

[0267] For example, the thickness of the current collectors 411 closest to the preset shell wall 11 on both sides is 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm or 100μm.

[0268] In this embodiment, the thickness of the current collector 411 closest to the preset shell wall 11 on both sides is 5μm to 100μm. The thickness of the current collector 411 is appropriate and conducive to improving the flow capacity of the current collector 411 closest to the preset shell wall 11 on both sides.

[0269] In some embodiments, please refer to Figures 2-4 Among all the current collectors 411 arranged sequentially along the first direction, the thickness of the current collectors 411 closest to the preset shell wall 11 on both sides is 10μm to 20μm.

[0270] For example, the thickness of the current collectors 411 closest to the preset shell wall 11 on both sides is 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm or 20μm.

[0271] In this embodiment, the thickness of the current collector 411 closest to the preset shell wall 11 on both sides is 5μm to 100μm. The thickness of the current collector 411 is appropriate. On the one hand, it is beneficial to improve the flow capacity of the current collector 411 closest to the preset shell wall 11 on both sides. On the other hand, it can prevent the current collector 411 from being too thick to a certain extent, thereby reducing costs.

[0272] In one embodiment, please refer to Figures 1-4 ,as well as Figure 7Each electrode 41 includes a current collector 411. The sidewall 14 of the housing 1 includes a preset housing wall 11 arranged opposite to each other along a first direction. The electrode assemblies 4 in at least two partition cavities 3 arranged sequentially along the first direction are connected in series. The battery cell also includes an electrode terminal 5 installed on the housing 1. Among all the current collectors 411 arranged sequentially along the first direction, the current collectors 411 closest to the preset housing wall 11 on both sides are electrically connected to the corresponding electrode terminal 5. The current collectors 411 closest to the preset housing wall 11 on both sides include a main body 4111 and a first tab 4112 disposed on the main body 4111. The direction in which the first tab 4112 protrudes from the main body 4111 and the direction intersecting the first direction are respectively the third direction. The ratio of the size of the first tab 4112 along the third direction to the size of the main body 4111 along the third direction is 20% to 40%.

[0273] Among all the current collectors 411 arranged sequentially along the first direction, the current collectors 411 that are closest to the preset shell wall 11 on both sides include the current collector 411 that is closest to the preset shell wall 11 on one side along the first direction and the current collector 411 that is closest to the preset shell wall 11 on the other side along the first direction.

[0274] For example, please refer to the figure, the first tab 4112 has a dimension of D2 along the third direction, the body 4111 has a dimension of D3 along the third direction, and 20% ≤ D2 / D3 ≤ 40%.

[0275] For example, please refer to Figures 2-4 Among all the current collectors 411 arranged sequentially along the first direction, the current collectors 411 closest to the preset shell wall 11 on both sides include the current collector 411 closest to the preset shell wall 11 on the left side of the figure and the current collector 411 closest to the preset shell wall 11 on the right side of the figure.

[0276] For example, among all the current collectors 411 arranged sequentially along the first direction, the first tab 4112 of the current collector 411 closest to the preset shell wall 11 on one side has a positive polarity, and the first tab 4112 of the current collector 411 closest to the preset shell wall 11 on the other side has a negative polarity.

[0277] The current collectors 411 closest to the preset shell wall 11 on both sides are the current collectors 411 of the preset electrode 41 of the corresponding electrode assembly 4.

[0278] For example, please refer to Figure 2 The first electrode ear 4112 protrudes from the main body 4111 and is arranged in the vertical direction.

[0279] For example, the ratio of the dimension of the first tab 4112 along a third direction to the dimension of the body 4111 along a third direction is 20%, 22%, 25%, 27%, 30%, 33%, 35%, 38%, or 40%.

[0280] In this embodiment, the ratio of the dimension of the first tab 4112 along the third direction to the dimension of the body 4111 along the third direction is 20% to 40%, which makes the proportion of the dimension of the first tab 4112 along the third direction more appropriate, and the first tab 4112 has better current carrying capacity.

[0281] In some embodiments, please refer to Figures 1-4 ,as well as Figure 7 The ratio of the dimension of the first electrode 4112 along the third direction to the dimension of the main body 4111 along the third direction is 30% to 40%.

[0282] For example, the ratio of the dimension of the first tab 4112 along a third direction to the dimension of the body 4111 along a third direction is 30%, 31%, 33%, 35%, 36%, 38%, 39%, or 40%.

[0283] For example, the first electrode 4112 protrudes from the main body 4111 and is arranged intersecting with the first direction, the first electrode 4112 protrudes from the main body 4111 and is arranged intersecting with the third direction, and the first direction is arranged intersecting with the third direction.

[0284] For example, the direction in which the first electrode 4112 protrudes from the main body 4111 is perpendicular to the first direction, and the direction in which the first electrode 4112 protrudes from the main body 4111 is perpendicular to the third direction, and the first direction is perpendicular to the third direction.

[0285] For example, the first tab 4112 protrudes upward from the main body 4111 and is arranged in the third direction along the second direction.

