Battery cell, battery and electric device

Abstract

Disclosed in the present application are a battery cell, a battery and an electric device. The battery cell comprises a case, a first insulating film and an adhesive layer, wherein the case comprises a first part and a second part, the first part being connected to the second part, and the surface energy of the second part being greater than the surface energy of the first part; the first insulating film covers at least part of the case; and the adhesive layer is arranged between the second part and the first insulating film and used for connecting the first insulating film to the second part. The technical solution provided in the present application can improve the reliability of the battery.

Description

Battery cells, batteries, and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202310265315.8, filed on March 17, 2023, entitled “Battery Cell, Battery, and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0005] In the development of battery technology, how to improve battery reliability is a technical problem that needs to be solved urgently.

[0006] Summary of the Invention

[0007] The present application provides a battery cell, a battery, and an electrical device, which can improve the reliability of the battery.

[0008] This application is achieved through the following technical solutions:

[0009] In a first aspect, the present application provides a battery cell comprising a housing, a first insulating film, and an adhesive layer. The housing comprises a first portion and a second portion, the first portion and the second portion being connected, and the surface energy of the outer surface of the second portion being greater than the surface energy of the outer surface of the first portion. The first insulating film covers at least a portion of the housing. The adhesive layer is disposed between the second portion and the first insulating film, connecting the first insulating film and the second portion.

[0010] In the above solution, by providing a second part whose outer surface has a surface energy greater than that of the first part, the adhesion between the glue layer and the outer shell can be improved compared to the outer shell which only includes the first part with lower surface energy, thereby reducing the risk of the first insulating film falling off due to insufficient adhesion between the glue layer and the outer shell, thereby improving the reliability of the battery.

[0011] According to some embodiments of the present application, the surface energy of the outer surface of the second portion is p, satisfying p>421N / m.

[0012] In the above scheme, at present, the surface energy of the outer surface of the shell of some battery cells is 421N / m, and the adhesion between it and the glue layer is relatively low. Therefore, in order to improve the adhesion between the glue layer and the shell, a second part with an outer surface surface energy greater than 421N / m is formed on the shell. This can effectively improve the problem of low adhesion between the shell and the glue layer, reduce the risk of the first insulating film falling off due to insufficient adhesion between the glue layer and the shell, and thereby improve the reliability of the battery.

[0013] According to some embodiments of the present application, 500 N / m≤p≤1500 N / m is satisfied.

[0014] In the above scheme, on the one hand, forming a second part on the outer surface of the shell with a surface energy greater than 500N / m can effectively improve the problem of low adhesion between the shell and the glue layer, reduce the risk of the first insulating film falling off due to insufficient adhesion between the glue layer and the shell, and thus improve the reliability of the battery. On the other hand, limiting the surface energy of the second part to no more than 1500N / m can effectively reduce the additional manufacturing cost of the shell due to the increase in surface energy, thereby controlling the manufacturing cost of the battery.

[0015] According to some embodiments of the present application, the first portion is a first metal layer, and the second portion is an oxide layer.

[0016] In the above scheme, the first part of the shell is the first metal layer, and the second part can be an oxide layer. The surface energy of the oxide layer is greater than the surface energy of the metal layer, and the adhesive layer can be effectively connected to the surface of the second part. To this end, by arranging the adhesive layer between the first insulating film and the second part, the connection stability between the first insulating film and the shell can be effectively improved, thereby improving the reliability of the battery.

[0017] According to some embodiments of the present application, the oxide layer is formed on the outer surface of the first metal layer.

[0018] In the above solution, an oxide layer can be efficiently formed on the outer surface of the first metal layer by means of anodization, electroplating, etc., so that the outer shell has a higher manufacturing efficiency, thereby improving the manufacturing efficiency of the battery.

[0019] According to some embodiments of the present application, the second part is chromium oxide or nickel oxide.

[0020] In the above scheme, in some embodiments, the second portion is chromium oxide. On the one hand, it can effectively improve the adhesion between the outer shell and the glue layer, thereby improving the connection strength between the outer shell and the first insulating film, and reducing the risk of the first insulating film falling off. On the other hand, chromium oxide can improve the corrosion resistance of the outer shell. Therefore, the second portion is chromium oxide, which can make the battery have higher reliability. In some embodiments, the second portion is nickel oxide. On the one hand, it can effectively improve the adhesion between the outer shell and the glue layer, thereby improving the connection strength between the outer shell and the first insulating film, and reducing the risk of the first insulating film falling off. On the other hand, nickel oxide has good insulation properties, which can reduce the risk of internal short circuits in the battery cells. Therefore, the second portion is nickel oxide, which can make the battery have higher reliability.

[0021] According to some embodiments of the present application, the first portion is aluminum, and the second portion is aluminum oxide.

[0022] In the above solution, the first part is aluminum and the second part is aluminum oxide, so that the second part can be formed on the first part at a lower cost, thereby reducing the cost of manufacturing the battery cell and further reducing the manufacturing cost of the battery.

[0023] According to some embodiments of the present application, the thickness of the second portion is M, satisfying 18um≤M≤100um.

[0024] In the above scheme, if the thickness of the second part, that is, the oxide layer, is too small, such as less than 18um, the adhesion force between the glue layer and the second part will be small, which will result in a higher risk of the first insulating film falling off; if the thickness of the second part is too large, such as greater than 100um, the volume of the shell will increase, affecting the volume energy density of the battery cell. For this reason, some embodiments of the present application limit the thickness M of the second part to between 18um and 100um, which can ensure a greater adhesion force between the glue layer and the second part, which makes the battery cell have a higher volume energy density, and thus makes the battery have higher reliability.

[0025] According to some embodiments of the present application, the surface where the second portion is connected to the adhesive layer is a concave-convex surface.

[0026] In the above solution, by setting the surface of the second part in contact with the glue layer to a concave-convex surface, the effective area between the glue layer and the second part can be increased, thereby improving the adhesion between the glue layer and the second part, and improving the connection strength between the first insulating film and the shell, so that the battery has higher reliability.

[0027] According to some embodiments of the present application, the first portion is a second metal layer, and the second portion is a third metal layer.

[0028] In the above scheme, in some embodiments, the material of the outer shell of the battery cell, that is, the material of the first part can be made of aluminum or other metal materials with low surface energy. In order to improve the stability between the first insulating film and the outer shell in some embodiments, a metal material with higher surface energy can be provided. For example, the surface energy of iron is higher than that of aluminum. To this end, the material of the second part can be iron or other metal materials with higher surface energy than aluminum to improve the connection strength between the first insulating film and the outer shell, so that the battery has higher reliability.

[0029] According to some embodiments of the present application, the first portion is a non-metal layer, and the second portion is a fourth metal layer and / or an oxide layer.

[0030] In the above scheme, in order to reduce the manufacturing cost of the battery, the shell of the battery cell can be made of non-metallic materials, that is, the first part of the shell can be a non-metallic layer, the material of which includes but is not limited to organic glass or polystyrene, and the surface energy of the non-metallic layer is low. For this reason, a second part can be provided, and the second part can be a fourth metal layer or an oxide layer with a larger surface energy to improve the problem of low adhesion between the first part and the glue layer, reduce the risk of the first insulating film falling off due to insufficient adhesion between the glue layer and the shell, and thus improve the reliability of the battery.

[0031] According to some embodiments of the present application, along the thickness direction of the shell, the outer surface of the second part is higher than the outer surface of the first part, or the outer surface of the second part is flush with the outer surface of the first part, or the outer surface of the second part is lower than the outer surface of the first part.

[0032] In the above solution, in some embodiments, the outer surface of the second portion is higher than the outer surface of the first portion to facilitate connection with the adhesive layer, thereby facilitating assembly of the first insulating film. In some embodiments, the outer surface of the second portion can be flush with the outer surface of the first portion, thereby minimizing the degree of protrusion of the first insulating film, adhesive layer, and second portion from the overall outer contour of the battery cell, thereby improving the smoothness of the outer contour of the battery cell. In some embodiments, the outer surface of the second portion can be lower than the outer surface of the first portion, thereby effectively reducing the degree of protrusion of the first insulating film, adhesive layer, and second portion from the overall outer contour of the battery cell, thereby improving the smoothness of the outer contour of the battery cell.

[0033] According to some embodiments of the present application, the melting point of the adhesive layer is P1, the melting point of the first insulating film is P2, and |P1-P2|≤30, unit: °C.

