Battery and power consuming device

Abstract

The embodiment of the application relates to the technical field of batteries, in particular to a battery and a power utilization device. The battery comprises a first battery monomer and a second battery monomer, the first battery monomer and the second battery monomer are arranged adjacently along a certain direction, the first battery monomer comprises a first surface perpendicular to the arrangement direction, the second battery monomer comprises a second surface perpendicular to the arrangement direction, the first surface is adjacent to the second surface, and the first battery monomer and the second battery monomer are configured to be recessed towards the inside of the first battery monomer and protrude towards the outside of the second battery monomer when the electric cycle number of the battery is greater than or equal to 100 times and the battery is in a full charge state. The first battery monomer and the second battery monomer in the application realize the concave-convex matching through the adjacent first surface and second surface, thereby reducing the expansion force of the whole battery monomer to the outside, reducing the probability of damage of parts of the battery under pressure, improving the service life and safety of the battery.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and more particularly to a battery and an electrical device. Background Technology

[0002] As batteries become more widely used, in some cases, in order to enable batteries to have greater power to drive large devices, multiple battery cells are often combined to form a battery module. One or more battery modules are combined to form a battery. Each battery module includes multiple battery cells and end plates, and the end plates are fixed at both ends of the multiple battery cells in the direction of their arrangement. The end plates are used to resist the expansion force of the multiple battery cells during the charging and discharging process.

[0003] When a battery module contains a large number of individual battery cells, the end plate needs to withstand greater expansion forces when multiple battery cells expand simultaneously, which reduces the reliability and safety of the battery module. Summary of the Invention

[0004] In view of the above problems, this application provides a battery and an electrical device that reduces the expansion force between adjacent battery cells and the overall expansion force of multiple battery cells, thereby reducing the probability of damage to battery cells and other components in the battery due to pressure, and improving the battery's service life and safety.

[0005] According to one aspect of the embodiments of this application, a battery is provided, the battery including a first battery cell and a second battery cell, the first battery cell and the second battery cell being arranged adjacent to each other along a certain direction, the first battery cell including a first surface perpendicular to the arrangement direction, the second battery cell including a second surface perpendicular to the arrangement direction, the first surface and the second surface being adjacent to each other, the first battery cell and the second battery cell being configured such that when the battery has a number of electrical cycles greater than or equal to 100 and is in a fully charged state, the first surface is recessed into the interior of the first battery cell, and the second surface is protruding into the exterior of the second battery cell.

[0006] By adopting the above scheme, in the fully charged state, the first surface and the second surface are adjacent to each other and have a concave-convex combination. The space formed by the concavity of the first surface is used to accommodate the convexity of the second surface, which reduces the interaction force between the first battery cell and the second battery cell, and also reduces the expansion force of the whole composed of multiple battery cells. This reduces the probability of other components in the battery being damaged due to the expansion force of the battery cells, and improves the battery's service life and safety.

[0007] In some embodiments, the first battery cell is configured such that when the battery has undergone 100 or more electrical cycles and is fully charged, the maximum indentation distance on the first surface is greater than or equal to 0.1 mm.

[0008] By adopting the above scheme, the greater the concavity distance of the first surface, the larger the space for accommodating the protrusion of the second surface, and the more significant the effect of reducing the interaction force between the first battery cell and the second battery cell.

[0009] In some embodiments, the first battery cell is configured such that when the battery has 100 or more electrical cycles and is fully charged, the maximum indentation distance on the first surface is less than or equal to 8 mm.

[0010] By adopting the above scheme, the larger the maximum indentation distance on the first surface, the more intense the compression of the first battery cell by the second battery cell. When the compression force is too great, the outer shell of the first battery cell may be damaged by holes, and the electrode assembly of the first battery cell may also be damaged or broken, leading to a deterioration in the electro-cycling performance of the first battery cell and a shortened lifespan. Therefore, limiting the maximum indentation distance on the first surface within the above range can optimize the electro-cycling performance of the first battery cell and improve its lifespan.

[0011] In some embodiments, the second battery cell is configured such that when the battery has undergone 100 or more electrical cycles and is fully charged, the maximum protrusion distance on the second surface is greater than or equal to 0.1 mm.

[0012] By adopting the above scheme, the second surface protrudes and abuts against the first surface, making the first battery cell and the second battery cell more closely adjacent, preventing the first battery cell and the second battery cell from shaking or displacing significantly when the battery vibrates, thereby improving the stability of the battery structure and the reliability of the electrical connection.

[0013] In some embodiments, the second battery cell is configured such that when the battery has 100 or more electrical cycles and is fully charged, the maximum protrusion distance on the second surface is less than or equal to 10 mm.

