CN221126207U - Battery cell, battery and energy storage device - Google Patents

Abstract

The utility model discloses a battery monomer, a battery and energy storage equipment, wherein the battery monomer comprises a shell, an electrode terminal and a first insulating film, and the shell is provided with an opening; the end cover is in sealing connection with the shell and seals the opening, the electrode terminal penetrates through the end cover along the thickness direction of the end cover, the first insulating film is arranged on the surface of the thickness direction of the end cover, and the edge, close to the opening, of the first insulating film is arranged at intervals with the opening. In the battery cell of the embodiment of the utility model, the first insulating film is arranged on the surface of the end cover in the thickness direction, and the first insulating film can isolate the surface of the end cover in the thickness direction from the electrode terminal, so that the risk of creepage between the electrode terminal and the end cover is reduced, and the use safety of the battery cell is improved.

Description

Battery cell, battery and energy storage device

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery monomer, a battery and energy storage equipment.

Background

In recent years, with the development of battery technology, batteries are widely used in energy storage power systems such as hydraulic power, firepower, wind power and solar power stations. In the related art, a battery includes a plurality of battery cells arranged in series or in parallel. The battery cell includes an end cap and an electrode terminal provided on the end cap, and the battery cell may be externally supplied with power through the electrode terminal. Because the battery monomer is applied to energy storage power supply system, the voltage of battery monomer is generally higher, and the phenomenon of creepage appears easily with the end cover to electrode terminal, has reduced the free safety in utilization of battery.

Disclosure of utility model

In view of the above problems, the present utility model provides a battery cell, a battery and an energy storage device, which can reduce the risk of creepage between an electrode terminal and an end cover, and improve the use safety of the battery cell.

In a first aspect, the present utility model provides a battery cell including a case formed with an opening, an electrode terminal, and a first insulating film; the end cover is in sealing connection with the shell and seals the opening, the electrode terminal penetrates through the end cover along the thickness direction of the end cover, the first insulating film is arranged on the surface of the thickness direction of the end cover, and the first insulating film is close to the edge of the opening and is arranged at intervals with the opening. In addition, the first insulating film is arranged close to the edge of the opening and is spaced from the opening, so that interference of the first insulating film when the end cover is connected with the shell can be reduced, and the shell is connected with the end cover more firmly.

In the battery cell of the embodiment of the utility model, the first insulating film is arranged on the surface of the end cover in the thickness direction, and the first insulating film can isolate the surface of the end cover in the thickness direction from the electrode terminal, so that the risk of creepage between the electrode terminal and the end cover is reduced, and the use safety of the battery cell is improved.

In some embodiments, the end cover includes a first surface and a second surface disposed opposite to each other in a thickness direction of the end cover, the first surface facing an inside of the case, and the first surface and/or the second surface being provided with the first insulating film. Therefore, when the first insulating film is arranged on the first surface of the end cover, the first insulating film can isolate the electrode terminal from the first surface of the end cover, so that the risk of creepage between the electrode terminal and the first surface of the end cover is reduced, the contact area between electrolyte and the end cover can be reduced, and the corrosion probability of the end cover is reduced; when the first insulating film is arranged on the second surface of the end cover, the first insulating film can isolate the electrode terminal from the second surface of the end cover, so that the risk of creepage phenomenon between the electrode terminal and the second surface of the end cover is reduced.

In some embodiments, the first insulating film has a thickness of 3 μm to 50 μm. Thus, the first insulating film not only has better insulating property, but also reduces the preparation cost of the first insulating film.

In some embodiments, the first insulating film has a thickness of 6 μm to 30 μm.

In some embodiments, the first insulating film is an aluminum oxide film or a polyimide film. Thus, the first insulating film has good insulating property and is easy to prepare, so that the preparation cost of the battery cell is low.

