CN221226384U - Battery, battery pack, power utilization device and energy storage device - Google Patents

Abstract

The present application discloses a battery, a battery pack, an electric device and an energy storage device, wherein the battery comprises: an electrode assembly; a shell, comprising a bottom wall and a side wall, wherein the side wall is connected to the bottom wall and surrounds the bottom wall to form a storage space, wherein the electrode assembly is stored in the storage space, wherein the bottom wall and the side wall are connected by a transition portion, wherein at least one of the bottom wall and the side wall comprises a main body and a thinning portion, wherein the thinning portion is connected between the main body and the transition portion, wherein the wall thickness of the thinning portion is thinner than that of the main body, and the inner side surface of the thinning portion is closer to the outer side of the shell than the inner side surface of the main body. Through the present application, the battery life and energy density can be improved.

Description

Batteries, battery packs, electrical devices and energy storage devices

Technical Field

The present application relates to the field of battery technology, and in particular to batteries, battery packs, electrical devices and energy storage devices.

Background technique

New energy batteries are being used more and more widely in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also being increasingly used in areas such as energy storage.

In new energy vehicles equipped with batteries, the batteries can be used to provide power in whole or in part. In the field of energy storage, the batteries can be installed in the energy storage box or directly on the user side. In these application scenarios, how to extend the service life of the battery is a current research topic. In addition, the industry has also put forward higher requirements for the volume energy density of the battery.

Utility Model Content

In order to solve the above technical problems, the present application provides a battery, a battery pack, an electrical device and an energy storage device that can extend the service life and improve the volume energy density of the battery.

This application is implemented through the following technical solutions.

The first aspect of the present application provides a battery, which includes: an electrode assembly; a shell, including a bottom wall and a side wall, the side wall is connected to the bottom wall and surrounds the bottom wall to form a storage space, the electrode assembly is accommodated in the storage space, the bottom wall and the side wall are connected by a transition portion, at least one of the bottom wall and the side wall includes a main body and a thinning portion, the thinning portion is connected between the main body and the transition portion, the wall thickness of the thinning portion is thinner than the wall thickness of the main body, and the inner side surface of the thinning portion is closer to the outside of the shell than the inner side surface of the main body.

Since the thinning portion is connected between the main body and the transition portion, the wall thickness of the thinning portion is thinner than that of the main body, and the inner side surface of the thinning portion is recessed toward the outer side of the shell. Such a design allows the transition portion to follow the thinning portion and deviate toward the outer side of the shell, thereby avoiding the electrode assembly. Even without adding a bottom support plate or changing the shape of the shell, the risk of interference and extrusion deformation between the electrode assembly and the transition portion can be reduced or eliminated, thereby extending the service life of the battery and helping to improve the volume energy density of the battery and even the entire battery pack.

In some embodiments, an outer side surface of the thinned portion is flush with an outer side surface of the main body portion.

As a result, the risk of extrusion deformation due to interference between the electrode assembly and the transition portion can be reduced or eliminated while basically maintaining the original external structure of the shell, thereby extending the service life of the battery and helping to improve the volume energy density of the entire battery pack.

In some embodiments, the electrode assembly includes at least two layers of electrode sheets, and the at least two layers of electrode sheets are configured as a winding structure. The side walls include relative first side walls and relative second side walls, and the first side walls are adjacent to and connected to the second side walls. Each of the first side walls and each of the second side walls are respectively connected to the bottom wall through the transition portion, and each of the first side walls is relatively arranged along the layer thickness direction of the electrode assembly, and the thinning portion is at least arranged on each of the first side walls.

The first side walls located on opposite sides in the layer thickness direction are usually the large surface of the shell. Setting a thinning portion on the first side wall of the larger surface can avoid most of the bottom of the electrode assembly while reducing the risk of reduced shell strength due to the thinning portion.

In some embodiments, the inner side surface of the thinned portion includes a plane.

The inner side surface of the thinned portion is a plane, which is easy to process and shape, thereby improving manufacturing efficiency; when the shell is injection molded, the inner side surface includes the plane thinned portion, which facilitates easier demoulding of the shell.