[0014] The greater the maximum protrusion distance on the second surface, the greater the expansion force of the second battery cell. Excessive expansion force may cause the casing of the second battery cell to break or fracture, or it may cause the second battery cell to exert a large compressive force on the first battery cell, accelerating the deterioration of the first battery cell's electro-cycling performance, resulting in a shortened lifespan of the first battery cell and damage to the casing of the second battery cell. The above limitations can avoid or reduce the probability of these adverse situations occurring.

[0015] In some embodiments, the first battery cell includes a first end cap, and the second battery cell includes a second end cap. The width direction of the first end cap and the width direction of the second end cap are both parallel to the arrangement direction of the first battery cell and the second battery cell. The ratio of the maximum recess distance to the maximum width of the first end cap is greater than or equal to 0.5%, and / or the ratio of the maximum protrusion distance to the maximum width of the second end cap is greater than or equal to 0.5%.

[0016] When the size ratio of the battery cell's casing to the electrode assembly is constant, the wider the first end cap, the larger the gap between the electrode assembly inside the first battery cell and the casing in the alignment direction during assembly. This means that, without subjecting the electrode assembly to excessive compressive force that could degrade cycle performance, the first battery cell can withstand a greater degree of casing deformation. Therefore, the ratio of the maximum indentation distance to the maximum width of the first end cap is limited to be greater than or equal to 0.5%, so that the maximum indentation distance on the first surface increases with the width of the first end cap. This provides a larger space on the first surface within the pressure resistance range of the first battery cell to accommodate the protrusion of the second battery cell, thereby reducing the interaction force between the first and second battery cells. Similarly, when the size ratio of the battery cell's casing to the electrode assembly is constant, the larger the width of the second end cap, the larger the maximum size of the second battery cell along the arrangement direction. This means that the electrode assembly inside the second battery cell is thicker in the arrangement direction. In a fully charged state, the electrode assembly inside the second battery cell will generate a large amount of expansion. By limiting the ratio of the maximum protrusion distance to the maximum width of the second end cap to be greater than or equal to 0.5%, the second surface of the second battery cell can reduce the expansion force inside the second battery cell by increasing the protrusion distance in a fully charged state. This, combined with the concavity of the first surface, achieves the effect of reducing the expansion force inside the second battery cell and reducing the expansion force between the first and second battery cells.

[0017] In some embodiments, the ratio of the maximum protrusion distance to the maximum width of the second end cap is less than or equal to 20%, and / or the ratio of the maximum recess distance to the maximum width of the first end cap is less than or equal to 20%.

[0018] When the size ratio of the battery cell's casing to the electrode assembly is constant, a larger width of the second end cap and a larger thickness of the electrode assembly result in greater expansion of the electrode assembly inside the second battery cell under full charge. This necessitates a larger protrusion in the casing of the second battery cell to accommodate the electrode assembly. However, if the protrusion distance on the second surface is too large, the casing of the second battery cell is at risk of breakage, especially at the junction of the casing and the first end cap. Furthermore, if the first surface has an excessively large indentation distance under the pressure of the second surface, it also risks perforation. Under excessive compressive force, the electrode assembly inside the first battery cell may break. Therefore, the above limitations prevent damage to both the second and first battery cells, extending their service life.

[0019] In some embodiments, in any pair of adjacent first and second surfaces, the difference between the maximum recess distance of the first surface and the maximum protrusion distance of the second surface is less than or equal to 0.2 mm.

[0020] By adopting the above scheme, the adjacent first surface and second surface can be matched well, the expansion of the second surface can be fully or relatively fully accommodated in the recess of the first surface, and the space formed by the concavity of the first surface is not wasted or is wasted less.

[0021] In some embodiments, the first battery cell further includes a first housing, with a first surface located on the first housing, and the second battery cell further includes a second housing, with a second surface located on the second housing, and the strength of the first housing is less than the strength of the second housing.

[0022] By adopting the above solution, the second casing is stronger and less prone to breakage. Since the second battery cell expands more significantly, it is more likely to break under the same casing strength. Therefore, the strength of the second casing can be increased, thus reducing the probability of breakage when the second battery cell deforms. The first battery cell expands less, making it less likely for the casing to rupture due to its own expansion. Therefore, the strength requirements for the first casing can be reduced.

[0023] In some embodiments, the first surface is located on the first wall of the first housing, the second surface is located on the second wall of the second housing, and the wall thickness of the first wall is less than the wall thickness of the second wall.

[0024] By adopting the above scheme, the strength of the first and second surfaces can be controlled by controlling the wall thickness of the first and second walls. The method is simple and will not affect the strength of other walls of the first and second shells.

[0025] According to another aspect of the embodiments of this application, an electrical device is provided, including a battery of any of the above-described embodiments, the battery being used to provide electrical energy.

[0026] By adopting the above scheme, the overall size of the battery pack after multiple battery cells are assembled can be reduced to a smaller extent, and the interaction force between the overall battery pack and other components of the battery can be reduced. This reduces the risk of other components in the battery being damaged due to compression, and improves the overall charging and discharging performance, service life and safety of the battery, thereby providing better power to electrical devices.

