Battery monomer, battery and electric device

Abstract

The utility model discloses a battery monomer, a battery and a power utilization device, and the battery monomer comprises an energy unit which comprises an electrode assembly and an electrolyte; the shell is used for containing the energy unit, an insulating part is arranged between the energy unit and the shell, and the insulating part is used for separating electrolyte in the energy unit from the shell. In the technical scheme of the embodiment of the invention, the insulating part can enable the electrolyte in the energy unit not to be in contact with the shell, so that no ion channel exists between the electrode assembly and the shell, the impedance between the electrode assembly and the shell is increased through the arrangement of the insulating part, and the voltage endurance capability of the battery monomer is improved; the problem that the battery monomer is broken down due to decomposition of the electrolyte under high voltage is solved to a certain extent, the probability of safety accidents such as corrosion and thermal runaway is reduced, and the reliability of the battery monomer is improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] 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.

[0003] In some cases, the battery may experience insulation failure. When insulation failure occurs, the battery's voltage resistance will be reduced, and battery corrosion and even thermal runaway may occur, posing a safety hazard. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can reduce the probability of safety accidents when the battery has insulation failure.

[0005] In a first aspect, the present application provides a battery cell, comprising: an energy unit including an electrode assembly and an electrolyte; and a shell for accommodating the energy unit, wherein an insulating member is provided between the energy unit and the shell, and the insulating member is used to separate the electrolyte in the energy unit from the shell.

[0006] In the technical solution of the embodiment of the present application, the insulating part can prevent the electrolyte in the energy unit from contacting the outer shell, so that there is no ion channel between the electrode assembly and the outer shell. The provision of the insulating part increases the impedance between the electrode assembly and the outer shell, increases the pressure resistance of the battery cell, and thus when the insulation failure of the battery cell occurs, to a certain extent avoids the decomposition of the electrolyte under high pressure, resulting in the breakdown of the battery cell, and reduces the probability of safety accidents such as corrosion and thermal runaway, thereby improving the reliability of the battery cell.

[0007] In some embodiments, the insulating member includes a bottom wall and side walls, the side walls being disposed on and connected to the bottom wall to define a storage space, with at least a portion of the energy cell located within the storage space. In the above technical solution, the electrolyte is isolated from the outer shell, and there is no ion channel between the electrode assembly and the outer shell, thereby increasing the pressure resistance of the battery cell, making it less likely to cause safety accidents in the event of insulation failure in the battery cell, and improving the reliability of the battery cell.

[0008] In some embodiments, the top of the insulating member is open. In the above technical solution, the insulating member is designed to have a bottom wall and a side wall. The structure of the insulating member is simple and can be made by a plastic packaging process or a bending process, which is convenient to manufacture and reduces the probability of interference between the insulating member and the electrode assembly.

[0009] In some embodiments, the insulating member further comprises a top wall, the top wall being opposite to the bottom wall and connected to the side wall, the top wall having an avoidance notch. In the above technical solution, the insulating member is designed to have a structure having a top wall, a bottom wall and a side wall, the insulating member defines a accommodating space, the main body of the electrode assembly and the electrolyte can be completely arranged in the accommodating space, the insulating member can be wrapped around the outside of the main body, the top wall has an avoidance notch, the electrode tab of the electrode assembly can extend through the avoidance notch to the top of the insulating member and be connected to the pole, the insulating member can be made into an insulating film wrapped around the outside of the energy unit through a plastic sealing process, the insulating member can completely separate the electrolyte of the energy unit from the outer shell, so that there is no ion channel between the electrode assembly and the outer shell, thereby increasing the impedance between the electrode assembly and the outer shell, increasing the pressure resistance of the battery cell, and making it less likely for the battery cell to cause a safety accident when insulation failure occurs.

[0010] In some embodiments, the electrode assembly includes a main body and a tab, the tab protruding from the main body in a first direction, and the size of the accommodation space in the first direction is not less than the size of the main body in the first direction. In the above technical solution, the insulating member can separate the main body of the electrode assembly from the outer shell, and the electrolyte can be provided between adjacent pole pieces of the main body, or can be deposited at the bottom of the accommodation space. By limiting the size of the accommodation space, the electrolyte in the energy unit will not contact the outer shell, so that there is no ion channel between the electrode assembly and the outer shell, thereby increasing the impedance between the electrode assembly and the outer shell, and increasing the pressure resistance of the battery cell. When the insulation of the battery cell fails, the electrolyte decomposition under high pressure, resulting in the breakdown of the battery cell, is avoided to a certain extent, and the probability of safety accidents such as battery corrosion and thermal runaway is reduced.

