WO2024040532A1 - 端盖组件、电池单体、电池及用电设备 - Google Patents

端盖组件、电池单体、电池及用电设备 Download PDF

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Publication number
WO2024040532A1
WO2024040532A1 PCT/CN2022/114899 CN2022114899W WO2024040532A1 WO 2024040532 A1 WO2024040532 A1 WO 2024040532A1 CN 2022114899 W CN2022114899 W CN 2022114899W WO 2024040532 A1 WO2024040532 A1 WO 2024040532A1
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WIPO (PCT)
Prior art keywords
section
pressure relief
battery cell
end cap
relief mechanism
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PCT/CN2022/114899
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English (en)
French (fr)
Inventor
陈龙
林蹬华
郑于炼
王鹏
金海族
Original Assignee
宁德时代新能源科技股份有限公司
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Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to PCT/CN2022/114899 priority Critical patent/WO2024040532A1/zh
Priority to CN202310484183.8A priority patent/CN117638389A/zh
Publication of WO2024040532A1 publication Critical patent/WO2024040532A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/103—Primary casings; Jackets or wrappings characterised by their shape or physical structure prismatic or rectangular
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of batteries, specifically, to an end cover assembly, a battery cell, a battery and electrical equipment.
  • Batteries are widely used in the field of new energy, such as electric vehicles and new energy vehicles. New energy vehicles and electric vehicles have become a new development trend in the automobile industry. The development of battery technology must consider multiple design factors at the same time, such as battery life, energy density, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery safety also needs to be considered. However, current batteries are less safe.
  • the purpose of the embodiments of the present application is to provide an end cap assembly, a battery cell, a battery and an electrical device, which is intended to improve the problem of poor battery safety in related technologies.
  • inventions of the present application provide an end cover assembly for a battery cell.
  • the end cover assembly includes an end cover and a pressure relief mechanism.
  • the end cover has a pressure relief hole, and the pressure relief mechanism covers The pressure relief hole; wherein, the pressure relief mechanism is made of polymer material, the pressure relief mechanism is provided with a weak portion, and the weak portion is configured to crack when the battery cell releases pressure.
  • the pressure relief mechanism is made of polymer materials, which can not only stably discharge the gas in the battery cells when the battery cells are depressurized, but also can During normal use, it blocks external moisture from penetrating into the battery cell, blocks water vapor and electrolyte from flowing inside and outside the battery cell through the pressure relief mechanism, and reduces the risk of short circuit of the battery cell.
  • the weak part can crack when the battery cell is relieved, forming an opening for gas to pass through smoothly.
  • the pressure relief mechanism is less likely to suffer from deformation, cracking, local openings and other problems that lead to poor pressure relief. , which is conducive to improving the safety of battery cells.
  • the weak portion is formed by providing a score groove on the pressure relief mechanism.
  • a scored groove is provided on the pressure relief mechanism to form a weak portion, which is simple and convenient, easy to process, and has low production cost.
  • the pressure relief mechanism has a pressure relief part, the scored groove extends along the edge of the pressure relief part, and the pressure relief part is configured to When the battery cell is depressurized, it is opened with the scored groove as a boundary.
  • the pressure relief portion since the notches are provided along the edge of the pressure relief portion, when the battery cell is depressurized, the pressure relief portion will open along the edge to provide a larger opening for gas to pass through.
  • the scored groove is a non-closed structure extending along a non-closed track.
  • the scored groove includes a first section, a second section and a third section connected in sequence, and the first section and the third section are arranged oppositely.
  • the pressure relief part when the battery cell is depressurized, the pressure relief part is opened with the first section, the second section and the third section as boundaries, and an end of the first section away from the second section and an end of the third section away from the third section are opened.
  • the connecting line at one end of the two sections serves as the rotation axis for the pressure relief part to rotate, so that the pressure relief part can be opened easily.
  • the second section is linear, and the first section and the third section are symmetrical about the mid-perpendicular line of the second section.
  • the first section and the third section are arranged symmetrically with respect to the mid-perpendicular line of the second section, so that the pressure relief portion is relatively evenly stressed when opening, which is beneficial to improving the opening efficiency of the pressure relief portion.
  • the first section and the third section are arc-shaped.
  • the first section and the third section are arranged in an arc shape, which is beneficial to encircling a larger range and making the area of the pressure relief portion larger.
  • the opening formed after the pressure relief part is opened for gas to pass through is larger, which facilitates smooth pressure relief.
  • the hole wall surface of the pressure relief hole includes a first flat surface, a second flat surface, a first arc surface and a second arc surface.
  • the first flat surface , the first arc surface, the second flat surface and the second arc surface are connected end to end; the first arc surface and the first section are coaxially arranged, and the second arc surface
  • the surface and the third section are coaxially arranged.
  • the shape of the pressure relief mechanism matches the shape of the pressure relief hole, so as to have a better covering effect on the pressure relief hole and at the same time reduce the material consumption of the pressure relief mechanism.
  • the pressure relief mechanism is provided with two scored grooves, and the two scored grooves are arranged back to back.
  • two notched grooves are provided on the pressure relief mechanism to form two corresponding pressure relief parts.
  • the two pressure relief parts move from the positions where the two notched grooves are located.
  • the pressure relief mechanism is not prone to problems such as deformation, cracking, and partial openings that lead to poor pressure relief. It has a good pressure relief effect and is conducive to improving the safety of the battery cells.
  • the two scored grooves partially overlap.
  • the two openings can be opened at the same time, which is beneficial to improving the opening efficiency of the pressure relief mechanism.
  • the area of the pressure relief part is S1
  • the area of the pressure relief hole is S2, satisfying: 0.3 ⁇ S1/S2 ⁇ 1.
  • the score groove includes a first section, a second section and a third section connected in sequence, the first section and the third section are arranged oppositely, and the The first section and the third section are semicircular, the second section is linear, and the first section and the third section are symmetrical about the mid-perpendicular of the second section;
  • the first and third sections are arranged in a semicircle, which is beneficial to encircling a larger range and making the area of the pressure relief part larger.
  • the opening is larger for smooth pressure relief.
  • the first section and the third section are arranged symmetrically with respect to the middle vertical line of the second section, so that the pressure relief part is relatively evenly stressed when opening, which is beneficial to improving the opening efficiency of the pressure relief part.
  • the pressure relief part includes a first section, a second section, a third section, and an area jointly defined by a line connecting one end of the first section away from the second section and one end of the third section away from the second section.
  • the scored groove is a closed structure extending along a closed track.
  • the scored groove is provided as a closed structure extending along a closed trajectory, so that when the pressure relief mechanism releases pressure, it splits along the scored groove to form an opening for gas to pass through.
  • the scored groove includes a first section, a second section, a third section and a fourth section connected in sequence, the first section and the third section
  • the second section and the fourth section are arranged oppositely, the first section and the third section are arc-shaped, and the second section and the fourth section are linear.
  • the first section and the third section are arc grooves, and the pressure relief mechanism forms a weak position at the middle position of the first section and the middle position of the third section, and the weak position is the first opening position of the pressure relief part. , so that the pressure relief part can be opened in time when the explosion pressure inside the battery cell is reached.
  • the second section and the fourth section are linear grooves extending along the length direction of the end cover, so that the second section and the fourth section are arranged in parallel. After the pressure relief section is split along the first section and the third section, it can be more easily open along the second and fourth sections, increasing the opening rate of the pressure relief portion and achieving rapid pressure relief.
  • the width of the notched groove is W
  • the thickness of the pressure relief mechanism is T, satisfying: 0 ⁇ W/T ⁇ 1.
