Patent Description:
Achieving energy conservation and emission reduction is the key to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages in energy conservation and environmental protection. For the electric vehicles, the battery technology is an important factor to their development.

Batteries such as lithium-ion batteries have been widely used in electronic devices such as mobile phones and laptops due to their advantages of high energy density, environmental friendliness, etc. In recent years, in order to deal with environmental problems and issues of gasoline prices and energy storage, the application of lithium-ion batteries has been rapidly expanded to gasoline-electric hybrid vehicles, ships, energy storage systems, etc..

A battery generally comprises a plurality of battery cells. Each battery cell comprises a housing, an electrode assembly and an electrolyte solution which are accommodated in the housing, and a cap assembly connected to the housing. The electrode assembly comprises a positive electrode plate, a negative electrode plate, and a separator that separates the positive electrode plate from the negative electrode plate. In order to avoid leakage of the electrolyte solution, the housing is generally sealed by the cap assembly. However, the electrode assembly generates gas in charging and discharging processes. With accumulation of the gas, the pressure inside the housing continuously increases, which easily results in the risk of deformation of the battery and deterioration of the performance of the electrode assembly. In the prior art, housing structures of battery cells are disclosed, for example, in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

In view of the above problems, the present application provides a battery cell, a battery, a power consuming device, and a method for manufacturing the battery cell. Gas inside a battery can be discharged to prevent the gas from accumulating inside the housing, thereby improving performance of an electrode assembly, prolonging service life of a secondary battery, and ensuring safety performance of the battery cell.

In a first aspect, the present application provides a battery cell, comprising a cover plate, a housing, and a gas-permeable film. The housing has an opening, and the cover plate covers the opening of the housing. The cover plate and/or housing have/has at least one through hole, and the inside and the outside of the battery cell are in communication with each other via the through hole; and the gas-permeable film is connected to the inside of the cover plate and/or housing and covers the at least one through hole. In this way, gas inside the battery cell can be discharged from the battery cell through the gas-permeable film, thereby reducing the risk of swelling or explosion of the battery cell; and the gas-permeable film can also prevent leakage of an electrolyte solution inside the battery cell and prevent external liquid from entering the battery cell. Moreover, since the gas-permeable film is connected to the inside of the cover plate or housing, an outward pressure is generated on the gas-permeable film <NUM> when the gas pressure inside the battery cell increases, so that the edge of the gas-permeable film is more closely connected to the cover plate or housing, and the gas-permeable film is less prone to being separated from the cover plate or housing.

The at least one through hole comprises an accommodating section and an extending section in a direction perpendicular to the plane of the cover plate or housing, the accommodating section having an average bore-diameter greater than the bore-diameter of the extending section, and the accommodating section being closer to the inside of the battery cell than the extending section; and the battery cell further comprises a backing material, the backing material being at least partially accommodated in the accommodating section. In this way, when the gas-permeable film tends to deform outward under the action of the gas pressure inside the battery cell, an internal wall of the through hole provides an additional support force to the backing material, which further increases the support force for the gas-permeable film, so that the gas-permeable film is less prone to deformation.

The backing material is made of a hydrophobic and gas-permeable material having a gas permeation volume greater than the gas permeation volume of the gas-permeable film, and/or having a melting point greater than the melting point of the gas-permeable film. In this way, gas inside the battery cell passing through the gas-permeable film can be smoothly discharged through the backing material to ensure safety performance of the battery cell. In addition, when the temperature of the battery cell reaches the melting point of the gas-permeable film, the gas-permeable film deforms and flows. Since the melting point of the backing material is greater than the melting point of the gas-permeable film, the backing material can support and fix the material of gas-permeable film to reduce the flow and deformation of the gas-permeable film.

In some embodiments, a recess is provided on the inside of the cover plate and/or housing, the recess is provided around the at least one through hole, and the gas-permeable film is at least partially accommodated in the recess. In this way, the internal space of the battery cell occupied by the gas-permeable film can be reduced, the overall thickness of the cover plate or housing can be reduced, and it is also ensured that gas inside the battery cell can be discharged from the battery cell through the gas-permeable film that is at least partially accommodated in the recess.

In some embodiments, a minimum distance from the edge of the gas-permeable film to the edge, inside the cover plate and/or housing, of the at least one through hole along the plane of the cover plate or housing is greater than or equal to <NUM>. In this way, it can be ensured that when the gas pressure inside the battery cell increases, the gas-permeable film and the cover plate or housing can still remain connected, and the degree of deformation of the gas-permeable film is within an acceptable range.

In some embodiments, when a plurality of through holes are provided, the plurality of through holes are adjacently arranged in the plane of the cover plate or housing. In this way, the requirements for the displacement of the battery cell can be met, a stronger support effect on the gas-permeable film can be generated by means of spacer portions between the plurality of through holes, and the area of the gas-permeable film can also be minimized on the premise of covering the plurality of through holes.

In some embodiments, the gas-permeable film is connected to the inside of the cap assembly and/or housing by thermal compounding or bonding. In this way, a connection manner between the gas-permeable film and the cover plate or housing is simplified, and an additional connecting structure is omitted, thus simplifying the manufacturing process and reducing the manufacturing cost.

In a second aspect, the present application provides a battery, comprising a battery cell in the foregoing embodiments.

In a third aspect, the present application provides a power consuming device, comprising a battery in the foregoing embodiments, the battery being used to provide electrical energy.

In a fourth aspect, the present application provides a method for manufacturing a battery cell, comprising: providing a cover plate, a housing, and a gas-permeable film, wherein the housing has an opening; covering the opening of the housing with the cover plate; providing at least one through hole in the cover plate and/or housing, the battery cell being in communication with the outside via the through hole; and connecting the gas-permeable film to the inside of the cover plate and/or housing with the at least one through hole covered. In this way, gas inside the battery cell can be discharged from the battery cell through the gas-permeable film, thereby reducing the risk of swelling or explosion of the battery cell; and the gas-permeable film can also prevent leakage of an electrolyte solution inside the battery cell and prevent external liquid from entering the battery cell. Moreover, since the gas-permeable film is connected to the inside of the cover plate or housing, an outward pressure is generated on the gas-permeable film when the gas pressure inside the battery cell increases, so that the edge of the gas-permeable film is more closely connected to the cover plate or housing, and the gas-permeable film is less prone to being separated from the cover plate or housing.