In some embodiments, the distance between the edge of the first insulating film near the opening and the opening is h1, and h is 1 mm-10 mm. Thus, the first insulating film not only can reduce interference when the end cover is connected with the shell, but also can effectively reduce the risk of creepage between the electrode terminal and the end cover.

In some embodiments, the battery cell includes a second insulating film and an electrode assembly disposed in the case, the second insulating film being disposed at a surface of the case, the second insulating film being disposed around the electrode assembly. In this way, the second insulating film is disposed on the surface of the housing, and the second insulating film is disposed around the electrode assembly, and the second insulating film can isolate the electrode assemblies of two adjacent battery cells, so that the risk that the electrolyte is decomposed due to the high voltage formed between the housing and other battery cells of the electrode assemblies can be reduced, and the service life of the battery applying the battery cells is prolonged.

In certain embodiments, the inner and/or outer surface of the housing is provided with the second insulating film. Therefore, when the second insulating film is arranged on the inner surface of the shell, the second insulating film can isolate the electrode assembly from other battery monomers, so that the risk of electrolyte decomposition of the battery monomers is reduced, the contact area of the electrolyte and the shell is reduced, and the corrosion probability of the shell is reduced; when the second insulating film is arranged on the outer surface of the shell, the probability that the shells of two adjacent battery monomers are contacted with each other can be reduced by the second insulating film, so that the phenomenon of short circuit between the two adjacent battery monomers is reduced.

In some embodiments, the second insulating film has a thickness of 3 μm to 50 μm. Thus, the second insulating film not only has better insulating property, but also reduces the preparation cost of the second insulating film.

In some embodiments, the second insulating film has a thickness of 6 μm to 30 μm.

In some embodiments, the second insulating film is an aluminum oxide film or a polyimide film. Thus, the second insulating film has good insulating property and is easy to prepare, so that the preparation cost of the battery cell is low.

In some embodiments, the second insulating film is disposed adjacent to an edge of the opening at a distance from the opening. Therefore, the second insulating film is arranged close to the edge of the opening and is spaced from the opening, interference of the second insulating film when the end cover is connected with the shell can be reduced, and the shell is connected with the end cover more firmly.

In some embodiments, the distance between the edge of the second insulating film, which is close to the opening, and the opening is h2, wherein h2 is greater than or equal to t-0.5mm, and t is the thickness of the end cover, and the unit is mm. Thus, the second insulating film can effectively reduce interference when the end cover is connected with the housing.

In some embodiments, the distance between the edge of the second insulating film near the opening and the opening is h2, and h2 is 1 mm-10 mm. Thus, the second insulating film can not only reduce interference when the end cover is connected with the housing, but also effectively realize an insulating effect on the electrode assembly.

In some embodiments, the electrode assembly includes an electrode body and a tab connected to the electrode body, and the second insulating film is located near an edge of the opening beyond an end of the electrode body facing the opening. Thus, the second insulating film can isolate the electrode assembly from other battery cells, and the risk of electrolyte decomposition of the battery cells is reduced.

In a second aspect, the present utility model provides a battery comprising a battery cell according to any one of the embodiments described above.

In a third aspect, the present utility model provides an energy storage device comprising a battery cell or battery according to any of the embodiments described above.

The foregoing description is only an overview of the present utility model, and is intended to be implemented in accordance with the teachings of the present utility model in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present utility model more readily apparent.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the utility model. Also, like reference numerals are used to designate like parts throughout the accompanying drawings. In the drawings:

Fig. 1 is a schematic view of a battery according to some embodiments of the present utility model;

FIG. 2 is an exploded view of a battery cell according to some embodiments of the present utility model;

FIG. 3 is a schematic cross-sectional view of a battery cell according to some embodiments of the utility model;

FIG. 4 is a schematic partial cross-sectional view of a battery cell according to some embodiments of the utility model;

FIG. 5 is another schematic partial cross-sectional view of a battery cell according to some embodiments of the utility model;

FIG. 6 is a schematic view, partially in section, of a battery cell according to some embodiments of the utility model;

fig. 7 is a schematic partial cross-sectional view of a battery cell according to some embodiments of the utility model.