  • the ratio of the width of the scored groove to the thickness of the pressure relief mechanism is greater than 0 and less than or equal to 1.
  • the width of the score groove should not be too wide, otherwise when the battery cell is released, the position where the score groove is located will not be susceptible to shear force, but will be prone to tensile strain, making it difficult for the pressure relief mechanism to crack from the position of the score groove. .
  • W/T>1 compared with the case of 0 ⁇ W/T ⁇ 1, it is more difficult for the pressure relief mechanism to crack from the notched groove position.
  • the width of the score groove is in the range of 0.004 to 0.018 mm, and the pressure relief mechanism is relatively easy to crack along the score groove when the battery cell is depressurized.
  • the thickness of the pressure relief mechanism is within 0.01 ⁇ 10mm. It can not only steadily discharge the gas in the battery cell when the battery cell is depressurized, but also block external moisture from penetrating into the battery cell during normal use, reducing battery cell short circuits. risk.
  • the depth of the notched groove is H in mm
  • the detonation pressure of the battery cell is P in MPa
  • the thickness of the pressure relief mechanism is T
  • the depth range of the notch groove that should be scored can be obtained according to the formula.
  • the polymer material includes at least one of fluorinated ethylene propylene copolymer and polychlorotrifluoroethylene.
  • fluorinated ethylene propylene copolymer and polychlorotrifluoroethylene have a better balance of air permeability and water barrier properties, and are made of at least one of fluorinated ethylene propylene copolymer and polychlorotrifluoroethylene.
  • the pressure relief mechanism can not only steadily discharge the gas in the battery cell when the battery cell is depressurized, but also block external moisture from penetrating into the battery cell during normal use, reducing the risk of short circuit of the battery cell.
  • inventions of the present application further provide a battery cell.
  • the battery cell includes an electrode assembly, a casing and the above-mentioned end cover assembly.
  • the casing has an accommodating space with at least one end open. The space is used to accommodate the electrode assembly, and the end cap closes the opening.
  • embodiments of the present application further provide a battery, which includes a box and the above-mentioned battery cell, and the battery cell is accommodated in the box.
  • embodiments of the present application further provide an electrical device, wherein the electrical device includes the above-mentioned battery, and the battery is used to provide electrical energy to the electrical device.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Figure 2 is an exploded view of a battery provided by some embodiments of the present application.
  • Figure 3 is an exploded view of a battery cell provided by some embodiments of the present application.
  • Figure 4 is an exploded view of an end cap assembly provided by some embodiments of the present application.
  • Figure 5 is an exploded view of an end cap assembly provided by other embodiments of the present application.
  • Figure 6 is a schematic top view of the end cap assembly (the scored groove is C-shaped) provided by some embodiments of the present application;
  • Figure 7 is a schematic top view of the end cap assembly provided by some embodiments of the present application (the scoring groove is double C-shaped, and the opening of each C shape faces the width direction of the end cap);
  • Figure 8 is a schematic top view of the end cap assembly provided by some embodiments of the present application (the scoring groove is double C-shaped, and the opening of each C shape faces the length direction of the end cap);
  • Figure 9 is a schematic top view of the end cap assembly (the scored groove is in the shape of a "king") provided by some embodiments of the present application;
  • Figure 10 is a schematic top view of the end cap assembly (the scored groove is O-shaped) provided by some embodiments of the present application;
  • Figure 11 is a schematic top view of the end cap assembly (the scored groove is an O-C combination) provided by some embodiments of the present application;
  • Figure 12 is a cross-sectional view at position A-A in Figure 6;
  • Figure 13 is an enlarged view of position B in Figure 9 (the cross-section of the scored groove is rectangular);
  • Figure 14 is an enlarged view of position B in Figure 9 (the cross-section of the scored groove is trapezoidal);
  • Figure 15 is an enlarged view of position B in Figure 9 (the cross-section of the scored groove is triangular).
  • Icon 10-box; 11-first part; 12-second part; 20-battery cell; 21-end cover assembly; 211-end cover; 2111-pressure relief hole; 2112-first flat surface; 2113- Second flat surface; 2114-first arc surface; 2115-second arc surface; 2116-groove; 212-pressure relief mechanism; 2121-scored groove; 21211-first section; 21212-second section; 21213-third section; 21214-fourth section; 2122-pressure relief part; 2123-convex part; 2124-weak part; 213-connector; 2131-slot; 214-seal; 22-electrode assembly; 23- Housing; 100-battery; 200-controller; 300-motor; 1000-vehicle.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
  • connection should be understood in a broad sense.
  • connection can be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • connection can be a fixed connection
  • connection can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • connection can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • “Plural” appearing in this application means two or more (including two).
  • battery cells may include lithium ion secondary battery cells, lithium ion primary battery cells, lithium sulfur battery cells, sodium lithium ion battery cells, sodium ion battery cells or magnesium ion battery cells, etc.
  • the embodiments of the present application are not limited to this.
  • the battery cell may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes, and the embodiments of the present application are not limited to this.
  • Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application are not limited to this.
  • the battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack.
  • Batteries generally include a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly consists of a positive electrode sheet, a negative electrode sheet and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the positive electrode current collector that is not coated with the positive electrode active material layer protrudes from the positive electrode current collector that is coated with the positive electrode active material layer.
  • the cathode current collector without coating the cathode active material layer serves as the cathode tab.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode current collector that is coated with the negative electrode active material layer.
  • the negative electrode current collector that is not coated with the negative electrode active material layer is used as the negative electrode tab.
  • the material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon.
  • the number of positive electrode lugs is multiple and stacked together, and the number of negative electrode lugs is multiple and stacked together.
  • the material of the isolation film can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the electrode assembly may have a rolled structure or a laminated structure, and the embodiments of the present application are not limited thereto.
  • Batteries are not only used in energy storage power systems such as hydraulic, thermal, wind and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles and electric cars, as well as in many fields such as military equipment and aerospace. As battery application fields continue to expand, its market demand is also expanding.
  • a pressure relief mechanism can be installed on the end cover of the battery cells. When the internal pressure of the battery cell reaches the detonation pressure, the pressure relief mechanism opens to release the pressure inside the battery cell to reduce the risk of battery cell explosion and fire.
  • the pressure relief mechanism can be made of polymer materials, and the breathable and water-blocking properties of the polymer materials can be used to block the flow of water vapor and electrolyte to the inside and outside of the battery cells through the pressure relief mechanism.
  • the pressure relief mechanism made of polymer materials has poor bursting consistency when the battery cells release pressure, which means that it is difficult to control the bursting pressure of each battery cell with the same specification within a reasonable fluctuation range, and it is high
  • the pressure relief mechanism made of molecular materials is opened, it often happens that the pressure relief mechanism is deformed but cannot be opened in time to relieve pressure.
  • the pressure relief mechanism made of polymer materials is easily affected by the internal air pressure of the battery cell and causes small cracks.
  • the gas can be partially released through the small cracks, making it difficult for the pressure relief mechanism to reach the bursting pressure. , but the speed of pressure relief from small cracks is slow, and the internal pressure of the battery cells cannot be released in time, so there is a safety risk.
  • the pressure relief mechanism made of polymer materials is prone to bulging (the pressure relief mechanism is deformed to form a convex bump) or cracking (small cracks appear in the pressure relief mechanism) when the battery cells are pressure relieved, resulting in inability to release the pressure. smooth, the blasting consistency is poor, and the safety of the battery cells is very unstable.
  • inventions of the present application provide an end cover assembly.
  • the pressure relief mechanism of the end cover assembly is made of polymer material.