[0027] This embodiment of the application arranges a first battery cell and a second battery cell inside the battery. The first and second battery cells are arranged adjacent to each other in a certain direction. The first surface of the first battery cell is adjacent to the second surface of the second battery cell. When the battery has been fully charged with 100 or more electrical cycles, the first surface is recessed into the interior of the first battery cell, and the second surface is protruded outward from the second battery cell. The space formed by the recess of the first surface is used to accommodate the protrusion of the second surface, which reduces the expansion force between the first and second battery cells and also reduces the overall expansion force of the multiple battery cells. This reduces the probability of the battery being damaged due to the expansion force of the battery cells, and improves the battery's service life and safety.

[0028] The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of this application more obvious and understandable, specific implementation methods of this application are described below. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of an electrical device in one embodiment of this application.

[0031] Figure 2 This is a schematic diagram of the battery structure in one embodiment of this application.

[0032] Figure 3 This is a schematic diagram of the exploded structure of a single battery cell in one embodiment of this application.

[0033] Figure 4This is a schematic diagram showing the arrangement of multiple battery cells in a non-fully charged state in one embodiment of this application.

[0034] Figure 5 This is a schematic diagram showing the arrangement of multiple battery cells in a fully charged state in one embodiment of this application.

[0035] Figure 6 This is a schematic diagram of the shape of the first battery cell in a fully charged state according to an embodiment of this application.

[0036] Figure 7 This is a schematic diagram of the shape of the second battery cell in a fully charged state according to one embodiment of this application.

[0037] Figure 8 This is a cross-sectional view of the first and second battery cells in a fully charged state according to an embodiment of this application.

[0038] Explanation of reference numerals in the attached drawings: 2, automobile; 200, battery; 210, controller; 220, motor; 300, battery module; 201, first housing; 202, second housing; 400, battery cell; 410, electrode assembly; 420, outer casing; 421, housing; 422, end cap; 4221, electrode terminal; 401, first battery cell; 4011, first surface; 4012, first end cap; 4013, first housing; 4014, first wall; 402, second battery cell; 4021, second surface; 4022, second end cap; 4023, second housing; 4024, second wall. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] 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 in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0041] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and drawings of this application are intended to cover without excluding other meanings. The words "a" or "an" do not exclude the presence of multiples.

[0042] The term "embodiment" as used herein 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 the phrase "embodiment" 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.

[0043] In this article, 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, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0044] The directional terms appearing in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the battery or electrical device of this application. For example, in the description of this application, terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0045] Furthermore, the descriptions of directions such as the X, Y, and Z directions used to explain the operation and construction of the components of the battery or electrical device in this embodiment are not absolute but relative. Although these directions are appropriate when the components of the battery pack are in the positions shown in the figure, they should be interpreted differently when these positions change to correspond to the changes.

[0046] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0047] In the description of this application, unless otherwise stated, "multiple" means two or more (including two), and similarly, "multiple groups" means two or more (including two groups).

[0048] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, "connection" or "linkage" in mechanical structures can refer to a physical connection, such as a fixed connection, for example, a connection fixed by fasteners, such as a connection fixed by screws, bolts, or other fasteners; a physical connection can also be a detachable connection, such as a snap-fit ​​or interlocking connection; a physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. In circuit structures, "connection" or "linkage" can refer not only to a physical connection but also to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate component, as long as the circuit is connected; it can also refer to the internal connection of two components. Signal connection can refer not only to signal connection through a circuit but also to signal connection through a media, such as radio waves. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] In this application, the battery cell may include lithium-ion battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc., and the embodiments of this application are not limited to this. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, cuboid / square battery cells, and pouch battery cells, and the embodiments of this application are not limited to this.

[0050] A battery cell includes a casing, electrode assembly, and electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrode plates. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated current collector protrudes beyond the coated current collector, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated current collector protrudes beyond the coated current collector, serving as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon or silicon, etc. To ensure that a large current can be carried without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together. The insulating material can be polypropylene (PP) or polyethylene (PE), etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiments of this application are not limited to these.

[0051] During the cycling process, the electrode components of a conventional lithium-ion battery expand and increase in volume. Once the volume of the electrode components increases to a certain extent, they often come into contact with the outer casing and squeeze the casing wall outward, causing a bulge.

[0052] As batteries become increasingly widely used, in some cases, to enable batteries to have greater power to drive large devices, multiple battery cells are often combined to form a battery. When a battery contains a large number of battery cells, the expansion force between adjacent battery cells is large when multiple battery cells expand simultaneously. The battery cells squeeze each other, which deteriorates the battery's cycle performance and causes abnormal battery current. Furthermore, the combination of multiple battery cells as a whole squeezes other components of the battery, such as the battery casing wall and the battery cooling system, causing them to break. As a result, the reliability and safety of the battery are reduced.