In some embodiments, the inner side surface of the thinned portion includes a curved surface.

The curved surface can disperse the stress at the connection position between the main body portion and the thinned portion and at the connection position between the transition portion and the thinned portion, thereby helping to improve the overall strength of the shell.

In some embodiments, the thinned portion is configured as a groove, and a surface of the groove includes a curved surface.

The thinned portion is configured as a groove, which occupies less wall thickness of the shell and helps to improve the overall strength of the shell.

In some embodiments, along the winding axis direction of the electrode assembly, the end of the electrode assembly abuts against the bottom wall.

Since the transition portion avoids the electrode assembly, when the electrode assembly is placed in the shell, one end of the electrode assembly will not interfere with the transition portion and deform. Even if a bottom support plate is not provided, one end of the electrode assembly can be intactly against the bottom wall, which helps to improve the volume energy density of a single battery.

In some embodiments, the transition portion has a transition radius.

The transition fillet facilitates demoulding of the housing, reduces wear between the injection mold and the formed housing, and maintains accuracy and dimensional stability.

In some embodiments, the maximum thinning thickness of the thinned portion relative to the main body portion is L1, and the wall thickness of the thinned portion is L, wherein L1 is 15% to 40% of L.

The appropriate wall thickness of the thinned portion can allow the transition portion to avoid the electrode assembly while meeting the strength requirements of the shell.

In some embodiments, the radius of the transition fillet is r, wherein r is 80% to 150% of L1.

The appropriate ratio between the thinning thickness L1 of the thinned portion and the transition fillet r enables the transition portion to avoid the electrode assembly and meet the strength requirements of the shell.

In some embodiments, a height of the thinned portion along the winding axis direction of the electrode assembly is h, and a height of the shell along the winding axis direction is H, wherein h is 5% to 10% of H.

The appropriate height of the thinned portion can meet the shell strength requirements and is easy to process and manufacture.

In some embodiments, a gap is formed between the thinned portion and the electrode assembly, and a filler is filled in the gap.

By filling the gap between the thinned portion and the electrode assembly with a filler, the gap is fully utilized, thereby improving the utilization rate of the internal space of the shell.

A second aspect of the present application provides a battery pack, comprising at least one battery provided by the first aspect.

A third aspect of the present application provides an electrical device, comprising the battery provided in the first aspect or the battery pack provided in the second aspect, wherein the battery can provide electrical energy to the electrical device.

A fourth aspect of the present application provides an energy storage device, comprising the battery provided in the first aspect or the battery pack provided in the second aspect, wherein the battery is capable of storing electrical energy and providing electrical energy.

Utility model effect:

Through the embodiments of the present application, the battery life and energy density can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

FIG1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

FIG2 is an exploded schematic diagram of a battery pack provided in some embodiments of the present application;

FIG3 is an exploded schematic diagram of a battery provided in some embodiments of the present application;

FIG4 is a cross-sectional schematic diagram of an electrode assembly provided in some embodiments of the present application;

FIG5 is a schematic diagram of a housing provided in some embodiments of the present application;

Fig. 6 is a schematic cross-sectional view taken along line A-A in Fig. 5;

FIG7 is a schematic diagram of a partial enlargement of B in FIG6;

FIG8 is a schematic diagram of a housing provided in some embodiments of the present application from another perspective;

Fig. 9 is a schematic cross-sectional view taken along line C-C in Fig. 8;

FIG10 is a schematic diagram of a partial enlargement of D in FIG9;

FIG11 is a partial cross-sectional schematic diagram of a housing provided in some other embodiments of the present application;

FIG12 is a partial cross-sectional schematic diagram of a housing provided in some other embodiments of the present application;

FIG13 is a partial cross-sectional schematic diagram of an electrode assembly disposed in a shell of the present application.