  • the pressure relief mechanism is provided with a weak portion, and the weak portion is configured to release pressure in the battery cell. split.
  • the pressure relief mechanism made of polymer materials can not only stably discharge the gas in the battery cells when the battery cells are depressurized, but also block external moisture when the battery cells are in normal use. Penetrates into the battery cell, blocks the flow of water vapor and electrolyte to the inside and outside of the battery cell through the pressure relief mechanism, and reduces the risk of short circuit of the battery cell.
  • the weak part can crack when the battery cell is relieved, forming an opening for gas to pass through smoothly.
  • the pressure relief mechanism is less likely to suffer from deformation, cracking, local openings and other problems that lead to poor pressure relief. , which is conducive to improving the safety of battery cells.
  • Power-consuming devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and power tools, etc.
  • Spacecraft include airplanes, rockets, space shuttles, spaceships, etc.
  • electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc.
  • electric tools include metal Cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and planers, etc.
  • the embodiments of this application impose no special restrictions on the above electrical equipment.
  • the electric equipment is the vehicle 1000 as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application.
  • the vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • the battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 .
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • FIG. 2 is an exploded view of the battery 100 provided by some embodiments of the present application.
  • the battery 100 includes a case 10 and battery cells 20 , and the battery cells 20 are accommodated in the case 10 .
  • the box 10 is used to provide an accommodation space for the battery cells 20, and the box 10 can adopt a variety of structures.
  • the box 10 may include a first part 11 and a second part 12 , the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a space for accommodating the battery cells 20 of accommodation space.
  • the second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure.
  • the first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define a receiving space.
  • the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 is covered with the open side of the second part 12.
  • the box 10 formed by the first part 11 and the second part 12 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.
  • the battery 100 there may be a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the plurality of battery cells 20 are connected in series and in parallel.
  • the plurality of battery cells 20 can be directly connected in series or in parallel or mixed together, and then the whole composed of the plurality of battery cells 20 can be accommodated in the box 10 ; of course, the battery 100 can also be a plurality of battery cells 20 First, the battery modules are connected in series, parallel, or mixed to form a battery module, and then multiple battery modules are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 10 .
  • the battery 100 may also include other structures.
  • the battery 100 may further include a bus component for realizing electrical connections between multiple battery cells 20 .
  • Each battery cell 20 may be a secondary battery cell or a primary battery cell; it may also be a lithium-sulfur battery cell, a sodium-ion battery cell or a magnesium-ion battery cell, but is not limited thereto.
  • the battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes.
  • FIG. 3 is an exploded structural diagram of a battery cell 20 provided in some embodiments of the present application.
  • the battery cell 20 refers to the smallest unit that constitutes the battery 100 .
  • the battery cell 20 includes an end cap assembly 21 , an electrode assembly 22 and a case 23 .
  • the end cap assembly 21 includes an end cap 211 and a pressure relief mechanism 212 .
  • the end cap 211 refers to a component that covers the opening of the housing 23 to isolate the internal environment of the battery cell 20 from the external environment.
  • the shape of the end cap 211 may be adapted to the shape of the housing 23 to fit the housing 23 .
  • the end cap 211 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 211 is less likely to deform when subjected to extrusion and collision, so that the battery cell 20 can have higher durability. Structural strength and safety performance can also be improved.
  • the end cap 211 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application.
  • the end cap assembly 21 may also include electrode terminals (not shown in the figure), and the electrode terminals are provided on the end cap 211 .
  • the electrode terminals may be used to electrically connect with the electrode assembly 22 for outputting or inputting electrical energy from the battery cell 20 .
  • the pressure relief mechanism 212 is provided on the end cover 211 .
  • the pressure relief mechanism 212 is used to open when the internal pressure or temperature of the battery cell 20 reaches the detonation pressure to release the internal pressure of the battery cell 20 .
  • the housing 23 is a component used to cooperate with the end cover 211 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 22 , electrolyte, and other components.
  • the housing 23 and the end cover 211 may be independent components, and an opening may be provided on the housing 23.
  • the end cover 211 covers the opening at the opening to form the internal environment of the battery cell 20.
  • the end cover 211 and the housing 23 can also be integrated.
  • the end cover 211 and the housing 23 can form a common connection surface before other components are put into the housing. When it is necessary to encapsulate the inside of the housing 23 When, the end cover 211 is closed with the housing 23 again.
  • the housing 23 can be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the housing 23 can be determined according to the specific shape and size of the electrode assembly 22 .
  • the housing 23 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application.
  • the electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur.
  • One or more electrode assemblies 22 may be contained within the housing 23 .
  • the electrode assembly 22 is mainly formed by winding or stacking positive electrode sheets and negative electrode sheets, and an isolation film is usually provided between the positive electrode sheets and the negative electrode sheets.
  • the portions of the positive electrode sheet and the negative electrode sheet that contain active material constitute the main body of the electrode assembly 22 , and the portions of the positive electrode sheet and the negative electrode sheet that do not contain active material each constitute tabs.
  • the positive electrode tab and the negative electrode tab can be located together at one end of the body part or respectively located at both ends of the body part.
  • FIG. 4 is an exploded view of the end cap assembly 21 provided in some embodiments of the present application.
  • the embodiment of the present application provides an end cover assembly 21 for the battery cell 20 .
  • the end cover assembly 21 includes an end cover 211 and a pressure relief mechanism 212.
  • the end cover 211 has a pressure relief hole 2111, and the pressure relief mechanism 212 covers the pressure relief hole 2111.
  • the pressure relief mechanism 212 is made of polymer material.
  • the pressure relief mechanism 212 is provided with a weak portion 2124 (shown in FIGS. 13 , 14 and 15 ) that is configured to rupture when the battery cell 20 is depressurized.
  • the pressure relief hole 2111 is a through hole that penetrates both surfaces of the end cover 211 in the thickness direction.
  • the pressure relief mechanism 212 covers the pressure relief hole 2111 to isolate the inside of the battery cell 20 from the outside when the battery cell 20 is in normal use, to prevent external impurities from entering the battery cell 20 or the electrolyte in the battery cell 20 from leaking.
  • the shape of the pressure relief hole 2111 is not limited.
  • the pressure relief hole 2111 can be a round hole, a square hole, an elliptical hole, etc.
  • Polymer materials also known as polymer materials, are materials composed of polymer compounds as a matrix and other additives (auxiliaries). Polymer materials are divided into natural polymer materials and synthetic polymer materials according to their sources.
  • Natural polymers are polymer substances that exist in animals, plants and living organisms. They can be divided into natural fibers, natural resins, natural rubber, animal glue, etc. Synthetic polymer materials mainly refer to the three major synthetic materials of plastics, synthetic rubber and synthetic fibers. In addition, they also include adhesives, coatings and various functional polymer materials. Synthetic polymer materials have properties that natural polymer materials do not have or are superior to - smaller density, higher mechanics, wear resistance, corrosion resistance, electrical insulation, etc.
  • the weak portion 2124 (shown in Figures 13, 14, and 15) is a lower-strength part of the pressure relief mechanism 212.
  • the weak portion 2124 opens under the pressure.
  • the internal pressure of the battery cell 20 is released to reduce the risk of explosion or fire of the battery cell 20 .
  • the dotted lines in Figures 13, 14 and 15 are to mark the range of the weak portion 2124 and do not represent the actual structure.
  • “When the battery cell 20 is depressurized” refers to when the internal pressure of the battery cell 20 reaches the detonation pressure. Since the pressure relief mechanism 212 is made of polymer material, and the polymer material has breathable and water-blocking properties, when the battery cell 20 is in normal use, the gas generated by this property entering and exiting the battery cell 20 cannot be called “leakage”. Pressure time”.