The at least one through hole is configured to comprise an accommodating section and an extending section in a direction perpendicular to the plane of the cover plate or housing, the accommodating section having an average bore-diameter greater than the bore-diameter of the extending section, and the accommodating section being closer to the inside of the battery cell than the extending section; and a backing material is provided, the backing material being at least partially accommodated in the accommodating section. In this way, when the gas-permeable film tends to deform outward under the action of the gas pressure inside the battery cell, an internal wall of the through hole provides an additional support force to the backing material, which further increases the support force for the gas-permeable film, so that the gas-permeable film is less prone to deformation.

In some embodiments, a minimum distance from the edge of the gas-permeable film to the edge, inside the cover plate and/or housing, of the through hole along the plane of the cover plate or housing is set to be greater than or equal to <NUM>. In this way, it can be ensured that when the gas pressure inside the battery cell increases, the gas-permeable film and the cover plate or housing can still remain connected, and the degree of deformation of the gas-permeable film is within an acceptable range.

In some embodiments, when a plurality of through holes are provided, the plurality of through holes are adjacently arranged in the plane of the cover plate and/or housing. In this way, the requirements for the displacement of the battery cell can be met, a stronger support effect on the gas-permeable film can be generated by means of spacer portions between the plurality of through holes, and the area of the gas-permeable film can also be minimized on the premise of covering the plurality of through holes.

In some embodiments, the gas-permeable film is connected to the inside of the cover plate and/or housing by thermal compounding or bonding.

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of preferred embodiments. Like components are denoted by like reference numerals throughout the drawings. In the drawings:.

Embodiments of the technical solutions of the present application will be described in more detail below with reference to the drawings.

At present, from the perspective of the development of the market situation, batteries are used more and more widely. The batteries are not only used in energy storage power systems such as hydroelectric power plants, thermal power plants, wind power plants and solar power plants, but also widely used in electric transportation means such as electric bicycles, electric motorcycles and electric vehicles and in many fields such as military equipment and aerospace. With the continuous expansion of the application field of batteries, the market demand for the batteries is also expanding.

Due to small capacity or power of a single battery cell, a plurality of battery cells are often required to arrange to form a battery for use. As the cycle time of a battery increases, a chemical system inside the battery cell will generate gas, causing the gas pressure inside the battery cell to keep rising. Therefore, an exhaust structure is required to be provided on the battery cell to discharge gas in a housing. Once thermal runaway of the battery cell occurs, the gas pressure inside the battery cell rises sharply. When a predetermined temperature and pressure are reached, a pressure relief mechanism is activated to release the gas pressure inside the battery cell which may also take away part of heat, thereby slowing down a rate at which the thermal runaway occurs.

<FIG> show schematic structural diagrams of a battery cell and a cap assembly thereof. Referring to <FIG>, the battery cell comprises a housing <NUM>, an electrode assembly <NUM>, and a cap assembly <NUM>. The cap assembly <NUM> comprises a cover plate <NUM> and electrode terminals <NUM>. The cover plate <NUM> is fixed to an opening of the housing <NUM> so as to close the electrode assembly <NUM> and an electrolyte solution in an accommodating cavity of the housing <NUM>. The electrode terminals <NUM> are provided on the cover plate <NUM> and comprise a negative electrode terminal and a positive electrode terminal. The two electrode terminals <NUM> are electrically connected to corresponding tabs by means of adapter plates <NUM>. The cover plate <NUM> is provided with a filling port <NUM>. The electrolyte solution is injected into the accommodating cavity of the housing <NUM> through the filling port <NUM>. The cover plate <NUM> is provided with an explosion-proof hole <NUM>, and a rupture disc <NUM> covers the explosion-proof hole <NUM>. The cap assembly <NUM> further comprises an insulating plate <NUM> to insulate the cover plate <NUM> from the electrode assembly <NUM>.

<FIG> is a structural exploded view of a cap assembly of the battery cell, <FIG> is a front view of the cap assembly, <FIG> is a cross-sectional view through line A-A in <FIG> is an enlarged view of part B in <FIG>.

As shown in <FIG>, the cap assembly <NUM> comprises a cover plate <NUM>, a gas-permeable film <NUM>, a sealing component <NUM>, and an annular metal press plate <NUM>. The cover plate <NUM> has a vent hole <NUM>, the vent hole <NUM> passes through the cover plate <NUM>, and the vent hole <NUM> is blocked with the gas-permeable film <NUM>. The gas-permeable film <NUM> has water blocking and gas permeation capabilities, so that gas in the battery cell can be diffused to the outside, thereby relieving the problem of the pressure inside the battery cell, and that external liquid can be prevented from entering the interior of the battery cell, thereby ensuring the sealing of the battery cell. The sealing component <NUM> is provided between the gas-permeable film <NUM> and the cover plate <NUM> and around the vent hole <NUM> for sealing a gap between the gas-permeable film <NUM> and the cover plate <NUM>. The annular metal press plate <NUM> has a through hole <NUM> passing through the annular metal press plate in its thickness direction, and the annular metal press plate is pressed to the gas-permeable film <NUM>, and is fixed to the cover plate <NUM> by welding, so that the gas-permeable film <NUM> is fixed to the cover plate <NUM>.

With the above structure, gas inside the battery cell can be discharged from the vent hole <NUM> through the gas-permeable film <NUM>, thereby achieving an effect of relieving the pressure inside the battery cell.

The inventor has noticed that in the above technical solution of the prior art, the gas-permeable film <NUM> is connected to the cover plate <NUM> by means of the annular metal press plate <NUM> and the sealing component <NUM>, resulting in a poor air tightness between the gas-permeable film <NUM> and the annular metal press plate <NUM> and the cover plate <NUM>. As time goes, the sealing component <NUM> ages, and the gas-permeable film <NUM> is deformed in the case of increasing internal pressure, which both lead to an increase in the gap between the cover plate <NUM> and the gas-permeable film <NUM>. In addition, since the gas-permeable film <NUM> has no support, it is more likely to be deformed during use, which also leads to an increase in the gap between the cover plate <NUM> and the gas-permeable film <NUM>. Moreover, since the annular metal press plate <NUM> is fixed to the cover plate <NUM> by welding, there is a risk of falling off of particles or metal scraps.

