CN219419220U - Battery cell, battery and electricity utilization device - Google Patents

Abstract

The application provides a battery cell, a battery and an electric device. The battery cell comprises a shell, the shell is provided with a side wall, the side wall comprises a normal area and a thinning area, the normal area and the thinning area are distributed along the circumferential direction of the shell, and the minimum thickness of the normal area is larger than that of the thinning area. The application provides a battery monomer is favorable to increasing the clearance between the attenuate district and the electrode assembly of casing, is carrying out the in-process of lying flat test to battery monomer, can set up the attenuate district and set up downwards along the direction of gravity to make the inside electrolyte of free state of battery monomer distribute as far as between electrode assembly and casing, reduce the possibility that electrolyte immersed electrode assembly, and then reduce electrode assembly's the thin district and produce the possibility of lithium phenomenon, be favorable to improving battery monomer's reliability.

Description

Battery cell, battery and electricity utilization device

Technical Field

The present disclosure relates to battery technology, and in particular, to a battery cell, a battery, and an electric device.

Background

Batteries are widely used in electronic devices such as cellular phones, notebook computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy vehicles, electric toy ships, electric toy airplanes, electric tools, and the like.

In the development of battery cell technology, in addition to improving the service performance of the battery cell, the reliability of the battery cell is also a problem to be considered. Therefore, how to improve the reliability of the battery cell is a continuous improvement in the battery technology.

Disclosure of Invention

The embodiment of the application provides a battery monomer, battery and power consumption device, can improve the reliability of battery monomer.

In a first aspect, a battery cell provided in an embodiment of the present application includes a housing having a sidewall including a normal region and a thinned region, the normal region and the thinned region being distributed along a circumference of the sidewall, a minimum thickness of the normal region being greater than a minimum thickness of the thinned region.

The battery monomer that this embodiment provided has normal district and attenuate district through setting up the casing to set up the minimum thickness in attenuate district and be less than the minimum thickness in normal district, be favorable to increasing the clearance between attenuate district and the electrode assembly of casing, in the in-process of lying flat test to the battery monomer, can set up attenuate district and set up downwards along the direction of gravity, so that the inside free electrolyte of battery monomer distributes between electrode assembly and casing as far as, reduce the electrolyte and immerse the possibility of electrode assembly, and then reduce the possibility that the thin district of electrode assembly produced out lithium phenomenon, be favorable to improving the single reliability of battery.

In some embodiments, the relationship between the thickness h1 of the normal region and the thickness h2 of the thinned region satisfies: h2/h1 is more than or equal to 0.2 and less than or equal to 0.6. Therefore, when the battery monomer is subjected to lying-down test, the liquid level of the electrolyte in the free state in the battery monomer is reduced, and the free electrolyte cannot enter the electrode assembly as far as possible, so that the structural strength of the thinning area of the shell is guaranteed, and the structural strength of the shell is improved. In other words, the h2/h1 is more than or equal to 0.2 and less than or equal to 0.6, so that better balance can be achieved between the structural strength of the shell and the liquid level of the electrolyte in the lying test process.

In some embodiments, the relationship between the thickness h1 of the normal region and the thickness h2 of the thinned region satisfies: h2/h1 is more than or equal to 0.3 and less than or equal to 0.5. The electrolyte level testing device is further beneficial to achieving better balance between ensuring the structural strength of the shell and reducing the electrolyte level in the lying test process.

In some embodiments, the shell is cylindrical, and the central angle α corresponding to the thinned region satisfies: alpha is more than or equal to 120 degrees and less than or equal to 180 degrees. So set up, when lying flat the test to the battery monomer, be favorable to reducing the liquid level of the inside free state's of battery monomer electrolyte, under the prerequisite that makes free electrolyte can not get into electrode assembly as far as possible, be favorable to guaranteeing the structural strength in the attenuate district of casing to improve the structural strength of casing. The structural strength of the shell is guaranteed, and the liquid level of electrolyte in the battery cell is reduced.

In some embodiments, the sidewall includes two first surfaces opposite in a first direction and two second surfaces opposite in a second direction, the first and second directions intersecting, the two first surfaces connecting the two second surfaces, the first surface having an area greater than an area of the second surface; at least a portion of the first surface is located in the thinned region. Therefore, the placement stability of the battery monomer in the lying test process is improved, and the size of the thinning area can be improved due to the larger area of the first surface, so that more electrolyte in a free state is contained between the battery monomer and the thinning area of the shell, and the liquid level of the electrolyte is reduced as much as possible.

In some embodiments, the battery cell further includes an end cap, the housing has an opening, the end cap covers the opening, the end cap has a liquid injection port penetrating along a thickness direction of the end cap, and the liquid injection port is located at one side of the end cap near the thinning region. In the process of electrolyte injection, the smoothness of electrolyte injection is improved, and in the process of lying flat test, the thinning area can be positioned by utilizing the liquid injection port, so that the thinning area is downwards arranged along the gravity direction.