  • the pressure relief mechanism 212 is made of polymer materials, which can not only stably discharge the gas in the battery cells 20 when the battery cells 20 are depressurized, but also can discharge the gas in the battery cells 20 normally when the battery cells 20 are in normal condition.
  • external moisture is blocked from penetrating into the battery cell 20 , water vapor and electrolyte are blocked from flowing to the inside and outside of the battery cell 20 through the pressure relief mechanism 212 , and the risk of short circuit of the battery cell 20 is reduced.
  • the weak portion 2124 cracks when the battery cell 20 releases pressure, forming an opening for gas to pass smoothly, and the pressure relief mechanism 212 is less likely to suffer from deformation, cracking, local openings and other problems. Poor pressure relief is beneficial to improving the safety of the battery cells 20 .
  • the pressure relief mechanism 212 may be bonded to the end cap 211 .
  • protrusions can be provided on the outer periphery of the pressure relief hole 2111, and the pressure relief mechanism 212 can be bonded to the protrusions.
  • FIG. 5 is an exploded view of the end cap assembly 21 provided in other embodiments of the present application.
  • the end cap assembly 21 includes a connecting piece 213 connected to the end cover 211 , and the pressure relief mechanism 212 is provided on the connecting piece 213 .
  • the connector 213 is welded to the end cap 211 .
  • the connecting piece 213 is provided with a latching slot 2131, and the edge of the pressure relief mechanism 212 is provided with a protruding portion 2123. The protruding portion 2123 engages with the latching groove 2131.
  • the connecting member 213 has an annular structure, and the through hole in the middle can allow the gas inside the battery cell 20 to flow to the pressure relief mechanism 212 .
  • a groove 2116 is formed on the end cover 211 , and the groove 2116 is used to accommodate at least a portion of the connector 213 to reduce the height of the pressure relief mechanism 212 protruding from the end cover 211 .
  • the end cap assembly 21 includes a seal 214 disposed between the connector 213 and the end cap 211 to seal the connector 213 and the end cap 211 .
  • the connecting member 213 can press the sealing member 214 against the end cover 211 , and the sealing member 214 can prevent external water vapor from entering the inside of the battery cell 20 from between the connecting member 213 and the end cover 211 .
  • the sealing member 214 is a sealing ring, and the through hole in the middle allows the gas inside the battery cell 20 to flow to the pressure relief mechanism 212 .
  • the weak portion 2124 is formed by providing a scored groove 2121 on the pressure relief mechanism 212 .
  • the scored groove 2121 may be a groove body recessed from the surface of the pressure relief mechanism 212 along the thickness direction of the end cover 211 .
  • the score groove 2121 can be provided on the surface of the pressure relief mechanism 212 facing the end cover 211 , or can be provided on the surface of the pressure relief mechanism 212 facing away from the end cover 211 .
  • the pressure relief mechanism 212 has a first surface and a second surface opposite to each other in the thickness direction of the end cover 211 . The first surface faces the end cover 211 and the second surface faces away from the end cover 211 .
  • the score groove 2121 may be provided on the first surface of the pressure relief mechanism 212 , or may be provided on the second surface of the pressure relief mechanism 212 .
  • the scored groove 2121 on the pressure relief mechanism 212 By arranging the scored groove 2121 on the pressure relief mechanism 212 to form the weak portion 2124, it is simple and convenient, easy to process, and the production cost is low.
  • the pressure relief mechanism 212 has a pressure relief portion 2122 , and the scored groove 2121 extends along the edge of the pressure relief portion 2122 .
  • the pressure relief portion 2122 is configured to open with the scored groove 2121 as a boundary when the battery cell 20 is pressure released.
  • the pressure relief portion 2122 can be regarded as a portion defined by the inner surface of the scored groove 2121 . Taking the inner surface of the scored groove 2121 as a rectangular shape as an example, the pressure relief portion 2122 is a rectangular portion of the pressure relief mechanism 212 defined by the inner surface of the scored groove 2121 .
  • the scored groove 2121 may also be a linear groove extending along a bending trajectory.
  • the bending trajectory is a U-shaped trajectory
  • the pressure relief portion 2122 is a U-shaped portion of the pressure relief mechanism 212 defined by the bending trajectory.
  • the bending track is a rectangular track
  • the pressure relief portion 2122 is a rectangular portion of the pressure relief mechanism 212 defined by the bending track.
  • the pressure relief portion 2122 can be opened with the score groove 2121 as a boundary to release the internal pressure of the battery cell 20 pressure.
  • the pressure relief portion 2122 Since the notches are provided along the edge of the pressure relief portion 2122, when the battery cell 20 is depressurized, the pressure relief portion 2122 will open along the edge to provide a larger opening for gas to pass through.
  • the pressure relief mechanism 212 has a pressure relief portion 2122 , and the pressure relief portion 2122 is the remaining portion of the pressure relief mechanism 212 after the scoring groove 2121 is provided.
  • the pressure relief mechanism 212 is configured to open from the pressure relief portion 2122 when the battery cell 20 is pressure relieved.
  • Figure 6 is a schematic top view of the end cap assembly 21 (the scored groove 2121 is C-shaped) provided by some embodiments of the present application.
  • the scored groove 2121 is a non-closed structure extending along a non-closed trajectory.
  • the non-closed trajectory can be a U-shaped trajectory, a C-shaped trajectory, an arc trajectory, a parabolic trajectory, etc.
  • the scored groove 2121 extends along a non-closed trajectory with a distance between both ends. Therefore, the scored groove 2121 may also be a U-shaped groove, a C-shaped groove, an arc groove, a parabolic groove, etc.
  • the pressure relief part 2122 can be used as a rotation axis, and the pressure relief part 2122 is flipped and opened around this rotation axis, which is beneficial to improving the opening efficiency of the pressure relief part 2122, making the pressure relief part 2122 less prone to problems such as deformation, cracking, partial openings, etc., resulting in poor pressure relief. It is beneficial to improve the safety of the battery cell 20 .
  • the scored groove 2121 includes a first section 21211, a second section 21212, and a third section 21213 connected in sequence, and the first section 21211 and the third section 21213 are arranged oppositely.
  • the first section 21211 and the third section 21213 are two groove sections arranged opposite each other in the scored groove 2121, and the second section 21212 is a groove section in the scored groove 2121 that connects the first section 21211 and the third section 21213. There is a gap between the end of the first section 21211 away from the second section 21212 and the end of the third section 21213 away from the second section 21212 to form a non-closed structure. Since the first section 21211 and the third section 21213 are arranged oppositely, the entire scored groove 2121 has a non-linear structure. In other words, the extension directions of at least two of the first section 21211, the second section 21212, and the third section 21213 are not on the same straight line.
  • the pressure relief part 2122 When the battery cell 20 is depressurized, the pressure relief part 2122 is opened with the first section 21211, the second section 21212, and the third section 21213 as boundaries, and the end of the first section 21211 away from the second section 21212 is in contact with the third section 21213.
  • the connecting line away from the end of the second section 21212 serves as a rotation axis for the pressure relief part 2122 to rotate, so that the pressure relief part 2122 can be opened.
  • the second section 21212 is linear, and the first section 21211 and the third section 21213 are symmetrical about the center vertical line of the second section 21212.
  • the second segment 21212 extends along a straight trajectory.
  • the mid-perpendicular line of the second segment 21212 refers to a straight line that passes through the midpoint of the second segment 21212 and is perpendicular to the second segment 21212.