In order to solve the above defects in the prior art, the inventor has designed a battery cell after intensive research, in which one or more through holes that connect the inside and the outside of the battery cell are provided in a cover plate as vent holes, and a gas-permeable film is connected to the inside of the cover plate by thermal compounding or bonding and covers the through hole. With this arrangement of the gas-permeable film, a connecting structure for the gas-permeable film and the cover plate is simplified, and the risk such as welding slag splashing caused by welding is avoided. When a plurality of vent holes are provided, the plurality of vent hole may be adjacently arranged, which improves a support capability for the gas-permeable film while ensuring a gas permeation volume, and also minimizes the area of the gas-permeable film. In addition, a backing material may also be accommodated in the vent hole, the backing material has a gas permeability stronger than the gas permeability of the gas-permeable film, and a melting point higher than the melting point of the gas-permeable film, so that the support capability for the gas-permeable film is further improved while ensuring the gas permeation volume. The inventor has further found that by a simplified manner for combining the gas-permeable film with the cover plate by thermal compounding or bonding, there is no need to provide a separate connecting structure on the cover plate to fix the gas-permeable film. Therefore, in addition to being provided in the cover plate, the vent hole may be provided at any position on a housing of the battery cell. In this case, the arrangement of the vent hole and the backing material and the connection manner between the gas-permeable film and the housing can be the same as the above manners for providing the vent hole in the cover plate and connecting the gas-permeable film and the cover plate.

The battery cell disclosed in the embodiments of the present application may be used in, but not limited to, a power consuming device such as a vehicle, a ship, or an aircraft. A power system having the power consuming device composed of the battery cell, the battery, etc. that are disclosed in the present application may be used, which is conductive to discharging gas inside the battery cell to prevent gas from accumulating inside the housing, thereby improving performance of an electrode assembly, prolonging service life of the battery cell, and ensuring safety performance of the battery cell.

The embodiments of the present application provide a power consuming device using a battery as a power source. The power consuming device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery cart, an electric vehicle, a ship, a spacecraft, etc. The electric toy may include a stationary or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc..

For ease of description of the following embodiments, an embodiment of the present application in which the power consuming device is a vehicle <NUM> is taken as an example for description.

Referring to <FIG> is a schematic structural diagram of a vehicle <NUM> according to an embodiment of the present application. The vehicle <NUM> may be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle may be a battery electric vehicle, a hybrid electric vehicle, an extended-range vehicle, etc. A battery <NUM> is provided inside the vehicle <NUM>, and the battery <NUM> may be provided at the bottom, the front or the back of the vehicle <NUM>. The battery <NUM> may be used for power supply for the vehicle <NUM>. For example, the battery <NUM> may serve as a power source for operating the vehicle <NUM>. The vehicle <NUM> may further comprise a controller <NUM> and a motor <NUM>, and the controller <NUM> is used to control the battery <NUM> to supply power to the motor <NUM>, for example, to satisfy the working power requirements during the starting, navigation and traveling of the vehicle <NUM>.

In some embodiments of the present application, the battery <NUM> can not only serve as a power source for operating the vehicle <NUM>, but also serve as a power source for driving the vehicle <NUM>, instead of or partially instead of fuel or natural gas, to provide driving power for the vehicle <NUM>.

Referring to <FIG> is an exploded schematic structural diagram of a battery <NUM> according to an embodiment of the present application. The battery <NUM> comprises a case <NUM> and a plurality of battery modules <NUM>. The plurality of battery modules <NUM> are accommodated in the case <NUM>. The case <NUM> is used to provide an accommodating space for the plurality of battery modules <NUM>, and the case <NUM> may be of various structures. In some embodiments, the case <NUM> may comprise a first portion <NUM> and a second portion <NUM>. The first portion <NUM> and the second portion <NUM> are fitted to each other in a covered manner, and the first portion <NUM> and the second portion <NUM> together define an accommodating space for accommodating the plurality of battery modules <NUM>. The second portion <NUM> may be of a hollow structure with one end open, the first portion <NUM> may be of a plate-like structure, and the first portion <NUM> is fitted to an open side of the second portion <NUM> in a covered manner such that the first portion <NUM> and the second portion <NUM> together define the accommodating space; and the first portion <NUM> and the second portion <NUM> may also be of a hollow structure with one side open, and an open side of the first portion <NUM> is fitted to the open side of the second portion <NUM> in a covered manner. Of course, the case <NUM> formed by the first portion <NUM> and the second portion <NUM> may be in various shapes such as a cylinder and a cuboid.

The battery module <NUM> may comprise one or more battery cells <NUM> in order to meet different power demands. The plurality of battery cells <NUM> may be in series connection or parallel connection or series-parallel connection to form one battery module <NUM>, and the plurality of battery modules <NUM> may then be in series connection or parallel connection or series-parallel connection to form a battery. The series-parallel connection refers to a combination of series connection and parallel connection. Exemplarily, the battery <NUM> may comprise a plurality of battery cells <NUM>, wherein the plurality of battery cells <NUM> may be in series connection or parallel connection or series-parallel connection. The plurality of battery cells <NUM> may be directly provided in the case. That is, the plurality of battery cells <NUM> may directly constitute a battery <NUM>, or may constitute a battery module <NUM> and the battery modules <NUM> then constitute a battery <NUM>. Each battery cell <NUM> may be a secondary battery or a primary battery, and may also be a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell <NUM> may be cylindrical, flat, rectangular, or in another shape.

Referring to <FIG> is an exploded schematic structural diagram of a battery cell <NUM> according to an embodiment of the present application. The battery cell <NUM> is the smallest unit of a battery. As shown in <FIG>, the battery cell <NUM> comprises a cover plate <NUM>, a housing <NUM>, an electrode assembly <NUM>, and other functional components.