In some embodiments, the battery cell further includes an electrode assembly including a pole piece including a body portion and a tab portion, the tab portion being led out from an end of the body portion, the body portion including a base region and a skived region, the skived region being disposed between the body portion and the tab portion, the skived region having a thickness less than a thickness of the base region. The shell comprises a normal area and a thinning area, so that the clearance between the shell corresponding to the thinning area and the electrode assembly is increased, more electrolyte can be contained in the process of carrying out lying test on the battery monomer, the liquid level of free electrolyte is reduced, and the possibility of lithium precipitation of the electrode assembly is reduced.

In some embodiments, the battery cell further includes an electrolyte contained within the housing, and the level of the electrolyte is between the electrode assembly and the thinned region with the thinned region disposed downwardly along the direction of gravity. Which is advantageous in further reducing the possibility of lithium precipitation of the electrode assembly.

In some embodiments, the dimension of the sidewall, along the extension of the sidewallAnd the size of the thinned region +.>The relation of (2) is as follows: />. The arrangement is beneficial to reducing the risk of free electrolyte in the battery cell to be immersed into the electrode assembly, and further reducing the possibility of lithium precipitation of the electrode assembly.

In a second aspect, embodiments of the present application provide a battery, including a battery cell provided in any one of the embodiments above.

The battery provided in the embodiment of the present application has the same technical effects due to the battery monomer provided in any one of the embodiments, and is not described herein again.

In a third aspect, an embodiment of the present application provides an electrical device, including a battery provided in the foregoing embodiment, where the battery is configured to provide electrical energy.

The power utilization device provided by the embodiment of the present application has the same technical effects due to the battery provided by the above embodiment, and is not described herein again.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and that other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a vehicle provided in an embodiment of the present application;

fig. 2 is a schematic structural view of a battery provided in an embodiment of the present application;

fig. 3 is a schematic structural view of a battery module in a battery according to an embodiment of the present application;

fig. 4 is an exploded view of a battery cell according to an embodiment of the present disclosure;

fig. 5 is a schematic view of an exploded structure of another battery cell according to an embodiment of the present application;

fig. 6 is a schematic top view of a housing in a battery cell according to an embodiment of the present disclosure;

fig. 7 is a schematic top view of an electrode assembly in a battery cell according to an embodiment of the present disclosure;

fig. 8 is a schematic cross-sectional view of fig. 7 taken along A-A.

In the drawings, the drawings are not necessarily to scale.

Marking:

1. a vehicle; 1a, a motor; 1b, a controller;

10. a battery; 11. a first box portion; 12. a second box portion;

20. a battery module;

30. a battery cell; 31. a housing; 311. a housing; 311a, openings; 3111. a sidewall; 3111a, normal region; 3111b, thinned region; 3112. a first surface; 3113. a second surface; 312. An end cap; 312a, a liquid injection port;

32. an electrode assembly; 321. a tab; 322. a pole piece; 3221. a main body portion; 3221a, matrix region; 3221b, skiving regions; 3222. a tab portion;

x, a first direction; y, second direction.

Detailed Description

Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the present application and are not intended to limit the scope of the application, i.e., the application is not limited to the embodiments described.

In the description of the present application, it is to be noted that, unless otherwise indicated, the meaning of "plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like indicate an orientation or positional relationship merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The "vertical" is not strictly vertical but is within the allowable error range. "parallel" is not strictly parallel but is within the tolerance of the error.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in the present application can be understood as appropriate by one of ordinary skill in the art.

The term "plurality" as used herein refers to more than two (including two).

In the present application, the battery cells may include lithium ion secondary battery cells, lithium ion primary battery cells, lithium sulfur battery cells, sodium lithium ion battery cells, sodium ion battery cells, or magnesium ion battery cells, and the embodiment of the present application is not limited thereto. The battery cells may be cylindrical, flat, rectangular, or otherwise shaped, as well as the embodiments herein are not limited in this regard.

The battery referred to in embodiments of the present application may include one or more battery cells to provide a single physical module of higher voltage and capacity. When a plurality of battery cells are provided, the plurality of battery cells are connected in series, in parallel or in series-parallel through the converging component.

In some embodiments, the battery may be a battery module; when a plurality of battery cells are provided, the plurality of battery cells are arranged and fixed to form a battery module.

In some embodiments, the battery may be a battery pack including a case and a battery cell, the battery cell or battery module being housed in the case.

In some embodiments, the tank may be part of the chassis structure of the vehicle. For example, a portion of the tank may become at least a portion of the floor of the vehicle, or a portion of the tank may become at least a portion of the cross member and the side member of the vehicle.

In some embodiments, the battery may be an energy storage device. The energy storage device comprises an energy storage container, an energy storage electric cabinet and the like.

The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge of the battery cell, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. The isolating film is arranged between the positive electrode and the negative electrode, can play a role in preventing the positive electrode and the negative electrode from being short-circuited, and can enable active ions to pass through.

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.