Reference numerals illustrate: 200-battery, 210-case, 211-first part, 212-second part, 100-battery cell, 10-case, 101-opening, 11-inner surface, 12-outer surface, 13-first wall, 14-second wall, 20-electrode terminal, 30-first insulating film, 40-end cap, 41-first surface, 42-second surface, 50-electrode assembly, 51-electrode body, 52-tab, 60-second insulating film.

Detailed Description

Embodiments of the technical scheme of the present utility model will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present utility model, and thus are merely examples, and are not intended to limit the scope of the present utility model.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model; the terms "comprising" and "having" and any variations thereof in the description of the utility model and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

In the description of embodiments of the present utility model, the technical terms "first," "second," and the like are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present utility model, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein 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 utility model. 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 appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present utility model, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present utility model, the term "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two), and "plural sheets" means two or more (including two).

In the description of the embodiments of the present utility model, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present utility model.

In the description of the embodiments of the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like should be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present utility model will be understood by those of ordinary skill in the art according to specific circumstances.

Currently, the more widely the battery is used in view of the development of market situation. The battery is not only applied to energy storage power supply systems of hydraulic power, firepower, wind power, solar power stations and the like.

Reference to a battery in accordance with an embodiment of the present utility model refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present utility model may include a battery module or a battery pack, or the like. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

The battery may include a plurality of battery cells arranged in series or in parallel. The battery monomer comprises a shell, an electrode assembly and electrolyte, wherein the electrode assembly consists of an anode plate, a cathode plate and a diaphragm. The battery cell mainly relies on metal ions to move between the positive pole piece and the negative pole piece to work.

The development of battery technology is taking into consideration various design factors such as energy density, discharge capacity, charge-discharge rate and other performance parameters, and the safety of batteries.

In the related art, the battery cell includes an end cap and an electrode terminal provided on the end cap, through which the battery cell may be externally supplied with power. Because the battery monomer is applied to energy storage power supply system, the voltage of battery monomer is generally higher, and the phenomenon of creepage appears easily with the end cover to electrode terminal, has reduced the free safety in utilization of battery.

In order to solve the problem that the creepage phenomenon easily occurs between the electrode terminal and the end cover, a first insulating film is arranged on the surface of the thickness direction of the end cover, and the first insulating film can isolate the surface of the thickness direction of the end cover from the electrode terminal, so that the risk of the creepage phenomenon between the electrode terminal and the end cover is reduced, and the use safety of the battery is improved.

The energy storage device of an embodiment of the present utility model includes a battery cell or battery in any of the following embodiments. In particular, the energy storage device may use a battery or a battery cell as an energy storage body. The energy storage equipment comprises an energy storage container, an energy storage electric cabinet and the like.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a battery 200 according to some embodiments of the utility model. The battery 200 according to the embodiment of the present utility model includes the battery cell 100 according to any one of the following embodiments. In this manner, since the electrode assembly can be effectively impregnated in the battery cell 100 and the function of the second insulating film is not greatly affected, the battery according to the embodiment of the present utility model has superior performance and can continuously and stably operate in a safe environment.

In the embodiment of the present utility model, the battery cell 100 may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited by the embodiment of the present utility model. The battery cell 100 may have a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, etc., which are not limited thereto according to the embodiment of the present utility model. The battery cells 100 are generally divided into three types in a package manner: the cylindrical battery cell, the prismatic battery cell, and the pouch battery cell, to which the embodiment of the present utility model is not limited.

The battery 200 generally includes a housing 210 for enclosing one or more battery cells 100. The plurality of battery cells 100 may be accommodated in the case 210, and the case 210 may prevent the liquid or other foreign matters from affecting the charge or discharge of the battery cells 100. The case 210 serves as a supporting body of the battery module, and plays a key role in safety work and protection of the battery module. The case 210 meets the strength and rigidity requirements and the protection level requirements of the electrical equipment housing while providing crash protection. The box 210 can be cast by steel plates, aluminum alloys and other materials; novel lightweight materials, such as glass fiber reinforced composites, carbon fiber reinforced composites, and the like, may also be used.