[0034] In the above solution, the difference between the melting point P1 of the adhesive layer and the melting point P2 of the first insulating film is 30°C, meaning they have similar melting points, facilitating their interconnection. In some embodiments, the adhesive layer and the first insulating film can be heat-fused together. Due to their similar melting points, the two layers can be heat-fused together more easily, reducing the difficulty of connecting them, improving the connection strength between the adhesive layer and the first insulating film, and reducing the risk of the first insulating film falling off, thereby enhancing the battery's reliability.

[0035] According to some embodiments of the present application, the first insulating film is connected to the adhesive layer by thermal melting.

[0036] In the above solution, the first insulating film is connected to the adhesive layer by hot-melt connection, which can improve the connection strength between the adhesive layer and the first insulating film, reduce the risk of the first insulating film falling off, and make the battery have higher reliability.

[0037] According to some embodiments of the present application, the battery cell further includes a second insulating film, which is connected to a surface of the first insulating film that is away from the adhesive layer.

[0038] In the above solution, by providing the second insulating film on the outer surface of the first insulating film, the outer shell can be further protected, so that the battery has higher reliability.

[0039] According to some embodiments of the present application, the first insulating film and the second insulating film are connected by thermal melting.

[0040] In the above scheme, the first insulating film and the second insulating film are connected by hot melting. On the one hand, it can reduce the difficulty of connecting the first insulating film and the second insulating film. On the other hand, it can improve the connection strength between the first insulating film and the second insulating film, reduce the risk of the second insulating film falling off, and make the battery have higher reliability.

[0041] According to some embodiments of the present application, the housing includes a shell and an end cap, the shell having an opening, the end cap being connected to the shell and closing the opening, the end cap and the shell being connected to form a first connecting portion, and the first insulating film covering the first connecting portion.

[0042] In the above solution, the first connection formed by the end cap and the housing is a relatively weak point of the housing. When the battery cell is impacted, the electrolyte in the housing is prone to leaking through the first connection. Therefore, by covering the first connection with a first insulating film, the first connection is protected, reducing the risk of electrolyte leakage and improving battery reliability.

[0043] According to some embodiments of the present application, the first insulating film includes a first sub-insulating film and a second sub-insulating film, wherein the first sub-insulating film covers at least a portion of an outer surface of the end cap, and the second sub-insulating film covers at least a portion of an outer surface of the housing. The second sub-insulating film is connected to the second portion via the adhesive layer to form a second connecting portion, and the second connecting portion is arranged along the circumference of the opening.

[0044] In the above scheme, the second sub-insulating film is connected to the second part through the adhesive layer to form a second connecting portion, and the second connecting portion is arranged to be arranged along the circumference of the opening. On the one hand, it can reduce the risk of the portion of the first insulating film corresponding to the second connecting portion being detached from the shell; on the other hand, the second connecting portion cooperates with the first sub-insulating film of the first insulating film, which can enable the first insulating film to hold the portion from the first connecting portion to the end cover, reducing the risk of electrolyte leaking from the first connecting portion leaking outside the first insulating film and affecting objects outside the battery cell (for example, adjacent battery cells, other components or the external environment), so that the battery has higher reliability.

[0045] According to some embodiments of the present application, the battery cell further includes an electrode terminal, the electrode terminal being mounted on the housing, the first insulating film having a first through-hole for exposing the electrode terminal, the first insulating film being connected to the second portion via the adhesive layer to form a third connecting portion, and the third connecting portion being disposed around the electrode terminal.

[0046] In the above scheme, on the one hand, by setting the first through hole on the first insulating film, the electrode terminal can be exposed to realize the output and input of electrical energy of the battery cell. On the other hand, the first insulating film is connected to the second part through the adhesive layer to form a third connection part, thereby improving the connection strength between the insulating film corresponding to the electrode terminal and the shell, effectively protecting the part of the shell where the electrode terminal is installed, reducing the risk of electrolyte leakage from the part of the shell where the electrode terminal is installed, or reducing the risk of electrolyte leaked from other parts (electrolyte leaked from other parts of the shell or electrolyte leaked from other battery cells) entering the interior of the battery cell from the part of the shell where the electrode terminal is installed, causing the battery cell to short-circuit, so that the battery has higher reliability.

[0047] According to some embodiments of the present application, a protrusion is provided on the outer surface of the housing, the protrusion is provided around the electrode terminal, and the protrusion is exposed from the first through hole.

[0048] In the above solution, the protrusions are provided, and the protrusions are arranged around the electrode terminals to protect the electrode terminals and block the flow of electrolyte. This reduces the risk of electrolyte leaking from areas of the housing not where the electrode terminals are mounted and affecting the electrode terminals, potentially leading to a short circuit in the battery cell, thereby improving battery reliability. In some embodiments, when the battery cell is inverted, or when the electrode terminals are relatively close to the ground, the protrusions cause the electrolyte to drip along the protrusions toward the ground under the action of gravity, reducing the risk of electrolyte affecting the electrode terminals.

[0049] According to some embodiments of the present application, the third connection portion is arranged along the circumference of the protrusion and is located on the outside of the protrusion.

[0050] In the above solution, the third connection portion is located outside the protrusion, that is, the third portion does not interfere with the protrusion, which effectively reduces the difficulty of connecting the second portion, the glue layer and the first insulating film and improves the manufacturing efficiency of the battery cell.

[0051] According to some embodiments of the present application, the battery cell further includes a pressure relief portion, the pressure relief portion being disposed on the housing and covered by the first insulating film. The first insulating film is connected to the second portion via the adhesive layer to form a fourth connecting portion, the fourth connecting portion being disposed around the pressure relief portion.

[0052] In the above solution, the first insulating film covers the pressure relief part, and the first insulating film is connected to the second part through the adhesive layer to form a fourth connecting part. The fourth connecting part is arranged around the pressure relief part, which can reduce the risk of the insulating film corresponding to the pressure relief part being detached from the outer shell, thereby reducing the risk of electrolyte leakage from the part of the outer shell where the pressure relief part is set, or reducing the risk of electrolyte leaking from the part of the outer shell where the pressure relief part is set to leak outside the insulating film, so that the battery has higher reliability.

[0053] According to some embodiments of the present application, the housing is provided with a liquid injection hole, the battery cell further includes a sealing member that seals the liquid injection hole, and the first insulating film covers the sealing member. The insulating film is connected to the second portion via the adhesive layer to form a fifth connecting portion, and the fifth connecting portion is provided around the liquid injection hole.

[0054] In the above solution, the first insulating film covers the sealing part, and the insulating film is connected to the second part through the adhesive layer to form a fifth connecting part. The fifth connecting part is arranged around the pressure relief part, which can reduce the risk of the insulating film corresponding to the sealing part being detached from the shell, thereby reducing the risk of electrolyte leakage from the part where the sealing part is installed on the shell, or reducing the risk of electrolyte leaking from the part where the sealing case is installed on the shell leaking out of the insulating film, so that the battery has higher reliability.

[0055] In a second aspect, the present application further provides a battery, comprising the battery cell described in any one of the first aspects.

[0056] In a second aspect, the present application further provides an electrical device, which includes the battery described in any one of the second aspect or the battery cell described in any one of the first aspect.

[0057] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0059] FIG1 is a schematic diagram of a vehicle in some embodiments of the present application;

[0060] FIG2 is an exploded perspective view of a battery in some embodiments of the present application;

[0061] FIG3 is a schematic diagram of a battery cell in some embodiments of the present application;

[0062] FIG4 is a perspective exploded view of a battery cell with the first insulating film hidden in some embodiments of the present application;

[0063] FIG5 is a schematic diagram of the first portion, the second portion, the adhesive layer, and the first insulating film in some embodiments of the present application;

[0064] FIG6 is a schematic diagram of the interior of a battery cell in some embodiments of the present application;

[0065] FIG7 is an enlarged view of point A in FIG6;

[0066] FIG8 is an enlarged view of point B in FIG6;

[0067] FIG9 is a schematic diagram of a battery cell in some other embodiments of the present application;

[0068] FIG10 is a schematic diagram of the first portion, the second portion, the adhesive layer, the first insulating film, and the second insulating film in some embodiments of the present application.