[0011] In some embodiments, the housing comprises a shell and an end cap. The shell has an opening on at least one side. The end cap is connected to the shell and is used to close the opening. At least a portion of the insulating member is in contact with the shell. In the above technical solution, the insulating member is fixed between the shell and the energy unit, reducing the probability of movement or deformation of the insulating member, thereby ensuring that the insulating member provides reliable insulation throughout the life cycle of the battery cell.

[0012] In some embodiments, the insulating member is connected to the end cap. In the above technical solution, the insulating member can be fixedly connected to the end cap by bonding or other means, thereby improving the stability of the insulating member's fixation and reducing the probability of the insulating member moving or deforming, thereby ensuring that the insulating member can provide a reliable insulation effect throughout the life cycle of the battery cell.

[0013] In some embodiments, the housing further includes a bottom support plate, which is located between the insulating member and the housing. In the above technical solution, the bottom support plate can separate the bottom wall of the insulating member from the housing, reducing the probability of the insulating member being punctured when the housing is damaged. This in turn reduces the risk of insulating member damage, electrolyte leakage, and short circuits, further improving the reliability of the battery cell.

[0014] In some embodiments, the insulating member is a bag-shaped structure with an open top and no interface. In the above technical solution, the insulating member can be directly placed on the outside of the energy unit to protect the energy unit, reduce the probability of safety accidents in the event of insulation failure in the battery cell, and improve the reliability of the battery cell.

[0015] In some embodiments, the insulating member is formed by folding a single insulating sheet, and the insulating member includes multiple bends, which are interconnected and sealed at the joints. In the above technical solution, the insulating member is formed by bending, which simplifies the manufacturing process and facilitates assembly. The insulating member is sealed at the joints of the bends, providing an isolation function, reducing the probability of safety accidents in the event of insulation failure in the battery cell, and improving the reliability of the battery cell.

[0016] In some embodiments, the insulating member is formed by heat shrinking a heat shrink film. In the above technical solution, the insulating member formed by heat shrinking a heat shrink film has a stable structure, is less likely to have holes or gaps in the insulating member as a whole, and can provide good isolation. The insulating member can protect the energy unit, reduce the probability of safety accidents in the battery cell when the insulation fails, and improve the reliability of the battery cell.

[0017] In some embodiments, the insulating member is integrally formed using a blown film process. In the above technical solution, the insulating member is an integrally formed member, which simplifies the manufacturing process and can be directly placed on the outside of the energy cell to protect the energy cell, reduce the probability of safety accidents in the event of insulation failure in the battery cell, and improve the reliability of the battery cell.

[0018] In some embodiments, the air permeability of the insulating member at 0.1 MPa is ρ, ρ≤10 L / (m 2 · 24h). In the above technical solution, the electrolyte of the energy unit is difficult to penetrate the insulating member, so that the insulating member has better sealing performance.

[0019] In a second aspect, the present application provides a battery comprising the battery cell in the above embodiment.

[0020] In a third aspect, the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0021] 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

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0023] Figure 1 is a schematic diagram of an electrical device in the related art;

[0024] Figure 2 A schematic diagram of a battery in the related art;

[0025] Figure 3 A schematic diagram of a battery cell in the related art;

[0026] Figure 4 A schematic diagram of a battery cell provided in some embodiments of the present application;

[0027] Figure 5 A schematic diagram of an insulating member provided in some embodiments of the present application;

[0028] Figure 6 Schematic diagrams of battery cells provided in some other embodiments of the present application;

[0029] Figure 7 Schematic diagrams of insulating members provided in other embodiments of the present application;

[0030] Figure 8 Schematic diagrams of insulating members provided in some further embodiments of the present application.

[0031] Reference numerals:

[0032] Battery 1000, power device 2000, box 200, upper box 210, lower box 220,

[0033] Battery cell 100,

[0034] Shell 10, housing 11, end cover 12, end cover body 121, support member 122,

[0035] Electrode assembly 20, main body 21, tab 22,

[0036] Insulation member 30, accommodating space 301, bottom wall 31, side wall 32, top wall 33, avoidance notch 331, bending portion 34, connection portion 35 of the bending portion,

[0037] Bottom support plate 40. DETAILED DESCRIPTION

[0038] 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.

[0039] 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 only for the purpose of describing specific embodiments 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", "second", etc. 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The term "plurality" used in this application refers to two or more (including two).

[0045] In this application, a battery refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the batteries mentioned in this application may include battery modules or battery packs. Some batteries may include a casing for enclosing one or more battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells. Of course, some batteries may not include the above-mentioned casing and are directly installed in the battery installation compartment of the electrical device.