In some embodiments, the case 210 may include a first portion 211 and a second portion 212, the first portion 211 and the second portion 212 being overlapped with each other, the first portion 211 and the second portion 212 together defining an accommodating space for accommodating the battery cell 100. The second portion 212 may be a hollow structure with one end opened, the first portion 211 may be a plate-shaped structure, and the first portion 211 covers the opening side of the second portion 212, so that the first portion 211 and the second portion 212 together define an accommodating space; the first portion 211 and the second portion 212 may be hollow structures with one side open, and the open side of the first portion 211 is covered with the open side of the second portion 212. Of course, the case 210 formed by the first portion 211 and the second portion 212 may be of various shapes, such as a cylinder, a rectangular parallelepiped, etc.

Referring to fig. 2 and 3, fig. 2 is an exploded view of a battery cell 100 according to some embodiments of the utility model. Fig. 3 is a schematic cross-sectional view of a battery cell according to some embodiments of the utility model. In some embodiments, the battery cell 100 includes a case 10, an electrode terminal 20, a first insulating film 30, and an end cap 40, the case 10 being formed with an opening 101; the end cap 40 is hermetically connected with the case 10 and closes the opening 101, and the electrode terminal 20 is penetrated through the end cap 40 in the thickness direction of the end cap 40; the first insulating film 30 is provided on the surface of the end cap 40 in the thickness direction.

Specifically, the housing 10 may have a cylindrical shape, a rectangular parallelepiped shape, a flat shape, or the like. The housing 10 may be made of steel, aluminum, or the like. The opening 101 of the case 10 is located at the end of the case 10, and the opening 101 makes it easier to assemble the components within the battery cell 100. The electrode terminal 20 is a component to which the battery cell 100 is connected to an external device. For example, two battery cells 100 are connected in series through the electrode terminals 20. The first insulating film 30 is a film material having insulating properties, and the first insulating film 30 may cover the surface of the end cap 40 completely or may cover a part of the surface of the end cap 40. The end cap 40 is hermetically connected with the case 10 and closes the opening 101, so that a closed space is formed inside the battery cell 100, effectively reducing the risk of leakage of the electrolyte.

It should be noted that, when the end cap 40 and the electrode terminal 20 are insulated from each other, or the end cap 40 and the electrode terminal 20 do not contact each other, the voltage between the end cap 40 and the electrode terminal 20 is large, and a creepage phenomenon is likely to occur between the end cap 40 and the electrode terminal 20. Therefore, the first insulating film 30 is disposed on the surface of the end cover 40 in the thickness direction, and the first insulating film 30 can isolate the surface of the end cover 40 in the thickness direction from the electrode terminal 20, so as to reduce the risk of creepage between the electrode terminal 20 and the end cover 40 and improve the use safety of the battery cell 100.

Referring to fig. 4-6, in some embodiments, the end cap 40 includes a first surface 41 and a second surface 42 disposed opposite to each other in a thickness direction of the end cap 40, the first surface 41 facing the inside of the case 10, and the first surface 41 and/or the second surface 42 being provided with the first insulating film 30.

As shown in fig. 4, the first surface 41 and the second surface 42 of the end cap 40 are each provided with the first insulating film 30. As shown in fig. 5, the second surface 42 of the end cap 40 is provided with the first insulating film 30; as shown in fig. 6, the first surface 41 of the end cap 40 is provided with the first insulating film 30.