[0069] Icons: 10-battery cell; 11a-electrode assembly; 11-shell; 110-first part; 111-second part; 112-shell; 1120-opening; 113-end cover; 114-liquid injection hole; 12-first insulating film; 120-first sub-insulating film; 121-second sub-insulating film; 122-first through hole; 13-glue layer; 14-electrode terminal; 15-protrusion; 16-pressure relief part; 17-sealing piece; 18-second insulating film; 21-first connecting part; 22-second connecting part; 23-third connecting part; 24-fourth connecting part; 25-fifth connecting part; 1000-vehicle; 200-controller; 300-motor; 100-battery; 30-case; 31-upper case; 32-lower case. DETAILED DESCRIPTION

[0070] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0071] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0072] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0073] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0074] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0075] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0076] The term "plurality" used in this application refers to two or more (including two).

[0077] In this application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, and the embodiments of this application are not limited thereto. Battery cells may be cylindrical, flat, rectangular, or in other shapes, and the embodiments of this application are not limited thereto.

[0078] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. A battery generally includes a housing that encloses one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0079] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The portion of the positive electrode collector not coated with the positive active material layer protrudes from the portion coated with the positive active material layer. The portion of the positive electrode collector not coated with the positive active material layer serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The portion of the negative electrode collector not coated with the negative active material layer protrudes from the portion coated with the negative active material layer. The portion of the negative electrode collector not coated with the negative active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative active material can be carbon or silicon, among others. To ensure high current flow without melting, multiple positive tabs are stacked together, and multiple negative tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene). Furthermore, the electrode assembly can be a wound or laminated structure, but the present invention is not limited thereto.

[0080] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0081] The development of battery technology must consider many design factors at the same time, such as battery life, energy density, discharge capacity, charge and discharge rate and other performance parameters. In addition, the reliability of the battery also needs to be considered. However, the reliability of current batteries is poor. The battery cell includes an outer shell and an insulating film. The insulating film is connected to the outer surface of the outer shell by an adhesive layer to protect the outer shell. On the one hand, it reduces the risk of damage to the outer shell by foreign objects, and on the other hand, it can reduce the risk of electrolyte leakage in the outer shell. However, the outer shell is generally a metal shell with low surface energy, such as an aluminum shell. Due to the low surface energy of aluminum, the adhesion between the outer shell and the adhesive layer is low, resulting in a low connection strength between the insulating film and the outer shell. The risk of the insulating film detaching from the outer shell is relatively high, which in turn leads to low reliability of the battery.

[0082] In view of this, in order to solve the problem that the insulating film is easily separated from the shell, resulting in low battery reliability, some embodiments of the present application design a battery cell, which includes a shell, an insulating film and an adhesive layer. The shell includes a first part and a second part that are connected. The first part can be regarded as a part of the current shell, and the second part can be regarded as a part formed by processing the shell based on the first part. The surface energy of the outer surface of the second part is higher than the surface energy of the outer surface of the first part. The insulating film covers at least a part of the shell to protect and safeguard the at least part. The adhesive layer is provided between the second part and the insulating film to connect the insulating film and the second part.

[0083] Compared with the solution in which the insulating film is directly connected to the first part with smaller surface energy (such as when the outer shell is an aluminum shell, the first part is aluminum) through the adhesive layer, in the above solution, the outer shell includes a first part with lower surface energy and a second part with larger surface energy. On the one hand, the first part is retained and the second part is additionally formed to control the manufacturing cost of the outer shell; on the other hand, the provision of the first part can effectively protect the electrode assembly and electrolyte inside the battery cell; on the other hand, since the second part has a high adhesion force with the adhesive layer, the connection strength between the insulating film and the outer shell can be improved, and the risk of the insulating film falling off can be reduced, so that the battery has higher reliability.

[0084] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0085] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, among others. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, among others; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, among others; and electric tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, among others. The embodiments of the present application do not impose any particular restrictions on the above-mentioned electrical devices.

[0086] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle 1000 as an example.

[0087] Please refer to Figure 1, which is a schematic diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0088] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000 , but also as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

[0089] Please refer to Figure 2, which is a perspective exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 30 and battery cells 10, with the battery cells 10 housed within the housing 30. The housing 30 is used to provide a storage space for the battery cells 10 and can have various structures. In some embodiments, the housing 30 can include an upper housing 31 and a lower housing 32, with the upper housing 31 and the lower housing 32 overlapping each other, and together defining a storage space for the battery cells 10. The lower housing 32 can be a hollow structure with one end open, and the upper housing 31 can be a plate-like structure, with the upper housing 31 overlapping the open side of the lower housing 32, so that the upper housing 31 and the lower housing 32 jointly define a storage space. Alternatively, both the upper housing 31 and the lower housing 32 can be hollow structures with one end open, with the open side of the upper housing 31 overlapping the open side of the lower housing 32. Of course, the box body 30 formed by the upper box body 31 and the lower box body 32 can be in various shapes, such as a cylinder, a cuboid, etc.

[0090] In the battery 100, there may be multiple battery cells 10, and the multiple battery cells 10 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 10. The multiple battery cells 10 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 100 may be housed within the housing 30. Of course, the battery 100 may also be in the form of a battery module 100, in which multiple battery cells 10 are first connected in series, in parallel, or in a hybrid connection, and then the multiple battery modules 100 are further connected in series, in parallel, or in a hybrid connection to form an entire battery 100, and then housed within the housing 30. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for electrically connecting the multiple battery cells 10.

[0091] Each battery cell 10 may be a secondary battery cell or a primary battery cell; it may also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 10 may be cylindrical, flat, rectangular, or in other shapes.

[0092] According to some embodiments of the present application, a battery cell 10 is provided, please refer to Figures 3 to 5. Figure 3 is a schematic diagram of the battery cell 10 in some embodiments of the present application, Figure 4 is a three-dimensional exploded view of the battery cell 10 in some embodiments of the present application in which the first insulating film 12 is hidden, and Figure 5 is a schematic diagram of the first part 110, the second part 111, the glue layer 13 and the first insulating film 12 in some embodiments of the present application.

[0093] The battery cell 10 includes a housing 11, a first insulating film 12, and an adhesive layer 13. The housing 11 includes a first portion 110 and a second portion 111. The surface energy of the outer surface of the second portion 111 is greater than the surface energy of the outer surface of the first portion 110. The first insulating film 12 covers at least a portion of the housing 11. The adhesive layer 13 is disposed between the second portion 111 and the first insulating film 12 to connect the first insulating film 12 and the second portion 111.

[0094] The housing 11 is a component having an internal chamber for accommodating the electrode assembly 11a and the electrolyte. In some embodiments, the housing 11 may be a metal housing, which may be made of a metal material such as aluminum, an aluminum alloy, or copper. In other embodiments, the housing 11 may be a non-metallic housing, which may be made of materials such as organic glass and polystyrene.

[0095] The first part 110 and the second part 111 are connected, which may mean that the edges of the first part 110 and the second part 111 are connected to each other, for example, the first part 110 and the second part 111 are stacked along the thickness direction of the shell; for another example, the first part 110 and the second part 111 are arranged in sequence along the height direction or the width direction of the shell; for another example, the second part 111 is surrounded by the first part 110; for another example, the first part 110 surrounds the second part 111; for another example, the second part 111 and the first part 110 are arranged crosswise.

[0096] In some embodiments, the housing may include two end walls disposed opposite each other along its height, and the first portion 110 and / or the second portion 111 may be disposed on the two end walls. The housing may include side walls surrounding the two opposing end walls, and the first portion and / or the second portion may be disposed on the side walls. The second portion 111 may be disposed on at least one of the two end walls and the side walls of the housing.

[0097] The surface energy of the outer surface of the second portion 111 is greater than the surface energy of the outer surface of the first portion 110, which may mean that the adhesive strength of the outer surface of the second portion 111 is greater than the adhesive strength of the outer surface of the first portion 110. In some embodiments, the surface energy of a portion can be regarded as the adhesive strength between the portion and the adhesive layer 13, which can be measured using a peel test method, such as a peel tester, and the unit of surface energy can be N / m.

[0098] The outer surface of the second portion 111 may refer to the surface of the second portion 111 facing away from the interior of the housing, and may be connected to the first insulating film 12 via the adhesive layer 13. The outer surface of the first portion 110 may refer to the surface of the first portion 110 facing away from the interior of the housing. In some implementations, the second portion 111 may cover the outer surface of the first portion 110. In other embodiments, the second portion 111 may expose at least a portion of the outer surface of the first portion 110.