  • the mid-perpendicular line of the second section 21212 can also be called the vertical bisector of the second section 21212.
  • the first section 21211 and the third section 21213 are arranged axially symmetrically with respect to the mid-perpendicular line of the second section 21212.
  • the first section 21211 and the third section 21213 are arranged symmetrically with respect to the mid-perpendicular line of the second section 21212, so that the pressure relief portion 2122 receives a relatively uniform force when opening, which is beneficial to improving the opening efficiency of the pressure relief portion 2122.
  • the first section 21211 and the third section 21213 are arc-shaped.
  • the first section 21211 and the third section 21213 respectively extend along arc trajectories, and the first section 21211 and the third section 21213 are bent in directions away from each other, so that the centers of the first section 21211 and the third section 21213 are located at the leakage point. inside the pressure part 2122.
  • first section 21211 and the third section 21213 can be semicircular.
  • the scored groove 2121 formed by connecting the first section 21211, the second section 21212 and the third section 21213 is C-shaped.
  • Setting the first section 21211 and the third section 21213 in an arc shape is beneficial to encircling a larger range and making the area of the pressure relief portion 2122 larger. In this way, the opening for gas to pass formed after the pressure relief portion 2122 is opened is larger, which facilitates smooth pressure relief.
  • the wall surface of the pressure relief hole 2111 includes a first flat surface 2112 , a second flat surface 2113 , a first arc surface 2114 and a second arc surface 2115 .
  • the first flat surface 2112, the first arc surface 2114, the second flat surface 2113 and the second arc surface 2115 are connected end to end.
  • the first arc surface 2114 and the first section 21211 are coaxially arranged, and the second arc surface 2115 and the third section 21213 are coaxially arranged.
  • the first flat surface 2112 and the second flat surface 2113 are both flat surfaces.
  • the first arc surface 2114 and the second arc surface 2115 are both curved surfaces, and the first arc surface 2114 and the second arc surface 2115 extend along the arc trajectory.
  • the first flat surface 2112 , the first arcuate surface 2114 , the second flat surface 2113 and the second arcuate surface 2115 jointly define a pressure relief hole 2111 .
  • the first arc surface 2114 and the first section 21211 are coaxially arranged means that the axis of the first arc surface 2114 passes through the center of the first section 21211.
  • the second arc surface 2115 and the third section 21213 are coaxially arranged means that the axis of the second arc surface 2115 passes through the center of the third section 21213.
  • the pressure relief hole 2111 is an O-shaped structure surrounded by a first flat surface 2112, a second flat surface 2113, a first arc surface 2114 and a second arc surface 2115.
  • the pressure relief portion 2122 is also O-shaped. In this way, the shape of the pressure relief hole 2111 is the same as the shape of the pressure relief portion 2122, so that the battery cell 20 can be split from the position of the score groove 2121 when the pressure of the battery cell 20 is released.
  • the shape of the pressure relief mechanism 212 matches the shape of the pressure relief hole 2111, so as to have a better covering effect on the pressure relief hole 2111 and at the same time reduce the material consumption of the pressure relief mechanism 212.
  • the pressure relief hole 2111 may also be rectangular, elliptical, etc. In this way, the shape of the pressure relief hole 2111 is similar to the shape of the pressure relief portion 2122, which also facilitates the battery cell 20 to be split from the position of the score groove 2121 when the pressure is released.
  • Figure 7 is a schematic top view of the end cap assembly 21 provided by some embodiments of the present application (the scoring groove 2121 is a double C shape, and the opening of each C shape faces the width direction of the end cap 211). .
  • Figure 8 is a schematic top view of the end cap assembly 21 provided by some embodiments of the present application (the scored groove 2121 is a double C shape, and the opening of each C shape faces the length direction of the end cap 211). It should be noted that the dotted lines in Figures 7 and 8 indicate the position of the pressure relief hole 2111.
  • the pressure relief mechanism 212 is provided with two scored grooves 2121, and the two scored grooves 2121 are arranged back to back.
  • the scored groove 2121 is a non-closed structure extending along a non-closed track with a distance between both ends.
  • the scored groove 2121 forms a pattern with an open end.
  • the arrangement of the two scoring grooves 2121 facing each other means that the opening ends of the two scoring grooves 2121 are oriented in opposite directions.
  • the two score grooves 2121 are both C-shaped grooves.
  • the open ends of the two scored grooves 2121 face the width direction of the end cap 211 .
  • the two scored grooves 2121 are both C-shaped grooves.
  • the open ends of the two scored grooves 2121 face the length direction of the end cap 211 .
  • two pressure relief parts 2122 are formed correspondingly.
  • the two pressure relief parts 2122 respectively move from the positions where the two notched grooves 2121 are located.
  • the pressure relief mechanism 212 is not prone to problems such as deformation, cracking, and partial openings that lead to poor pressure relief, and has a good pressure relief effect, which is conducive to improving the safety of the battery cells 20 .
  • two score grooves 2121 partially overlap.
  • Each scoring groove 2121 may include a first section 21211, a second section 21212, and a third section 21213 connected in sequence, and the first section 21211 and the third section 21213 are arranged oppositely.
  • the first section 21211 and the third section 21213 are arc-shaped, and the second section 21212 is a straight line.
  • the first section 21211 and the third section 21213 are symmetrical about the mid-perpendicular of the second section 21212.
  • the second sections 21212 of the two score grooves 2121 can be overlapped.
  • the partial overlap of the two scored grooves 2121 may be that the two scored grooves 2121 are arranged to intersect, or the two scored grooves 2121 are arranged to be tangential.
  • the two openings can be opened at the same time, which is beneficial to improving the opening efficiency of the pressure relief mechanism 212.
  • FIG. 9 is a schematic top view of the end cap assembly 21 (the scored groove 2121 is in the shape of a "king") provided by some embodiments of the present application.
  • the pressure relief mechanism 212 is provided with a plurality of scored grooves 2121, and at least two of the plurality of scored grooves 2121 are arranged to intersect.
  • the pressure relief mechanism 212 includes four scored grooves 2121, and the four scored grooves 2121 are arranged to intersect to form a "king"-shaped structure.
  • the area of the pressure relief portion 2122 is S1
  • the area of the pressure relief hole 2111 is S2, which satisfies: 0.3 ⁇ S1/S2 ⁇ 1.
  • S1/S2 represents the ratio of the area of the pressure relief portion 2122 to the area of the pressure relief hole 2111.
  • the ratio of the area of the pressure relief portion 2122 to the area of the pressure relief hole 2111 is made greater than 0.3 and less than or equal to 1, it is ensured that the pressure relief portion 2122 has a larger area, so that the pressure relief portion 2122 forms a larger supply after being opened.
  • the opening allows gas to pass through, thereby allowing the battery cell 20 to release pressure smoothly.
  • the scored groove 2121 includes a first section 21211, a second section 21212, and a third section 21213 connected in sequence, and the first section 21211 and the third section 21213 are arranged oppositely.
  • the first section 21211 and the third section 21213 are semicircular, and the second section 21212 is a straight line.
  • the first section 21211 and the third section 21213 are symmetrical about the mid-perpendicular line of the second section 21212.
  • the first section 21211 and the third section 21213 are arranged symmetrically with respect to the mid-perpendicular line of the second section 21212, so that the pressure relief portion 2122 receives a relatively uniform force when opening, which is beneficial to improving the opening efficiency of the pressure relief portion 2122.