[0286] In this embodiment, the ratio of the dimension of the first tab 4112 along the third direction to the dimension of the body 4111 along the third direction is 30% to 40%, which makes the proportion of the dimension of the first tab 4112 along the third direction more appropriate, and the first tab 4112 has better current carrying capacity.

[0287] In some embodiments, an insulating member 22 is provided between the top wall 16 and the upper side of the conductive member 21, and the top wall 16 and the upper side of the conductive member 21 are both sealed to the corresponding insulating member 22 to isolate the electrolyte in the adjacent partition cavities 3 on both sides of the partition member 2.

[0288] The bottom wall 15, top wall 16 and side wall 14 are all sealed to the conductive element 21, so that the conductive element 21 is sealed to the outer shell 1.

[0289] For example, the spacer 2 is sealed to the housing 1.

[0290] The partition 2 is sealed to the outer shell 1, and the adjacent partition cavities 3 on both sides of the partition 2 are completely sealed and separated. The adjacent partition cavities 3 on both sides of the partition 2 are not connected.

[0291] For example, when the spacer 2 is sealed to the housing 1, the stacked electrode assembly 4 can be electrically connected to the conductive member 21 through the current collector 411 without tabs on the preset electrode 41.

[0292] For example, when the spacer 2 is sealed to the housing 1, the wound electrode assembly 4 can be electrically connected to the conductive member 21 through the second tab of the electrode assembly 4.

[0293] In this embodiment, the electrode assemblies 4 of the two side partition cavities 3 of the separator 2 are connected in series through the conductive component 21. Since the separator 2 is sealed and connected to the outer shell 1, the adjacent partition cavities 3 on both sides of the separator 2 are not connected. No matter how the battery cells are arranged, the electrolyte in the partition cavity 3 on one side of the separator 2 will not flow to the partition cavity 3 on the other side of the separator 2. The separation of the electrolyte in the two side partition cavities 3 by the separator 2 is not limited by the arrangement of the battery cells. It can better adapt to various application scenarios of battery cell arrangement and has wide adaptability.

[0294] It is understood that the specific arrangement of the separator 2 is not limited. For example, the upper side of the separator 2 is spaced apart from the top wall 16. For example, the upper side of the conductive element 21 is spaced apart from the top wall 16.

[0295] In one embodiment, please refer to Figures 8-10 The electrode assembly 4 includes an isolator 42 and at least two electrode plates 41. The electrode plates 41 and the isolator 42 are wound together to form a wound structure. An isolator 42 is provided between each two adjacent electrode plates 41. A second electrode tab is formed at least one end of the electrode assembly 4 along the winding axis of the electrode assembly 4. The electrode assemblies 4 of different partition cavities 3 are connected in series through the second electrode tab.

[0296] For example, please refer to Figure 8 The second electrode with positive polarity is called the positive electrode 441, and the second electrode with negative polarity is called the negative electrode 442.

[0297] The electrode 41 and the separator 42 are wound together to form a wound structure, and the electrode assembly 4 is a wound electrode assembly 4.

[0298] For the wound electrode assembly 4, the insulating member 42 is wrapped around the outside of the wound electrode assembly 4 for insulation. The wound electrode assembly 4 needs to be provided with tabs to bring out the positive and negative electrodes of the electrode assembly 4.

[0299] For example, in the wound electrode assembly 4, the electrode 41 includes a current collector 411 and an active material layer. The current collector 41 of the electrode 41 with positive polarity is provided with an active material layer with positive polarity on both sides of the current collector 411, and the current collector 411 of the electrode 41 with negative polarity is provided with an active material layer with negative polarity on both sides of the current collector 411.

[0300] For example, the power conversion unit formed by the separator 42 and the corresponding electrode 41 of the wound electrode assembly 4 is generally in parallel.

[0301] For example, the positive polarity electrode 41, the negative polarity electrode 41, and the separator 42 preceding the positive polarity electrode 41 and the negative polarity electrode 41 are wound together to form a wound structure.

[0302] In this embodiment of the application, for the wound electrode assembly 4, the second tab of the electrode assembly 4 can be used to conveniently realize the series connection between the two electrode assemblies 4.

[0303] In some embodiments, please refer to Figure 8 At least two of the partition cavities 3 are arranged in a first direction, and the winding axis of the electrode assembly 4 is arranged to intersect with the first direction.

[0304] For example, the winding axis of the electrode assembly 4 is perpendicular to the first direction.

[0305] For example, the winding axis is arranged in the vertical direction.

[0306] In this embodiment, the winding axis of the electrode assembly 4 intersects with the first direction, and the second tabs of different polarities at at least one end of the winding axis of the electrode assembly 4 can be separated to both sides of the electrode assembly 4 along the first direction so as to be connected in series with the electrode assembly 4 of the adjacent partition cavity 3 along the first direction.