[0046] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0047] For example, a battery cell may include a housing, an electrode assembly, and an electrolyte, wherein the housing is used to contain the electrode assembly and the electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer, and the positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.

[0048] The negative electrode sheet consists of a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The negative current collector uncoated with the negative active material layer protrudes from the negative current collector coated with the negative active material layer. The negative current collector uncoated with the negative active material layer serves as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon, silicon, or other materials. To ensure that high currents can pass without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together.

[0049] The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

[0050] Battery cells can be equipped with terminals and other components connected to the tabs, serving as electrical connections. Furthermore, they can have pressure relief features. When the internal pressure in a battery cell becomes excessive (e.g., due to thermal runaway), these features release substances (e.g., gas, liquid, particulate matter, etc.) from the cell to reduce the internal pressure. This prevents excessive internal pressure from causing dangerous accidents such as explosions. For example, these relief features can be explosion-proof valves, explosion-proof discs, and the like.

[0051] For example Figure 1 and Figure 2 As shown, some electrical devices 2000 are powered by batteries 1000. Battery 1000 includes a housing 200 and battery cells 100. Housing 200 includes an upper housing 210 and a lower housing 220. In conventional technology, battery 1000 includes an electrode assembly 20 and a housing 10. A Mylar film is provided on the outside of electrode assembly 20. The Mylar film has a porous structure, thus forming an ion conduction circuit, i.e., a free electrolyte exists between electrode assembly 20 and housing 10.

[0052] Among them, the battery 1000 may experience insulation failure in some cases. For example, when the outer shell 10 of the battery cell 100 causes electrolyte leakage due to collision or foreign objects, or when the coolant leaks, insulation failure occurs. When insulation failure occurs, the potential between the metal outer shell 10 and the pole of the battery cell 100 changes. The potential between the outer shell 10 and the pole is greater than the decomposition voltage of the electrolyte, causing the electrolyte to decompose, thereby reducing the voltage breakdown resistance of the battery cell 100, and causing corrosion of the battery 1000 or even thermal runaway, posing a safety hazard.

[0053] Therefore, the present application proposes a battery cell 100 including: an energy unit and a shell 10, the energy unit including an electrode assembly 20 and an electrolyte, the shell 10 is used to accommodate the energy unit, wherein an insulating member 30 is provided between the energy unit and the shell 10, and the insulating member 30 is used to separate the electrolyte in the energy unit from the shell 10.

[0054] In the battery cell 100 of the above-mentioned structure, the insulating part 30 can prevent the electrolyte in the energy unit from contacting the outer shell 10, so that there is no ion channel between the electrode assembly 20 and the outer shell 10. The provision of the insulating part 30 increases the impedance between the electrode assembly 20 and the outer shell 10, and increases the pressure resistance of the battery cell 100. Therefore, when the insulation failure of the battery cell 100 occurs, it avoids the decomposition of the electrolyte under high pressure to a certain extent, causing the battery cell 100 to be punctured, and reduces the probability of safety accidents such as corrosion of the battery 1000 and thermal runaway.

[0055] The battery 1000 including the battery cell 100 disclosed in the embodiment of the present application can be used for, but not limited to, an electrical device 2000 such as a vehicle, ship or aircraft. The power supply system of the electrical device 2000 composed of the battery 1000 disclosed in the present application can ensure the safety and reliability of the electrical device 2000.

[0056] For example, the power-consuming device 2000 disclosed in the embodiments of the present application may be, but is not limited to, a vehicle, a mobile phone, a tablet, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. A vehicle may be a fuel vehicle, a gas vehicle, a new energy vehicle, or a rail vehicle, and a new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc.; a spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc.; an electric toy includes a fixed or mobile electric toy, such as a game console, an electric vehicle toy, an electric ship toy, and an electric airplane toy, etc.; an electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, etc.

[0057] Hereinafter, a battery cell 100 according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0058] like Figure 4-Figure 8 As shown, Figure 4 and Figure 6 They are schematic diagrams of battery cells 100 provided in some embodiments of the present application; Figure 5 、 Figure 7 and Figure 8They are schematic diagrams of the insulating member 30 provided in some embodiments of the present application. The battery cell 100 of the embodiment of the present application includes: an energy unit and a shell 10, the energy unit includes an electrode assembly 20 and an electrolyte, and the shell 10 is used to accommodate the energy unit, wherein an insulating member 30 is provided between the energy unit and the shell 10, and the insulating member 30 is used to separate the electrolyte in the energy unit from the shell 10.