[0053] To address the aforementioned issues, the common solution in existing technologies is to add additional mechanical components such as buffer pads and barrier strips between adjacent battery cells. These components are placed between adjacent battery cells to pre-determine space for expansion. However, the addition of these components also means increasing the number of process steps during battery assembly, including fixing the mechanical components and positioning them with the battery cells. The increased process steps lead to complexity in battery production and a decrease in battery reliability. Problems such as mechanical components falling off during battery assembly or use may occur, or uneven stress may occur on the battery cells, leading to a deterioration in the electrochemical performance of the battery cells in the later stages of use.

[0054] In view of the above problems, this application provides a battery and an electrical device that reduces the expansion force between adjacent battery cells and the overall expansion force of the battery cells, thereby reducing the probability of damage to the battery cells and other components within the battery, and improving the battery's lifespan and safety.

[0055] The battery in this application embodiment can be applied to various battery-using devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, electric vehicles, ships, and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft, but are not limited thereto.

[0056] like Figure 1 As shown, Figure 1 This is a schematic diagram of an electrical device according to an embodiment of this application. Taking a car 2 as an example, the car 2 can be a gasoline car, a natural gas car, or a new energy vehicle. A new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. The car 2 includes a battery 200, a controller 210, and a motor 220. The battery 200 supplies power to the controller 210 and the motor 220, serving as the operating power and drive power for the car 2. For example, the battery 200 meets the power requirements for starting, navigation, and operation of the car 2. For instance, the battery 200 supplies power to the controller 210, which controls the battery 200 to supply power to the motor 220. The motor 220 receives and uses the power from the battery 200 as the drive power for the car 2, replacing or partially replacing gasoline or natural gas to provide driving power for the car 2.

[0057] like Figure 2As shown, in order to enable the battery 200 to achieve a high power output to meet usage requirements, the battery 200 may include multiple battery modules 300 and a housing that are electrically connected to each other. The housing includes a first housing 201 and a second housing 202, wherein the first housing 201 and the second housing 202 are interlocked, and the multiple battery modules 300 are arranged within the space enclosed by the first housing 201 and the second housing 202. The first housing 201 and the second housing 202 may be made of aluminum, aluminum alloy, or other metal materials. In some embodiments, the first housing 201 and the second housing 202 are sealed together.

[0058] like Figure 2 As shown, the battery module 300 may include one or more battery cells 400. When the battery module 300 includes multiple battery cells 400, the multiple battery cells 400 can be electrically connected in series, parallel, or mixed connection to achieve a larger current or voltage. Mixed connection refers to a combination of series and parallel connections. Furthermore, the multiple battery cells 400 can be arranged according to a predetermined rule, such as... Figure 2 As shown, the battery cell 400 can be placed upright, and the height direction of the battery cell 400 is consistent with the Z direction. Multiple battery cells 400 are arranged side by side along the Y direction.

[0059] Figure 3 This is a schematic diagram of the exploded structure of a single battery cell provided in an embodiment of this application, as shown below. Figure 3 As shown, the battery cell 400 includes an electrode assembly 410 and a housing 420. The structure of the electrode assembly 410 is the same as that in the previous embodiment, and will not be described again in this embodiment. The housing 420 includes a shell 421 and an end cap 422. The shell 421 has a receiving cavity with an opening on one side. One or more electrode assemblies 410 are placed in the receiving cavity through the opening. The end cap 422 cooperates with the opening of the shell 421 to seal the electrode assembly 410 inside the shell 421. The end cap 422 is provided with electrode terminals 4221 for electrical connection with the electrode assembly 410. The battery cell 400 is electrically connected to an external device through the electrode terminals 4221. The shape and size of the shell 421 are determined according to the shape and number of electrode assemblies 410.

[0060] In some embodiments, both the housing 421 and the end cap 422 are metals, such as aluminum or aluminum alloys, and the housing 421 and the end cap 422 are connected by welding.

[0061] Figure 4 This is a schematic diagram illustrating the arrangement of multiple battery cells in a battery under non-fully charged conditions, as provided in an embodiment of this application. Figure 5 This is a schematic diagram illustrating the arrangement of multiple battery cells in a fully charged state, as provided in an embodiment of this application. Figure 6 This is a schematic diagram of the shape of the first battery cell in a fully charged state according to an embodiment of this application. Figure 7 This is a schematic diagram of the second battery cell in a fully charged state, as shown in the embodiments of this application. Figure 4 and Figure 5 As shown, the battery 200 includes a first battery cell 401 and a second battery cell 402, which are arranged adjacent to each other along a certain direction, such as... Figure 6 and Figure 7 As shown, the first battery cell 401 includes a first surface 4011 arranged in a vertical direction, and the second battery cell 402 includes a second surface 4021 arranged in a vertical direction. The first surface 4011 and the second surface 4021 are adjacent to each other. The first battery cell 401 and the second battery cell 402 are configured such that when the battery 200 has undergone more than or equal to 100 electrical cycles and is in a fully charged state, the first surface 4011 is recessed into the interior of the first battery cell 401, and the second surface 4021 protrudes outward from the interior of the second battery cell 402.