Description of reference numerals:

1000-Vehicle; 100-Battery Pack; 200-Controller; 300-Motor;

1-battery; 2-box; 3-bottom shell; 4-cover;

10-electrode assembly; 10b-one end; 11-bending area; 12-straight area; 113-pole piece; 113a-positive electrode piece; 113b-negative electrode piece; 114-isolator;

20-shell; 20a-accommodating space; 20b-gap; 21-bottom wall; 22-side wall; 221-first side wall; 222-second side wall; 23-transition part; 24-main body; 24a-outer side surface of the main body; 24b-inner side surface of the main body; 25-thinning part; 25a-outer side surface of the thinning part; 25b-inner side surface of the thinning part;

30-top cover; 31-electrode terminal; 32-pressure relief mechanism;

40-filler;

X-layer thickness direction; Y-length direction; Z-winding axis direction.

Detailed ways

The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship.

In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

In the embodiment of the present application, the battery may be a secondary battery, which refers to a battery that can be continuously used by activating the active material by charging after the battery is discharged.

The battery can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

Batteries generally include an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the battery charging and discharging process, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet 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 facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as 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 traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO ₄ (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO ₄ ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

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

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

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

In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

In some embodiments, the battery further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

In some embodiments, the electrode assembly is a laminate structure.

As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

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

In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

In some embodiments, the battery may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

As an example, the battery can be a cylindrical battery, a prismatic battery, a soft-pack battery or a battery of other shapes. Prismatic batteries include square shell batteries, blade-shaped batteries, and polygonal prismatic batteries. Polygonal prismatic batteries are, for example, hexagonal prismatic batteries, etc. There is no particular limitation in the present application.

In some embodiments, the housing includes an end cap and a shell, the shell is provided with an opening, and the end cap closes the opening to form a closed space for accommodating substances such as the electrode assembly and the electrolyte. The shell may be provided with one or more openings. One or more end caps may also be provided.

In some embodiments, at least one electrode terminal is disposed on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal may be directly connected to the tab, or indirectly connected to the tab via a transition component. The electrode terminal may be disposed on the end cap, or on the housing.

In some embodiments, a pressure relief mechanism is provided on the housing, and the pressure relief mechanism is used to release the internal pressure of the battery.

In some embodiments, the battery may be a battery module, which includes one or more batteries to provide a single physical module with higher voltage and capacity. When there are multiple batteries, the multiple batteries are connected in series, in parallel, or in mixed series through a busbar. Multiple batteries are arranged and fixed to form a battery module.

An embodiment of the present application further provides a battery pack, which includes a box and batteries, wherein the batteries or battery modules are accommodated in the box.

In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

Below, this application is described in detail.

At present, new energy batteries are being used more and more widely in life and industry. New energy batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as in aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding. In these application scenarios, how to extend the service life of the battery is a current research topic. In addition, the industry has also put forward higher requirements for the volume energy density of batteries.

Due to the needs of battery design and manufacturing, the bottom wall and side wall of the battery shell are usually connected by a transition part (such as a transition fillet, also known as an R corner). During the process of inserting the electrode assembly into the shell, the end of the electrode assembly is easily interfered with and squeezed and deformed by the transition part, thereby causing the risk of short circuit of the electrode assembly and shedding of active materials, which in turn has an adverse effect on the service life of the battery. By adding a bottom support plate between the bottom wall of the shell and the electrode assembly, the risk of squeezing and deforming the end of the electrode assembly and the transition part can be reduced. However, adding the bottom support plate occupies the internal space of the shell, which is not conducive to improving the energy density of the battery. At the same time, the additional processes and materials will also increase costs.

In this regard, the present application provides a battery, which includes: an electrode assembly and a shell, the shell includes a bottom wall and a side wall, the side wall is connected to the bottom wall and surrounds the bottom wall to form a accommodating space, the electrode assembly is accommodated in the accommodating space, the bottom wall and the side wall are connected by a transition portion, at least one of the bottom wall and the side wall includes a main body and a thinning portion, the thinning portion is connected between the main body and the transition portion, the wall thickness of the thinning portion is thinner than the wall thickness of the main body, and the inner side surface of the thinning portion is closer to the outside of the shell than the inner side surface of the main body.