[0099] In some embodiments, the second part 111 can be formed on the surface of the first part 110. For example, the second part 111 is formed on the surface of the first part 110 by mechanical surface treatment, such as sandblasting, shot blasting, grinding, tumbling, polishing, brushing, spraying or painting. For another example, the second part 111 is formed on the surface of the first part 110 by chemical surface treatment, such as bluing and blackening, phosphating, pickling, chemical plating of various metals and alloys, chemical oxidation, etc. For another example, the second part 111 is formed on the surface of the first part 110 by electrochemical surface treatment, such as anodizing, electrochemical polishing, electroplating, etc. For another example, the second part 111 is formed on the surface of the first part 110 by modern surface treatment, such as chemical vapor deposition, physical vapor deposition, ion implantation, ion plating, laser surface treatment, etc.

[0100] In some embodiments, when the second portion 111 and the first portion 110 are made of different materials, they can be connected to each other by riveting, welding, or other processes to form a shell capable of accommodating the electrode assembly and the electrolyte.

[0101] First insulating film 12 is a membrane-like component with insulating properties that can cover at least a portion of housing 11 or the entire housing 11 to shield and protect housing 11 and reduce the risk of damage to the outer surface of housing 11 caused by foreign objects. In some embodiments, technicians refer to the first insulating member as a blue film.

[0102] Adhesive layer 13 is a component disposed between second portion 111 and first insulating film 12. It is adhesive and can bond to second portion 111. In some embodiments, when the outer surface of second portion 111 is the outer surface of housing 11, that is, the outer surface of housing 11 is entirely second portion 111, adhesive layer 13 may connect the entire outer surface of housing 11 or a portion thereof. In some embodiments, when the outer surface of housing 11 is composed of the outer surface of second portion 111 and the outer surface of first portion 110, adhesive layer 13 may connect the entire outer surface of housing 11, the entire outer surface of second portion 111, or a portion thereof.

[0103] Compared with the solution in which the first insulating film 12 is directly connected to the first part 110 with smaller surface energy (for example, when the outer shell is an aluminum shell, the first part 110 is aluminum) through the adhesive layer 13, in the above solution, the outer shell 11 includes the first part 110 with lower surface energy and the second part 111 with larger surface energy. On the one hand, the first part 110 is retained and the second part 111 is additionally formed to control the manufacturing cost of the outer shell 11; on the other hand, the provision of the first part 110 can effectively protect the electrode assembly and electrolyte inside the battery cell 10; on the other hand, since the second part 111 has a higher adhesion force with the adhesive layer 13, the risk of the first insulating film 12 falling off due to the low adhesion force between the adhesive layer 13 and the outer shell 11 is reduced, thereby improving the reliability of the battery 100.

[0104] According to some embodiments of the present application, the surface energy of the outer surface of the second portion 111 is p, satisfying p>421 N / m.

[0105] In some embodiments, when the outer shell is an aluminum shell, that is, a conventional aluminum shell, its surface energy, that is, the adhesion between it and the adhesive layer 13 can be measured by a peel test method, such as by a peel tester, and the measured value is 421N / m. Therefore, for the current conventional aluminum shell, by setting a second part with a surface energy p greater than 421N / m on the conventional aluminum shell, the problem of low adhesion between the outer shell and the adhesive layer can be improved.

[0106] In the above scheme, at present, the surface energy of the outer surface of the shell of some battery cells is 421N / m, and the adhesion between it and the glue layer 13 is relatively low. Therefore, in order to improve the adhesion between the glue layer 13 and the shell 11, a second part 111 with an outer surface surface energy greater than 46N / m is formed on the shell 11. This can effectively improve the problem of low adhesion between the shell 11 and the glue layer 13, reduce the risk of the first insulating film 12 falling off due to insufficient adhesion between the glue layer 13 and the shell 11, and thereby improve the reliability of the battery.

[0107] According to some embodiments of the present application, 500 N / m≤p≤1500 N / m is satisfied.

[0108] For conventional aluminum shells, the low adhesion between the outer shell 11 and the adhesive layer 13 can be improved by providing a second portion 111 having a surface energy p greater than 421 N / m. To further improve the adhesion between the outer shell 11 and the adhesive layer 13, the second portion 111 can be made of a material or structure with a surface energy between 500 N / m and 1000 N / m.

[0109] In the above scheme, on the one hand, forming the second part 111 on the outer surface of the outer shell 11 with a surface energy greater than 500N / m can effectively improve the problem of low adhesion between the outer shell 11 and the glue layer 13, and reduce the risk of the first insulating film 12 falling off due to insufficient adhesion between the glue layer and the outer shell, thereby improving the reliability of the battery. On the other hand, limiting the surface energy of the second part 111 to no more than 1500N / m can effectively reduce the additional manufacturing cost of the outer shell 11 due to the increase in surface energy, thereby controlling the manufacturing cost of the battery.

[0110] According to some embodiments of the present application, the first portion 110 is a first metal layer, and the second portion 111 is an oxide layer.

[0111] In some embodiments, when the housing 11 is made of aluminum, the first portion 110 may be an aluminum layer, and the second portion 111 may be an oxide layer formed on the outer surface of the first portion 110, such as aluminum oxide, chromium oxide, or nickel oxide.

[0112] In some embodiments, the surface of the oxide layer can be porous, so the connection area between the adhesive layer 13 and the second portion 111 is larger, which can improve the adhesion between the second portion 111 and the adhesive layer 13. The first insulating film 12 is connected to the housing 11 by connecting to the adhesive layer 13.

[0113] In the above scheme, the first part 110 of the shell 11 is a first metal layer, and the second part 111 can be an oxide layer. The surface energy of the oxide layer is greater than the surface energy of the metal layer. The adhesive layer 13 can be effectively connected to the surface of the second part 111. To this end, by arranging the adhesive layer 13 between the first insulating film 12 and the second part 111, the connection stability between the first insulating film 12 and the shell 11 can be effectively improved, thereby improving the reliability of the battery.

[0114] According to some embodiments of the present application, the oxide layer is formed on an outer surface of the first metal layer.

[0115] In the above scheme, an oxide layer can be efficiently formed on the outer surface of the first metal layer by chemical surface treatment, such as chemical oxidation, or by electrochemical surface treatment, such as anodization, electroplating, etc., so that the outer shell 11 has a higher manufacturing efficiency, thereby improving the manufacturing efficiency of the battery.

[0116] According to some embodiments of the present application, the second portion 111 is chromium oxide or nickel oxide.

[0117] In some embodiments, chromium oxide or nickel oxide may be formed on the first portion 110 by electroplating, sputtering, or the like.

[0118] The above solution is that, in some embodiments, the second portion 111 is chromium oxide. On the one hand, it can effectively improve the adhesion between the outer shell 11 and the glue layer 13, thereby improving the connection strength between the outer shell 11 and the first insulating film 12, and reducing the risk of the first insulating film 12 falling off. On the other hand, chromium oxide can improve the corrosion resistance of the outer shell 11. Therefore, the second portion 111 is chromium oxide, which can make the battery 100 have higher reliability. In some embodiments, the second portion 111 is nickel oxide. On the one hand, it can effectively improve the adhesion between the outer shell 11 and the glue layer 13, thereby improving the connection strength between the outer shell 11 and the first insulating film 12, and reducing the risk of the first insulating film 12 falling off. On the other hand, nickel oxide has good insulation properties, which can reduce the risk of internal short circuits in the battery cell 10. Therefore, the second portion 111 is nickel oxide, which can make the battery 100 have higher reliability.

[0119] According to some embodiments of the present application, the first portion 110 is aluminum, and the second portion 111 is aluminum oxide.

[0120] In some embodiments, aluminum oxide may be formed on the surface of the first portion 110 through an anodizing process.

[0121] In the above solution, the first portion 110 is aluminum and the second portion 111 is alumina, so that the second portion 111 can be formed on the first portion 110 at a lower cost, thereby reducing the manufacturing cost of the battery cell 10 and further reducing the manufacturing cost of the battery 100.

[0122] According to some embodiments of the present application, referring to FIG. 5 , the thickness of the second portion 111 is M, satisfying 18 um ≤ M ≤ 100 um.

[0123] In some embodiments, the thickness M of the second portion 111 may be 18um, 19um, 20um, 21um...97um, 98um, 99um, 100um.

[0124] In the above scheme, if the thickness of the second part 111 is too small, such as less than 18um, the adhesion force between the glue layer 13 and the second part 111 will be small, which will increase the risk of the first insulating film 12 falling off; if the thickness of the second part 111 is too large, such as greater than 100um, the volume of the shell 11 will increase, affecting the volume energy density of the battery cell 10. For this reason, some embodiments of the present application limit the thickness M of the second part 111 to between 18um and 100um, which can ensure that there is a greater adhesion force between the glue layer 13 and the second part 111, which makes the battery cell 10 have a higher volume energy density, and thus makes the battery 100 have higher reliability.