[0062] The recess on the first surface 4011 of the first battery cell 401 can be artificially created. That is, before the battery cell 400 is assembled into the battery 200, the recess on the first surface 4011 of the first battery cell 401 is created by mechanical processing. For example, the recess can be created by calendering, deep drawing, or stamping. Similarly, the protrusion on the second surface 4021 of the second battery cell 402 can also be artificially created. That is, before the battery cell 400 is assembled into the battery, the protrusion on the second surface 4021 of the second battery cell 402 is created by mechanical processing. For example, the protrusion can be created by calendering, deep drawing, or stamping.

[0063] The depressions on the first surface 4011 and the protrusions on the second surface 4021 can also be generated during the use of the battery 200, for example, as Figure 4 As shown, when the first battery cell 401 and the second battery cell 402 are assembled to form the battery 200, both the first surface 4011 and the second surface 4021 are flat. During the use of the battery 200, the electrode components of the first battery cell 401 and the second battery cell 402 will expand. However, after the first battery cell 401 expands, it cannot contact the inside of the first surface 4011, resulting in the first surface 4011 lacking support or having weak support inside the first battery cell 401. On the other hand, after the second battery cell 402 expands, it contacts the inside of the second surface 4021 and squeezes the second surface 4021 from the inside, causing the second surface 4021 to bulge outward. After the bulge abuts against the first surface 4011, it pushes the first surface 4011, causing the first surface 4011 to be recessed into the first battery cell 401.

[0064] When the first surface 4011 and the second surface 4021 are formed during use, the concave state of the first surface 4011 when the battery 200 is fully charged and the convex state of the second surface 4021 when the battery 200 is fully charged may gradually stabilize into plastic deformation, or they may recover their deformation after the entire module is removed. Therefore, by simulating the constraint of other components in the battery 200, such as end plates and side plates, on multiple battery cells 400 and making the overall number of electrical cycles greater than or equal to 100 and in a fully charged state, it is possible to observe whether the first surface 4011 has a concave state and whether the second surface 4021 has a convex state, so as to identify the first battery cell 401 and the second battery cell 402, making the identification of the first battery cell 401 and the second battery cell 402 more accurate, and thus more precisely defining the protection scope of the battery 200 in this application.

[0065] The first battery cell 401 and the second battery cell 402 can have the same chemical system or different chemical systems. For example, both the first battery cell 401 and the second battery cell 402 can be ternary lithium-ion battery cells; or the first battery cell 401 is a ternary lithium-ion battery cell and the second battery cell 402 is a lithium iron phosphate battery cell; or the first battery cell 401 is a ternary lithium-ion battery cell and the second battery cell 402 is a sodium-ion battery cell, etc. The embodiments of this application do not limit this.

[0066] In this embodiment, the height, length, and width directions of the battery cell 400 are mutually perpendicular. The height direction of the battery cell 400 can refer to the direction from which the electrode terminals 4221 of the battery cell 400 are led out. The width dimension of the battery cell 400 is less than or equal to the length dimension of the battery cell 400. For example, in Figures 3 to 7 In the diagram, the X direction represents the length of the battery cell, the Y direction represents the width of the battery cell, and the Z direction represents the height of the battery cell.

[0067] In the above embodiments, a certain direction, i.e., the arrangement direction of the plurality of battery cells 400, can be the length direction of the battery cell 400, i.e. Figure 3 The X direction in the text can also be the width direction of the 400mm cell, i.e. Figure 3 The Y direction. Considering that the dimensional change of a battery cell 400 in the width direction is generally greater than the dimensional change of a battery cell 400 in the length direction when fully charged, the arrangement direction of the multiple battery cells 400 in this embodiment is defined as the width direction of the battery cell 400. Of course, in other embodiments of this application, this direction can also be defined as the length direction of the battery cell 400.

[0068] A battery's electrical cycle refers to the process of charging the battery to a fully charged state and then discharging it to a fully discharged state. A fully charged state refers to a battery with a state of charge greater than 99%, while a fully discharged state refers to a battery with a state of charge less than 1%.

[0069] By adopting the above scheme, in the fully charged state, the first surface 4011 and the second surface 4021 are adjacent and have a concave-convex combination. The space formed by the concavity of the first surface 4011 can be used to accommodate the convexity of the second surface 4021, reducing the interaction force between the first battery cell 401 and the second battery cell 402. At the same time, it also reduces the expansion force of the whole composed of multiple battery cells 400, thereby reducing the probability of other components of the battery 200 being damaged due to the excessive expansion force of the battery cell 400, and improving the service life and safety of the battery 200.