The cover plate <NUM> refers to a component that covers an opening of the housing <NUM> to isolate an internal environment of the battery cell <NUM> from an external environment. Without limitation, the cover plate <NUM> may have a shape adapted to that of the housing <NUM> to fit with the housing <NUM>. Optionally, the cover plate <NUM> may be made of a material with certain hardness and strength, and thus the cover plate <NUM> is less prone to deformation when being squeezed or collided, so that the battery cell <NUM> can have a higher structural strength, and safety performance can also be improved. The cover plate <NUM> is provided with a through hole <NUM> that is used to discharge gas inside the battery cell <NUM>; an explosion-proof hole <NUM> that is used to quickly release gas inside the battery cell when thermal runaway occurs in the battery cell <NUM> and an internal gas pressure rises rapidly; and a filling port <NUM> through which an electrolyte solution is injected into the accommodating cavity of the housing <NUM>. Functional components, such as electrode terminals, may be provided on the cover plate <NUM>. The electrode terminals may be used for electrical connection to the electrode assembly <NUM> for outputting or inputting electrical energy of the battery cell <NUM>. The cover plate <NUM> may also be made of various materials, such as copper, iron, aluminum, stainless steel, an aluminum alloy, and plastic, or other materials with certain hardness and strength, which is not particularly limited in the embodiments of the present application. In some embodiments, an insulating member (not shown) may be further provided on an inner side of the cover plate <NUM>. The insulating member may be used to isolate electrical connection components within the housing <NUM> from the cover plate <NUM> so as to reduce the risk of short circuit. Exemplarily, the insulating member may be made of plastic, rubber, etc..

The housing <NUM> is an assembly that is used to fit with the cover plate <NUM> to form an internal environment of the battery cell <NUM>, where the formed internal environment may be used for accommodating the electrode assembly <NUM>, an electrolyte solution and other components. The housing <NUM> and the cover plate <NUM> may be separate components, and the housing <NUM> may be provided with an opening, at which the cover plate <NUM> covers the opening to form the internal environment of the battery cell <NUM>. Without limitation, the cover plate <NUM> and the housing <NUM> may also be integrated. Specifically, the cover plate <NUM> and the housing <NUM> can firstly form a common connection surface before other components are placed into the housing, and then the cover plate <NUM> covers the housing <NUM> when the interior of the housing <NUM> needs to be packaged. The housing <NUM> may be in various shapes and various sizes, for example, in the shape of a cuboid, a cylinder, a hexagonal prism, etc. Specifically, the shape of the housing <NUM> may be determined depending on the specific shape and size of the electrode assembly <NUM>. The housing <NUM> may be made of various materials, such as copper, iron, aluminum, stainless steel, an aluminum alloy, and plastic, or other materials with certain hardness and strength, which is not particularly limited in the embodiments of the present application.

The electrode assembly <NUM> is a component, where an electrochemical reaction occurs, in the battery cell <NUM>. One or more electrode assemblies <NUM> may be contained in the housing <NUM>. The electrode assembly <NUM> is mainly formed by winding or lamination of a positive plate and a negative plate, and a separator is usually provided between the positive plate and the negative plate. The portions of the positive plate and the negative plate that have an active material constitute a main body portion of the electrode assembly, and the portions of the positive plate and the negative plate that have no active material each constitute a tab. A positive electrode tab and a negative electrode tab can be both located at one end of the main body portion or respectively at two ends of the main body portion. During the charging and discharging of the battery, a positive active material and a negative active material react with the electrolyte solution, and the tabs are connected to the electrode terminals to form a current loop.

According to comparative embodiments to aid understanding of the present application, referring to <FIG>, <FIG> is an exploded schematic structural diagram of a battery cell <NUM> according to a comparative embodiment, <FIG> is a front view of the cover plate, and <FIG> is a cross-sectional view through line B-B in <FIG> (the whole cover plate is not shown), and <FIG> is an enlarged view of part C in <FIG>.

The present application provides a battery cell <NUM>. The battery cell <NUM> comprises a cover plate <NUM>, a housing <NUM>, and a gas-permeable film <NUM>. The housing <NUM> has an opening, and the cover plate <NUM> covers the opening of the housing <NUM>. The cover plate <NUM> and/or housing <NUM> have/has at least one through hole <NUM>, and the battery cell is in communication with the outside via the through hole <NUM>. The gas-permeable film <NUM> is connected to the inside of the cover plate <NUM> and/or housing <NUM> and covers the at least one through hole <NUM>.

In <FIG>, at least one through hole <NUM> is schematically provided in the cover plate <NUM>. However, the at least one through hole <NUM> may also be provided at any position on each side plate or bottom plate of the housing <NUM>, and the arrangement and position relationship between the through hole <NUM> and the housing <NUM> are the same as the arrangement and position relationship between the through hole <NUM> and the cover plate <NUM> shown in <FIG>.

In addition, schematically, through holes <NUM> in <FIG> are represented as a plurality of through holes <NUM> with fixed bore-diameters.

As shown, the housing <NUM> is filled with the electrolyte solution, and at least one electrode assembly <NUM> is arranged in the housing <NUM>. Those skilled in the art can understand that the battery cell further comprises other components not shown in the drawings.

The through hole <NUM> passes through the cover plate <NUM> or housing <NUM>. One or more through holes <NUM> are provided , as long as the minimum area of the through holes <NUM> in the plane of the cover plate <NUM> or the plane of the housing <NUM> can meet the requirements for the displacement of the battery cell. The bore-diameter of the through hole <NUM> may be fixed or variable. When the bore-diameter of the through hole <NUM> is a fixed bore-diameter, and when one through hole <NUM> is provided, the minimum area of the through hole <NUM> in the plane of the cover plate <NUM> or housing <NUM> is the opening area of the through hole <NUM> in the plane of the cover plate <NUM> or housing <NUM>. When the bore-diameter of the through holes <NUM> is a fixed bore-diameter, and when a plurality of through holes <NUM> are provided, the minimum area of the through holes <NUM> in the plane of the cover plate <NUM> or housing <NUM> is the sum of the opening areas of the through holes <NUM> in the plane of the cover plate <NUM> or housing <NUM>. When the bore-diameter of the through hole <NUM> is a variable bore-diameter, and when one through hole <NUM> is provided, the minimum area of the through hole <NUM> in the plane of the cover plate <NUM> or housing <NUM> is the smaller of the opening areas of the through hole <NUM> in the planes of an inner surface and an outer surface of the cover plate <NUM> or housing <NUM>. When the bore-diameter of the through hole <NUM> is a variable bore-diameter, and when a plurality of through holes <NUM> are provided, the minimum area of the through holes <NUM> in the plane of the cover plate <NUM> or housing <NUM> is the smaller of the sums of the opening areas of the plurality of through holes <NUM> in the planes of an inner surface and an outer surface of the cover plate <NUM> or housing <NUM>.