As an example, the positive electrode current collector has two surfaces opposing in its own thickness direction, and the positive electrode active material is provided on either or both of the two surfaces opposing the positive electrode current collector.

As an example, the positive electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, silver-surface-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, or the like can be used. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (e.g., a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material may be used. These positive electrode active materials may be used alone or in combination of two or more.

In some embodiments, the positive electrode may be a metal foam. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, foam carbon or the like. When the metal foam is used as the positive electrode, the surface of the metal foam may not be provided with the positive electrode active material, but may be provided with the positive electrode active material. As an example, a lithium source material, which is lithium metal and/or a lithium-rich material, potassium metal or sodium metal, may also be filled and/or deposited within the foam metal.

In some embodiments, the negative electrode may be a negative electrode tab, which may include a negative electrode current collector.

As an example, the negative electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, silver-surface-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, or the like can be used. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (e.g., a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

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.

As an example, the anode current collector has two surfaces opposing in its own thickness direction, and the anode active material is provided on either or both of the two surfaces opposing the anode current collector.

As an example, a negative active material for a battery cell, which is well known in the art, may be used. As an example, the anode 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, lithium titanate, and the like.

In some embodiments, the negative electrode may employ a metal foam. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, foam carbon or the like. When the foam metal is used as the negative electrode sheet, the surface of the foam metal does not need to be provided with a negative electrode active material, and the surface of the foam metal can be provided with the negative electrode active material.

As an example, a lithium source material, which is a lithium metal and/or a lithium-rich material, potassium metal, or sodium metal, may also be filled and/or deposited within the negative electrode current collector.

In some embodiments, the material of the positive electrode current collector may be aluminum and the material of the negative electrode current collector may be copper.

In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode. The type of the separator is not particularly limited, and any known porous separator having good chemical stability and mechanical stability may be used.

As an example, the main material of the separator may be at least one selected from glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.

In some embodiments, the battery cell further includes an electrolyte that serves to conduct ions between the positive and negative electrodes. The type of electrolyte is not particularly limited in this application, and may be selected according to the need. The electrolyte may be liquid, gel or solid.

In some embodiments, the electrode assembly is a rolled structure. The positive plate and the negative plate are wound into a winding structure.

In some embodiments, the electrode assembly is a lamination stack.

The positive plate and the negative plate can be respectively arranged in a plurality, and the positive plates and the negative plates are alternately laminated.

As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheets are folded to form a plurality of folded sections arranged in a stacked manner, with one positive electrode sheet sandwiched between adjacent folded sections.

As an example, the positive and negative electrode sheets are each folded to form a plurality of folded sections in a stacked arrangement.

As an example, the separator may be provided in plurality, respectively between any adjacent positive electrode sheet or negative electrode sheet.

As an example, the separator may be continuously provided, being disposed between any adjacent positive or negative electrode sheets by folding or winding.

In some embodiments, the electrode assembly may have a cylindrical shape, a flat shape, a polygonal column shape, or the like.

In some embodiments, the electrode assembly is provided with tabs that can conduct current away from the electrode assembly. The tab includes a positive tab and a negative tab.

The battery cell further includes a case inside which a receiving chamber for receiving the electrode assembly is formed. The case may protect the electrode assembly from the outside to prevent foreign substances from affecting the charge or discharge of the electrode assembly.

In the related art, after the battery cell is manufactured, during the lying test, the free electrolyte in the battery cell submerges a portion of the electrode assembly, so that the free electrolyte in the battery cell enters into a gap inside the battery cell, such as between the electrode plates inside the thinned region of the electrode assembly. One part of the thinning area is immersed in electrolyte, the corresponding electrolyte is more, the other part of the electrolyte is less, lithium ions and the like can be converged in the area with more electrolyte in the process of charging the battery monomer, and the phenomenon of lithium precipitation is easily caused at the part of the thinning area of the battery monomer immersed by the electrolyte along with the continuous charging process of the battery monomer, so that the reliability of the battery monomer is seriously affected.

In view of this, this application embodiment provides a technical scheme, it has normal district and attenuate district through the casing, and set up the minimum thickness that normal district is greater than the minimum thickness in attenuate district, so, in the in-process of carrying out the flat test of lying to the battery monomer, can set up the attenuate district of casing and follow the direction of gravity and set up downwards, so, can hold more free electrolyte of state between the attenuate district of battery monomer and the electrode assembly, free electrolyte can be stored preferentially between the attenuate district of electrode assembly and casing, be favorable to reducing the electrolyte and immerse the part of electrode assembly and cause the risk that the thin district takes place the lithium phenomenon that separates, be favorable to improving the reliability of battery monomer.

The technical scheme described in the embodiment of the application is applicable to a battery cell, a battery comprising the battery cell and an electric device using the battery.

The electric device may be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool, or the like. The vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle; spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, and an electric airplane toy; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete shakers, and electric planers, among others. The embodiment of the application does not limit the electric device in particular.