[0125] According to some embodiments of the present application, the surface where the second portion 111 is connected to the adhesive layer 13 is a concave-convex surface.

[0126] In some embodiments, the outer surface of the second portion 111 may be a concave-convex surface, such as providing a print on the outer surface of the second portion 111 to make the outer surface of the second portion 111 uneven, thereby increasing the surface area of ​​the outer surface of the second portion 111 .

[0127] In the above solution, by setting the surface where the second part 111 contacts the adhesive layer 13 to a concave-convex surface, the effective area between the adhesive layer 13 and the second part 111 can be increased, thereby increasing the adhesion between the adhesive layer 13 and the second part 111 and improving the connection strength between the first insulating film 12 and the outer shell 11, so that the battery 100 has higher reliability.

[0128] According to some embodiments of the present application, the first portion is a second metal layer, and the second portion is a third metal layer.

[0129] In some embodiments, when the housing 11 is made of aluminum, the first portion 110 may be an aluminum layer, and the second portion 111 may be a metal layer having a surface energy greater than that of aluminum, for example, the second portion may be an iron layer.

[0130] In some embodiments, the first part 110 and the second part 111 can be welded to each other, and the surfaces of the two are flush; or a groove is set on the surface of the first part 110 so that the second part 111 is embedded in the groove, so that the surfaces of the two are on the same plane; or, the second part 111 is directly set, such as welded to the surface of the first part 110.

[0131] In the above scheme, in some embodiments, the material of the outer shell 11 of the battery cell 10, that is, the material of the first part 110 can be made of aluminum or other metal materials with low surface energy. In order to improve the stability between the first insulating film 12 and the outer shell 11 in some embodiments, a metal material with higher surface energy can be provided. For example, the surface energy of iron is higher than that of aluminum. To this end, the material of the second part 111 can be iron or other metal materials with higher surface energy than aluminum to improve the connection strength between the first insulating film 12 and the outer shell 11, so that the battery has higher reliability.

[0132] According to some embodiments of the present application, the first portion 110 is a non-metal layer, and the second portion 111 is a fourth metal layer and / or an oxide layer.

[0133] In some embodiments, the main body of the housing 11 can be made of a non-metallic material, that is, the first portion 110 can be a non-metallic layer, for example, a layer of organic glass or a polypropylene layer. Taking organic glass as an example, the main portion of the housing 11 is made of organic glass, and a groove structure is provided on the surface of the organic glass to accommodate the second portion 111 with a higher surface energy. The second portion 111 can be a fourth metal layer, such as an iron layer, or an oxide layer, such as an aluminum oxide layer, disposed in the groove. To enhance the connection stability between the second portion 111 and the first portion 110, the groove can be filled with an adhesive.

[0134] In the above scheme, in order to reduce the manufacturing cost of the battery, the shell 11 of the battery cell 10 can be made of non-metallic materials, that is, the first part 110 of the shell 11 can be a non-metallic layer, and its material includes but is not limited to organic glass or polystyrene, etc., and the surface energy of the non-metallic layer is low. For this reason, a second part 111 can be provided, and the second part 111 can be a fourth metal layer or an oxide layer with a larger surface energy to improve the problem of low adhesion between the first part 110 and the glue layer 13, reduce the risk of the first insulating film 12 falling off due to insufficient adhesion between the glue layer 13 and the shell 11, and thereby improve the reliability of the battery.

[0135] According to some embodiments of the present application, along the thickness direction of the housing 11, the outer surface of the second portion 111 is higher than the outer surface of the first portion 110. Alternatively, according to other embodiments of the present application, the outer surface of the second portion 111 is flush with the outer surface of the first portion 110. Alternatively, according to other embodiments of the present application, the outer surface of the second portion 111 is lower than the outer surface of the first portion 110.

[0136] In some embodiments, the first part 110 can be the main part of the shell 11. Combined with Figure 5, along the thickness direction of the shell 11, the second part 111 can be directly arranged on the outer surface of the first part 110, so that on the same surface of the shell 11, the outer surface of the second part 111 is higher than the outer surface of the first part 110. For example, the second part 111 can be an aluminum oxide layer formed on a conventional aluminum shell.

[0137] In some embodiments, the first part 110 can be the main part of the shell 11, and a groove can be formed on the surface of the first part 110 along the thickness direction of the shell 11, and the second part 111 can be directly arranged in the groove, so that on the same surface of the shell 11, the outer surface of the second part 111 is flush with the outer surface of the non-groove part of the first part 110. For example, the second part 111 can be an aluminum oxide layer formed in a groove set on a conventional aluminum shell.

[0138] In some embodiments, the first part 110 can be the main part of the shell 11, and a groove can be formed on the surface of the first part 110 along the thickness direction of the shell 11, and the second part 111 can be directly arranged in the groove, so that on the same surface of the shell 11, the outer surface of the second part 111 is lower than the outer surface of the first part 110. For example, the second part 111 can be an aluminum oxide layer formed in a groove set on a conventional aluminum shell, and the groove is deeper, or the aluminum oxide layer is thinner.

[0139] In the above scheme, in some embodiments, the outer surface of the second portion 111 is higher than the outer surface of the first portion 110 to facilitate connection with the adhesive layer 13, thereby facilitating assembly of the first insulating film 12. In some embodiments, the outer surface of the second portion 111 can be flush with the outer surface of the first portion 110, thereby minimizing the degree to which the connection between the first insulating film 12, the adhesive layer 13, and the second portion 111 protrudes from the overall outer contour of the battery cell 10, thereby improving the smoothness of the outer contour of the battery cell 10. In some embodiments, the outer surface of the second portion 111 can be lower than the outer surface of the first portion 110, thereby effectively reducing the degree to which the connection between the first insulating film 12, the adhesive layer 13, and the second portion 111 protrudes from the overall outer contour of the battery cell 10, thereby improving the smoothness of the outer contour of the battery cell 10.

[0140] According to some embodiments of the present application, the melting point of the glue layer 13 is P1, the melting point of the first insulating film 12 is P2, and |P1-P2|≤30, in degrees Celsius.

[0141] |P1-P2| can refer to the absolute value of P1 minus P2.

[0142] In some embodiments, the material of the adhesive layer 13 may be MPP adhesive. MPP adhesive may refer to a component made of polypropylene microporous foam material. The full name of MPP may be Microcellular Polypropylene Foam.

[0143] In the above embodiment, the difference between the melting point P1 of the adhesive layer 13 and the melting point P2 of the first insulating film 12 is 30°C, that is, the two have similar melting points, for example, the difference is 1°C, 2°C, 3°C...28°C, 29°C, 30°C, which facilitates the connection between the two. In some embodiments, the adhesive layer 13 and the first insulating film 12 can be connected by heat fusion. Due to the similar melting points, the adhesive layer 13 and the first insulating film 12 can be heat fused to each other more easily, reducing the difficulty of connecting the adhesive layer 13 and the first insulating film 12, improving the connection strength between the adhesive layer 13 and the first insulating film 12, reducing the risk of the first insulating film 12 falling off, and making the battery 100 more reliable.

[0144] In some other embodiments, the difference between the melting point P1 of the glue layer 13 and the melting point P2 of the first insulating film 12 is 31° C., 32° C., or 33° C., etc.

[0145] According to some embodiments of the present application, the first insulating film 12 is connected to the adhesive layer 13 by thermal melting.

[0146] In some embodiments, the first insulating film 12 can be connected to the adhesive layer 13 by hot-melt bonding. In other embodiments, the first insulating film 12 can also be connected to the adhesive layer 13 by adhesive bonding. In other embodiments, the first insulating film 12 is hot-melt bonded to the adhesive layer 13 at a location corresponding to the second portion 111, and the first insulating film 12 can be adhesively bonded to the adhesive layer 13 at other locations.

[0147] In some embodiments, when not mounted on the outer shell 11 of the battery cell 10, the first insulating film 12 can be a flat sheet-like structure, folded over to cover the outer shell 11. The first insulating film 12 can be heat-fused to the adhesive layer 13 at the location corresponding to the second portion 111. Referring to Figure 9 , the hatched portion in Figure 9 may be the area of ​​the second portion 111, i.e., the location where the first insulating film 12 is heat-fused to the adhesive layer 13. In Figure 9 , the hatched portion may refer to the second connecting portion 22, the third connecting portion 23, the fourth connecting portion 24, and the fifth connecting portion 25.