In this example, the plane of the cover plate <NUM> refers to the plane where the cover plate <NUM> is located, the plane of the housing <NUM> refers to four side surfaces or a bottom surface of the housing where the through hole <NUM> is provided, the plane of the inner surface of the cover plate <NUM> or housing <NUM> refers to a surface, inside the battery cell <NUM>, of the cover plate <NUM> or housing <NUM>, and the plane of the outer surface of the plane of the cover plate <NUM> or housing <NUM> refers to a surface, outside the battery cell <NUM>, of the cover plate <NUM> or housing <NUM>. Optionally, the gas-permeable film <NUM> is made of a polymer material with gas permeation properties (e.g., a combination of one or two or more of PP, PE, and PU), and can block liquid. The gas-permeable film <NUM> is connected to the inside of the cover plate <NUM> and/or housing <NUM> and covers the at least one through hole <NUM>.

With the above arrangement, gas inside the battery cell <NUM> can be discharged from the battery cell <NUM> through the gas-permeable film <NUM>, thereby reducing the risk of swelling or explosion of the battery cell <NUM>; and the gas-permeable film can also prevent leakage of the electrolyte solution inside the battery cell <NUM> and prevent external liquid from entering the battery cell <NUM>. Moreover, since the gas-permeable film <NUM> is connected to the inside of the cover plate <NUM> or housing <NUM>, an outward pressure is generated on the gas-permeable film <NUM> when the gas pressure inside the battery cell <NUM> increases, so that the edge of the gas-permeable film <NUM> is more closely connected to the cover plate <NUM> or housing <NUM>, and the gas-permeable film <NUM> is less prone to being separated from the cover plate <NUM> or housing <NUM>. Moreover, as the number of through holes <NUM> increases, the support capability of spacer portions <NUM> between the plurality of through holes <NUM> in the cover plate <NUM> or housing <NUM> for the gas-permeable film <NUM> is also accordingly increased, so that the gas-permeable film <NUM> is less prone to deformation.

<FIG> show examples of one through hole <NUM> with a variable bore-diameter in some comparative embodiments and embodiments of the present invention. In <FIG>, the through hole <NUM> comprises an accommodating section <NUM> and an extending section <NUM> in a direction perpendicular to the plane of the cover plate <NUM> or housing <NUM>. The accommodating section <NUM> is closer to the inside of the battery cell <NUM> than the extending section <NUM>. The accommodating section <NUM> has an average bore-diameter greater than the average bore-diameter of the extending section <NUM>. The battery cell <NUM> further comprises a backing material <NUM>, the backing material <NUM> being at least partially accommodated in the accommodating section <NUM>.

The space from the accommodating section <NUM> to the extending section <NUM> may be reduced step by step (e.g., as shown in <FIG> and <FIG> ), or gradually reduced (e.g., as shown in <FIG>). <FIG> and <FIG> only exemplarily show one step. A configuration in which more steps are provided is also possible. The accommodating section <NUM> and the extending section <NUM> only exemplarily define a variable bore-diameter. There may be an obvious dividing point (e.g., as shown in <FIG> and <FIG>) or no obvious dividing point (e.g., as shown in <FIG>) between the accommodating section <NUM> and the extending section <NUM>. When there is no obvious dividing point, a specific position in the through hole may be appropriately selected as a dividing point between the accommodating section <NUM> and the extending section <NUM>.

When the through hole is as shown in <FIG> and <FIG>, the bore-diameters of the accommodating section <NUM> and the extending section <NUM> are fixed, and the average bore-diameter is equal to the respective bore-diameter of the accommodating section <NUM> and the extending section <NUM>. When the through hole is as shown in <FIG>, a section from the dividing point to the opening of the through hole <NUM> outside the battery cell <NUM> is the extending section <NUM>, and the average bore-diameter of the extending section is an average value of the bore-diameters at various positions on this section; and a section from the dividing point to the opening of the through hole <NUM> inside the battery cell <NUM> is the accommodating section <NUM>, and the average bore-diameter of the section is an average value of the bore-diameters at various positions on this section. Therefore, a portion of the through hole <NUM> that is closer to the inside of the battery cell <NUM>, that is, the accommodating section <NUM> has an average bore-diameter greater than the average bore-diameter of a portion that is closer to the outside of the battery cell <NUM>, that is, the extending section <NUM>. It can be understood that when a plurality of through holes <NUM> are provided, the through holes <NUM> may have a fixed bore-diameter, or a variable bore-diameter, or may be a combination of through holes <NUM> having a fixed bore-diameter and various variable bore-diameters.

According to the invention, the backing material <NUM> is also contained in the through hole <NUM>. In the drawings of the present application, the backing material <NUM> is indicated by a dot matrix background. As shown in the comparative embodiment of <FIG>, only the accommodating section <NUM> is filled with the backing material <NUM>. As shown in <FIG>, the accommodating section <NUM> and the extending section <NUM> are filled with the backing material <NUM>. As shown in <FIG>, the through hole <NUM> with a gradually-varied bore-diameter is filled with the backing material <NUM>. It can be understood that when a plurality of through holes <NUM> are provided, part of the space of some of the through holes, or the entire space of all the through holes may be filled with the backing material <NUM>.

The through holes <NUM> may have a fixed bore-diameter, or a variable bore-diameter, or may be a combination of through holes <NUM> having a fixed bore-diameter and various variable bore-diameters.

With the above arrangement of the through holes <NUM>, when the gas-permeable film <NUM> tends to deform outward under the action of the gas pressure inside the battery cell <NUM>, an internal wall of the through hole <NUM> in an exemplary shape given in <FIG> provides an additional support force to the backing material <NUM>, which further increases the support force for the gas-permeable film <NUM>, so that the gas-permeable film <NUM> is less prone to deformation. According to some embodiments of the present application, optionally, the backing material <NUM> is made of a hydrophobic and gas-permeable material having a gas permeation volume greater than the gas permeation volume of the gas-permeable film <NUM>, and/or having a melting point greater than the melting point of the gas-permeable film <NUM>.

The backing material <NUM> is made of a hydrophobic and gas-permeable material, so that in addition to satisfying support requirements for the gas-permeable film <NUM>, it can be ensured that gas passing through the gas-permeable film <NUM> can smoothly pass through the backing material <NUM>, thereby ensuring a gas permeation effect of the gas-permeable film <NUM>; external liquid, etc., can be blocked, thereby preventing the external liquid from entering the interior of the battery cell <NUM> to affect the battery cell <NUM>; and leakage of the electrolyte solution inside the battery cell <NUM> can be prevented.