For convenience of explanation, the following examples will be described taking an electric device as an example of a vehicle.

As shown in fig. 1, a battery 10 is provided inside a vehicle 1. The battery 10 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, for example, the battery 10 may serve as an operating power source of the vehicle 1.

The vehicle 1 may further include a controller 1b and a motor 1a. The controller 1b is used to control the battery 10 to supply power to the motor 1a, for example, for operating power requirements at start-up, navigation and travel of the vehicle 1.

In some embodiments of the present application, the battery 10 may not only serve as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, providing driving power for the vehicle 1 instead of or in part instead of fuel oil or natural gas.

Referring to fig. 2, the battery 10 includes a battery cell (not shown in fig. 2). The battery 10 may further include a case for accommodating the battery cells.

The box is used for holding battery monomer, and the box can be multiple structural style. In some embodiments, the housing may include a first housing portion 11 and a second housing portion 12. The first housing part 11 and the second housing part 12 are mutually covered. The first and second casing parts 11 and 12 together define an accommodating space for accommodating the battery cells. The second case 12 may have a hollow structure with one end opened, the first case 11 has a plate-like structure, and the first case 11 is covered on the opening side of the second case 12 to form a case having an accommodation space; the first housing part 11 and the second housing part 12 may each have a hollow structure with one side opened. The open side of the first casing part 11 is closed to the open side of the second casing part 12 to form a casing having an accommodation space. Of course, the first and second case portions 11 and 12 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the sealing property after the first casing part 11 and the second casing part 12 are connected, a sealing member, such as a sealant, a sealing ring, or the like, may be further provided between the first casing part 11 and the second casing part 12.

Assuming that the first housing part 11 is covered with the second housing part 12, the first housing part 11 may also be referred to as an upper case cover, and the second housing part 12 may also be referred to as a lower case.

In the battery 10, the number of battery cells may be one or more. If the number of the battery cells is multiple, the battery cells can be connected in series, in parallel or in series-parallel. The series-parallel connection refers to that a plurality of battery monomers are connected in series or in parallel. The plurality of battery cells can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells is accommodated in the box body, or the plurality of battery cells can be connected in series or in parallel or in series-parallel to form the battery module 20. The plurality of battery modules 20 are then connected in series or parallel or a series-parallel combination to form a unit and are accommodated in a case.

In some embodiments, as shown in fig. 3, fig. 3 is a schematic structural view of the battery module 20 shown in fig. 2. In the battery module 20, the battery cells 30 are plural. The plurality of battery cells 30 are first connected in series or parallel or a series-parallel combination to form the battery module 20. The plurality of battery modules 20 are then connected in series or parallel or a series-parallel combination to form a unit and are accommodated in a case.

In some embodiments, electrical connection between the plurality of battery cells 30 in the battery module 20 may be achieved through a bus bar component to achieve parallel or serial or parallel-serial connection of the plurality of battery cells 30 in the battery module 20.

Referring to fig. 4, fig. 4 is an exploded view of the battery cell 30 shown in fig. 3. The battery cell 30 provided in the embodiment of the application includes an electrode assembly 32 and a housing 31, the housing 31 has a receiving cavity, and the electrode assembly 32 is received in the receiving cavity.

In some embodiments, the case 31 may include a case 311 and an end cap 312, the case 311 being a hollow structure having one side opened, the end cap 312 covering at the opening 311a of the case 311 and forming a sealing connection to form a sealed space for accommodating the electrode assembly 32 and the electrolyte.

In assembling the battery cell 30, the electrode assembly 32 may be first placed in the case 311, then the end cap 312 is covered on the opening of the case 311, and then the electrolyte is injected into the case 311 through the electrolyte injection port on the end cap 312.

In some embodiments, the housing 31 may also be used to contain an electrolyte, such as an electrolyte solution. The housing 31 may take a variety of structural forms.

The housing 311 may be of various shapes, such as a cylinder, a rectangular parallelepiped, etc. The shape of the case 311 may be determined according to the specific shape of the electrode assembly 32. For example, if the electrode assembly 32 has a cylindrical structure, the case 311 may alternatively have a cylindrical structure. If the electrode assembly 32 has a rectangular parallelepiped structure, the case 311 may have a rectangular parallelepiped structure. In fig. 4, the case 311 and the electrode assembly 32 are each exemplarily rectangular parallelepiped in structure.

The material of the housing 311 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., which is not particularly limited in the embodiment of the present application.

The electrode assembly 32 accommodated in the case 311 may be one or more. In fig. 4, the number of electrode assemblies 32 accommodated in the case 311 is two.

As shown in fig. 4 and 5, the battery cell 30 provided according to the embodiment of the present application includes a case 311, the case 311 having a sidewall 3111, the sidewall 3111 including a normal region 3111a and a thinned region 3111b, the normal region 3111a and the thinned region 3111b being distributed along a circumferential direction of the sidewall 3111, a minimum thickness of the normal region 3111a being greater than a minimum thickness of the thinned region 3111b.