[0148] In the above solution, the first insulating film 12 is connected to the adhesive layer 13 by hot melt, which can improve the connection strength between the adhesive layer 13 and the first insulating film 12 and reduce the risk of the first insulating film 12 falling off, so that the battery 100 has higher reliability.

[0149] According to some embodiments of the present application, the battery cell 10 also includes a second insulating film 18 (as shown in Figure 10, Figure 10 is a schematic diagram of the first part 110, the second part 111, the glue layer 13, the first insulating film 12 and the second insulating film 18 in some embodiments of the present application), and the second insulating film 18 is connected to the surface of the first insulating film 12 facing away from the glue layer 13.

[0150] In some embodiments, the first insulating film 12 and the second insulating film 18 may be made of the same material. In other embodiments, the first insulating film 12 and the second insulating film 18 may be made of different materials.

[0151] In the above solution, by providing the second insulating film 18 on the outer surface of the first insulating film 12 , the outer shell 11 can be further protected, so that the battery 100 has higher reliability.

[0152] According to some embodiments of the present application, the first insulating film 12 and the second insulating film 18 are connected by thermal fusion.

[0153] In the above scheme, the first insulating film 12 and the second insulating film 18 are connected by hot melting. On the one hand, it can reduce the difficulty of connecting the first insulating film 12 and the second insulating film 18. On the other hand, it can improve the connection strength between the first insulating film 12 and the second insulating film 18, reduce the risk of the second insulating film 18 falling off, and make the battery 100 have higher reliability.

[0154] According to some embodiments of the present application, please refer to Figures 6 and 7. Figure 6 is an internal schematic diagram of the battery cell 10 in some embodiments of the present application, and Figure 7 is an enlarged view of point A in Figure 6.

[0155] The housing 11 includes a shell 112 and an end cap 113 . The shell 112 has an opening 1120 . The end cap 113 is connected to the shell 112 and closes the opening 1120 . The end cap 113 and the shell 112 are connected to form a first connecting portion 21 . The first insulating film 12 covers the first connecting portion 21 .

[0156] In some embodiments, the housing 112 and the end cap 113 can be two independent components. The end cap 113 and the end cap 113 are connected to each other to form a first connection portion 21, so that the end cap 113 can seal the opening 1120 of the housing 112, reducing the risk of foreign objects affecting the interior of the housing 11. In some embodiments, the end cap 113 can be connected to the housing 112 by welding, that is, the first connection portion 21 can be a weld. In other embodiments, the end cap 113 can be connected to the housing 112 by bonding, in which case the first connection portion 21 can be an adhesive component.

[0157] The first insulating film 12 covers the first connecting portion 21 , which may mean that the first connecting portion 21 is not exposed to the outside world. The first insulating film 12 isolates the outside world from the first connecting portion 21 to protect the first insulating film 12 .

[0158] In the above embodiment, the outer shell 11 includes a housing 112 and an end cap 113. The first connection portion 21 formed by the connection between the end cap 113 and the housing 112 is a relatively weak point of the outer shell 11. When the battery cell 10 is impacted, the electrolyte within the outer shell 11 is prone to leaking through the first connection portion 21. Therefore, by covering the first connection portion 21 with the first insulating film 12, the first connection portion 21 is protected, reducing the risk of electrolyte leakage and ensuring higher reliability of the battery 100.

[0159] According to some embodiments of the present application, as shown in FIG3 , first insulating film 12 includes a first sub-insulating film 120 and a second sub-insulating film 121. First sub-insulating film 120 covers at least a portion of the outer surface of end cap 113, and second sub-insulating film 121 covers at least a portion of the outer surface of housing 112. Second sub-insulating film 121 is connected to second portion 111 via adhesive layer 13 to form a second connecting portion 22. Second connecting portion 22 is arranged along the circumference of opening 1120.

[0160] In some implementations, the first sub-insulating film 120 and the second sub-insulating film 121 may be connected to each other. The first sub-insulating film 120 may be a portion of the first insulating film 12, which covers at least a portion of the outer surface of the end cap 113. For example, when the end cap 113 is mounted with an electrode terminal 14 (a component of the battery cell 10 used to output and input electrical energy, also referred to as a terminal by technicians in some embodiments), this portion of the first insulating film 12 does not cover the portion of the end cap 113 where the electrode terminal 14 is mounted.

[0161] The second sub-insulating film 121 may be a portion of the first insulating film 12 that covers at least a portion of the outer surface of the housing 11. In some embodiments, the second sub-insulating film 121 may cover the entire outer surface of the housing 11.

[0162] The second connecting portion 22 is formed by connecting the second sub-insulating film 121 to the second portion 111 via the adhesive layer 13. It is arranged along the circumference of the opening 1120. In some embodiments, the second connecting portion 22 can surround the first connecting portion 21. Referring to Figures 3 and 7, the first connecting portion 21 is located between the inner side of the housing 11 and the outer side of the end cap 113. The second connecting portion 22 is located outside the housing 11 and is annular.

[0163] In some embodiments, referring to FIG3 , the area indicated by the second connecting portion 22 and the remaining areas marked with fill lines in FIG3 may refer to areas where the second portion 111 is located, and the remaining blank areas may refer to areas where the second portion 111 is not provided. In other embodiments, the second portion 111 may be provided on all outer surfaces of the housing 112.

[0164] In the above scheme, the second sub-insulating film 121 is connected to the second part 111 through the adhesive layer 13 to form a second connecting portion 22, and the second connecting portion 22 is arranged to be arranged along the circumference of the opening 1120, which can reduce the risk of the first insulating film 12 at the corresponding position being separated from the shell 112. In conjunction with the first sub-insulating film 120 of the first insulating film 12, it can reduce the risk of the electrolyte leaking from the first connecting portion 21 leaking outside the first insulating film 12 and affecting objects outside the battery cell 10 (for example, adjacent battery cells 10, other components or the external environment), so that the battery 100 has higher reliability.

[0165] According to some embodiments of the present application, see Figures 3 and 4 . Battery cell 10 further includes an electrode terminal 14 mounted on housing 11. First insulating film 12 has a first through-hole 122 that exposes electrode terminal 14. First insulating film 12 is connected to second portion 111 via adhesive layer 13 to form a third connecting portion 23. Third connecting portion 23 surrounds electrode terminal 14.

[0166] The electrode terminal 14 is a component installed on the housing 11, which can realize the input and output of electrical energy. In some embodiments, technicians also refer to the electrode terminal 14 as a pole. When the polarity of the electrode terminal 14 is positive, it is a positive pole, and when the polarity of the electrode terminal 14 is negative, it is a negative pole. The positive pole and the negative pole can be installed on the same wall of the housing 11, or on different walls of the housing 11. In some embodiments, the wall of the housing 11 forms a through hole, and the electrode terminal 14 is inserted into the through hole and installed on the housing 11 by riveting or other methods. In some embodiments, the electrode terminal 14 is installed on the end cover 113 of the housing 11.

[0167] The first insulating film 12 is provided with a first through hole 122. The first through hole 122 can expose the electrode terminal 14 to the outside, so that the electrode terminal 14 can be electrically connected to external components to achieve the input and output of electrical energy. In some embodiments, when there are two electrode terminals 14, the first insulating film 12 is also provided with two corresponding first through holes 122.

[0168] The third connecting portion 23 is formed by connecting the first insulating film 12 to the second portion 111 via the adhesive layer 13. It is located around the first through-hole 122 and arranged along the circumference of the electrode terminal 14. In conjunction with some of the embodiments provided above, the third connecting portion 23 can be formed by connecting the first sub-insulating film 120 to the second portion 111 via the adhesive layer 13.

[0169] In some embodiments, referring to FIG3 , the portion indicated by the third connecting portion 23 and the remaining portions indicated by fill lines in FIG3 may refer to the portion where the second portion 111 is located, and the remaining blank portions may refer to portions where the second portion 111 is not provided. In other embodiments, the second portion 111 may be provided on all outer surfaces of the housing 112.

[0170] In the above scheme, on the one hand, by setting the first through hole 122 on the first insulating film 12, the electrode terminal 14 can be exposed to realize the output and input of electrical energy of the battery cell 10. On the other hand, the first insulating film 12 is connected to the second part 111 through the glue layer 13 to form a third connecting part 23, thereby improving the connection strength between the insulating film corresponding to the electrode terminal 14 and the outer shell 11, effectively protecting the part of the outer shell 11 where the electrode terminal 14 is installed, reducing the risk of electrolyte leakage from the part of the outer shell 11 where the electrode terminal 14 is installed, or reducing the risk of electrolyte leaked from other parts (electrolyte leaked from other parts of the outer shell 11 or electrolyte leaked from other battery cells 10) entering the interior of the battery cell 10 from the part of the outer shell 11 where the electrode terminal 14 is installed, causing the battery cell 10 to short-circuit, so that the battery 100 has higher reliability.