The thinning portion is connected between the main body and the transition portion, the wall thickness of the thinning portion is thinner than that of the main body, and the inner side surface of the thinning portion is closer to the outer side of the shell than the inner side surface of the main body. This design allows the transition portion to follow the thinning portion and deviate to the outer side of the shell, thereby avoiding the electrode assembly. Even without adding a bottom support plate or changing the shape of the shell, the risk of interference, extrusion and deformation between the electrode assembly and the transition portion is reduced or eliminated, thereby extending the service life of the battery, and at the same time is beneficial to improving the volume energy density of the battery and even the entire battery pack.

The embodiment of the present application also provides an electric device including the above-mentioned battery or battery pack for providing electric energy, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

In the following embodiments, for the convenience of description, the electric device of some embodiments of the present application is taken as a vehicle 1000 as an example for description. The following is a description with reference to the accompanying drawings.

FIG1 is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. As shown in FIG1 , a battery pack 100 is provided inside the vehicle 1000, and the battery pack 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery pack 100 may be used to power the vehicle 1000, for example, the battery pack 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery pack 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

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

As shown in FIGS. 2 and 3 , the battery pack 100 includes a case 2 and at least one battery 1 . The case 2 includes a bottom shell 3 and a cover 4 . The cover 4 covers the bottom shell 3 , thereby forming a storage space for the battery 1 between the bottom shell 3 and the cover 4 .

In the battery pack 100, there can be multiple batteries 1, and the multiple batteries 1 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple batteries 1 are both connected in series and in parallel. Multiple batteries 1 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple batteries 1 is placed in the accommodation space formed by the bottom shell 3 and the cover body 4; of course, the battery pack 100 can also be a battery module formed by connecting multiple batteries 1 in series, in parallel, or in mixed connection, and then the multiple battery modules are connected in series, in parallel, or in mixed connection to form a whole, and are accommodated in the accommodation space formed by the bottom shell 3 and the cover body 4. The battery pack 100 can also include other structures. For example, the battery pack 100 can also include a busbar component for realizing electrical connection between multiple batteries 1.

Below, some embodiments of the present application are described in detail with reference to FIGS. 3 to 13 .

The embodiment of the present application provides a battery 1, including: an electrode assembly 10 and a shell 20, the shell 20 includes a bottom wall 21 and a side wall 22, the side wall 22 is connected to the bottom wall 21 and surrounds the bottom wall 21 to form a accommodating space 20a, the electrode assembly 10 is accommodated in the accommodating space 20a, the bottom wall 21 and the side wall 22 are connected by a transition portion 23, at least one of the bottom wall 21 and the side wall 22 includes a main body 24 and a thinning portion 25, the thinning portion 25 is connected between the main body 24 and the transition portion 23, the wall thickness of the thinning portion 25 is thinner than the wall thickness of the main body 24, and the inner side surface 25b of the thinning portion is closer to the outer side of the shell 20 than the inner side surface 24b of the main body.

3 and 4, the electrode assembly 10 includes at least two layers of pole sheets 113, and the at least two layers of pole sheets 113 include a positive pole sheet 113a and a negative pole sheet 113b, and a separator 114 is sandwiched between the positive pole sheet 113a and the negative pole sheet 113b. The positive pole sheet 113a, the separator 114, and the negative pole sheet 113b can be wound around the winding axis to form a winding structure. Of course, the positive pole sheet 113a, the separator 114, and the negative pole sheet 113b can be stacked together, so that the electrode assembly 10 is constituted as a laminated structure.

In the embodiment of the present application, the electrode assembly 10 is described by taking a winding structure as an example. In the embodiment of the present application, X, Y, and Z respectively represent the layer thickness direction X of the electrode assembly 10, the winding axis direction Z of the electrode assembly 10, and the length direction Y of the electrode assembly 10, wherein the layer thickness direction X, the winding axis direction Z, and the length direction Y are perpendicular to each other.

The winding structure includes a straight region 12 and bending regions 11 located at both ends of the straight region 12, and the straight region 12 and the bending region 11 are connected to each other. The electrode assembly 10 includes two opposite ends along the winding axis (extension) direction Z.