Thus, when the first insulating film 30 is disposed on the first surface 41 of the end cover 40, the first insulating film 30 can insulate the electrode terminal 20 from the first surface 41 of the end cover 40, reduce the risk of creepage between the electrode terminal 20 and the first surface 41 of the end cover 40, reduce the risk of contact between the electrolyte and the end cover 40, and reduce the corrosion probability of the end cover 40. When the first insulating film 30 is disposed on the second surface 42 of the end cover 40, the first insulating film 30 can insulate the electrode terminal 20 from the second surface 42 of the end cover 40, so as to reduce the risk of creepage between the electrode terminal 20 and the second surface 42 of the end cover 40.

Referring to fig. 5, in some embodiments, the thickness D1 of the first insulating film 30 is 3 μm to 50 μm. For example, D1 may be 3 μm, 10 μm, 18 μm, 20 μm, 30 μm, 40 μm, 50 μm, or the like, and thus, when the thickness D1 of the first insulating film 30 is in the above range, the first insulating film 30 may have a good insulating property, and also the manufacturing cost of the first insulating film 30 may be reduced. When the thickness of the first insulating film 30 is less than 3 μm, the insulating performance of the first insulating film 30 is poor, and it is difficult to satisfy the insulation requirements of the battery cell 100. When the thickness of the first insulating film 30 is greater than 50 μm, the performance of the first insulating film 30 is excessive, and the preparation time of the first insulating film 30 is long, so that the preparation cost of the first insulating film 30 is high.

In some embodiments, the thickness D1 of the first insulating film 30 is 6 μm to 30 μm. For example, D1 may be 6 μm, 10 μm, 15 μm, 20 μm, 22 μm, 25 μm, 30 μm, etc. in size.

In some embodiments, the first insulating film 30 is an aluminum oxide film or a polyimide film. In particular, the end cap 40 may be an aluminum alloy shell and the aluminum oxide film may be formed by an anodic oxidation process. For example, the end cap 40 may be subjected to an electrochemical reaction as an anode, that is, the surface of the end cap 40 may be subjected to an oxidation reaction, the reaction product being alumina powder, and the alumina powder being bonded as a film on the surface of the end cap 40, that is, an alumina film attached to the surface of the end cap 40 may be obtained. It should be noted that the alumina film has good insulation properties, so that it can provide better insulation protection for the end cap 40. Polyimide (PI) film may be formed on the surface of the cap 40 by spraying, electrophoresis, or the like. In this way, the aluminum oxide film or the polyimide film is adopted so that the insulating performance of the first insulating film 30 is better and is easy to prepare, so that the preparation cost of the battery cell 100 is lower.

Referring to fig. 2, 4 and 5, in some embodiments, the first insulating film 30 is disposed near the edge of the opening 101 and spaced apart from the opening 101.

In general, the end cap 40 and the housing 10 may be connected by a welding process. When the end cap 40 is welded with the housing 10, a molten pool is formed at the welding position of the end cap 40 and the housing 10, so that the end cap 40 is firmly connected with the housing 10. The edge of the first insulating film 30 near the opening 101 is spaced from the opening 101, that is, the first insulating film 30 is not disposed near the opening 101, so that a molten pool is more easily formed between the end cover 40 and the housing 10 during welding, and defects such as cold welding and the like formed between the end cover 40 and the housing 10 during welding are reduced, therefore, the edge of the first insulating film 30 near the opening 101 is spaced from the opening 101, interference of the first insulating film 30 when the end cover 40 is connected with the housing 10 can be reduced, and the housing 10 is more firmly connected with the end cover 40.

Referring to FIG. 5, in some embodiments, the distance between the edge of the first insulating film 30 near the opening 101 and the opening 101 is h1,1 mm.ltoreq.h1.ltoreq.10mm. For example, h1 may be 1mm, 3mm, 4mm, 5mm, 10mm, etc. in size. In this way, the first insulating film 30 can not only reduce interference when the cap 40 is connected to the case 10, but also effectively insulate the electrode assembly 50.

Of course, in the embodiment of fig. 6 to 7, the first insulating film 30 may also extend to the opening 101.