[0171] In some embodiments, when the battery cell 10 is used upside down, that is, when the electrode terminal 14 is the component of the battery cell 10 that is closer to the ground, there is a greater risk of leakage of the electrolyte from the portion of the outer shell 11 where the electrode terminal 14 is installed. To this end, by providing a third connecting portion 23, the risk of leakage of the electrolyte from the portion of the outer shell 11 where the electrode terminal 14 is installed can be reduced, as can the risk of leakage of the electrolyte from the portion of the outer shell 11 where the electrode terminal 14 is installed to the outside of the first insulating film 12.

[0172] According to some embodiments of the present application, please refer to FIG8 , which is an enlarged view of point B in FIG6 . A protrusion 15 is provided on the outer surface of the housing 11 . The protrusion 15 surrounds the electrode terminal 14 and is exposed from the first through hole 122 .

[0173] Referring to Figure 8 , protrusion 15 is a component that protrudes from the outer surface of housing 11. Protrusion 15 is annular and surrounds electrode terminal 14. In some embodiments, a gap exists between protrusion 15 and electrode terminal 14 to reduce interference with electrode terminal 14 and facilitate electrical connection between electrode terminal 14 and external components. Protrusion 15 is exposed through first through-hole 122. This means that protrusion 15 is located within first through-hole 122, meaning that electrode terminal 14 is located inside the annular protrusion 15, and third connection portion 23 is located outside the annular protrusion 15.

[0174] The protrusion 15 can be a component independent of the housing 11 and can be made of an insulating material. The protrusion 15 can also be a component formed by the housing 11 itself, for example, the protrusion 15 can be a component formed by stamping the housing 11.

[0175] In the above solution, the protrusion 15 is provided, and the protrusion 15 is arranged around the electrode terminal 14 to protect the electrode terminal 14 and block the flow of electrolyte. This reduces the risk of electrolyte leaking from areas of the housing 112 other than where the electrode terminal 14 is mounted and affecting the electrode terminal 14, thereby causing a short circuit in the battery cell 10, thereby improving the reliability of the battery 100. In some embodiments, when the battery cell 10 is inverted, or when the electrode terminal 14 is the component of the battery cell 10 that is closer to the ground, the provision of the protrusion 15 causes the electrolyte to drip along the protrusion 15 toward the ground under the action of gravity, reducing the risk of electrolyte affecting the electrode terminal 14.

[0176] According to some embodiments of the present application, the third connection portion 23 is provided along the circumference of the protrusion 15 and is located outside the protrusion 15 .

[0177] In the above solution, the third connection portion 23 is located outside the protrusion 15, that is, the third portion 13 does not interfere with the protrusion 15, which effectively reduces the connection difficulty of the second portion 111, the glue layer 13 and the first insulating film 12, and improves the manufacturing efficiency of the battery cell.

[0178] In some other embodiments, the third connection portion 23 may also be located on the protrusion 15 , or located on the inner side of the protrusion 15 .

[0179] According to some embodiments of the present application, please refer to Figure 4 and Figure 9. Figure 9 is a schematic diagram of a battery cell 10 in some other embodiments of the present application.

[0180] The battery cell 10 further includes a pressure relief portion 16 disposed on the housing 11 and covered by the first insulating film 12 . The first insulating film 12 is connected to the second portion 111 via the adhesive layer 13 to form a fourth connecting portion 24 , which surrounds the pressure relief portion 16 .

[0181] The pressure relief portion 16 is a component provided on the outer shell 11 that releases internal pressure from the battery cell 10, thereby enhancing the reliability of the battery cell 10. In some embodiments, the pressure relief portion 16 can be a pressure relief valve or a notch provided on the outer shell 11. In some embodiments, the pressure relief portion 16 can be provided on the end cap 113.

[0182] The fourth connecting portion 24 is formed by connecting the first insulating film 12 to the second portion 111 via the adhesive layer 13, and is disposed around the pressure relief portion 16. In conjunction with some of the embodiments provided above, the fourth connecting portion 24 can be formed by connecting the first sub-insulating film 120 to the second portion 111 via the adhesive layer 13.

[0183] In some embodiments, referring to FIG9 , the portion indicated by the fourth connecting portion 24 and the remaining portions indicated by filled lines in FIG9 may refer to the portion where the second portion 111 is located, and the remaining blank portions may refer to portions where the second portion 111 is not provided. In other embodiments, the second portion 111 may be provided on all outer surfaces of the housing 112.

[0184] In the above scheme, the first insulating film 12 covers the pressure relief portion 16, and the first insulating film 12 is connected to the second portion 111 through the adhesive layer 13 to form a fourth connecting portion 24. The fourth connecting portion 24 is arranged around the pressure relief portion 16 to reduce the risk of the insulating film corresponding to the pressure relief portion 16 being detached from the outer shell 11, thereby reducing the risk of electrolyte leakage from the portion where the pressure relief portion 16 is set on the outer shell 11, or reducing the risk of electrolyte leaking from the portion where the pressure relief portion 16 is set on the outer shell 11 to leak outside the insulating film, so that the battery 100 has higher reliability.

[0185] According to some embodiments of the present application, the housing 11 is provided with a liquid injection hole 114. The battery cell 10 further includes a sealing member 17, which seals the liquid injection hole 114. The first insulating film 12 covers the sealing member 17. The insulating film is connected to the second portion 111 via the adhesive layer 13 to form a fifth connecting portion 25, which is disposed around the liquid injection hole 114.

[0186] The injection hole 114 is a hole structure provided on the housing 11, through which electrolyte can be injected into the interior of the housing 11. In some embodiments, the injection hole 114 can be provided on the end cap 113 of the housing 11. The sealing member 17 is a component that seals the injection hole 114 and can be a sealing nail or a sealing screw, etc., capable of sealing the injection hole 114.

[0187] The fifth connecting portion 25 is formed by connecting the first insulating film 12 to the second portion 111 via the adhesive layer 13, and is disposed around the blocking member 17. In conjunction with some of the embodiments provided above, the fifth connecting portion 25 can be formed by connecting the first sub-insulating film 120 to the second portion 111 via the adhesive layer 13.

[0188] In some embodiments, referring to FIG9 , the area indicated by the fifth connecting portion 25 and the remaining areas marked with fill lines in FIG9 may refer to areas where the second portion 111 is located, and the remaining blank areas may refer to areas where the second portion 111 is not provided. In other embodiments, the second portion 111 may be provided on all outer surfaces of the housing 112.

[0189] In the above solution, the first insulating film 12 covers the sealing member 17, and the insulating film is connected to the second part 111 through the adhesive layer 13 to form a fifth connecting portion 25. The fifth connecting portion 25 is arranged around the pressure relief portion 16 to reduce the risk of the insulating film corresponding to the sealing member 17 being detached from the outer shell 11, thereby reducing the risk of electrolyte leakage from the part where the sealing member 17 is installed on the outer shell 11, or reducing the risk of electrolyte leaking from the part where the sealing member 17 is installed on the outer shell 11 to leak outside the insulating film, so that the battery 100 has higher reliability.

[0190] According to some embodiments of the present application, a battery 100 is further provided. The battery 100 includes any one of the battery cells 10 described above.

[0191] According to some embodiments of the present application, an electrical device is further provided, comprising the battery 100 provided above and / or the battery cell 10 provided above. The battery 100 is used to provide electrical energy. The battery cell 10 is used to provide electrical energy.

[0192] According to some embodiments of the present application, please refer to Figures 3 to 9.

[0193] Some embodiments of the present application provide a battery cell 10, which includes an outer shell 11, a first insulating film 12 and an adhesive layer 13. The outer shell 11 includes a shell 112 and an end cover 113, the shell 112 has an opening 1120, the end cover 113 is connected to the shell 112 and closes the opening 1120, and the end cover 113 is connected to the shell 112 to form a first connection portion 21. In some embodiments, the end cover 113 and the shell 112 can be welded to each other, and the first connection portion 21 is a weld. An injection hole 114 is provided on the end cover 113, and the injection hole 114 is used to inject electrolyte into the interior of the outer shell 11. A sealing member 17 is installed on the end cover 113, and the sealing member 17 blocks the injection hole 114. An electrode terminal 14 and a pressure relief portion 16 are installed on the end cover 113.