[0059] The outer shell 10 is the outermost structural component of the battery cell 100 and contains the electrode assembly 20 and electrolyte, etc. The outer shell 10 can fix and seal the electrochemical system of the battery cell 100.

[0060] The energy unit is used to store or release energy of the battery cell 100 , and includes an electrode assembly 20 and an electrolyte.

[0061] The electrode assembly 20 can be a laminated type, that is, multiple electrode sheets of the electrode assembly 20 are stacked; the electrode assembly 20 can also be a wound type, where the positive electrode sheet and the negative electrode sheet of the electrode assembly 20 are stacked with the separator and then wound into shape.

[0062] The electrolyte plays the role of conducting ions between the positive and negative electrodes. The type of electrolyte can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0063] The insulating member 30 is arranged on the outside of the energy unit, and the insulating member 30 is located in the outer shell 10. The insulating member 30 can be a membrane structure with insulating properties, or a box-shaped structure with insulating properties. The insulating member 30 can be an integral part, or a structure formed by connecting multiple structural parts and the connection is insulated and sealed; wherein, the insulating member 30 can wrap a part of the electrode assembly 20, so that there is a non-porous insulating member 30 between the bottom of the electrode assembly 20 and the outer shell 10, and at the same time, there is a non-porous insulating member 30 between the side of the electrode assembly 20 and the outer shell 10, so that the electrolyte around the electrode assembly 20 can be separated from the outer shell 10 by the insulating member 30.

[0064] According to the battery cell 100 of the embodiment of the present application, the insulating part 30 can prevent the electrolyte in the energy unit from contacting the outer shell 10, so that there is no ion channel between the electrode assembly 20 and the outer shell 10. The provision of the insulating part 30 increases the impedance between the electrode assembly 20 and the outer shell 10, and increases the pressure resistance of the battery cell 100. Therefore, when the insulation failure of the battery cell 100 occurs, it avoids to a certain extent the problem that the electrolyte decomposes under high pressure and causes the battery cell 100 to be punctured, reduces the probability of safety accidents such as corrosion and thermal runaway, and improves the reliability of the battery cell 100.

[0065] It should be noted that an electrolyte may also be provided outside the insulating part 30, that is, between the insulating part 30 and the outer shell 10. Under the action of the insulating part 30, there is no ion channel between the electrode assembly 20 and the outer shell 10, and thus there will be no ion conduction circuit between the electrode assembly 20 and the outer shell 10, thereby avoiding the reduction of the pressure resistance of the battery cell 100 and improving the reliability of the battery cell 100.

[0066] like Figure 5 、 Figure 7 and Figure 8 As shown, in some embodiments, the insulating member 30 includes a bottom wall 31 and a side wall 32 , wherein the side wall 32 is provided on the bottom wall 31 and connected to the bottom wall 31 to define an accommodating space 301 , and at least a portion of the energy unit is located in the accommodating space 301 .

[0067] When the battery cell 100 is used on the electrical device 2000, the wall on the lower side of the insulating part 30 is the bottom wall 31, and the upper side of the insulating part 30 may have a top wall 33, or the top wall 33 may be omitted, so that the top of the insulating part 30 is open, and the part located between the top of the insulating part 30 and the bottom wall 31 is the side wall 32 of the insulating part 30.

[0068] The bottom wall 31 of the insulating part 30 is not provided with an opening, and the side wall 32 is also not provided with an opening. There is no gap at the connection between the bottom wall 31 and the side wall 32. The insulating part 30 is connected by the bottom wall 31 and the side wall 32 to form a accommodating space 301. A part of the electrode assembly 20 can be located in the accommodating space 301, and the electrolyte can be located in the accommodating space 301, thereby isolating the electrolyte from the outer shell 10. There is no ion channel between the electrode assembly 20 and the outer shell 10, which increases the pressure resistance of the battery cell 100, makes it less likely for the battery cell 100 to cause a safety accident when insulation failure occurs, and improves the reliability of the battery cell 100.

[0069] Furthermore, during use of the battery cell 100 , even if decarbonization occurs in the electrode assembly, the detached carbon falls into the accommodation space 301 under the action of gravity and does not come into contact with the outer shell 10 , thereby reducing the probability of outer shell corrosion caused by decarbonization.

[0070] like Figure 4 and Figure 5 As shown, in some embodiments, the top of the insulating member 30 is open.