One electrode assembly 10 or multiple electrode assemblies 10 may be disposed in the housing 20. When multiple electrode assemblies 10 are disposed in the housing 20, the multiple electrode assemblies 10 may be connected in series or in parallel with each other. As a specific example, two electrode assemblies 10 are disposed in the housing 20, and the two electrode assemblies 10 are disposed in contact with each other in the layer thickness direction X of the electrode assembly 10.

The housing 20 includes a bottom wall 21 and a side wall 22 . The side wall 22 is connected to the bottom wall 21 and surrounds the bottom wall 21 to form an accommodation space 20 a for accommodating the electrode assembly 10 .

One or more side walls 22 may be provided. When there is one side wall 22, the side wall 22 may be cylindrical, so that the housing 20 is configured as a cylindrical housing. When there are multiple side walls 22, the housing 20 may have a variety of shapes, such as square, polygonal prism, etc., and the polygonal prism may be, for example, a hexagonal prism, etc. As a specific example, referring to FIG. 3 , the housing 20 is a square housing of a tetrahedral structure, having a first side wall 221 opposite to the second side wall 222, and the first side wall 221 is adjacent to the second side wall 222 and connected to each other. In some embodiments, the surface area of the first side wall 221 is greater than the surface area of the second side wall 222, so that the first side wall 221 is configured as a so-called large surface.

The bottom wall 21 and the side wall 22 are connected via a transition portion 23 , and the transition portion 23 may be rounded or chamfered.

At least one of the bottom wall 21 and the side wall 22 includes a main body 24 and a thinned portion 25, and the thinned portion 25 is connected between the main body 24 and the transition portion 23. It can be understood that the thinned portion 25 is formed on the bottom wall 21 or the side wall 22, or on both the bottom wall 21 and the side wall 22.

The wall thickness of the thinning portion 25 is thinner than that of the main body 24, and the inner side surface 25b of the thinning portion is closer to the outer side of the shell 20 than the inner side surface 24b of the main body. It can be understood that the wall thickness of the thinning portion 25 is thinner than that of the main body 24, and the inner side surface 25b of the thinning portion with a thinner wall thickness is offset toward the outer side of the shell 20 compared with the inner side surface of the main body 24, so that the transition portion 23 follows the thinning portion 25 and is offset toward the outer side of the shell 20, thereby avoiding the electrode assembly 10.

As a specific example, referring to Figures 5 to 10, the side wall 22 has a main body 24 and a thinned portion 25, the thinned portion 25 is connected between the main body 24 and the transition portion 23, the wall thickness of the thinned portion 25 is thinner than the wall thickness of the main body 24, and the inner side surface 25b of the thinned portion is recessed toward the outside of the shell 20 (in the opposite direction of the arrow direction indicated by the X direction in Figure 5), so that the transition portion 23 follows the thinned portion 25 and deviates toward the outside of the shell 20 to avoid the electrode assembly 10.

The main body portion 24 and the thinned portion 25 may be formed on the first side wall 221 , or the main body portion 24 and the thinned portion 25 may be formed on the first side wall 221 and the second side wall 222 , respectively.

As another specific example, referring to FIG. 11 , the bottom wall 21 has a main body 24 and a thinned portion 25, the thinned portion 25 being connected between the main body 24 and the transition portion 23, the wall thickness of the thinned portion 25 being thinner than the wall thickness of the main body 24, and the inner side surface 25b of the thinned portion being recessed toward the outside of the shell 20 (in the direction opposite to the direction of the arrow indicated in the Z direction in FIG. 11 ), so that the transition portion 23 follows the thinned portion 25 and deviates toward the outside of the shell 20 to avoid the electrode assembly 10.

Since the thinning portion 25 is connected between the main body and the transition portion, the wall thickness of the thinning portion 25 is thinner than the wall thickness of the main body 24. This design allows the transition portion 23 to be offset to the outside of the shell 20 along with the thinning portion 25, thereby avoiding the electrode assembly 10. Even without adding a bottom support plate and changing the shape of the shell 20, the risk of interference, extrusion and deformation between the electrode assembly 10 and the transition portion 23 is reduced or eliminated, thereby extending the service life of the battery. At the same time, it is beneficial to improve the volume energy density of the battery 1 and even the entire battery pack 100.