It is understood that the distance between the edge of the first insulating film 30 near the opening 101 and the opening 101 may be equal to the distance between the edge of the first insulating film 30 near the opening 101 and the inner surface of the case 10.

Referring to fig. 2 and 3, in some embodiments, the battery cell 100 includes an electrode assembly 50 and a second insulating film 60, the electrode assembly 50 is disposed in the case 10, the second insulating film 60 is disposed on a surface of the case 10, and the second insulating film 60 is disposed around the electrode assembly 50.

Specifically, the second insulating film 60 is a film material having insulating properties, and the second insulating film 60 may cover the surface of the housing 10 completely or may cover a part of the surface of the housing 10.

As such, since the second insulating film 60 is disposed on the surface of the case 10 and the second insulating film 60 is disposed around the electrode assembly 50, the second insulating film 60 may insulate the battery cell 100 from the case of the battery 200 or from the electrolyte and the case 10, which may reduce the risk of decomposition of the electrolyte due to formation of high voltage between the battery cell 100 and the case of the battery 200 or the risk of corrosion of the case 10 of the battery cell 100 by the electrolyte, thereby extending the life of the battery 200 to which the battery cell 100 is applied.

In some embodiments, the second insulating film 60 may be a film layer having an equal thickness or a film layer having a different thickness.

In certain embodiments, the inner surface 11 and/or the outer surface 12 of the housing 10 is provided with a second insulating film 60. As shown in fig. 4, the inner surface 11 of the housing 10 is provided with a second insulating film 60; as shown in fig. 5, the outer surface 12 of the housing 10 is provided with a second insulating film 60; as shown in fig. 6, the inner surface 11 and the outer surface 12 of the housing 10 are each provided with a second insulating film 60.

The outer surface 12 of the housing 10 refers to a surface facing the inside of the housing 10, and the outer surface 12 of the housing 10 refers to a surface facing the outside of the housing 10. The inner surface 11 and the outer surface 12 of the housing 10 may be one plane, one curved surface, or include a plurality of planes, a plurality of curved surfaces, and a combination of planes and curved surfaces.

In this way, when the second insulating film 60 is provided on the inner surface 11 of the case 10, the second insulating film 60 can reduce the area where the electrolyte contacts the case 10, and reduce the probability of corrosion of the case 10 by the electrolyte.

When the second insulating film 60 is disposed on the outer surface 12 of the housing 10, the second insulating film 60 not only can isolate the battery cell 100 from the housing of the battery 200, reduce the risk of electrolyte decomposition caused by high voltage formed between the battery cell 100 and the housing of the battery 200, but also can reduce the probability of the housings 10 of two adjacent battery cells 100 contacting each other, thereby reducing the risk of leakage, temperature rise or thermal runaway of the battery cell 100 caused by high voltage formed between the two battery cells 100 due to short circuit between the two adjacent battery cells 100.

It should be noted that the "high voltage" referred to in the embodiments of the present utility model is a voltage greater than 100V.

Referring to fig. 2 and 4, in some embodiments, the housing 10 includes a first wall 13 and a second wall 14 connected to the first wall 13, the first wall 13 having an area larger than that of the second wall 14, the inner surfaces of the first wall 13 and the second wall 14 each being provided with a second insulating film 60, and/or the outer surfaces of the first wall 13 and the second wall 14 each being provided with a second insulating film 60.

For example, the inner surface of the first wall 13 and the inner surface of the second wall 14 are each provided with a second insulating film 60; as another example, the outer surface of the first wall 13 and the outer surface of the second wall 14 are both provided with the second insulating film 60; for another example, the inner and outer surfaces of the first wall 13 and the inner and outer surfaces of the second wall 14 are provided with the second insulating film 60.