[0071] During the actual application of the battery cell 100, the electrolyte usually injected into the battery cell 100 has a tendency to settle downward under the action of gravity. The top of the insulating part 30 is open, and the electrolyte can be injected into the energy unit through the open port at the top of the insulating part 30. At the same time, it is also convenient for the pole ear 22 of the electrode assembly 20 to extend out of the top of the insulating part 30 and connect with the pole. Therefore, the insulating part 30 is designed to have a structure with a bottom wall 31 and a side wall 32. The structure of the insulating part 30 is simple. The insulating part 30 can be made by a plastic sealing process or a bending process, which is easy to manufacture and reduces the probability of interference between the insulating part 30 and the electrode assembly 20.

[0072] like Figure 6 and Figure 7 As shown, in some embodiments, the insulating member 30 further includes a top wall 33 , which is opposite to the bottom wall 31 and connected to the side wall 32 . The top wall 33 has an avoidance notch 331 .

[0073] The insulating part 30 is designed to have a structure with a top wall 33, a bottom wall 31 and a side wall 32. The insulating part 30 defines a accommodating space 301. The main body 21 of the electrode assembly 20 and the electrolyte can be completely arranged in the accommodating space 301. The insulating part 30 can be wrapped around the outside of the main body 21. The top wall 33 has an avoidance gap 331. The pole ear 22 of the electrode assembly 20 can extend out of the top of the insulating part 30 through the avoidance gap 331 and be connected to the pole. The insulating part 30 can be made into an insulating film wrapped around the outside of the energy unit through a plastic packaging process. The insulating part 30 can completely separate the electrolyte of the energy unit from the outer shell 10, so that there is no ion channel between the electrode assembly 20 and the outer shell 10, thereby increasing the impedance between the electrode assembly 20 and the outer shell 10, and increasing the pressure resistance of the battery cell 100, so that the battery cell 100 is not prone to cause safety accidents when insulation failure occurs.

[0074] like Figure 4 and Figure 6 As shown, in some embodiments, the electrode assembly 20 includes a main body 21 and a tab 22 , the tab 22 protrudes from the main body 21 in the first direction, and the size of the accommodating space 301 in the first direction is not less than the size of the main body 21 in the first direction.

[0075] The electrode assembly 20 includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet includes a positive electrode body and a positive electrode tab. The positive electrode tab is led out from one end of the positive electrode body. Most areas of the positive electrode tab are not coated with positive electrode active materials, and most areas of the positive electrode body are coated with positive electrode active materials. The negative electrode sheet includes a negative electrode body and a negative electrode tab. The negative electrode tab is led out from one end of the negative electrode body. Most areas of the negative electrode tab are not coated with negative electrode active materials, and most areas of the negative electrode body are coated with negative electrode active materials. The positive electrode body and the negative electrode body constitute the main body 21 of the electrode assembly 20, and the positive electrode tab and the negative electrode tab constitute the tab 22 of the electrode assembly 20.

[0076] The first direction is Figure 4 As shown in the upper and lower directions, in the first direction, the size of the accommodating space 301 is larger than the size of the main body 21, or the size of the accommodating space 301 is equal to the size of the main body 21, so that the insulating part 30 can separate the main body 21 of the electrode assembly 20 from the outer shell 10, and the electrolyte can be arranged between adjacent pole pieces of the main body 21, or can be deposited at the bottom of the accommodating space 301. By limiting the size of the accommodating space 301, the electrolyte in the energy unit will not contact the outer shell 10, so that there is no ion channel between the electrode assembly 20 and the outer shell 10, thereby increasing the impedance between the electrode assembly 20 and the outer shell 10, and increasing the pressure resistance of the battery cell 100. When the insulation failure of the battery cell 100 occurs, the decomposition of the electrolyte under high pressure, which leads to the breakdown of the battery cell 100, is avoided to a certain extent, thereby reducing the probability of safety accidents such as corrosion and thermal runaway of the battery 100.

[0077] like Figure 3 As shown, in some embodiments, the housing 10 includes: a shell 11 and an end cover 12, at least one side of the shell 11 has an opening, the end cover 12 is connected to the shell 11 and is used to close the opening, and at least a portion of the insulating member 30 is in contact with the shell 11.

[0078] The housing 11 may be a hollow structure with an opening at one end, or a hollow structure with openings at two opposite ends. The housing 11 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, and the like.

[0079] The end cap 12 is a component that closes the opening of the shell 11 to isolate the internal environment of the battery cell 100 from the external environment. The end cap 12 and the shell 11 together define a storage space 301 for accommodating the electrode assembly 20, electrolyte and other components. The end cap 12 can be connected to the shell 11 by welding or crimping to close the opening of the shell 11. The shape of the end cap 12 can be adapted to the shape of the shell 10. For example, the shell 11 is a rectangular parallelepiped structure, and the end cap 12 is a rectangular plate structure adapted to the shell 10. The material of the end cap 12 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0080] In the battery cell 100, there can be one or two end caps 12. In embodiments where the housing 11 is a hollow structure with openings at both ends, two end caps 12 can be provided. The two end caps 12 respectively close the two openings of the housing 11, and the two end caps 12 and the housing 11 together define a storage space 301. In embodiments where the housing 11 is a hollow structure with an opening at one end, there can be one end cap 12 provided. The end cap 12 closes the opening at one end of the housing 11, and the end cap 12 and the housing 11 together define a storage space 301.