  • the pressure relief part 2122 includes a first section 21211, a second section 21212, a third section 21213, and a line connecting an end of the first section 21211 away from the second section 21212 and an end of the third section 21213 away from the second section 21212.
  • FIG. 10 is a schematic top view of the end cap assembly 21 (the scored groove 2121 is O-shaped) provided in some embodiments of the present application.
  • the scored groove 2121 is a closed structure extending along a closed trajectory.
  • a "closed trajectory” refers to a trajectory that is connected together at both ends. Closed trajectories can be circular trajectories, elliptical trajectories, polygonal trajectories, etc.
  • the scoring groove 2121 extends along a closed track. Therefore, the scoring groove 2121 may also be a circular groove, an elliptical groove, a polygonal groove, etc.
  • the scored groove 2121 is configured as a closed structure extending along a closed trajectory, so that when the pressure relief mechanism 212 releases pressure, it splits along the scored groove 2121 to form an opening for gas to pass through.
  • the scoring groove 2121 includes a first section 21211, a second section 21212, a third section 21213, and a fourth section 21214 connected end to end.
  • the first section 21211 and the third section 21213 are arranged oppositely, and the second section 21212 and the fourth section 21214 are arranged oppositely.
  • the first section 21211 and the third section 21213 are arc-shaped, and the second section 21212 and the fourth section 21214 are linear.
  • the first section 21211 and the third section 21213 can be bent in the same direction or in opposite directions.
  • the first section 21211 and the third section 21213 can be bent in a direction close to each other, so that the center of the circle of the first section 21211 and the center of the third section 21213 are located outside the pressure relief portion 2122.
  • the first section 21211 and the third section 21213 can also be bent in a direction away from each other, and the center of the circle of the first section 21211 and the center of the third section 21213 are located in the pressure relief portion 2122.
  • the first section 21211 and the third section 21213 are bent in directions away from each other, the second section 21212 and the fourth section 21214 are linear grooves extending along the length direction of the end cover 211, and the second section 21212 and the fourth segment 21214 are both tangent to the first segment 21211, and the second segment 21212 and the fourth segment 21214 are both tangent to the third segment 21213, so that the first segment 21211, the second segment 21212, the third segment 21213 and the The scored groove 2121 formed by the four sections 21214 is O-shaped.
  • the first section 21211 and the third section 21213 are arc grooves.
  • the pressure relief mechanism 212 forms a weak position at the middle position of the first section 21211 and the third section 21213.
  • the weak position is the first opening position of the pressure relief part 2122. , so that the pressure relief part 2122 can be opened in time when the internal battery cell 20 reaches the detonation pressure.
  • the second section 21212 and the fourth section 21214 are linear grooves extending along the length direction of the end cover 211, so that the second section 21212 and the fourth section 21214 are arranged in parallel, and the pressure relief portion 2122 is along the first section 21211 and the third section. After 21213 is split, it can be opened more easily along the second section 21212 and the fourth section 21214, increasing the opening rate of the pressure relief portion 2122 and achieving rapid pressure relief.
  • the pressure relief mechanism 212 includes a plurality of scored grooves 2121, some of which are non-enclosed structures extending along a non-enclosed trajectory. Other scored grooves 2121 are closed structures extending along closed tracks. Multiple score grooves 2121 are intersected.
  • the pressure relief mechanism 212 includes three scored grooves 2121 , where both of the two scored grooves 2121 are C-shaped grooves.
  • the open ends of the two scored grooves 2121 face the width direction of the end cap 211 .
  • the other scoring groove 2121 is an O-shaped groove.
  • the two C-shaped scoring grooves 2121 are located inside the O-shaped scoring groove 2121, and the open ends of the two C-shaped scoring grooves 2121 are both O-shaped scoring. Slot 2121 is closed.
  • Figure 12 is a cross-sectional view at position A-A in Figure 5.
  • Figure 13 is an enlarged view of position B in Figure 9 (the cross-section of the score groove 2121 is rectangular).
  • Figure 14 is an enlarged view of position B in Figure 9 (the cross-section of the scoring groove 2121 is trapezoidal).
  • FIG. 15 is an enlarged view of position B in FIG. 9 (the cross section of the scoring groove 2121 is triangular).
  • the width of the scored groove 2121 is W
  • the thickness of the pressure relief mechanism 212 is T, which satisfies: 0 ⁇ W/T ⁇ 1.
  • the cross-sectional shape of the score groove 2121 is not limited.
  • the cross-section shape of the score groove 2121 is rectangular.
  • the cross-section shape of the score groove 2121 is trapezoidal.
  • the cross-section shape of the score groove 2121 is triangular.
  • the width of the scored groove 2121 refers to the width of the notch of the scored groove 2121 on the cross section of the scored groove 2121.
  • the width of the score groove 2121 at different positions can be different or the same.
  • the ratio of the width of the score groove 2121 at any position to the thickness of the pressure relief mechanism 212 should be greater than 0 and less than or equal to 1.
  • the ratio of the width of the scoring groove 2121 to the thickness of the pressure relief mechanism 212 is greater than 0 and less than or equal to 1.
  • the width of the score groove 2121 should not be too wide, otherwise when the battery cell 20 is depressurized, the position of the score groove 2121 will not be susceptible to shear force, but will be prone to tensile strain, causing the pressure relief mechanism 212 to be difficult to release from the score.
  • the slot 2121 is cracked.
  • W/T>1 compared with the case of 0 ⁇ W/T ⁇ 1, it is more difficult for the pressure relief mechanism 212 to crack from the scored groove 2121 position.
  • the width of the score groove 2121 is in the range of 0.004-0.018 mm, and the pressure relief mechanism 212 is relatively easy to crack along the score groove 2121 when the battery cell 20 releases pressure.
  • the thickness of the pressure relief mechanism 212 is within 0.01-10 mm, which not only can stably discharge the gas in the battery cell 20 when the battery cell 20 is depressurized, but can also block external moisture from penetrating into the battery cell 20 when the battery cell 20 is in normal use. within, reducing the risk of short circuit of the battery cell 20 .
  • the depth of the scored groove 2121 is H in mm.
  • the detonation pressure of the battery cell 20 is P, and the unit is MPa.
  • the depth of the score groove 2121 is such that the bottom of the score groove 2121 is at the end cover 211 The maximum distance in the thickness direction from the surface of the pressure relief mechanism 212 away from the end cover 211 .
  • the detonation pressure refers to the air pressure value that can cause the pressure relief mechanism 212 to open.
  • the pressure relief mechanism 212 opens to relieve pressure.
  • the pressure relief mechanism 212 has an opposite first surface and a second surface.
  • the thickness of the pressure relief mechanism 212 refers to the distance between the first surface and the second surface along the thickness direction of the end cover 211.
  • K is the coefficient. 0.1 ⁇ K ⁇ 5.
  • the depth range that should be scored by the scoring groove 2121 can be obtained according to the formula.
  • the polymer material includes at least one of fluorinated ethylene propylene copolymer and polychlorotrifluoroethylene.
  • Fluorinated ethylene propylene copolymer and polychlorotrifluoroethylene have a better balance of air permeability and water resistance.
  • the pressure relief mechanism 212 is made of at least one of fluorinated ethylene propylene copolymer and polychlorotrifluoroethylene, which not only It can stably discharge the gas in the battery cell 20 when the battery cell 20 is depressurized, and can also block external moisture from penetrating into the battery cell 20 when the battery cell 20 is in normal use, reducing the risk of short circuit of the battery cell 20 .
  • the embodiment of the present application also provides a battery cell 20.
  • the battery cell 20 includes an electrode assembly 22, a casing 23 and the above-mentioned end cover assembly 21.