[0307] In some embodiments, please refer to Figure 8 The second tab of each electrode assembly 4 is located at one end of the corresponding electrode assembly 4 along the winding axis. In the second tab of each electrode assembly 4, the second tabs with positive polarity and the second tabs with negative polarity are arranged alternately in directions that intersect the winding axis and the first direction, respectively.

[0308] For example, please refer to Figure 8 The second electrode with positive polarity is called the positive electrode 441, and the second electrode with negative polarity is called the negative electrode 442.

[0309] The second tab of each electrode assembly 4 is located at one end of the corresponding electrode assembly 4 along the winding axis. That is, one end of the electrode assembly 4 along the winding axis has both a second tab with positive polarity and a second tab with negative polarity. The other end of the electrode assembly 4 along the winding axis does not have a second tab.

[0310] For example, please refer to Figure 8 The positive and negative polarity second electrodes are arranged alternately along the second direction, and the winding axis extends in the vertical direction.

[0311] For example, please refer to Figure 8 The first direction intersects with the large surface of the electrode assembly 4.

[0312] For example, please refer to Figure 8 The first direction is perpendicular to the large surface of the electrode assembly 4.

[0313] The large surface of electrode assembly 4 is the surface with the largest area.

[0314] For example, please refer to Figure 8 and Figure 10 The electrode assembly 4 has a straight region 45 and a corner region 46. The two sides of the straight region 45 each have a corner region 46. The positive polarity second electrode tab and the negative polarity second electrode tab are arranged alternately along the arrangement direction of the two corner regions 46.

[0315] For example, please refer to Figure 8 and Figure 10 The arrangement directions of the two corner areas 46 are respectively intersecting the first direction and the winding axis.

[0316] For example, please refer to Figure 8 and Figure 10 The arrangement directions of the two corner areas 46 are perpendicular to the first direction and the winding axis, respectively, with the first direction being perpendicular to the winding axis.

[0317] For example, please refer to Figure 8 and Figure 10 The positive and negative second electrode tabs are arranged alternately along the second direction, that is, the positive electrode tab 441 and the negative electrode tab 442 are arranged alternately along the second direction.

[0318] For example, please refer to Figure 8 and Figure 10 The arrangement of the corner areas 46 on both sides is along the second direction.

[0319] In this embodiment, the positive and negative polarity second electrodes are arranged alternately in directions that intersect the winding shaft and the first direction, respectively. This facilitates the connection of the second electrodes of different electrode assemblies 4 to achieve series connection, and the spacing between the second electrodes with different polarities reduces the possibility of short circuits between them.

[0320] In some embodiments, please refer to Figure 8In two adjacent partition cavities 3 along the first direction, one partition cavity 3 corresponds to the direction in which the positive polarity of the second electrode tab of the electrode assembly 4 points to the direction in which the negative polarity of the second electrode tab points, which is opposite to the direction in which the positive polarity of the second electrode tab of the electrode assembly 4 of the other partition cavity 3 points to the direction in which the negative polarity of the second electrode tab points.

[0321] For example, please refer to Figure 8 The second electrode with positive polarity is called the positive electrode 441, and the second electrode with negative polarity is called the negative electrode 442.

[0322] In this embodiment, since the direction of the positive polarity second tab of the electrode assembly 4 corresponding to one of the partition 3 is opposite to that of the negative polarity second tab, the positions of the opposite polarity second tabs of the electrode assembly 4 corresponding to the other partition 3 are closer, which facilitates the electrical connection of the electrode assemblies 4 of the adjacent partition 3 on both sides to form a series connection.

[0323] It is understood that the arrangement of the electrode assembly 4 is not limited. For example, the direction in which the positive polarity of the second electrode tab of one partition cavity 3 corresponds to the negative polarity of the second electrode tab of the electrode assembly 4 can be the same as the direction in which the positive polarity of the second electrode tab of the electrode assembly 4 corresponds to the negative polarity of the second electrode tab of the other partition cavity 3.

[0324] In some embodiments, please refer to Figure 8 and Figure 9 The battery cell also includes electrode terminals 5, and the electrode assemblies 4 corresponding to the partition cavities 3 arranged sequentially along the first direction are connected in series. The side wall 14 of the outer casing 1 includes preset shell walls 11 arranged opposite to each other along the first direction. The second tabs of the electrode assemblies 4 closest to the preset shell walls 11 on both sides of the electrode assemblies 4 connected in series are electrically connected to the corresponding electrode terminals 5. The number of partition cavities 3 arranged sequentially along the first direction is odd.

[0325] For example, please refer to Figure 8 The second electrode with positive polarity is called the positive electrode 441, and the second electrode with negative polarity is called the negative electrode 442.

[0326] For example, the number of partition cavities 3 arranged sequentially along the first direction is three, five, or seven.

[0327] For example, the battery cell also includes an electrode terminal 5 mounted on the housing 1, and the second tab is electrically connected to the corresponding electrode terminal 5.

[0328] For example, electrode terminal 5 is a pole post.