[0081] Among them, the insulating part 30 includes a side wall 32, which can be fitted with the inner wall surface of the shell 11, thereby fixing the insulating part 30 between the shell 11 and the energy unit, reducing the probability of movement or deformation of the insulating part 30, and thus enabling the insulating part 30 to play a reliable insulating effect throughout the life cycle of the battery cell 100.

[0082] In some embodiments, the insulator 30 is connected to the end cap 12 .

[0083] like Figure 4 and Figure 6 As shown, the end cap 12 includes an end cap body 121 and a support member 122. The support member 122 is made of an insulating material and can be used to isolate the electrical connection components within the housing 10 from the housing 10 to reduce the risk of short circuits. For example, the support member 122 can be made of plastic, rubber, etc. The insulating member 30 can be connected to the support member 122 by, for example, bonding, hot-melting, or clamping.

[0084] The insulating member 30 can be fixedly connected to the end cover 12 by bonding or other methods, thereby improving the stability of the fixing of the insulating member 30 and reducing the probability of the insulating member 30 moving or deforming, so that the insulating member 30 can provide a reliable insulation effect throughout the life cycle of the battery cell 100.

[0085] like Figure 4 and Figure 6 As shown, in some embodiments, the housing 10 further includes a bottom support plate 40 , which is located between the insulating member 30 and the housing 10 .

[0086] like Figure 4 As shown, the bottom support plate 40 is provided at the bottom of the shell 11 of the battery cell 100, and is used to support the electrode assembly 20 of the battery cell 100. The provision of the bottom support plate 40 can reduce the risk of short circuit between the electrode assembly 20 and the shell 10. The insulating member 30 is supported on the bottom support plate 40. Figure 5As shown, the insulating member 30 includes a bottom wall 31, which can abut against the bottom support plate 40, thereby separating the bottom wall 31 of the insulating member 30 from the outer shell 10, reducing the probability of puncturing the insulating member 30 when the outer shell 10 is damaged, thereby reducing the risk of damage to the insulating member 30, electrolyte outflow causing short circuit, etc., and further improving the reliability of the battery cell 100.

[0087] In some embodiments, the insulating member 30 is a bag-shaped structure with an open top and no interface.

[0088] The bag-shaped structure has a top opening without an interface, that is, the insulating part 30 has an opening only on the top wall, and the bottom wall and the side wall are integrally formed, and the side wall may include multiple side walls, and the multiple side walls are also integrally formed without a connection point, thereby ensuring the relative sealing of the insulating part 30 and having a good isolation effect.

[0089] In the above technical solution, the insulating member 30 can be directly sleeved on the outside of the energy unit to protect the energy unit, reduce the probability of safety accidents when the battery cell 100 fails in insulation, and improve the reliability of the battery cell 100.

[0090] In some embodiments, the insulating member 30 is formed by folding a piece of insulating sheet. The insulating member 30 includes a plurality of bent portions 34 . The plurality of bent portions 34 are connected to each other, and the connection points 35 are sealed.

[0091] The multiple bent portions 34 of the insulating member 30 are connected to each other, and the connection points 35 can be sealed by methods such as heat pressing to form the insulating member 30. The electrode assembly 20 and the electrolyte can be placed in the insulating member 30.

[0092] The packaging is then fed into a laminator or heat sealer, where it is sealed at the appropriate temperature and pressure. The heat sealer heats the insulating sheet with a hot press, fusing it together at the seal to create a seal.

[0093] The insulating member 30 is formed by bending, which has a simple manufacturing process and is easy to assemble. The insulating member 30 is sealed at the connection 35 of the bent portion 34, so that the insulating member 30 has an isolation effect, reducing the probability of safety accidents occurring in the battery cell 100 when insulation failure occurs, and improving the reliability of the battery cell 100.

[0094] In some embodiments, the insulating member 30 is formed by heat shrinking a heat shrink film.

[0095] When exposed to heat, the heat-shrinkable film shrinks, forming an insulating member 30 that tightly wraps around the exterior of the energy cell. This insulating member 30, formed by shrinking the heat-shrinkable film, is structurally stable and is less prone to holes or gaps. This provides excellent isolation, protecting the energy cell and reducing the likelihood of safety incidents in the event of insulation failure within the battery cell 100, thereby improving the reliability of the battery cell 100.