In some embodiments, the outer side surface 25a of the thinned portion is flush with the outer side surface 24a of the main body, so that the outer side surface 25a of the thinned portion and the outer side surface 24a of the main body form a flat surface. As a specific example, each outer side surface of the housing 20 is a flat surface.

The outer side surface 25a of the thinning portion is flush with the outer side surface 24a of the main body, and the inner side surface 25b of the thinning portion is recessed toward the outside of the shell 20, so that the wall thickness of the thinning portion 25 is thinner than the wall thickness of the main body 24. While basically maintaining the original external structure of the shell 20, the risk of interference, extrusion and deformation between the electrode assembly 10 and the transition portion 23 is reduced or eliminated, thereby extending the service life of the battery and helping to improve the volume energy density of the entire battery pack 100.

In some embodiments, the electrode assembly 10 includes at least two layers of electrode sheets 113, and the at least two layers of electrode sheets are configured as a winding structure. The side wall 22 of the shell 20 includes a relative first side wall 221 and a relative second side wall 222, and the first side wall 221 is adjacent to and connected to the second side wall 222. Each first side wall 221 and each second side wall 222 is respectively connected to the bottom wall 21 through a transition portion 23, and each first side wall 221 is relatively arranged along the layer thickness direction X of the electrode assembly 10, and the thinning portion 25 is at least arranged on each first side wall 221.

Referring to Figures 3 and 4, in the electrode assembly 10 with a winding structure, since the bottom straight edges of the electrode assembly 10 located in the straight area 12 on the opposite sides of the layer thickness direction X are more likely to interfere with the transition portion 23 than the bottom arc-shaped edges located in the bending area 11, and the first side walls 221 located on the opposite sides of the layer thickness direction X are usually the large surfaces of the shell 20, therefore, setting a thinning portion 25 on the first side wall 221 of the larger surface can avoid most of the bottom of the electrode assembly 10 while reducing the risk of reduced strength of the shell 20 due to the thinning portion 25.

As a specific example, a thinning portion 25 is provided on each side wall (eg, each first side wall 221 and each second side wall 222 ).

In some embodiments, referring to FIGS. 7 , 10 , and 11 , the inner side surface 25 b of the thinned portion includes a plane.

The inner side surface 25 b of the thinned portion may be partially or entirely a plane, and the plane may be perpendicular to the bottom wall 21 or have an acute angle with the bottom wall 21 .

The inner side surface 25b of the thinned portion is a plane, which is easy to process and shape, thereby improving manufacturing efficiency. When the shell 20 is injection molded, the inner side surface 25b of the thinned portion includes the planar thinned portion 25 to facilitate easier demoulding of the shell 20.

In some embodiments, the inner side surface 25b of the thinned portion includes a curved surface.

The arc surface can disperse the stress at the connection position between the main body portion 24 and the thinned portion 25 and the connection position between the transition portion 23 and the thinned portion 25 , which helps to improve the overall strength of the housing 20 .

In some embodiments, referring to FIG. 12 , the thinned portion 25 is configured as a groove, and the surface of the groove includes a curved surface.

The thinned portion 25 is configured as a groove, which can occupy less wall thickness of the housing 20 and help improve the overall strength of the housing 20 .

For example, the arc surface of the concave surface can be an arc surface, and the radius of the arc surface can be substantially equal to the fillet radius of the transition portion 23, so that the surface of the thinned portion 25 and the inner surface of the transition portion 23 together constitute a substantially semicircular arc surface.

In some embodiments, one end 10 b of the electrode assembly 10 along the winding axis direction Z abuts against the bottom wall 21 . The winding axis direction Z is perpendicular to the layer thickness direction X of the electrode assembly 10 .

One end 10b of the electrode assembly 10 along the winding axis direction Z faces the bottom wall 21 of the shell 20, and the other end faces the top cover 30. The other end may be provided with a tab for connecting to an electrode terminal 31 provided on the top cover 30 at the open end of the shell 20. A pressure relief mechanism 32 may be provided on the top cover 30.