In some optional embodiments, the melting point of the backing material <NUM> is greater than the melting point of the gas-permeable film <NUM>. Optionally, a difference value between the melting point of the backing material <NUM> and the melting point of the gas-permeable film <NUM> is greater than or equal to <NUM>.

The gas-permeable film <NUM> is made of a material for achieving a gas permeation effect of the battery cell, and gas passing through the gas-permeable film <NUM> needs to be smoothly discharged to the outside of the battery cell <NUM> through the backing material <NUM>. Therefore, It is necessary that the backing material <NUM> has a gas permeation volume greater than the gas permeation volume of the gas-permeable film <NUM>, so that gas inside the battery cell <NUM> passing through the gas-permeable film <NUM> can be smoothly discharged through the backing material <NUM> to ensure safety performance of the battery cell <NUM>.

Since the melting point of the backing material <NUM> is greater than the melting point of the gas-permeable film <NUM>, the gas-permeable film <NUM> deforms and flows when the temperature of the battery cell <NUM> reaches the melting point of the gas-permeable film <NUM>. Since the melting point of the backing material <NUM> is greater than the melting point of the gas-permeable film <NUM>, in this case, the backing material <NUM> does not reach its melting point, and thus can support and fix the material of the gas-permeable film <NUM> to reduce the flow and deformation of the gas-permeable film <NUM>.

According to some embodiments, referring to <FIG>, a plurality of through holes <NUM> being provided is taken as an example in <FIG> and <FIG>, and one through hole <NUM> being provided is taken as an example in <FIG>, which show schematic diagrams of a recess <NUM> being provided on the inside of the cover plate <NUM> or housing <NUM>. Optionally, the recess <NUM> is provided on the inside of the cover plate <NUM> and/or housing <NUM>, the recess <NUM> is provided around the at least one through hole <NUM>, and the gas-permeable film <NUM> is at least partially accommodated in the recess.

The recess <NUM> is provided on the inside of the cover plate <NUM> or housing <NUM> and around the at least one through hole <NUM> for at least partially accommodating the gas-permeable film <NUM> therein, so that the gas-permeable film <NUM> can cover the at least one through hole <NUM> while being partially accommodated in the recess <NUM>.

By providing the recess <NUM>, the internal space of the battery cell <NUM> occupied by the gas-permeable film <NUM> can be reduced, the overall thickness of the cover plate <NUM> or housing <NUM> can be reduced, and it is also ensured that gas inside the battery cell <NUM> can be discharged to the outside of the battery cell <NUM> through the gas-permeable film that is at least partially accommodated in the recess <NUM>.

Referring to <FIG>, according to some embodiments, optionally, a minimum distance D0 from the edge of the gas-permeable film <NUM> to the edge, inside the cover plate <NUM> and/or housing <NUM>, of the at least one through hole <NUM> along the plane of the cover plate <NUM> or housing <NUM> is greater than or equal to <NUM>.

When a plurality of through holes <NUM> are provided, the minimum distance D0 is a minimum distance from the edge, inside the cover plate <NUM> or housing <NUM>, of the through hole <NUM> that is closest to the edge of the gas-permeable film <NUM> from the plurality of through holes <NUM> to the edge of the gas-permeable film <NUM> along the plane of the cover plate <NUM> or housing <NUM>, as shown in <FIG>, <FIG> and <FIG>. When one through hole <NUM> is provided, the D0 is a minimum distance from the edge, inside the cover plate <NUM> or housing <NUM>, of the through hole <NUM> to the edge of the gas-permeable film <NUM> along the plane of the cover plate <NUM> or housing <NUM>, as shown in <FIG> and <FIG>.

By simulating internal pressure conditions of different battery cells <NUM>, tests are carried out for different minimum distances D0. When the minimum distance D0 is greater than or equal to <NUM>, the gas-permeable film <NUM> and the cover plate <NUM> or housing <NUM> can still remain connected, and the degree of deformation of the gas-permeable film <NUM> is within an acceptable range.

According to some embodiments of the present application, optionally, when a plurality of through holes <NUM> are provided, the plurality of through holes <NUM> are adjacently arranged in the plane of the cover plate <NUM> or housing <NUM>.

<FIG> schematically show adjacent arrangements of a plurality of through holes <NUM>. It can be understood that the arrangements of the plurality of through holes <NUM> and the number of through holes <NUM> are not limited to the three modes shown in <FIG>. The plurality of through holes <NUM> may also be adjacently arranged in other regular or irregular ways.

Since the plurality of through holes <NUM> are adjacently arranged, the requirements for the displacement of the battery cell <NUM> can be met, a stronger support effect on the gas-permeable film <NUM> can be generated by means of spacer portions <NUM> between the plurality of through holes <NUM>, and the area of the gas-permeable film <NUM> can also be minimized on the premise of covering the plurality of through holes.

According to some embodiments of the present application, optionally, the gas-permeable film <NUM> is connected to the inside of the cover plate <NUM> and/or housing <NUM> by thermal compounding and/or bonding.

The gas-permeable film <NUM> is connected to the cover plate <NUM> or housing <NUM> by thermal compounding, so that at a bonding surface of the gas-permeable film <NUM> and the cover plate <NUM> or housing <NUM>, functional groups of the gas-permeable film <NUM> are bonded to functional groups of the cover plate <NUM>, the housing <NUM>, or the backing material <NUM> by chemical bonds, so that a strong connection force is obtained. In some embodiments, the gas-permeable film <NUM> may also be connected to the cover plate <NUM> or housing <NUM> by bonding.

With the above connection manner of thermal compounding or bonding, the connection manner between the gas-permeable film <NUM> and the cover plate <NUM> or housing <NUM> is simplified, and an additional connecting structure is omitted. Therefore, the manufacturing process is simplified and the manufacturing cost is reduced.

According to some embodiments of the present application, optionally, the present application further provides a battery, comprising a battery cell <NUM> according to the foregoing embodiments.

The battery may comprise one or more battery modules, and the plurality of battery modules may be in series connection or parallel connection or series-parallel connection to constitute the battery. The battery module further comprises one or more battery cells <NUM>. The plurality of battery cells may be in series connection or parallel connection or series-parallel connection to constitute the battery module. Alternatively, the battery may directly comprise one or more battery cells <NUM> as described above. The plurality of battery cells may be in series connection or parallel connection or series-parallel connection to constitute the battery.