[0096] In some embodiments, the insulating member 30 is integrally formed by a film blowing process.

[0097] After the sheet-like insulating material is expanded by blowing, a bag-shaped insulating member 30 with an opening on one side is formed, so that the insulating member 30 is an integrally formed member, the manufacturing process is simple, the production efficiency is high, and the cost is low. The insulating member can be directly put on the outside of the energy unit to protect the energy unit, reduce the probability of safety accidents occurring in the battery cell when the insulation fails, and improve the reliability of the battery cell.

[0098] In some embodiments, the air permeability of the insulating member 30 at 0.1 MPa is ρ, ρ≤10 L / (m 2 ·24h).

[0099] Air permeability refers to the amount of medium that can pass through the insulating member 30 per unit area per unit time. At 0.1 MPa, the amount of medium that can pass through the insulating member 30 per square meter within 24 hours should not exceed 10 liters. This prevents the electrolyte in the energy unit from penetrating the insulating member 30, ensuring a good seal. The air permeability test is carried out in accordance with GB / T 1038-2000, Plastic Film and Sheeting Gas Permeability Test Method - Pressure Difference Method.

[0100] In some embodiments, the material of the insulating member 30 includes at least one of polyamide, polypropylene, polyethylene terephthalate, and polyimide.

[0101] The material of the insulating part 30 can be polyamide, polypropylene, polyethylene terephthalate or polyimide, or a composite material. By controlling the type of the main material of the insulating part 30, the material has good insulation and resistance to electrolyte corrosion, ensuring its reliability throughout the life cycle of the battery cell 100.

[0102] The battery 1000 according to the second aspect embodiment of the present application includes the battery cell 100 according to the above-mentioned first aspect embodiment of the present application. By adopting the above-mentioned battery cell 100, the electrolyte in the energy unit will not contact the outer shell 10, and there is no ion channel between the electrode assembly 20 and the outer shell 10. The setting of the insulating part 30 increases the impedance between the electrode assembly 20 and the outer shell 10, and increases the pressure resistance of the battery cell 100. Therefore, when the insulation failure of the battery cell 100 occurs, it avoids to a certain extent the decomposition of the electrolyte under high pressure, resulting in the breakdown of the battery cell 100, and reduces the probability of safety accidents such as corrosion and thermal runaway of the battery 100.

[0103] According to the third embodiment of the present application, the power device 2000 includes the battery 1000 according to the second embodiment of the present application, and the battery 1000 is used to provide power to the power device 2000. Therefore, by using the above-mentioned battery 1000, the safety and reliability of the power device 2000 are improved.

[0104] Alternatively, as Figure 1 As shown, when battery 1000 is used in a vehicle, it can be installed at the bottom, front, or rear of the vehicle. Battery 1000 can be used to power the vehicle, for example, as an operating power source for the vehicle. The vehicle may also include a controller and a motor. The controller is used to control battery 1000 to power the motor, for example, to meet the vehicle's starting, navigation, and driving needs.

[0105] A battery 1000 and a vehicle having the same according to a specific embodiment of the present application will be described below with reference to the accompanying drawings.

[0106] like Figure 1 As shown, the battery 1000 is located at the bottom of the vehicle and Figure 2 and Figure 4 As shown, the battery 1000 includes a plurality of battery cells 100, each of which includes an energy unit, an insulating member 30, a bottom support plate 40, and a housing 10. The energy unit includes an electrode assembly 20 and an electrolyte.

[0107] like Figure 5 As shown, the insulating part 30 is made of an insulating material through a bending process. The insulating part 30 includes a plurality of bending parts 34, and the plurality of bending parts 34 are connected to each other. The connection 35 of the plurality of bending parts 24 is sealed by hot pressing and edge sealing, thereby forming a structure with a bottom wall 31 and a side wall 32. The bottom wall 31 and the side wall 32 are connected to form a receiving space 301. The main body 21 of the electrode assembly 20 and the electrolyte can be located in the receiving space 301, that is, the insulating part 30 separates the electrolyte in the energy unit from the outer shell 10.

[0108] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0109] Example 1

[0110] Preparation of battery cells: stack the positive electrode sheet, separator, and negative electrode sheet in order, so that the separator is in the middle of the positive and negative electrode sheets to isolate the positive and negative electrodes, wind them to obtain a bare cell, weld the tabs, and place them in the Figure 5 The insulating part shown is placed in the figure, and the bare battery cell with the insulating part is placed in an aluminum shell, the electrolyte is injected into the dried shell, and the battery is packaged, left to stand, formed, shaped, and capacity tested to prepare a ternary lithium-ion battery, wherein a bar is welded on the aluminum shell.