[0329] The electrode assembly 4 connected in series with the electrode assembly 4 having the two sides closest to the preset shell wall 11 includes the electrode assembly 4 having the side closest to the preset shell wall 11 along the first direction and the electrode assembly 4 having the other side closest to the preset shell wall 11 along the first direction.

[0330] Please see Figure 8 The electrode assemblies 4 connected in series include the electrode assembly 4 closest to one side of the preset shell wall 11 along the first direction and the electrode assembly 4 closest to the other side of the preset shell wall 11 along the first direction. Of the three electrode assemblies 4 shown, except for the middle electrode assembly 4 along the first direction, the other two electrode assemblies 4 are the electrode assemblies closest to the preset shell wall 11 on both sides.

[0331] In this embodiment, since the direction of the positive polarity second electrode tab of one of the partition cavities 3 corresponding to the electrode assembly 4 is opposite to that of the negative polarity second electrode tab, and the direction of the positive polarity second electrode tab of the electrode assembly 4 corresponding to the other partition cavities 3 is opposite to that of the negative polarity second electrode tab, the number of partition cavities 3 is set to an odd number. This makes it possible that among the electrode assemblies 4 closest to the preset shell wall 11 on both sides along the first direction, the second electrode tab of one side of the electrode assembly 4 closest to the preset shell wall 11 that is electrically connected to the corresponding electrode terminal 5 can be spaced as far apart as possible from the second electrode tab of the other side of the electrode assembly 4 closest to the preset shell wall 11 that is electrically connected to the corresponding electrode terminal 5. The corresponding electrode terminals 5 with opposite polarities can also be spaced as far apart as possible, reducing the possibility of short circuit of the electrode terminals 5.

[0332] In some embodiments, the separator 2 is made of insulating plastic.

[0333] The material of the separator 2 is insulating plastic. The separator 2 is not conductive and has no conductive part 21.

[0334] In this embodiment, the separator 2 is made of insulating plastic, which can reduce the weight of the separator 2 to a certain extent compared to the metal separator 2, thereby reducing the weight of the battery cell.

[0335] In some embodiments, please refer to Figure 8 and Figure 9 The upper end of the separator 2 is spaced apart from the top wall 16. In two adjacent separator cavities 3, the second electrode tab of the electrode assembly 4 in at least one separator cavity 3 passes through the gap between the upper end of the corresponding separator 2 and the top wall 16, so as to be electrically connected to the second electrode tab of the electrode assembly 4 in the other separator cavity 3.

[0336] For example, please refer to Figure 8The second electrode with positive polarity is called the positive electrode 441, and the second electrode with negative polarity is called the negative electrode 442.

[0337] For example, the winding shaft is arranged in the vertical direction.

[0338] In this embodiment, the upper end of the separator 2 is spaced apart from the outer shell 1, so that a space is left between the upper end of the separator 2 and the outer shell 1 for the second tab of the electrode assembly 4 corresponding to one side of the separator cavity 3 to extend to the separator cavity 3 on the other side, so that the electrode assemblies 4 corresponding to adjacent separator cavities 3 on both sides of the separator 2 can be electrically connected through the second tab to achieve series connection.

[0339] It is understood that the arrangement of the separator 2 is not limited. For example, when the separator 2 is sealed to the housing 1 to isolate the electrolyte in the adjacent partition cavities 3 on both sides of the separator 2, the second electrode can be electrically connected to the conductive element 21 to realize the series connection of the electrode assembly 4 of the adjacent partition cavities 3 on both sides.

[0340] In some embodiments, the battery cell is a sodium-ion battery cell.

[0341] In this embodiment, when sodium crystals are deposited in a single battery cell to form sodium branches, the possibility of the separator 42 being punctured is reduced because the sodium branches are relatively round.

[0342] The type of battery cell is not limited. For example, the battery cell can be a lithium-ion battery.

[0343] In some embodiments, please refer to Figure 5 , Figure 6 and Figure 10 The electrode assembly 4 includes an isolator 42 and at least two electrodes 41. An isolator 42 is provided between each pair of adjacent electrodes 41. Each electrode 41 includes a current collector 411, which is made of aluminum.

[0344] For example, at least one electrode 41 of each electrode assembly 4 further includes an active material layer disposed on the current collector 411.

[0345] For example, each electrode 41 includes an active material layer disposed on a current collector 411.

[0346] In this embodiment, sodium ions do not form an alloy with aluminum, which helps to better maintain the capacity of the battery cell. Aluminum is less expensive than copper, and the current collector 411 is made of aluminum, which helps to reduce costs.

[0347] The material of the current collector 411 is not limited. For example, the material of the current collector 411 can be copper.

[0348] In some embodiments, please refer to Figure 11At least two of the partition cavities 3 are arranged in a first direction. The outer shell 1 includes a shell 12 and an end cap 13. The side wall 14 is formed in the shell 12. The end cap 13 covers the shell 12. The partition 2 is connected within the space enclosed by the shell 12 and the end cap 13 to divide the space enclosed by the end cap 13 and the shell 12 into at least two partition cavities 3. The arrangement directions of the end cap 13 and the shell 12 are intersected with the first direction. The top wall 16 and / or the side wall 14 are formed in the end cap 13.