[0194] The housing 11 includes a first portion 110 and a second portion 111 formed on the first portion 110. In some embodiments, the first portion 110 is an aluminum layer, i.e., the main body of the housing 11 is an aluminum shell, and the second portion 111 is formed on the outer surface of the aluminum shell. In some embodiments, the second portion 111 is chromium oxide formed by electroplating. In other embodiments, the second portion 111 is aluminum oxide formed by an anodizing process. In some embodiments, the thickness of the second portion 111 is M, satisfying 18 μm ≤ M ≤ 100 μm.

[0195] The first insulating film 12 includes a first sub-insulating film 120 and a second sub-insulating film 121. The first sub-insulating film 120 covers the end cap 113, and the second sub-insulating film 121 covers the housing 112. The second sub-insulating film 121 is connected to the second portion 111 via the adhesive layer 13 to form a second connecting portion 22. The second connecting portion 22 is arranged along the circumference of the opening 1120. In some embodiments, the second connecting portion 22 can be formed between the first insulating film 12 and the adhesive layer 13 using a hot melt process. A first through-hole 122 can be provided in the first sub-insulating film 120 of the first insulating film 12, which can expose the electrode terminal 14. The portion of the first insulating film 12 located around the first through-hole 122 is connected to the second portion 111 via the adhesive layer 13 to form a third connecting portion 23. In some embodiments, the third connecting portion 23 can be formed between the first insulating film 12 and the adhesive layer 13 using a hot melt process. As shown in Figure 8 , to reduce the risk of electrolyte from externally acting on the electrode terminals 14 and causing a short circuit in the battery cell 10, a protrusion 15 is provided on the outer surface of the end cap 113, which is exposed through the first through-hole 122. The first insulating film 12 is connected to the second portion 111 via the adhesive layer 13 to form a fourth connecting portion 24, which is disposed around the pressure relief portion 16.

[0196] In some embodiments, the fourth connection portion 24 can be formed between the first insulating film 12 and the adhesive layer 13 by a hot melt process. The first insulating film 12 is connected to the second portion 111 through the adhesive layer 13 to form the fifth connection portion 25, which is arranged around the injection hole 114.

[0197] In some embodiments, the fifth connection portion 25 may be formed between the first insulating film 12 and the adhesive layer 13 by a hot melt process.

[0198] Some embodiments of the present application provide comparative examples and exemplary embodiments, demonstrating that forming a second portion 111 on the outer surface of a first portion 110 improves the adhesion between the adhesive layer 13 and the outer shell 11. The comparative example is a battery cell 10 having an outer shell 11 formed as a conventional aluminum shell, and the adhesion between the outer shell 11 and the adhesive layer 13; the exemplary embodiment is a battery cell 10 having a second portion 111 formed on the surface, and the adhesion between the outer shell 11 and the adhesive layer 13 (in some embodiments, technicians also refer to this adhesion as adhesion). The adhesion can be measured using a peel test method, such as a peel tester. Please refer to Table 1. In Table 1, "an outer shell having aluminum oxide formed on the surface (aluminum oxide thickness 30 μm)" may refer to an outer shell having aluminum oxide with a thickness of 30 μm formed on the outer surface of a conventional aluminum shell; and "an outer shell having chromium oxide formed on the surface (aluminum oxide thickness 50 μm)" may refer to an outer shell having chromium oxide with a thickness of 50 μm formed on the outer surface of a conventional aluminum shell.

[0199] Table 1:

[0200] As can be seen from Table 1, the outer shell 11 with the second portion 111 formed on the surface has a stronger adhesive force with the adhesive layer 13 , and the first insulating film 12 is more difficult to separate from the outer shell 11 , so the reliability of the battery cell 10 is higher.

[0201] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, wherein: include: The housing comprises a first part and a second part, wherein the first part and the second part are connected, and the surface energy of the outer surface of the second part is greater than the surface energy of the outer surface of the first part; a first insulating film covering at least a portion of the housing; The adhesive layer is arranged between the second part and the first insulating film, and is used to connect the first insulating film and the second part.

2. The battery cell according to claim 1, wherein: The surface energy of the outer surface of the second portion is p, satisfying p>421 N / m.

3. The battery cell according to claim 2, wherein: Satisfies, 500N / m≤p≤1500N / m.

4. The battery cell according to any one of claims 1 to 3, wherein: The first portion is a first metal layer, and the second portion is an oxide layer.

5. The battery cell according to claim 4, wherein: The oxide layer is formed on the outer surface of the first metal layer.

6. The battery cell according to claim 4 or 5, wherein: The second portion is chromium oxide or nickel oxide.

7. The battery cell according to claim 4 or 5, wherein: The first portion is aluminum, and the second portion is aluminum oxide.

8. The battery cell according to any one of claims 4 to 7, wherein: The thickness of the second portion is M, satisfying 18um≤M≤100um.

9. The battery cell according to any one of claims 1 to 8, wherein: The surface of the second part connected to the adhesive layer is a concave-convex surface.

10. The battery cell according to any one of claims 1 to 3, wherein: The first portion is a second metal layer, and the second portion is a third metal layer.

11. The battery cell according to any one of claims 1 to 3, wherein: The first portion is a non-metal layer, and the second portion is a fourth metal layer and / or an oxide layer.

12. The battery cell according to any one of claims 1 to 11, wherein: Along the thickness direction of the shell, the outer surface of the second part is higher than the outer surface of the first part, or the outer surface of the second part is flush with the outer surface of the first part, or the outer surface of the second part is lower than the outer surface of the first part.

13. The battery cell according to any one of claims 1 to 12, wherein: The melting point of the adhesive layer is P1, and the melting point of the first insulating film is P2, satisfying |P1-P2|≤30, in degrees Celsius.

14. The battery cell according to any one of claims 1 to 13, wherein: The first insulating film is connected to the adhesive layer by thermal melting.

15. The battery cell according to any one of claims 1 to 14, wherein: The battery cell further includes a second insulating film, and the second insulating film is connected to a surface of the first insulating film that is away from the adhesive layer.

16. The battery cell according to claim 15, wherein: The first insulating film and the second insulating film are thermally fused and connected.

17. The battery cell according to any one of claims 1 to 16, wherein: The housing comprises a shell and an end cover, the shell has an opening, the end cover is connected to the shell and closes the opening, and the end cover is connected to the shell to form a first connection portion; The first insulating film covers the first connection portion.

18. The battery cell according to claim 17, wherein: The first insulating film includes a first sub-insulating film and a second sub-insulating film, the first sub-insulating film covers at least a portion of the outer surface of the end cap, and the second sub-insulating film covers at least a portion of the outer surface of the shell; The second sub-insulating film is connected to the second portion through the adhesive layer to form a second connecting portion. Circumferential arrangement of openings.

19. The battery cell according to any one of claims 1 to 18, wherein: The battery cell also includes an electrode terminal, which is installed on the shell. The first insulating film has a first through hole that exposes the electrode terminal. The first insulating film is connected to the second part through the adhesive layer to form a third connecting part, and the third connecting part is arranged around the electrode terminal.

20. The battery cell according to claim 19, wherein: A protrusion is disposed on the outer surface of the housing, the protrusion is disposed around the electrode terminal, and the protrusion is exposed from the first through hole.

21. The battery cell according to claim 20, wherein: The third connection portion is arranged along the circumference of the protrusion and is located outside the protrusion.

22. The battery cell according to any one of claims 1 to 21, wherein: The battery cell further includes a pressure relief portion, the pressure relief portion is disposed on the housing, and the first insulating film covers the pressure relief portion; The first insulating film is connected to the second portion through the adhesive layer to form a fourth connecting portion, and the fourth connecting portion is arranged around the pressure relief portion.

23. The battery cell according to any one of claims 1 to 22, wherein: The housing is provided with a liquid injection hole, the battery cell further comprises a blocking piece, the blocking piece blocks the liquid injection hole, and the first insulating film covers the blocking piece; The first insulating film is connected to the second portion through the adhesive layer to form a fifth connecting portion, and the fifth connecting portion is arranged around the injection hole.

24. A battery, wherein: The battery comprises the battery cell according to any one of claims 1 to 23.

25. An electrical device, wherein: Comprising the battery according to claim 24, and / or the battery monomer according to any one of claims 1-23.

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