Referring to fig. 5, in some embodiments, the thickness D2 of the second insulating film 60 is 3 μm to 50 μm. For example, D2 may be 3 μm, 10 μm, 18 μm, 20 μm, 30 μm, 40 μm, 50 μm, or the like, and thus, when the thickness D2 of the second insulating film 60 is in the above range, the second insulating film 60 may have a good insulating property, and the manufacturing cost of the second insulating film 60 may be reduced. When the thickness of the second insulating film 60 is less than 3 μm, the insulating performance of the second insulating film 60 is poor, and it is difficult to satisfy the insulation requirements of the battery cell 100. When the thickness of the second insulating film 60 is greater than 50 μm, the performance of the second insulating film 60 is excessive, and the preparation time of the second insulating film 60 is long, so that the preparation cost of the second insulating film 60 is high.

In some embodiments, the thickness D2 of the second insulating film 60 is 6 μm to 30 μm. For example, D2 may be 6 μm, 10 μm, 15 μm, 20 μm, 22 μm, 25 μm, 30 μm, etc.

In some embodiments, the second insulating film 60 is an aluminum oxide film or a polyimide film. Specifically, the outer case 10 may be an aluminum alloy case, and the aluminum oxide film may be formed by an anodic oxidation process. For example, the surface of the casing 10 may be oxidized by performing an electrochemical reaction using the casing 10 as an anode, and the reaction product is alumina powder, and the alumina powder is bonded to the surface of the casing 10 to form a film, thereby obtaining an alumina film attached to the surface of the casing 10. It should be noted that the alumina film has good insulation properties, so that it can provide better insulation protection for the outer shell 10. Polyimide (PI) film may be formed on the surface of the case 10 by spraying, electrophoresis, or the like. In this way, the aluminum oxide film or the polyimide film is adopted so that the second insulating film 60 has better insulating performance and is easy to prepare, so that the preparation cost of the battery cell 100 is low.

Referring to fig. 2, 3 and 7, in some embodiments, the second insulating film 60 is disposed near the edge of the opening 101 and spaced apart from the opening 101.

In general, the end cap 40 and the housing 10 may be connected by a welding process. When the end cap 40 is welded with the housing 10, a molten pool is formed at the welding position of the end cap 40 and the housing 10, so that the end cap 40 is firmly connected with the housing 10. The second insulating film 60 is disposed near the edge of the opening 101 and spaced from the opening 101, that is, the second insulating film 60 is not disposed near the opening 101, so that a molten pool is more easily formed between the end cover 40 and the housing 10 during welding, and defects such as cold welding and the like formed between the end cover 40 and the housing 10 during welding are reduced, therefore, the edge of the second insulating film 60 near the opening 101 and spaced from the opening 101, interference of the second insulating film 60 on connection between the end cover 40 and the housing 10 can be reduced, and the connection between the housing 10 and the end cover 40 is firmer.

Referring to FIG. 7, in some embodiments, the distance between the edge of the second insulating film 60 near the opening 101 and the opening 101 is h2, where h2 is equal to or greater than t-0.5mm, where t is the thickness of the end cap 40 in mm. In one example, the thickness t of the end cap 40 is 1.5mm, where h2 is greater than or equal to 1mm, or the distance between the second insulating film 60 and the opening 101 is greater than or equal to 1mm. For example, h2 may be 1mm, 3mm, 4mm, 5mm, 10mm, etc. in size. In this way, the second insulating film 60 makes the welding pool formed between the end cover 40 and the housing 10 easier in the welding process, so that interference when the end cover 40 is connected with the housing 10 can be effectively reduced, and the connection firmness of the end cover 40 and the housing 10 is improved.

It is understood that the distance between the edge of the second insulating film 60 near the opening 101 and the opening 101 may be equal to the distance between the edge of the second insulating film 60 near the opening 101 and the end face of the case 10 where the opening 101 is formed.

Referring to FIG. 7, in some embodiments, the distance between the edge of the second insulating film 60 near the opening 101 and the opening 101 is h2,1 mm.ltoreq.h2.ltoreq.10mm. For example, h2 may be 1mm, 3mm, 4mm, 5mm, 10mm, etc. in size. In this way, the second insulating film 60 can not only reduce interference when the cap 40 is connected to the case 10, but also effectively insulate the electrode assembly 50.