[0349] The sidewall 14 is formed in the housing 12 and is at least a part of the housing 12.

[0350] For example, the housing 12 may be surrounded by sidewalls 14. For example, the housing 12 may include sidewalls 14 and a bottom wall 15 connected to the bottom of the sidewalls 14.

[0351] For example, the end cap 13 is located at the upper end of the housing 12, and the top wall 16 is formed on the end cap 13.

[0352] For example, the upper and lower ends of the housing 12 are provided with end caps 13, and the top wall 16 and the bottom wall 15 are both formed on the end caps 13, that is, the bottom wall 15 is formed on the bottom end cap 13, and the top wall 16 is formed on the top end cap 13.

[0353] For example, the end cap 13 is located at the lower end of the housing 12, and the bottom wall 15 is formed on the end cap 13.

[0354] For example, the housing 12 is welded to the end cap 13 to seal the space enclosed by the housing 12 and the end cap 13, and the electrolyte is located within the space enclosed by the housing 12 and the end cap 13.

[0355] For example, the end cap 13 and the housing 12 are arranged in a direction perpendicular to the first direction.

[0356] For example, the end cap 13 and the housing 12 are arranged in the vertical direction.

[0357] For example, the insulating element 22 is disposed between the conductive element 21 and the housing 12 to insulate the conductive element 21 from the housing 12.

[0358] For example, the end cap 13 is provided with a corresponding insulating structure on the side facing the electrode assembly 4, and the separator 2 may not need to be provided with an additional insulating member 22 on the side facing the end cap 13.

[0359] For example, the electrode terminal 5 may be disposed on the end cap 13 or the housing 12.

[0360] In this embodiment, since the end cap 13 and the housing 12 are arranged in a cross direction with the first direction, the end cap 13 covers most of the openings of the partition cavities 3 arranged along the first direction. Before the end cap 13 covers the housing 12, most of the partition cavities 3 arranged along the first direction are in an open state, which makes it easier to place the electrode assembly 4 into each partition cavity 3, making the installation of the electrode assembly 4 more convenient.

[0361] In some embodiments, please refer to Figure 5 , Figure 6 and Figure 10 The electrode assembly 4 includes an insulating member 42 and at least two electrodes 41. An insulating member 42 is disposed between each pair of adjacent electrodes 41. Each electrode 41 includes a current collector 411. At least one electrode 41 of each electrode assembly 4 also includes an active material layer disposed on the current collector 411. The material of the active material layer with positive polarity contains sodium.

[0362] For example, an active material layer with negative polarity may be provided on the current collector 411 of the electrode 41 with negative polarity, or no active material layer may be provided.

[0363] In this embodiment, the active material layer with positive polarity contains sodium. Sodium ions reciprocate through the separator 42, enabling the charging and discharging of the battery cell. When sodium crystals are deposited in the battery cell, forming sodium branches, the relatively rounded shape of these crystals reduces the likelihood of the separator 42 being punctured.

[0364] It is understood that the material of the positively polar active material layer is not limited. For example, the material of the positively polar active material layer includes lithium.

[0365] In some embodiments, please refer to the figure, the material of the positively polar active material layer is a sodium-containing oxide, a sodium-containing Prussian compound, or a sodium-containing polyanionic compound.

[0366] For example, the sodium-containing oxide can be a layered oxide or a tunnel-structured oxide.

[0367] For example, the oxide containing sodium can be sodium oxide, cobalt oxide (NaCoO2), manganese oxide, nickel oxide, etc.

[0368] Prussian compounds containing sodium, namely ferrocyanide, are coordination compounds.

[0369] Polyanionic compounds are macromolecular compounds formed by the aggregation of multiple negatively charged molecules, ions, or groups. Sodium-containing polyanionic compounds are those that contain sodium.

[0370] For example, the sodium-containing polyanionic compound can be a cobaltate, manganate, or ferrate.