[0111] The preparation method of the battery cell 100 in Comparative Example 1-2 is the same as that in Example 1, except that a mylar film is set on the outside of the bare battery cell in Comparative Example 2, and the mylar has holes at the bottom and holes at the folded edge. The bare battery cell in Comparative Example 2 is set on the outside of the mylar, and the mylar has holes at the bottom and no holes at the folded edge.

[0112] The capacity of the battery cells prepared in Example 1 and Comparative Examples 1-2 is 150 Ah, and the ternary lithium-ion batteries are in a state of 100% SOC.

[0113] The impedance and withstand voltage capability of the battery cells obtained in Example 1 and Comparative Examples 1-2 were measured.

[0114] The impedance measurement method is to use 1kHz AC impedance to test the impedance between the negative pole and the shell. The impedance measurement results are shown in Table 1.

[0115] The withstand voltage capability is measured by connecting an external 200V DC power supply, with the positive terminal of the power supply connected to the negative terminal of the battery cell and the negative terminal of the power supply connected to the battery cell casing (for example, connected to the tab on the casing). The withstand voltage capability results are shown in Table 1.

[0116] Table 1

[0117] Impedance between the negative pole and the shell Test results Comparative Example 1 50Ω Fire in 1s Comparative Example 2 200Ω Fire in 3 seconds Example 1 >2500Ω No fire in 2 hours

[0118] Based on the data of Example 1 and Comparative Examples 1-2, it can be seen that the battery cells of Comparative Examples 1 and 2 have smaller impedances and catch fire quickly in a shorter time, while the battery cell of Example 1 has larger impedance and does not catch fire within 2 hours. The voltage resistance capability of the battery cell of Example 1 is greatly improved compared with the comparative examples.

[0119] That is, by adopting the solution of the above-mentioned embodiment of the present application, the provision of the insulating member 30 increases the impedance between the electrode assembly 20 and the outer shell 10, and increases the pressure resistance of the battery cell 100. Therefore, when the insulation failure occurs in the battery cell 100, it avoids the decomposition of the electrolyte under high pressure to a certain extent, causing the battery cell 100 to be punctured, and reduces the probability of safety accidents such as corrosion and thermal runaway, thereby improving the reliability of the battery cell 100.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: an energy cell, including an electrode assembly and an electrolyte; a housing for accommodating the energy unit, An insulating member is provided between the energy unit and the shell, and the insulating member is used to separate the electrolyte in the energy unit from the shell. The shell also has a bottom support plate, and the bottom support plate is located between the insulating member and the shell.

2. The battery cell according to claim 1, wherein: The insulating member includes a bottom wall and a side peripheral wall, wherein the side peripheral wall is provided on the bottom wall and connected to the bottom wall to define an accommodation space, and at least a portion of the energy unit is located in the accommodation space.

3. The battery cell according to claim 2, characterized in that: The top of the insulating member is open.

4. The battery cell according to claim 2, characterized in that: The insulating member further includes a top wall, which is opposite to the bottom wall and connected to the side wall, and has an avoidance gap.

5. The battery cell according to claim 2, characterized in that: The electrode assembly includes a main body and a tab, wherein the tab protrudes from the main body in a first direction, and a size of the accommodation space in the first direction is not smaller than a size of the main body in the first direction.

6. The battery cell according to claim 1, characterized in that The housing includes a shell and an end cover. At least one side of the shell has an opening. The end cover is connected to the shell and is used to close the opening. At least a portion of the insulating member is in contact with the shell.

7. The battery cell according to claim 6, characterized in that The insulating member is connected to the end cover.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The insulating member is a bagged structure with an open top and no interface.

9. The battery cell according to any one of claims 1 to 7, characterized in that: The insulating member is formed by folding an insulating sheet. The insulating member includes a plurality of bent portions, and the plurality of bent portions are connected to each other and the connection portions are sealed.

10. The battery cell according to any one of claims 1 to 7, characterized in that: The insulating member is formed by heat shrinking a heat shrinkable film, or the insulating member is integrally formed by a film blowing process.

11. The battery cell according to claim 1, characterized in that The air permeability of the insulating member at 0.1 MPa is ρ, ρ≤10L / (m 2 ·24h).

12. A battery, wherein: The invention comprises a battery cell according to any one of claims 1 to 11.

13. An electrical device, wherein: The battery according to claim 12 is included for providing electrical energy.

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