Of course, in the embodiment of fig. 4 to 6, the second insulating film 60 may also extend to the opening 101.

Referring to fig. 2 and 4-7, in some embodiments, the electrode assembly 50 includes an electrode body 51 and a tab 52 connected to the electrode body 51, and the edge of the second insulating film 60 near the opening 101 exceeds the end of the electrode body 51 facing the opening 101. Specifically, the electrode body 51 is a main constituent of the electrode assembly 50, and the electrode body 51 has an active material, which may be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate, carbon or silicon, or the like. The tab 52 is not coated with an active material. The volume of the electrode body 51 is much larger than the volume of the tab 52. During use of the battery cell 100, the electrode body 51 is impregnated with an electrolyte. Therefore, the edge of the second insulating film 60 near the opening 101 exceeds the end of the electrode body 51 facing the opening 101, so that the electrode body 51 is completely surrounded by the second insulating film 60, and the second insulating film 60 is higher than the liquid level of the electrolyte, thereby effectively isolating the electrolyte from the casing 10 and reducing the risk of corrosion of the casing 10.

In some embodiments, the second insulating film 60 is disposed equidistant from the opening 101 near the edge of the opening 101, thereby making the second insulating film 60 easier to dispose.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model, and are intended to be included within the scope of the appended claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present utility model is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (16)

1. A battery cell, comprising:

A housing formed with an opening;

The end cover is in sealing connection with the shell and seals the opening;

The electrode terminal is penetrated on the end cover along the thickness direction of the end cover; and

The first insulating film is arranged on the surface of the end cover in the thickness direction, and the first insulating film is arranged close to the edge of the opening and is spaced from the opening.

2. The battery cell according to claim 1, wherein the end cap includes a first surface and a second surface that are disposed opposite to each other in a thickness direction of the end cap, the first surface facing an inside of the case, and the first surface and/or the second surface being provided with the first insulating film.

3. The battery cell of claim 1, wherein the first insulating film has a thickness of 3 μιη to 50 μιη.

4. The battery cell of claim 3, wherein the first insulating film has a thickness of 6 μm to 30 μm.

5. The battery cell of claim 1, wherein the first insulating film is an aluminum oxide film or a polyimide film.

6. The battery cell according to claim 1, wherein a distance between an edge of the first insulating film adjacent to the opening and the opening is h1,1 mm.ltoreq.h1.ltoreq.10mm.

7. The battery cell of any one of claims 1-6, wherein the battery cell comprises a second insulating film and an electrode assembly, the electrode assembly disposed in the housing, the second insulating film disposed on a surface of the housing, the second insulating film disposed around the electrode assembly.

8. The battery cell according to claim 7, wherein the second insulating film is provided on an inner surface and/or an outer surface of the case.

9. The battery cell of claim 7, wherein the second insulating film has a thickness of 3 μm to 50 μm.

10. The battery cell according to claim 7, wherein the second insulating film is an aluminum oxide film or a polyimide film.

11. The battery cell of claim 7, wherein the second insulating film is disposed adjacent an edge of the opening in spaced relation to the opening.

12. The battery cell of claim 11, wherein a distance between an edge of the second insulating film adjacent to the opening and the opening is h2, h2 ≡t-0.5mm, wherein t is a thickness of the end cap in mm.

13. The battery cell of claim 11, wherein a distance between an edge of the second insulating film adjacent to the opening and the opening is h2,1mm ∈h2 ∈10mm.

14. The battery cell of claim 11, wherein the electrode assembly includes an electrode body and a tab connected to the electrode body, the edge of the second insulating film proximate the opening exceeding an end of the electrode body toward the opening.

15. A battery comprising a cell according to any one of claims 1-14.

16. An energy storage device comprising the battery cell of any one of claims 1-14 or the battery of claim 15.