[0371] In some embodiments, please refer to Figures 1 to 11 The battery cell includes a casing 1, a separator 2, an electrode assembly 4, and an electrolyte. The casing 1 forms an internal cavity in which the electrode assembly 4 is housed. The casing 1 includes a side wall 14, a bottom wall 15, and a top wall 16. The side wall 14 is annular and encloses the cavity. The bottom wall 15 is fixedly connected to the side wall 14 and seals the cavity from one side, supporting the electrode assembly 4. The top wall 16 is fixedly connected to the side wall 14 and is positioned opposite to the bottom wall 15. The separator 2 is fixedly connected to the bottom wall 15 and the side wall 14, dividing the cavity into at least two partition cavities 3. At least two electrode assemblies 4 are provided, with at least two partition cavities 3 containing one electrode assembly 4. The electrode assemblies 4 in different partition cavities 3 are connected in series. Each partition cavity 3 housing the electrode assembly 4 contains a portion of the electrolyte, and the electrolytes in different partition cavities 3 are isolated from each other by the partition 2. The potential difference of the electrode assembly 4 in each partition cavity 3 is 4.5V. The input potential difference of the battery cell is 8V to 50V, and the number of electrode assemblies 4 connected in series is three. The partition 2 includes a conductive element 21 and an insulating element 22. The conductive element 21 is electrically connected to the electrode assembly 4 in the corresponding adjacent partition cavities 3 on both sides to connect the electrode assemblies 4 in series on both sides. The insulating element 22 is sealed to the conductive element 21 and the outer casing 1 to isolate the electrolyte in the corresponding adjacent partition cavities 3 on both sides of the conductive element 21. The battery cell is a sodium-ion battery. The outer casing 1 includes a housing 12 and an end cap 13. End cap 13 is placed on housing 12, and separator 2 is connected in the space enclosed by housing 12 and end cap 13 to divide the space enclosed by end cap 13 and housing 12 into at least two partition cavities 3. The arrangement direction of end cap 13 and housing 12 is intersected with the first direction.

[0372] Please see Figures 1 to 7 ,as well as Figure 11The electrode assembly 4 is a stacked electrode assembly 4, with a positively polarized active material layer 412 and a negatively polarized active material layer 413. A positively polarized active material layer is provided on the side of the electrode assembly 41 facing the isolator 42 along one side of the first direction, and this positively polarized active material layer is in contact with the corresponding isolator 42. The other side of the isolator 42 is either a negatively polarized active material layer or the side of the current collector 411 without an active material layer. The conductive element 21 is electrically connected to the electrode 41 of the electrode assembly 4 in the adjacent partition cavities 3 on both sides. The conductive element 21 is electrically bonded to the corresponding current collector 411 for electrical connection. Each isolator 42 and the adjacent electrode 41 on opposite sides of the isolator 42 constitute a power conversion unit, and at least two power conversion units are connected in series. Each electrode 41 includes a current collector 411. The sidewall 14 of the housing 1 includes a preset housing wall 11 arranged opposite to each other along a first direction. The electrode assemblies 4 in at least two partition cavities 3 arranged sequentially along the first direction are connected in series. The battery cell also includes an electrode terminal 5 installed on the housing 1. Among all the current collectors 411 arranged sequentially along the first direction, the current collectors 411 closest to the preset housing wall 11 on both sides are electrically connected to the corresponding electrode terminal 5. The current collectors 411 closest to the preset housing wall 11 on both sides include a main body 4111 and a first tab 4112 disposed on the main body 4111. Other current collectors 411 may not be provided with tabs. Each electrode 41 includes a current collector 411. The shell wall of the outer casing 1 includes preset shell walls 11 arranged opposite each other along a first direction. Electrode assemblies 4 in at least two partition cavities 3 arranged sequentially along the first direction are connected in series. The battery cell also includes electrode terminals 5 installed on the outer casing 1. Among all the current collectors 411 arranged sequentially along the first direction, the current collectors 411 closest to the preset shell walls 11 on both sides are electrically connected to the corresponding electrode terminals 5. The thickness of the current collectors 411 closest to the preset shell walls 11 on both sides is 10μm to 20μm. Each electrode 41 includes a current collector 411 and an active material layer disposed on the current collector 411. In each electrode assembly 4, the current collector 411, the positively polarized active material layer, the separator 42, and the negatively polarized active material layer are arranged alternately along the first direction so that at least two energy conversion units are connected in series. Each electrode 41 includes a current collector 411, and at least one electrode 41 also includes a positively polarized active material layer disposed on the corresponding current collector 411. In each electrode assembly 4, the current collector 411, the positively polarized active material layer, and the separator 42 are arranged alternately along a first direction so that at least two energy conversion units are connected in series.

[0373] Please see Figures 8-10 ,as well as Figure 11The electrode assembly 4 is a wound electrode assembly 4, and the separator 2 is made of plastic. In two adjacent separator cavities 3, the positive polarity second electrode tab of the electrode assembly 4 in one separator cavity 3 points in the direction of the negative polarity second electrode tab, and the positive polarity second electrode tab of the electrode assembly 4 in the other separator cavity 3 points in the opposite direction to the negative polarity second electrode tab. The electrode assemblies 4 of two adjacent separator cavities 3 are connected in series through the second electrode tabs. The amount of electrolyte in each separator cavity 3 can be equal or unequal. The battery cell also includes electrode terminals 5. The electrode assemblies 4 corresponding to the separator cavities 3 arranged sequentially along the first direction are connected in series. The side wall of the outer casing 1 includes preset shell walls 11 arranged opposite each other along the first direction. The second electrode tabs of the electrode assemblies 4 closest to the preset shell walls 11 on both sides of the sequentially connected electrode assemblies 4 are electrically connected to the corresponding electrode terminals 5. The number of separator cavities 3 arranged sequentially along the first direction is odd.

[0374] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and all should be covered within the scope of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way.