The battery may comprise a housing for housing and sealing the battery modules or battery cells therein, or may not comprise a housing but enable the battery modules or battery cells to be exposed. Various shapes of the housing can be selected according to specific requirements, so as to adapt to the shape of the battery module or battery cell therein, or to adapt to the arrangement of a power consuming device using the battery.

Since the battery comprises the battery cell <NUM> in the foregoing embodiments, gas inside the battery cell <NUM> can be discharged from the battery cell <NUM> in a timely manner, thereby reducing the risk of swelling or explosion of the battery cell <NUM>, and thus further reducing the safety risk of the battery.

According to some embodiments of the present application, optionally, the present application further provides a power consuming device, comprising a battery according to the foregoing embodiments, the battery being used to provide electrical energy for the power consuming device.

The power consuming device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery cart, an electric vehicle, a ship, a spacecraft, etc. The electric toy may include a stationary or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc..

Since the power consuming device comprises the battery cell <NUM> in the foregoing embodiments, gas inside the battery cell <NUM> can be discharged from the battery cell <NUM> in a timely manner, thereby reducing the risk of swelling or explosion of the battery cell <NUM>, and thus further reducing the safety risk of the power consuming device.

According to some embodiments of the present application, optionally, referring to <FIG>, the present application further provides a method for manufacturing a battery cell, which specifically comprises the following steps:.

The type, material, shape, and arrangement of the cover plate, the housing, the gas-permeable film, and the through hole, and the connection relationships between the various parts are all the same as those defined in the foregoing embodiments.

By means of a battery cell manufactured by the above method, the risk of swelling or explosion of the battery cell <NUM> can be reduced, leakage of the electrolyte solution inside the battery cell <NUM> can be prevented, and external liquid can also be prevented from entering into the battery cell <NUM>. Moreover, since the gas-permeable film <NUM> is connected to the inside of the cover plate <NUM> or housing <NUM>, an outward pressure is generated on the gas-permeable film <NUM> when the gas pressure inside the battery cell <NUM> increases, so that the edge of the gas-permeable film <NUM> is more closely connected to the cover plate <NUM> or housing <NUM>, and the gas-permeable film <NUM> is less prone to being separated from the cover plate <NUM> or housing <NUM>. Moreover, as the number of through holes <NUM> increases, the support capability of spacer portions <NUM> between the plurality of through holes <NUM> in the cover plate <NUM> or housing <NUM> for the gas-permeable film <NUM> is also accordingly increased, so that the gas-permeable film <NUM> is less prone to deformation.

According to some embodiments of the present application, optionally, the at least one through hole <NUM> is configured to comprise an accommodating section <NUM> and an extending section <NUM> in a direction perpendicular to the plane of the cover plate <NUM> or housing <NUM>, the accommodating section <NUM> having an average bore-diameter greater than the bore-diameter of the extending section <NUM>, and the accommodating section <NUM> being closer to the inside of the battery cell <NUM> than the extending section <NUM>. A backing material <NUM> is provided, the backing material <NUM> being at least partially accommodated in the accommodating section <NUM>.

The shape, arrangement and position relationship of the through hole <NUM>, the accommodating section <NUM>, the extending section <NUM>, and the backing material <NUM> are the same as those in the foregoing embodiments.

With the above arrangement of the through hole <NUM>, when the gas-permeable film <NUM> tends to deform outward under the action of the gas pressure inside the battery cell <NUM>, an internal wall of the through hole <NUM> in an exemplary shape given in <FIG> provides a stronger support force to the backing material <NUM>, which further increases a support force for the gas-permeable film <NUM>, so that the gas-permeable film <NUM> is less prone to deformation. According to some embodiments of the present application, optionally, the backing material <NUM> is made of a hydrophobic and gas-permeable material having a gas permeation volume greater than the gas permeation volume of the gas-permeable film <NUM>, and/or having a melting point greater than the melting point of the gas-permeable film <NUM>.

According to some embodiments of the present application, referring to <FIG>, a plurality of through holes <NUM> being provided is taken as an example in <FIG> and <FIG>, and one through hole <NUM> being provided is taken as an example in <FIG>, which show schematic diagrams of a recess <NUM> being provided on the inside of the cover plate <NUM> or housing <NUM>. Optionally, the recess <NUM> is provided on the inside of the cover plate <NUM> and/or housing <NUM>, the recess <NUM> is provided around the at least one through hole <NUM>, and the gas-permeable film <NUM> is at least partially accommodated in the recess.

Referring to <FIG>, according to some embodiments of the present application, optionally, a minimum distance D0 from the edge of the gas-permeable film <NUM> to the edge, inside the cover plate <NUM> and/or housing <NUM>, of the at least one through hole <NUM> along the plane of the cover plate <NUM> or housing <NUM> is greater than or equal to <NUM>, and/or a peeling force between the gas-permeable film <NUM> and the cover plate <NUM> and/or housing <NUM> is greater than or equal to <NUM> N/mm.

When a plurality of through holes <NUM> are provided, the D0 is a minimum distance from the edge, inside the cover plate <NUM> or housing <NUM>, of the through hole <NUM> that is closest to the edge of the gas-permeable film <NUM> from the plurality of through holes <NUM> to the edge of the gas-permeable film <NUM> along the plane of the cover plate <NUM> or housing <NUM>, as shown in <FIG>, <FIG> and <FIG>. When one through hole <NUM> is provided, the D0 is a minimum distance from the edge, inside the cover plate <NUM> or housing <NUM>, of the through hole <NUM> to the edge of the gas-permeable film <NUM> along the plane of the cover plate <NUM> or housing <NUM>, as shown in <FIG> and <FIG>.

By simulating internal pressure conditions of different battery cells <NUM>, tests are carried out for different D0. When the minimum distance D0 is greater than or equal to <NUM>, the gas-permeable film <NUM> and the cover plate <NUM> or housing <NUM> can still remain connected, and the degree of deformation of the gas-permeable film <NUM> is within an acceptable range.

Referring to <FIG>, a specific embodiment in which a plurality of through holes are provided is exemplarily shown. A battery cell <NUM> is provided. The battery cell <NUM> comprises a cover plate <NUM>, a housing <NUM>, an electrode assembly <NUM>, and a gas-permeable film <NUM>. The cover body <NUM> comprises a plurality of through holes <NUM> and a plurality of spacer portions <NUM> between the plurality of through holes <NUM>. In <FIG>, the cover body <NUM> and the plurality of spacer portions <NUM> thereof are indicated by a diagonal background, the plurality of through holes <NUM> are indicated by a white background, and the gas-permeable film <NUM> is indicated by a black background, where five vent holes <NUM> are exemplarily shown.