The side wall 3111 of the case 311 may be an annular wall portion where the case 311 is connected to the end cap 312, and the side wall 3111 may have a cylindrical shape, a square shape, or other shapes according to the shape of the battery cell 30.

The sidewall 3111 includes a normal region 3111a and a thinned region 3111b, the normal region 3111a and the thinned region 3111b may be disposed adjacently, a minimum thickness of the normal region 3111a is greater than a minimum thickness of the thinned region 3111b, and a thickness of a majority region of the normal region 3111a is greater than a thickness of a majority region of the thinned region 3111b, and a thickness of a partial region may be greater at the thinned region 3111b and a rib or the like may be disposed to secure structural strength of the thinned region 3111b. The thinning-out regions 3111b may be provided continuously or a plurality of thinning-out regions 3111b may be provided at intervals. The thickness of the normal region 3111a may be fixed, or the thickness of different locations of the normal region 3111a may be different. The thickness of the thinned region 3111b may be fixed or the thickness of the thinned region 3111b may be different at different positions, and illustratively, the thickness of the thinned region 3111b may be gradually reduced from the region adjacent to the normal region 3111a to a direction away from the normal region 3111a to reduce stress concentration phenomenon of the region adjacent to the thinned region 3111b and the normal region 3111a, which is advantageous for improving the structural strength of the housing 311.

As shown in fig. 5, 7 and 8, the battery cell 30 may further include an electrode assembly 32, the electrode assembly 32 is accommodated in the case 311, the electrode assembly 32 includes a electrode tab 322, the electrode tab 322 may include a base region 3221a and a thinned region 3221b, the thinned region 3221b is lower in thickness relative to the base region 3221a, and the thinned region 3221b is located at an end of the base region 3221a adjacent to the tab 321. In this way, after the electrode piece 322 is wound to form the electrode assembly 32, a gap exists between two adjacent turns of the electrode piece 322 corresponding to the thinned region 3221b, and when the electrolyte is immersed in the electrode assembly 32, the electrolyte enters the gap between the electrode pieces 322 in the thinned region 3221 b.

If a part of the electrode assembly 32 is immersed in the electrolyte, lithium ions and the like are preferentially accumulated on the electrode sheet 322 having a large distribution of the electrolyte during the process of charging the battery cell 30, and thus, the portion of the thinned region 3221b of the electrode assembly 32 immersed in the electrolyte is susceptible to the phenomenon of lithium precipitation.

The minimum thickness of the thinning area 3111b is smaller than the minimum thickness of the normal area 3111a, compared with the normal area 3111a, more space is provided between the thinning area 3111b of the housing 311 and the electrode assembly 32, and during the lying test of the battery cell 30, the thinning area 3111b may be arranged downward along gravity, so that the thinning area 3111b and the electrode assembly 32 may accommodate more electrolyte, which is beneficial to reducing the liquid level of free electrolyte in the battery cell 30, and by reasonably arranging the size and thickness of the thinning area 3111b, it may be achieved that the electrolyte in the free state in the electrode assembly 32 is fully accommodated between the thinning area 3111b and the electrode assembly 32, which is beneficial to reducing the possibility that the electrolyte is immersed into a portion of the thinning area 3221b of the electrode assembly 32, and even making the electrolyte in the free state not immersed into the electrode assembly 32, so that during the lying test of the battery cell 30, the electrolyte in the free state does not enter the thinning area of the electrode assembly 32, and the electrolyte in the free state in the battery cell 30 may not enter the thinning area of the electrode assembly 1b of the electrode assembly 32, which is beneficial to reducing the lithium ion distribution of the electrode assembly 322 in the lithium ion distribution of the battery cell 32232 in the lithium ion storage of the electrode assembly 3221b is more beneficial to reducing the lithium ion distribution of the electrode assembly 322 in the electrode assembly 322.

According to the battery cell 30 provided by the embodiment of the application, the shell 311 is provided with the normal region 3111a and the thinning region 3111b, and the minimum thickness of the thinning region 3111b is smaller than that of the normal region 3111a, so that the gap between the thinning region 3111b of the shell 311 and the electrode assembly 32 is increased, the thinning region 3111b can be arranged downwards along the gravity direction in the process of carrying out the lying test on the battery cell 30, so that electrolyte in a free state inside the battery cell 30 is distributed between the electrode assembly 32 and the shell 311 as much as possible, the possibility that the electrolyte is immersed into the electrode assembly 32 is reduced, the possibility that the lithium precipitation phenomenon is generated in the thinning region 3221b of the electrode assembly 32 is reduced, and the reliability of the battery cell 30 is improved.

As shown in fig. 6, in some embodiments, the relationship between the thickness h1 of the normal region 3111a and the thickness h2 of the thinned region 3111b satisfies: h2/h1 is more than or equal to 0.2 and less than or equal to 0.6.

Illustratively, h2/h1 may be 0.3, 0.4, 0.5, or 0.6, etc.