Claims

1. A battery cell, characterized in that, include: Electrode assembly; The outer shell has an internal cavity for housing the electrode assembly. The outer shell includes a side wall, a bottom wall, and a top wall. The side wall is annular and encloses the cavity. The bottom wall is fixedly connected to the side wall and blocks the cavity from one side. The bottom wall supports the electrode assembly. The top wall is fixedly connected to the side wall and is disposed opposite to the bottom wall. A separator is fixedly connected to the bottom wall and the side wall and divides the receiving cavity into at least two partition cavities. The electrode assembly is configured to be at least two, with at least two partition cavities containing the electrode assembly. Each partition cavity containing the electrode assembly contains at least one electrode assembly, and the electrode assemblies in different partition cavities are connected in series. The electrolyte is contained in each partition cavity that houses the electrode assembly, and the electrolytes in different partition cavities are isolated from each other by the partition.

2. The battery cell according to claim 1, characterized in that, At least two of the partition cavities are arranged in a first direction. The bottom wall is sealed to the lower side of the partition member, and the side wall is sealed to the opposite sides of the partition member along a second direction to isolate the electrolyte in the adjacent partition cavities on the corresponding sides of the partition member. The second direction is arranged to intersect the first direction and the vertical direction, and the first direction is arranged to intersect the vertical direction.

3. The battery cell according to claim 1, characterized in that, The potential difference of the electrode assembly within each of the partitioned cavities is less than or equal to 5V.

4. The battery cell according to claim 3, characterized in that, The potential difference of the electrode assembly within each of the partitioned cavities is less than or equal to 4.5V.

5. The battery cell according to claim 1, characterized in that, The output or input potential difference of the battery cell is 8V to 50V; and / or the number of electrode assemblies connected in series is greater than or equal to two.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The separator includes: The conductive element is electrically connected to the electrode assembly in the adjacent partition cavity on both sides respectively, so that the electrode assembly on both sides is connected in series; An insulating element is provided between the bottom wall and the conductive element, and between the side wall and the conductive element. The bottom wall, the side wall, the side of the conductive element facing the bottom wall, and the opposite sides of the conductive element facing the side wall are all sealed to the corresponding insulating element to isolate the electrolyte in the adjacent partition cavities on the corresponding sides of the conductive element.

7. The battery cell according to claim 6, characterized in that, The arrangement direction of at least two of the partition cavities is a first direction. The electrode assembly includes an isolator and at least two electrodes. The electrodes and the isolator are stacked to form a stacked structure. An isolator is provided between each pair of adjacent electrodes. The electrodes and the isolator are stacked along the first direction. The conductive element is electrically connected to the electrodes of the electrode assembly in the adjacent partition cavities on both sides so that the electrode assemblies corresponding to the adjacent partition cavities on both sides are connected in series.

8. The battery cell according to claim 7, characterized in that, Each electrode includes a current collector, and at least one electrode in each electrode assembly further includes an active material layer disposed on the current collector. At least two electrodes in each electrode assembly are preset electrodes. All electrodes in each electrode assembly except the preset electrodes are located between two preset electrodes along the first direction. The active material layer of the electrode assembly is located between the current collectors of the two preset electrodes. The conductive element is in conductive contact with the current collectors of the corresponding preset electrodes in the electrode assemblies on both sides along the first direction.

9. The battery cell according to claim 8, characterized in that, The polarity of the preset electrode plates that are in conductive contact with both sides of the conductive element along the first direction is opposite to that of the conductive element on the side away from the conductive element.

10. The battery cell according to claim 7, characterized in that, Each of the isolation elements and the adjacent electrodes on opposite sides of the isolation elements constitute a power conversion unit, and at least two power conversion units are connected in series.

11. The battery cell according to claim 10, characterized in that, Each electrode includes a current collector and an active material layer disposed on the current collector. In each electrode assembly, the current collector, the positively polarized active material layer, the separator, and the negatively polarized active material layer are arranged alternately along the first direction so that at least two energy conversion units are connected in series.

12. The battery cell according to claim 10, characterized in that, Each electrode includes a current collector, and at least one electrode also includes a positively polarized active material layer disposed on the corresponding current collector. In each electrode assembly, the current collector, the positively polarized active material layer, and the separator are arranged alternately along the first direction so that at least two energy conversion units are connected in series.

13. The battery cell according to claim 10, characterized in that, Each electrode includes a current collector, the sidewall of the housing includes preset housing walls arranged opposite each other along the first direction, the electrode assemblies in at least two partition cavities arranged sequentially along the first direction are connected in series, the battery cell also includes electrode terminals installed on the housing, among all the current collectors arranged sequentially along the first direction, the current collectors closest to the preset housing walls on both sides are electrically connected to the corresponding electrode terminals, and the thickness of the current collectors closest to the preset housing walls on both sides is 5μm to 100μm.

14. The battery cell according to claim 13, characterized in that, Among all the current collectors arranged sequentially along the first direction, the thickness of the current collectors closest to the preset shell wall on both sides is 10μm to 20μm.