[0070] In some embodiments, the first battery cell 401 is configured such that when the battery 200 has undergone more than or equal to 100 electrical cycles and is in a fully charged state, the maximum indentation distance of the first surface 4011 is greater than or equal to 0.1 mm.

[0071] By adopting the above scheme, the greater the recess distance of the first surface 4011, the greater the space for accommodating the protrusion of the second surface 4021, and the more significant the effect of reducing the expansion force between the first battery cell 401 and the second battery cell 402. As a result, the overall expansion amount and expansion force of the battery 200 when it is fully charged are smaller, which reduces the probability of damage to the components of the battery 200 under pressure and improves the service life and safety of the battery 200.

[0072] In some embodiments, the first battery cell 401 is configured such that when the battery has 100 or more electrical cycles and is fully charged, the maximum indentation distance of the first surface 4011 is less than or equal to 8 mm.

[0073] The greater the maximum indentation distance on the first surface 4011, the more intense the compression of the first battery cell 401 by the second battery cell 402. When the compression force is too great, the outer shell of the first battery cell 401 may be damaged by holes, and the electrode assembly of the first battery cell 401 may also be damaged or broken, resulting in a deterioration of the electric cycle performance of the first battery cell 401 and a shortened lifespan of the first battery cell 401.

[0074] Therefore, by limiting the maximum recess distance of the first surface 4011 within the above-mentioned range, the electrical cycle performance of the first battery cell 401 and the service life of the first battery cell 401 can be optimized.

[0075] In some embodiments, the second battery cell 402 is configured such that when the battery has undergone 100 or more electrical cycles and is fully charged, the maximum protrusion distance of the second surface 4021 is greater than or equal to 0.1 mm.

[0076] By adopting the above scheme, the second surface 4021 protrudes and abuts against the first surface 4011, making the first battery cell 401 and the second battery cell 402 more closely adjacent, preventing the first battery cell 401 and the second battery cell 402 from shaking or displacing significantly when the battery vibrates, thereby improving the stability of the battery structure and the reliability of the electrical connection.

[0077] In some embodiments, the second battery cell 402 is configured such that when the battery has 100 or more electrical cycles and is fully charged, the maximum protrusion distance of the second surface 4021 is less than or equal to 10 mm.

[0078] The greater the maximum protrusion distance of the second surface 4021, the greater the expansion force of the second battery cell 402. Excessive expansion force may cause damage or breakage of the casing of the second battery cell 402, or it may cause the second battery cell 402 to exert a large compressive force on the first battery cell 401, which can easily accelerate the deterioration of the electric cycle performance of the first battery cell 401, resulting in a shortened lifespan of the first battery cell 401 and damage to the casing of the second battery cell 402. By adopting the above-mentioned limitations, the embodiments of this application can avoid or reduce the probability of the above-mentioned adverse situations occurring.

[0079] like Figure 6 and Figure 7 As shown, in some embodiments, the first battery cell 401 includes a first end cap 4012, and the second battery cell 402 includes a second end cap 4022. The width direction of the first end cap 4012 and the width direction of the second end cap 4022 are both parallel to the arrangement direction of the plurality of battery cells 400. The ratio of the maximum recess distance to the maximum width of the first end cap 4012 is greater than or equal to 0.5%, and / or the ratio of the maximum protrusion distance to the maximum width of the second end cap 4022 is greater than or equal to 0.5%.

[0080] Generally, in the casing of a battery cell 400, the end cap has a greater strength than the casing. Therefore, when the casing is subjected to force, the end cap is not easily deformed. Thus, during the use of the battery cell 400, the shape and size of the end cap remain unchanged or undergo only minor deformation. Therefore, at any moment during the use of the battery cell 400, the size of the end cap in the width direction can be used to relatively accurately measure the dimensional changes of the battery cell 400 in any direction.

[0081] When the size ratio of the casing to the electrode assembly of the battery cell 400 is constant, the larger the width of the first end cap 4012, the larger the gap between the electrode assembly inside the first battery cell 401 and the casing in the arrangement direction during assembly. That is, the first battery cell 401 can withstand a greater degree of casing deformation without causing the electrode assembly to be subjected to excessive compressive force, which would lead to a deterioration in cycle performance. Therefore, the ratio of the maximum indentation distance to the maximum width of the first end cap 4012 is limited to be greater than or equal to 0.5%, so that the maximum indentation distance of the first surface 4011 increases with the increase of the width of the first end cap 4012. This allows the first surface 4011 to have a larger space to accommodate the protrusion of the second battery cell 402 within the pressure resistance range of the first battery cell 401, thereby reducing the interaction force between the first battery cell 401 and the second battery cell 402. Similarly, when the size ratio of the outer shell of the battery cell 400 to the electrode assembly is constant, the larger the width of the second end cap 4022, the larger the maximum size of the second battery cell 402 along the arrangement direction. That is, the thicker the electrode assembly inside the second battery cell 402 in the arrangement direction. In the fully charged state, the electrode assembly inside the second battery cell 402 will generate a large amount of expansion. By limiting the ratio of the maximum protrusion distance to the maximum width of the second end cap 4022 to be greater than or equal to 0.5%, the second surface 4021 of the second battery cell 402 can reduce the expansion force inside the second battery cell 402 by increasing the protrusion distance in the fully charged state. This, combined with the concavity of the first surface 4011, achieves the effect of reducing the expansion force inside the second battery cell 402 and reducing the expansion force between the first battery cell 401 and the second battery cell 402.