The gas-permeable film <NUM> is connected to the inside of the cover plate <NUM> and/or housing <NUM> by thermal compounding and/or bonding. The gas-permeable film <NUM> is connected to the cover plate <NUM> or housing <NUM> by thermal compounding, so that at a bonding surface of the gas-permeable film <NUM> and the cover plate <NUM> or housing <NUM>, functional groups of the gas-permeable film <NUM> are bonded to functional groups of the cover plate <NUM>, the housing <NUM>, or the backing material <NUM> by chemical bonds, so that a strong connection force is obtained. In some embodiments, the gas-permeable film <NUM> may also be connected to the cover plate <NUM> or housing <NUM> by bonding.

Referring to <FIG>, the minimum distance D0 from the edge of the gas-permeable film <NUM> to the edge, inside the cover plate <NUM> and/or housing <NUM>, of the through hole that is closest to the edge of the gas-permeable film <NUM> from the plurality of through holes along the plane of the cover plate <NUM> or housing <NUM> is greater than or equal to <NUM>. The minimum distance D0 is set to ensure that when the gas pressure inside the battery cell <NUM> increases, and a pressure toward the outside of the battery cell <NUM> is generated on the gas-permeable film, the gas-permeable film <NUM> and the cover plate <NUM> or housing <NUM> can still remain connected, and the degree of deformation of the gas-permeable film <NUM> is within an acceptable range.

Referring to <FIG>, a specific embodiment in which one through hole is provided is exemplarily shown. <FIG> only shows the specific structure at the through hole. Other parts other than the through hole, such as the cover plate, the housing, and the electrode assembly, may be the same as those in other embodiments.

In this embodiment, the through hole <NUM> may be divided into an extending section <NUM> and an accommodating section <NUM>. The extending section <NUM> is a cylinder with a bore-diameter of L11 and a height of H11, and the accommodating section <NUM> is a cylinder with a bore-diameter of L12 and a height of H12. The accommodating section <NUM> is closer to the inside of the battery cell <NUM> than the extending section <NUM>, and the accommodating section <NUM> has a diameter greater than the diameter of the extending section <NUM>.

The accommodating section <NUM> and the extending section <NUM> shown in <FIG> are two coaxial cylinders. However, those skilled in the art can understand that when the accommodating section <NUM> and the extending section <NUM> each is a cylinder, the axes of the two may coincide or not coincide, may be parallel or not be parallel, as long as it is ensured that the through hole <NUM> composed of the accommodating section <NUM> and the extending section <NUM> can pass through the inside and outside of the battery cell <NUM>. In addition, the accommodating section <NUM> and the extending section <NUM> may also have other regular or irregular shapes. When the accommodating section <NUM> and the extending section <NUM> have non-fixed bore-diameters, it is only necessary to ensure that the accommodating section <NUM> has an average bore-diameter greater than the average bore-diameter of the extending section <NUM>.

With the above arrangement of the through hole <NUM>, when the gas-permeable film <NUM> tends to deform outward under the action of the gas pressure inside the battery cell <NUM>, the step-shaped reduced bore-diameter from the accommodating section <NUM> to the extending section <NUM> enables an hole wall to provide an additional support force to the backing material <NUM>, which further increases the support force for the gas-permeable film <NUM>, so that the gas-permeable film <NUM> is less prone to deformation. Of course, the gradually reduced bore-diameter from the accommodating section <NUM> to the extending section <NUM> can also provide the additional support force described above.

As shown in <FIG>, the accommodating section <NUM> and the extending section <NUM> are filled with the backing material <NUM>, the backing material <NUM> is indicated by a dot matrix background in <FIG>, and the material of the backing material <NUM> is the same as that in the foregoing embodiments.

As shown in <FIG>, a recess <NUM> is also provided on the inside of the cover plate <NUM>. In the figure, the recess <NUM> is a cylinder with a height of H46 and a bore-diameter of L46. The recess <NUM> is provided around the through hole <NUM> and accommodates the gas-permeable film <NUM> therein. Those skilled in the art can understand that the recess <NUM> may also have other regular or irregular shapes, as long as it is provided around the through hole and can at least partially accommodate the gas-permeable film <NUM>.

By providing the recess <NUM>, the internal space of the battery cell <NUM> occupied by the gas-permeable film <NUM> can be reduced, the overall thickness of the cover plate <NUM> can be reduced, and it is also ensured that gas inside the battery cell <NUM> can be discharged to the outside of the battery cell <NUM> through the gas-permeable film that is at least partially accommodated in the recess <NUM>.

Claim 1:
A battery cell (<NUM>), comprising a cover plate (<NUM>), a housing (<NUM>), and a gas-permeable film (<NUM>), wherein:
the housing (<NUM>) has an opening and the cover plate (<NUM>) covers the opening of the housing (<NUM>);
the cover plate (<NUM>) and/or housing (<NUM>) have/has at least one through hole (<NUM>), and the inside and the outside of the battery cell (<NUM>) are in communication with each other via the through hole (<NUM>);
the gas-permeable film (<NUM>) is connected to the inside of the cover plate (<NUM>) and/or housing (<NUM>) and covers the at least one through hole (<NUM>);
the at least one through hole (<NUM>) comprises an accommodating section (<NUM>) and an extending section (<NUM>) in a direction perpendicular to the plane of the cover plate (<NUM>) or housing (<NUM>), the accommodating section (<NUM>) having an average bore-diameter greater than the average bore-diameter of the extending section (<NUM>), and the accommodating section (<NUM>) being closer to the inside of the battery cell (<NUM>) than the extending section (<NUM>);
the battery cell (<NUM>) further comprises a backing material (<NUM>), the backing material (<NUM>) being at least partially accommodated in the accommodating section (<NUM>) and being contained in the through hole (<NUM>); and
the backing material (<NUM>) is made of a hydrophobic and gas-permeable material having a gas permeation volume greater than the gas permeation volume of the gas-permeable film (<NUM>), and/or having a melting point greater than the melting point of the gas-permeable film (<NUM>).