  • the casing 23 has an accommodating space with at least one end open, and the accommodating space is used to accommodate Electrode assembly 22, end cap 211 closes the opening.
  • the embodiment of the present application also provides a battery 100.
  • the battery 100 includes a box 10 and the above-mentioned battery cells 20.
  • the battery cells 20 are accommodated in the box 10.
  • An embodiment of the present application also provides an electrical device.
  • the electrical device includes the above-mentioned battery 100.
  • the battery 100 is used to provide electrical energy to the electrical device.
  • the embodiment of the present application provides an end cover assembly 21 for the battery cell 20 .
  • the end cover assembly 21 includes an end cover 211 and a pressure relief mechanism 212.
  • the end cover 211 has a pressure relief hole 2111, and the pressure relief mechanism 212 covers the pressure relief hole 2111.
  • the pressure relief mechanism 212 is made of polymer material.
  • the pressure relief mechanism 212 is provided with a weak portion 2124, and the weak portion 2124 is configured to rupture when the battery cell 20 releases pressure.
  • the weak portion 2124 is formed by providing a score groove 2121 on the pressure relief mechanism 212 .
  • the pressure relief mechanism 212 has a pressure relief portion 2122.
  • the scored groove 2121 extends along the edge of the pressure relief portion 2122.
  • the pressure relief portion 2122 is configured to open with the scored groove 2121 as a boundary when the battery cell 20 releases pressure.
  • the scored groove 2121 is a non-closed structure extending along a non-closed track with a distance between both ends.
  • the pressure relief mechanism 212 is made of polymer materials, which can not only stably discharge the gas in the battery cells 20 when the battery cells 20 are depressurized, but also can discharge the gas in the battery cells 20 normally when the battery cells 20 are in normal operation.
  • external moisture is blocked from penetrating into the battery cell 20 , water vapor and electrolyte are blocked from flowing to the inside and outside of the battery cell 20 through the pressure relief mechanism 212 , and the risk of short circuit of the battery cell 20 is reduced.
  • the pressure relief mechanism 212 is provided with a score groove 2121 to form a weak portion 2124 on the pressure relief mechanism 212 to ensure that the pressure relief mechanism 212 can be torn from the position of the score groove 2121 when the battery cell 20 is depressurized.
  • the pressure relief mechanism 212 is less likely to suffer from problems such as deformation, cracking, and partial openings, resulting in poor pressure relief, which is beneficial to improving the safety of the battery cell 20 . Since the notches are provided along the edge of the pressure relief portion 2122, when the battery cell 20 is depressurized, the pressure relief portion 2122 will open along the edge to provide a larger opening for gas to pass through.
  • the part between the two ends of the scored groove 2121 can be used as a rotation axis, and the pressure relief part 2122 is flipped open around this rotation axis. , which is conducive to improving the opening efficiency of the pressure relief part 2122, making the pressure relief part 2122 less prone to problems such as deformation, cracking, and partial openings, resulting in poor pressure relief, and is conducive to improving the safety of the battery cell 20.
  • the scored groove 2121 includes a first section 21211, a second section 21212, and a third section 21213 connected in sequence.
  • the first section 21211 and the third section 21213 are arranged oppositely.
  • the first section 21211 and the third section 21213 are arc-shaped, and the second section 21212 is a straight line.
  • the first section 21211 and the third section 21213 are symmetrical about the mid-perpendicular of the second section 21212.
  • the area of the pressure relief portion 2122 is S1, and the area of the pressure relief hole 2111 is S2, which satisfies: 0.3 ⁇ S1/S2 ⁇ 1.
  • the width of the scored groove 2121 is W, and the thickness of the pressure relief mechanism 212 is T, which satisfies: 0 ⁇ W/T ⁇ 1.
  • the ratio of the width of the scoring groove 2121 to the thickness of the pressure relief mechanism 212 is greater than 0 and less than or equal to 1.