[0082] In some embodiments, the ratio of the maximum protrusion distance to the maximum width of the second end cap 4022 is less than or equal to 20%, and / or the ratio of the maximum recess distance to the maximum width of the first end cap 4012 is less than or equal to 20%.

[0083] When the size ratio of the casing to the electrode assembly of the battery cell 400 is constant, the greater the width of the second end cap 4022, the greater the thickness of the electrode assembly. The electrode assembly inside the second battery cell 402 expands significantly under full charge, requiring a larger bulge in the casing to accommodate it. However, if the bulge distance of the second surface 4021 is too large, the casing of the second battery cell 402 is at risk of breakage, especially at the junction of the casing and the first end cap 4012. Similarly, if the first surface 4011 has an excessively large indentation distance under the pressure of the second surface 4021, the first surface 4011 is also at risk of perforation. Furthermore, under excessive pressure, the electrode assembly inside the first battery cell 401 may break. Therefore, through the above limitations, damage to the second battery cell 402 and the first battery cell 401 can be prevented, extending the service life of both.

[0084] Therefore, by limiting the ratio of the maximum protrusion distance to the maximum width of the second end cap 4022 to less than or equal to 20%, and / or the ratio of the maximum indentation distance to the maximum width of the first end cap 4012 to less than or equal to 20%, damage to the second battery cell 402 and the first battery cell 401 can be prevented, thereby extending the service life of the first battery cell 401 and the second battery cell 402.

[0085] In some embodiments, in any pair of adjacent first surfaces 4011 and second surfaces 4021, the difference between the maximum recess distance of the first surface 4011 and the maximum protrusion distance of the second surface 4021 is less than or equal to 0.2 mm.

[0086] In any pair of adjacent first surfaces 4011 and second surfaces 4021, the maximum concave distance of the first surface 4011 may be greater than the maximum convex distance of the second surface 4021, or the maximum concave distance of the first surface 4011 may be less than the maximum convex distance of the second surface 4021.

[0087] It should be noted that the difference between the maximum recessed distance of the first surface 4011 and the maximum protrusion distance of the second surface 4021 can be either the maximum recessed distance of the first surface 4011 minus the maximum protrusion distance of the second surface 4021, or the maximum protrusion distance of the second surface 4021 minus the maximum recessed distance of the first surface 4011, as long as the subtrahend is greater than or equal to the minuend. For example, when the maximum recessed distance D1 of the first surface 4011 is 3.5mm, the maximum protrusion distance of the second surface 4021... If the distance D2 is 3.4mm, then the difference between the maximum concave distance of the first surface 4011 and the maximum convex distance of the second surface 4021 is D1-D2=3.5-3.4=0.1mm; when the maximum concave distance D1 of the first surface 4011 is 3.4mm and the maximum convex distance D2 of the second surface 4021 is 3.5mm, then the difference between the maximum concave distance of the first surface 4011 and the maximum convex distance of the second surface 4021 is D2-D1=3.5-3.4=0.1mm.

[0088] By adopting the above scheme, the adjacent first surface 4011 and second surface 4021 can be matched well. The expansion of the second surface 4021 can be fully or relatively fully accommodated in the recess of the first surface 4011. Furthermore, the space formed by the recess of the first surface 4011 is not wasted or is wasted less. This reduces the expansion force between the first battery cell 401 and the second battery cell 402, while increasing the energy density of the entire battery.

[0089] like Figure 8 As shown, in some embodiments, the first battery cell 401 further includes a first housing 4013, with a first surface 4011 located on the first housing 4013, and the second battery cell 402 further includes a second housing 4023, with a second surface 4021 located on the second housing 4023. The strength of the first housing 4013 is less than the strength of the second housing 4023.

[0090] The strength of the first housing 4013 and the second housing 4023 can be achieved by using different materials for the first housing 4013 and the second housing 4023, by using different thicknesses for the first housing 4013 and the second housing 4023, or by using different materials and different thicknesses for the first housing 4013 and the second housing 4023. This application embodiment does not limit the implementation of the above solutions.