It will be appreciated that the thicker the sidewall 3111, the more advantageous it is to increase the structural strength of the case 311, while the smaller the thickness of the reduced region 3111b, the more advantageous it is to increase the amount of free electrolyte contained between the reduced region 3111b and the electrode assembly 32 during the lying test of the battery cell 30.

The inventor finds that, after a great number of experiments and theoretical analysis, setting h2/h1 to be more than or equal to 0.2 and less than or equal to 0.6 is beneficial to reducing the liquid level of the electrolyte in the free state inside the battery cell 30 when the battery cell 30 is subjected to the lying-down test, so that the free electrolyte cannot enter the electrode assembly 32 as much as possible, and is beneficial to ensuring the structural strength of the thinning region 3111b of the shell 311 so as to improve the structural strength of the shell 311. In other words, the setting of h2/h1 is more than or equal to 0.2 and less than or equal to 0.6, so that better balance can be achieved between ensuring the structural strength of the shell 311 and reducing the liquid level of the electrolyte in the lying test process.

In some embodiments, the relationship between the thickness h1 of the normal region 3111a and the thickness h2 of the thinned region 3111b satisfies: h2/h1 is more than or equal to 0.3 and less than or equal to 0.5.

Illustratively, h2/h1 may be 0.3, 0.4, 0.5, or the like.

The inventor finds that h2/h1 is more than or equal to 0.3 and less than or equal to 0.5 after a great number of experiments and theoretical analysis, and is further beneficial to ensuring the structural strength of the shell 311 and reducing the liquid level of electrolyte in the lying test process to obtain better balance.

With continued reference to fig. 6, in some embodiments, the housing 311 has a cylindrical shape, and the central angle α corresponding to the thinned region 3111b satisfies: alpha is more than or equal to 120 degrees and less than or equal to 180 degrees.

The housing 311 is cylindrical, and the corresponding battery cell 30 is a cylindrical battery cell 30.

Illustratively, the central angle α corresponding to the thinned region 3111b may be 120 °, 130 °, 140 °, 150 °, 160 °, 170 °, 180 °, or the like.

It will be appreciated that the greater the central angle α corresponding to the thinned region 3111b, the more advantageous the thinned region 3111b and the electrode assembly 32 accommodate more electrolyte during the lying test of the battery cell 30, while the smaller the central angle α corresponding to the thinned region 3111b, the more advantageous the structural strength of the housing 311.

The inventor finds that the setting of the angle alpha is 120 degrees or more and 180 degrees or less after a great number of experiments and system analysis, when the lying-down test is carried out on the battery cell 30, the liquid level of the electrolyte in the free state inside the battery cell 30 is reduced, the free electrolyte cannot enter the electrode assembly 32 as much as possible, and the structural strength of the thinned region 3111b of the shell 311 is guaranteed, so that the structural strength of the shell 311 is improved. I.e., a better balance is achieved between ensuring the structural strength of the case 311 and reducing the level of the electrolyte inside the battery cell 30.

As shown in fig. 4, in some embodiments, the sidewall 3111 includes two first surfaces 3112 opposing along the first direction X and two second surfaces 3113 opposing along the second direction Y, the first direction X and the second direction Y intersecting, the two first surfaces 3112 connecting the two second surfaces 3113, the area of the first surfaces 3112 being greater than the area of the second surfaces 3113, at least a portion of the first surfaces 3112 being located at the thinned region 3111b.

The first direction X and the second direction Y intersect, and the first direction X and the second direction Y are, illustratively, perpendicular to each other.

At least a portion of the first surface 3112 is located in the thinned region 3111b, and the thinned region 3111b may be disposed to occupy a portion of the first surface 3112, or the thinned region 3111b may be disposed to occupy the entire first surface 3112, i.e., one of the first surfaces 3112 may be disposed to be entirely thinned.

The side wall 3111 includes a first surface 3112 and a second surface 3113, and the first surface 3112 and the second surface 3113 are intersected, so that the corresponding battery cell 30 may be a square battery cell 30. Since the area of the first surface 3112 is larger than that of the second surface 3113, the first surface 3112 corresponds to a large face of the battery cell 30.

In order to improve stability of the battery cell 30 during the lying test of the battery cell 30, the risk of shaking or falling of the battery cell 30 is reduced, the first surface 3112 of the sidewall 3111 may be set downward along the gravity direction, so that at least a portion of the first surface 3112 is located in the thinning region 3111b, which is favorable for improving placement stability of the battery cell 30 during the lying test, and the size of the thinning region 3111b may be increased due to the larger area of the first surface 3112, so as to accommodate more electrolyte in a free state between the battery cell 30 and the thinning region 3111b of the housing 311, and reduce the level of the electrolyte as much as possible.

As shown in fig. 4 and 5, in some embodiments, the battery unit 30 further includes an end cap 312, the housing 311 has an opening 311a, the end cap 312 covers the opening 311a, the end cap 312 has a liquid injection port 312a penetrating along the thickness direction of the end cap 312, and the liquid injection port 312a is located at one side of the end cap 312 near the thinning region 3111b.