Since the transition part 23 avoids the electrode assembly 10, when the electrode assembly 10 is placed in the shell 20, one end 10b of the electrode assembly 10 no longer interferes with the deformation of the transition part 23. Even in the case where a bottom support plate is not provided, one end 10b of the electrode assembly 10 can be intactly pressed against the bottom wall 21, which helps to improve the volume energy density of a single battery. In addition, it is conducive to the bottom of the electrode assembly 10 and the bottom wall of the shell 20 to fit together, reduce the displacement due to shaking between the two, reduce collisions, improve the stability of the electrode assembly in the shell, and reduce the probability of short circuit caused by metal wires caused by the electrode assembly 10 scraping against the inner wall of the shell 20.

In some embodiments, the transition portion 23 has a transition radius.

The transition fillet facilitates demoulding of the housing 20 , reduces wear between the injection mold and the formed housing 20 , and maintains accuracy and dimensional stability.

In some embodiments, referring to FIG. 6 and FIG. 7 , the maximum thinning thickness of the thinning portion 25 relative to the main body 24 is L1, and the wall thickness of the thinning portion 25 is L, wherein the value range of L1 is 15% to 40% of L.

For example, L1 can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 30%, 35%, and 40% of L.

The appropriate wall thickness of the thinned portion 25 can allow the transition portion 23 to avoid the electrode assembly 10 while meeting the strength requirement of the shell 20 .

In some embodiments, referring to FIG. 7 , the radius of the transition fillet of the transition portion 23 is r, wherein r is 80% to 150% of L1.

For example, r is 80%, 90%, 100%, 110%, 120%, 125%, 130%, 140%, or 150% of L1.

The appropriate ratio between the thinned thickness L1 of the thinned portion 25 and the transition fillet r enables the transition portion 23 to avoid the electrode assembly 10 and meet the strength requirement of the shell 20 .

In some embodiments, referring to FIGS. 6 and 7 , the height of the thinned portion 25 along the winding axis direction Z of the electrode assembly 10 is h, and the total height of the shell 20 along the winding axis direction Z is H, wherein the value range of h is 5% to 10% of H.

For example, h is 5%, 6%, 6.5%, 7%, 8%, 9%, 9.5%, or 10% of H.

The appropriate height of the thinned portion 25 can meet the strength requirement of the housing 20 and is easy to process and manufacture.

In some embodiments, referring to FIG. 13 , a gap 20 b is formed between the thinned portion 25 and the electrode assembly 10 , and a filler 40 is filled in the gap 20 b.

The filler 40 may be a substance that alleviates gas production, thereby alleviating the amount of gas in the electrolyte, inhibiting battery expansion, reducing the risk of thermal runaway, and increasing the battery life.

The filler 40 may be a coating having a certain thickness coated on the inner side of the thinned portion 25 , which may improve the strength of the thinned portion 25 .

The gap 20 b between the thinned portion 25 and the electrode assembly 10 is filled with the filler 40 , so that the gap 20 b is fully utilized and the utilization rate of the internal space of the shell 20 is improved.

Next, a specific example of the present application is described.

2 to 10, the battery 1 provided in the embodiment of the present application includes an electrode assembly 10 and a shell 20, the shell 20 is square, including a bottom wall 21, an opposite first side wall 221 and an opposite second side wall 222, the first side wall 221 is adjacent to and connected to the second side wall 222, each first side wall 221 and each second side wall 222 is also respectively connected to the bottom wall 21 and surrounds the bottom wall 21 to form a receiving space 20a, the electrode assembly 10 is accommodated in the receiving space 20a, wherein the opposite The first side walls 221 of the electrode assembly 10 are located at opposite sides in the layer thickness direction, the bottom wall 21 is connected to each first side wall 221 and each second side wall 222 through a transition portion 23, the first side wall 221 and the second side wall 222 each include a main body 24 and a thinning portion 25, the thinning portion 25 is connected between the main body 24 and the transition portion 23, the wall thickness of the thinning portion 25 is thinner than the wall thickness of the main body 24, and the inner side surface 25b of the thinning portion is closer to the outer side of the shell 20 than the inner side surface 24b of the main body. The thinning portions 25 of each first side wall 221 and each second side wall 222 surround a square space, or surround a ring space with an arc surface.