[0091] By adopting the above solution, the second casing 4023 has greater strength and is less prone to breakage. Since the second battery cell 402 expands significantly, it is more likely to break under the same casing strength. Therefore, the strength of the second casing 4023 can be increased, thus reducing the probability of breakage when the second battery cell 402 deforms. The first battery cell 401 expands less, making it less likely for its casing to rupture due to its own expansion. Therefore, the strength requirements for the first casing 4013 can be reduced.

[0092] like Figure 8 As shown, in some embodiments, the first surface 4011 is located on the first wall 4014 of the first housing 4013, and the second surface 4021 is located on the second wall 4024 of the second housing 4023, wherein the wall thickness of the first wall 4014 is less than the wall thickness of the second wall 4024.

[0093] By adopting the above scheme, the strength of the first surface 4011 and the second surface 4021 can be controlled by controlling the wall thickness of the first wall 4014 and the second wall 4024. The method is simple and will not affect the strength of the other walls of the first shell 4013 and the second shell 4023.

[0094] According to another aspect of the embodiments of this application, an electrical device is provided, including a battery of any of the above-described embodiments, the battery being used to provide electrical energy.

[0095] By adopting the above scheme, the expansion force between multiple battery cells is smaller, which reduces the risk of damage to each battery cell. Furthermore, the expansion force between the overall battery cell assembly and other battery components is smaller, making it less likely for other battery components to be damaged. The overall charging and discharging performance, service life, and safety of the battery are improved, thereby providing better power to electrical devices.

[0096] In summary, the embodiments of this application, by setting a first battery cell 401 and a second battery cell 402 inside the battery, with the first battery cell 401 and the second battery cell 402 arranged adjacent to each other in a certain direction, and the first surface 4011 of the first battery cell 401 and the second surface 4021 of the second battery cell 402 adjacent to each other, and when the battery has been fully charged with 100 or more electrical cycles, the first surface 4011 is recessed into the interior of the first battery cell 401, and the second surface 4021 is protruding outward from the second battery cell 402. This reduces the expansion force between the first battery cell 401 and the second battery cell 402, and also reduces the overall expansion force of the multiple battery cells, thereby reducing the probability of the battery being damaged due to the expansion force of the battery cells, and improving the battery's service life and safety.

[0097] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0098] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery, characterized in that, include: A first battery cell and a second battery cell are arranged adjacent to each other along a certain direction. The first battery cell includes a first surface perpendicular to the arrangement direction, and the second battery cell includes a second surface perpendicular to the arrangement direction. The first surface and the second surface are adjacent to each other. The first battery cell and the second battery cell are configured such that when the battery has a number of electrical cycles greater than or equal to 100 and is fully charged, the first surface is recessed into the interior of the first battery cell, and the second surface is protruding outward from the second battery cell. The first battery cell further includes a first housing, with the first surface located on the first housing; the second battery cell further includes a second housing, with the second surface located on the second housing; and the strength of the first housing is less than the strength of the second housing.

2. The battery according to claim 1, characterized in that, The first battery cell is configured such that when the battery has undergone 100 or more electrical cycles and is fully charged, the maximum indentation distance on the first surface is greater than or equal to 0.1 mm.

3. The battery according to claim 1, characterized in that, The first battery cell is configured such that when the battery has 100 or more electrical cycles and is fully charged, the maximum indentation distance on the first surface is less than or equal to 8 mm.

4. The battery according to claim 1, characterized in that, The second battery cell is configured such that when the battery has undergone 100 or more electrical cycles and is fully charged, the maximum protrusion distance on the second surface is greater than or equal to 0.1 mm.

5. The battery according to claim 1, characterized in that, The second battery cell is configured such that when the battery has 100 or more electrical cycles and is fully charged, the maximum protrusion distance on the second surface is less than or equal to 10 mm.

6. The battery according to any one of claims 2-5, characterized in that, The first battery cell includes a first end cap, and the second battery cell includes a second end cap. The width direction of the first end cap and the width direction of the second end cap are both parallel to the arrangement direction. The ratio of the maximum recess distance to the maximum width of the first end cap is greater than or equal to 0.5%, and / or the ratio of the maximum protrusion distance to the maximum width of the second end cap is greater than or equal to 0.5%.

7. The battery according to claim 6, characterized in that, The ratio of the maximum protrusion distance to the maximum width of the second end cap is less than or equal to 20%, and / or the ratio of the maximum indentation distance to the maximum width of the first end cap is less than or equal to 20%.

8. The battery according to any one of claims 1-5, characterized in that, In any pair of adjacent first and second surfaces, the difference between the maximum concave distance of the first surface and the maximum convex distance of the second surface is less than or equal to 0.2 mm.

9. The battery according to claim 1, characterized in that, The first surface is located on the first wall of the first housing, and the second surface is located on the second wall of the second housing. The wall thickness of the first wall is less than the wall thickness of the second wall.

10. An electrical device, characterized in that, Includes the battery according to any one of claims 1-9, the battery being used to provide electrical energy.

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