The liquid injection port 312a may be used to inject the electrolyte into the housing 311 during the manufacturing process of the battery cell 30, and after the electrolyte injection is completed, the liquid injection port 312a is plugged to seal the housing 311.

The filling port 312a is located at a side of the end cap 312 near the thinning region 3111b, and the shortest distance between the filling port 312a and the thinning region 3111b is smaller than the shortest distance between the filling port and the normal region 3111 a. The specific positions of the filling port 312a and the thinning region 3111b may be set according to actual needs.

Since there is more space between the thinning region 3111b and the electrode assembly 32 than between the normal region 3111a and the electrode assembly 32, the liquid injection port 312a is disposed on the side of the end cap 312 close to the thinning region 3111b, which is advantageous for improving the smoothness of electrolyte injection during electrolyte injection, and the liquid injection port 312a can be used to position the thinning region 3111b during lying-down test, so that the thinning region 3111b is disposed downward along the gravity direction.

As shown in fig. 5, 7, and 8, in some embodiments, the battery cell 30 further includes an electrode assembly 32, the electrode assembly 32 includes a pole piece 322, the pole piece 322 includes a main body portion 3221 and a pole ear portion 3222, the pole ear portion 3222 is led out from an end of the main body portion 3221, the main body portion 3221 includes a base region 3221a and a thinned region 3221b, the thinned region 3221b is disposed between the main body portion 3221 and the pole ear portion 3222, and the thinned region 3221b has a thickness less than that of the base region 3221 a.

The thickness of the thinned region 3221b is smaller than that of the base region 3221a, so that after the electrode assembly 32 is formed by winding the electrode plate 322, a gap exists between two adjacent turns of the electrode assembly 32 corresponding to the thinned region 3221b, if the electrode assembly 32 is immersed by electrolyte, the gap is filled with the electrolyte, and during the lying test of the battery cell 30, the electrolyte is immersed into a part of the electrode assembly 32, so that a certain risk of lithium precipitation is caused to the thinned region 3221 b.

Therefore, in the battery cell 30 provided in the embodiment of the present application, the housing 311 includes the normal region 3111a and the thinned region 3111b, so as to increase the gap between the housing 311 and the electrode assembly 32 corresponding to the thinned region 3111b, and in the process of performing the lying test on the battery cell 30, more electrolyte can be contained, which is favorable for reducing the liquid level of the free electrolyte, and further reducing the possibility of lithium precipitation of the electrode assembly 32.

In some embodiments, the battery cell 30 further includes an electrolyte contained within the case 311, and the level of the electrolyte is located between the electrode assembly 32 and the thinning region 3111b in the case where the thinning region 3111b is disposed downward in the direction of gravity.

In the gravity direction, in the case where the thinning area 3111b is disposed downward, that is, the side wall 3111 is disposed horizontally, the battery cell 30 is in a lying state, and in the case where the thinning area 3111b of the side wall 3111 is disposed downward, the electrolyte level is located between the electrode assembly 32 and the thinning area 3111b, so that the battery cell 30 is located between the electrode assembly 32 and the thinning area 3111b with the level of free electrolyte in the battery cell 30 during the lying test, and the free electrolyte does not infiltrate into the electrode assembly 32, thereby being beneficial to further reducing the possibility of lithium precipitation of the electrode assembly 32.

It is to be understood that the thinned region 3111b may be disposed in the entire area of the sidewall 3111 along the self-extending direction, or may be disposed in a portion of the sidewall 3111 along the self-extending direction, which may be specifically selected according to practical needs.

As shown in fig. 5, in some embodiments, the dimension of the sidewall 3111 is along the extension of the sidewall 3111And the dimension +.>The relation of (2) is as follows: />。

The extension direction of the side wall 3111 may be the thickness direction of the end cap 312 of the battery cell 30,then illustratively, < >>May be 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.

It will be appreciated that the size of the thinned region 3111bThe larger is more advantageous to contain more electrolyte between the sidewall 3111 and the electrode assembly 32, thereby reducing the risk of electrolyte immersion into the electrode assembly 32.

The inventors have found, after extensive experimentation and systematic analysis, that the setupIt is advantageous to reduce the risk of free electrolyte in the battery cell 30 from immersing into the electrode assembly 32, further reducing the likelihood of lithium precipitation from the electrode assembly 32.

The battery 10 provided according to the embodiment of the present application includes the battery cell 30 provided in any of the embodiments described above.

The battery 10 provided in the embodiment of the present application has the same technical effects due to the use of the battery cell 30 provided in any one of the embodiments, and will not be described herein.

The power utilization device provided according to the embodiment of the present application includes the battery 10 provided in the above embodiment, and the battery 10 is used for providing electric energy.

The power consumption device provided in the embodiment of the present application has the same technical effects due to the battery 10 provided in the embodiment of the present application, and will not be described in detail herein.