The electrode assembly 10 is a winding structure, and one end 10 b of the electrode assembly 10 along the winding axis direction Z abuts against and fits against the bottom wall 21 of the shell 20 .

A gap is formed between the electrode assembly 10 and the space surrounded by the thinned portions 25 in a square or annular shape, and a buffer gas substance may be filled in the gap.

The present application also provides a battery pack 100 , comprising at least one battery 1 mentioned above.

The battery pack 100 may be a battery module formed by connecting a plurality of batteries 1 together.

2 , the battery pack 100 may further include a box body 2 , which includes a bottom shell 3 and a cover body 4 . The cover body 4 covers the bottom shell 3 , thereby forming a storage space for the battery 1 between the bottom shell 3 and the cover body 4 .

The present application also provides an electrical device, which includes the battery or battery pack mentioned above for providing electrical energy.

The present application also provides an energy storage device, including the battery or battery pack mentioned above for providing electrical energy, and the battery can store electrical energy and provide electrical energy.

The energy storage device may be an energy storage box or an energy storage cabinet. The energy storage cabinet includes a plurality of battery compartments for accommodating batteries. In addition, the energy storage cabinet may also include a thermal management component and a power control component.

The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the present application.

Claims (15)

1. A battery, comprising:

An electrode assembly;

A case including a bottom wall and a side wall connected to the bottom wall and surrounding the periphery of the bottom wall to form a receiving space in which the electrode assembly is received,

The bottom wall is connected with the side wall through a transition part, at least one of the bottom wall and the side wall comprises a main body part and a thinning part, the thinning part is connected between the main body part and the transition part, the wall thickness of the thinning part is thinner than that of the main body part, and the inner side surface of the thinning part is closer to the outer side of the shell than the inner side surface of the main body part.

2. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

The outer side surface of the thinning part is flush with the outer side surface of the main body part.

3. The battery according to claim 1 or 2, wherein,

The inner side surface of the thinned portion includes a plane.

4. The battery according to claim 1 or 2, wherein,

The inner side surface of the thinning part comprises an arc surface.

5. The battery of claim 4, wherein the battery is provided with a plurality of electrodes,

The thinning part is formed into a groove, and the surface of the groove comprises an arc surface.

6. The battery according to claim 1 or 2, wherein,

The electrode assembly comprises at least two layers of pole pieces, the at least two layers of pole pieces are formed into a winding structure,

The side walls comprise opposite first side walls and opposite second side walls, the first side walls are adjacent to and connected with the second side walls, each first side wall and each second side wall are respectively connected with the bottom wall through the transition part, each first side wall is oppositely arranged along the layer thickness direction of the electrode assembly,

The thinning portions are at least arranged on the first side walls.

7. The battery according to claim 1 or 2, wherein,

Along the winding axis direction of the electrode assembly, the end of the electrode assembly abuts against the bottom wall.

8. The battery according to claim 1 or 2, wherein,

The transition portion has a transition fillet.

9. The battery of claim 8, wherein the battery is configured to provide the battery with a battery cell,

The maximum thickness of the thinned part relative to the main body part is L1, and the wall thickness of the thinned part is L, wherein L1 is 15-40% of L.

10. The battery of claim 9, wherein the battery is configured to provide the battery with a plurality of cells,

The radius of the transition fillet is r, wherein r is 80 to 150% of L1.

11. The battery of claim 9, wherein the battery is configured to provide the battery with a plurality of cells,

The height of the thinning portion along the winding axis direction of the electrode assembly is H, and the height of the case along the winding axis direction is H, wherein H is 5% to 10% of H.

12. The battery according to claim 1 or 2, wherein,

A gap is formed between the thinned portion and the electrode assembly, and a filler is filled in the gap.

13. A battery pack comprising at least one battery according to any one of claims 1 to 12.

14. An electrical device comprising a battery according to any one of claims 1 to 12 or a battery pack according to claim 13, the battery being capable of providing electrical energy to the electrical device.

15. An energy storage device comprising a battery according to any one of claims 1 to 12 or a battery pack according to claim 13, said battery being capable of storing electrical energy and providing electrical energy.