15. The battery cell according to claim 10, characterized in that, Each electrode includes a current collector, the sidewall of the housing includes a preset housing wall arranged opposite to each other along the first direction, the electrode assemblies in at least two partition cavities arranged sequentially along the first direction are connected in series, the battery cell also includes an electrode terminal installed on the housing, among all the current collectors arranged sequentially along the first direction, the current collectors closest to the preset housing wall on both sides are electrically connected to the corresponding electrode terminal, the current collectors closest to the preset housing wall on both sides include a main body and a first electrode tab disposed on the main body, the direction in which the first electrode tab protrudes from the main body and the direction intersecting the first direction are respectively a third direction, the ratio of the size of the first electrode tab along the third direction to the size of the main body along the third direction is 20% to 40%.

16. The battery cell according to claim 15, characterized in that, The ratio of the dimension of the first electrode tab along the third direction to the dimension of the body along the third direction is 30% to 40%.

17. The battery cell according to claim 6, characterized in that, An insulating element is provided between the top wall and the upper side of the conductive element. Both the top wall and the upper side of the conductive element are sealed to the corresponding insulating element to isolate the electrolyte in the adjacent partition cavities on both sides of the partition.

18. The battery cell according to any one of claims 1 to 5, characterized in that, The electrode assembly includes an isolator and at least two electrodes. The electrodes and the isolator are wound together to form a wound structure. An isolator is provided between each pair of adjacent electrodes. A second tab is formed at at least one end of the electrode assembly along the winding axis of the electrode assembly. Electrode assemblies with different partition cavities are connected in series through the second tab.

19. The battery cell according to claim 18, characterized in that, At least two of the partition cavities are arranged in a first direction, and the winding axis of the electrode assembly is arranged to intersect the first direction.

20. The battery cell according to claim 19, characterized in that, The second tab of each electrode assembly is located at one end of the corresponding electrode assembly along the winding axis. In each electrode assembly, the second tabs with positive polarity and the second tabs with negative polarity are arranged alternately in directions that intersect the winding axis and the first direction, respectively.

21. The battery cell according to claim 20, characterized in that, In two adjacent partition cavities along the first direction, one partition cavity corresponds to the direction in which the positive polarity of the second electrode tab of the electrode assembly points to the direction in which the negative polarity of the second electrode tab is pointed, which is opposite to the direction in which the positive polarity of the second electrode tab of the electrode assembly points to the direction in which the negative polarity of the second electrode tab is pointed in the other partition cavity.

22. The battery cell according to claim 21, characterized in that, The battery cell also includes electrode terminals, and the electrode assemblies corresponding to the partition cavities arranged sequentially along the first direction are connected in series. The side wall of the housing includes a preset housing wall arranged opposite to each other along the first direction. The second tabs of the electrode assemblies closest to the preset housing wall on both sides of the sequentially connected electrode assemblies are electrically connected to the corresponding electrode terminals. The number of partition cavities arranged sequentially along the first direction is odd.

23. The battery cell according to claim 18, characterized in that, The separator is made of insulating plastic.

24. The battery cell according to claim 18, characterized in that, The upper end of the separator is spaced apart from the top wall. In two adjacent separator cavities, the second electrode tab of the electrode assembly in at least one separator cavity passes through the gap between the upper end of the separator and the top wall to be electrically connected to the second electrode tab of the electrode assembly in the other separator cavity.

25. The battery cell according to any one of claims 1 to 5, characterized in that, The battery cell is a sodium-ion battery cell.

26. The battery cell according to claim 25, characterized in that, The electrode assembly includes an isolator and at least two electrodes, with the isolator disposed between each pair of adjacent electrodes. Each electrode includes a current collector made of aluminum.

27. The battery cell according to any one of claims 1 to 5, characterized in that, At least two of the partition cavities are arranged in a first direction, and the outer shell includes: A housing, wherein the sidewalls are formed in the housing; An end cap is disposed on the housing, and a separator is connected within the space enclosed by the housing and the end cap to divide the space enclosed by the end cap and the housing into at least two partition cavities. The end cap and the housing are arranged in an intersecting direction with the first direction, and the top wall and / or the bottom wall are formed on the end cap.

28. The battery cell according to any one of claims 1 to 5, characterized in that, The electrode assembly includes an isolator and at least two electrodes, with the isolator disposed between each pair of adjacent electrodes. Each electrode includes a current collector, and at least one electrode of each electrode assembly further includes an active material layer disposed on the current collector. The active material layer, which is positively polar, is made of sodium.

29. The battery cell according to claim 28, characterized in that, The active material layer with positive polarity is made of sodium-containing oxides, sodium-containing Prussian compounds, or sodium-containing polyanionic compounds.

30. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1 to 29.

31. An electrical device, characterized in that, Includes a battery cell according to any one of claims 1 to 29 or a battery device according to claim 30, wherein the battery cell or the battery device is used to store or provide electrical energy.

Images