The battery cell 30 provided according to the embodiment of the present application includes a case 311, an end cap 312, an electrolyte, and an electrode assembly 32, the case 311 having an opening 311a, the end cap 312 covering the opening 311a, the electrode assembly 32 and the electrolyte being contained in the case 311. The housing 311 has a side wall 3111, the side wall 3111 includes a normal region 3111a and a thinned region 3111b, the normal region 3111a and the thinned region 3111b are distributed along a circumferential direction of the housing 311, and a thickness of the normal region 3111aThe degree is greater than the thickness of the thinned region 3111b. The relationship between the thickness h1 of the normal region 3111a and the thickness h2 of the thinned region 3111b satisfies: h2/h1 is more than or equal to 0.3 and less than or equal to 0.5. The housing 311 is cylindrical, and the central angle α corresponding to the thinned region 3111b satisfies: alpha is more than or equal to 120 degrees and less than or equal to 180 degrees. The end cap 312 has a liquid inlet 312a penetrating in the thickness direction thereof, and the liquid inlet 312a is located at a side of the end cap 312 near the thinning region 3111b. Electrode assembly 32 includes a pole piece 322, pole piece 322 including a main body portion 3221 and a pole ear portion 3222, pole ear portion 3222 being led out from an end of main body portion 3221, main body portion 3221 including a base region 3221a and a thinned region 3221b, thinned region 3221b being disposed between main body portion 3221 and pole ear portion 3222, thinned region 3221b having a thickness less than a thickness of base region 3221 a. Dimension of the side wall 3111 along extending direction of the side wall 3111And the dimension +.>The relation of (2) is as follows: />. In the case where the thinning-out region 3111b is provided downward in the gravitational direction, the level of the electrolyte is located between the electrode assembly 32 and the thinning-out region 3111b.

According to the battery cell 30 provided by the embodiment of the application, the shell 311 is provided with the normal region 3111a and the thinning region 3111b, the thickness of the thinning region 3111b is smaller than that of the normal region 3111a, the gap between the thinning region 3111b of the shell 311 and the electrode assembly 32 is increased, the thinning region 3111b can be arranged downwards along the gravity direction in the process of carrying out the lying test on the battery cell 30, so that electrolyte in a free state inside the battery cell 30 is distributed between the electrode assembly 32 and the shell 311 as much as possible, the possibility that the electrolyte is immersed into the electrode assembly 32 is reduced, the possibility that the lithium precipitation phenomenon is generated in the thinning region 3221b of the electrode assembly 32 is reduced, and the reliability of the battery cell 30 is improved.

While the present application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the present application, and in particular, the technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (11)

1. A battery cell, comprising:

the shell is provided with a side wall, the side wall comprises a normal area and a thinning area, the normal area and the thinning area are distributed along the circumferential direction of the side wall, and the minimum thickness of the normal area is larger than that of the thinning area.

2. The battery cell according to claim 1, wherein a relation between the thickness h1 of the normal region and the thickness h2 of the thinned region satisfies: h2/h1 is more than or equal to 0.2 and less than or equal to 0.6.

3. The battery cell according to claim 2, wherein a relation between the thickness h1 of the normal region and the thickness h2 of the thinned region satisfies: h2/h1 is more than or equal to 0.3 and less than or equal to 0.5.

4. The battery cell according to claim 1, wherein the housing is cylindrical, and the central angle α corresponding to the thinned region satisfies: alpha is more than or equal to 120 degrees and less than or equal to 180 degrees.

5. The battery cell of claim 1, wherein the sidewall includes two first surfaces opposing in a first direction and two second surfaces opposing in a second direction, the first and second directions intersecting, the two first surfaces connecting the two second surfaces, the first surfaces having an area greater than an area of the second surfaces; at least a portion of the first surface is located in the thinned region.

6. The battery cell of claim 1, further comprising an end cap, wherein the housing has an opening, wherein the end cap is covered by the opening, wherein the end cap has a liquid injection port penetrating along a thickness direction of the end cap, and wherein the liquid injection port is positioned at a side of the end cap adjacent to the thinning region.

7. The battery cell of claim 1, further comprising an electrode assembly comprising a pole piece, the pole piece comprising a body portion and a pole ear portion, the pole ear portion being routed out of an end of the body portion, the body portion comprising a base region and a skived region, the skived region being disposed between the body portion and the pole ear portion, the skived region having a thickness that is less than a thickness of the base region.

8. The battery cell of claim 7, further comprising an electrolyte contained within the housing, wherein a liquid level of the electrolyte is between the electrode assembly and the thinning region with the thinning region disposed downwardly along a direction of gravity.

9. The battery cell of claim 1, wherein the side wall is sized in the direction of extension of the side wallAnd the size of the thinned region +.>The relation of (2) is as follows: />。

10. A battery comprising a battery cell according to any one of claims 1 to 9.

11. An electrical device comprising a battery as claimed in claim 10, said battery being arranged to provide electrical energy.