  • the width of the score groove 2121 should not be too wide, otherwise when the battery cell 20 is depressurized, the position of the score groove 2121 will not be susceptible to shear force, but will be prone to tensile strain, causing the pressure relief mechanism 212 to be difficult to release from the score.
  • the slot 2121 is cracked. When W/T>1, compared with the case of 0 ⁇ W/T ⁇ 1, it is more difficult for the pressure relief mechanism 212 to crack from the scored groove 2121 position.
  • the depth of the notched groove 2121 is H in mm
  • the detonation pressure of the battery cell 20 is P in MPa

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Gas Exhaust Devices For Batteries (AREA)

Abstract

本申请提供了一种端盖组件、电池单体、电池及用电设备，涉及电池领域。端盖组件包括端盖和泄压机构，端盖具有泄压孔，泄压机构覆盖泄压孔。其中，泄压机构为高分子材料。泄压机构设有薄弱部，薄弱部被配置为在电池单体泄压时裂开。采用高分子材料制成泄压机构，不但能够在电池单体泄压时稳定排出电池单体内的气体，还能够在电池单体正常使用时阻隔外界水分渗入电池单体内，降低电池单体短路风险。通过在泄压机构设置薄弱部，薄弱部在电池单体泄压时能够裂开，形成供气体顺畅通过的开口，泄压机构不易出现变形、开裂、局部开口等问题导致泄压不畅，有利于提高电池单体的安全性。

Description

端盖组件、电池单体、电池及用电设备 技术领域
本申请涉及电池领域，具体而言，涉及一种端盖组件、电池单体、电池及用电设备。
背景技术
电池在新能源领域应用甚广，例如电动汽车、新能源汽车等，新能源汽车、电动汽车已经成为汽车产业的发展新趋势。电池技术的发展要同时考虑多方面的设计因素，例如，电池寿命、能量密度、放电容量、充放电倍率等性能参数。另外，还需要考虑电池的安全性。然而，目前的电池的安全性较差。
发明内容
本申请实施例的目的在于提供一种端盖组件、电池单体、电池及用电设备，其旨在改善相关技术中电池的安全性较差的问题。
第一方面，本申请实施例提供了一种端盖组件，用于电池单体，所述端盖组件包括端盖和泄压机构，所述端盖具有泄压孔，所述泄压机构覆盖所述泄压孔；其中，所述泄压机构为高分子材料，所述泄压机构设有薄弱部，所述薄弱部被配置为在所述电池单体泄压时裂开。
在上述技术方案中，由于高分子材料具有透气阻水的性质，采用高分子材料制成泄压机构，不但能够在电池单体泄压时稳定排出电池单体内的气体，还能够在电池单体正常使用时阻隔外界水分渗入电池单体内，阻断水汽和电解液通过泄压机构向电池单体内外流通，降低电池单体短路风险。另外，通过在泄压机构设置薄弱部，薄弱部在电池单体泄压时能够裂开，形成供气体顺畅通过的开口，泄压机构不易出现变形、开裂、局部开口等问题导致泄压不畅，有利于提高电池单体的安全性。
作为本申请实施例的一种可选技术方案，所述薄弱部由在所述泄压机构上设置刻痕槽形成。
在上述技术方案中，通过在泄压机构上设置刻痕槽，以形成薄弱部，简单方便，易于加工，生产成本较低。
作为本申请实施例的一种可选技术方案，所述泄压机构具有泄压部，所述刻痕槽沿着所述泄压部的边缘延伸，所述泄压部被配置为在所述电池单体泄压时以所述刻痕槽为边界打开。
在上述技术方案中，由于刻痕沿着泄压部的边缘设置，因此在电池单体泄压时，泄压部会沿着边缘打开，以提供较大的供气体通过的开口。
作为本申请实施例的一种可选技术方案，所述刻痕槽为沿非封闭轨迹延伸的非封闭结构。
在上述技术方案中，非封闭轨迹的两端存在距离，也即沿非封闭轨迹延伸的刻痕槽的两端之间存在距离，这样，在电池单体泄压时，刻痕槽的两端之间的部分可以作为转动轴，泄压部绕着这个转动轴翻转打开，有利于提升泄压部的打开效率，使得泄压部不易出现变形、开裂、局部开口等问题导致泄压不畅，有利于提高电池单体的安全性。
作为本申请实施例的一种可选技术方案，所述刻痕槽包括依次连接的第一 段、第二段和第三段，所述第一段和所述第三段相对设置。
在上述技术方案中，当电池单体泄压时，泄压部以第一段、第二段和第三段为边界打开，并且，第一段远离第二段的一端与第三段远离第二段的一端的连线作为泄压部转动的转动轴，以便于泄压部打开。
作为本申请实施例的一种可选技术方案，所述第二段为直线形，所述第一段和所述第三段关于所述第二段的中垂线对称。
在上述技术方案中，将第一段和第三段关于第二段的中垂线对称设置，使得泄压部在打开时受力较为均匀，有利于提升泄压部的打开效率。
作为本申请实施例的一种可选技术方案，所述第一段和所述第三段为圆弧形。
在上述技术方案中，将第一段和第三段设置为圆弧形，有利于圈出较大的范围，使得泄压部的面积较大。这样泄压部打开后形成的供气体通过的开口较大，便于顺畅泄压。
作为本申请实施例的一种可选技术方案，所述泄压孔的孔壁面包括第一平直面、第二平直面、第一圆弧面和第二圆弧面，所述第一平直面、所述第一圆弧面、所述第二平直面和所述第二圆弧面首尾依次连接；所述第一圆弧面和所述第一段同轴设置，所述第二圆弧面和所述第三段同轴设置。
在上述技术方案中，泄压机构的形状与泄压孔的形状相匹配，以在对泄压孔具有较好的覆盖效果的同时，减少泄压机构的材料消耗。
作为本申请实施例的一种可选技术方案，所述泄压机构设置有两个所述刻痕槽，两个所述刻痕槽背对设置。
在上述技术方案中，通过在泄压机构上设置两个刻痕槽，对应形成两个泄压部，在电池单体泄压时，两个泄压部分别从两个刻痕槽所在的位置裂开，打开两个开口泄压。泄压机构不易出现变形、开裂、局部开口等问题导致泄压不畅，具有较好的泄压效果，有利于提高电池单体的安全性。
作为本申请实施例的一种可选技术方案，两个所述刻痕槽部分重合。
在上述技术方案中，两个刻痕槽重合的部分开裂时，可以同时打开两个开口，有利于提升泄压机构的打开效率。
作为本申请实施例的一种可选技术方案，所述泄压部的面积为S1，所述泄压孔的面积为S2，满足：0.3＜S1/S2≤1。
在上述技术方案中，通过使泄压部的面积与泄压孔的面积之比大于0.3且小于或等于1，以保证泄压部具有较大的面积，使得泄压部在打开后形成较大的供气体通过的开口，从而使电池单体泄压顺畅。
作为本申请实施例的一种可选技术方案，所述刻痕槽包括依次连接的第一段、第二段和第三段，所述第一段和所述第三段相对设置，所述第一段和所述第三段为半圆形，所述第二段为直线形，所述第一段和所述第三段关于所述第二段的中垂线对称；
所述第二段的长度为L，所述第一段和所述第三段的半径均为r，满足：S1＝πr 2+2rL。
在上述技术方案中，将第一段和第三段设置为半圆形，有利于圈出较大的范围，使得泄压部的面积较大，这样泄压部打开后形成的供气体通过的开口较大，便于顺畅泄压。将第一段和第三段关于第二段的中垂线对称设置，使得泄压部在打开时受力较为均匀，有利于提升泄压部的打开效率。此时，泄压部包括第一段、第二段、第 三段以及第一段远离第二段的一端和第三段远离第二段的一端的连线共同限定出的区域，泄压部的面积为：S1＝πr 2+2rL。
作为本申请实施例的一种可选技术方案，所述刻痕槽为沿着封闭轨迹延伸的封闭结构。
在上述技术方案中，将刻痕槽设置为沿着封闭轨迹延伸的封闭结构，以便于泄压机构泄压时沿着刻痕槽裂开，形成供气体通过的开口。
作为本申请实施例的一种可选技术方案，所述刻痕槽包括首尾依次连接的第一段、第二段、第三段和第四段，所述第一段和所述第三段相对布置，所述第二段和所述第四段相对布置，所述第一段和所述第三段为圆弧形，所述第二段和所述第四段为直线形。
在上述技术方案中，第一段和第三段为圆弧槽，泄压机构在第一段的中间位置和第三段的中间位置形成薄弱位置，薄弱位置为泄压部的最先开启位置，使得泄压部在电池单体内部达到起爆压力时能够及时打开。第二段和第四段均为沿端盖的长度方向延伸的直线槽，使得第二段和第四段平行设置，泄压部沿着第一段和第三段裂开后，能够更为容易地沿着第二段和第四段打开，提高泄压部的打开速率，实现快速泄压。
作为本申请实施例的一种可选技术方案，所述刻痕槽的宽度为W，所述泄压机构的厚度为T，满足：0＜W/T≤1。
在上述技术方案中，刻痕槽的宽度与泄压机构的厚度的比值大于0且小于或等于1。刻痕槽的宽度不宜过宽，否则在电池单体泄压时，刻痕槽所在的位置不易受到剪力作用，而是容易出现拉伸应变，导致泄压机构不易从刻痕槽位置裂开。当W/T＞1时，相比于0＜W/T≤1的情况，泄压机构从刻痕槽位置裂开的难度更大。
作为本申请实施例的一种可选技术方案，还满足：0.004mm≤W≤0.018mm；和/或，0.01mm≤T≤10mm。
在上述技术方案中，刻痕槽的宽度在0.004～0.018mm范围内，泄压机构较为容易在电池单体泄压时沿着刻痕槽开裂。泄压机构的厚度在0.01～10mm内，不但能够在电池单体泄压时稳定排出电池单体内的气体，还能够在电池单体正常使用时阻隔外界水分渗入电池单体内，降低电池单体短路风险。
作为本申请实施例的一种可选技术方案，所述刻痕槽的深度为H，单位为mm，所述电池单体的起爆压力为P，单位为MPa，所述泄压机构的厚度为T，单位为mm，满足：H＝K(-0.181P+T-0.246)，K∈[0.1，5]。
在上述技术方案中，若已知电池单体的起爆压力和泄压机构的厚度，即可根据公式得到刻痕槽应该刻痕的深度范围。
作为本申请实施例的一种可选技术方案，所述高分子材料包括氟化乙烯丙烯共聚物和聚氯三氟乙烯中的至少一种。
在上述技术方案中，氟化乙烯丙烯共聚物和聚氯三氟乙烯的透气性和阻水性的平衡性能较好，采用氟化乙烯丙烯共聚物和聚氯三氟乙烯中的至少一种制成泄压机构，不但能够在电池单体泄压时稳定排出电池单体内的气体，还能够在电池单体正常使用时阻隔外界水分渗入电池单体内，降低电池单体短路风险。
第二方面，本申请实施例还提供了一种电池单体，所述电池单体包括电极组件、壳体和上述的端盖组件，所述壳体具有至少一端开口的容纳空间，所述容纳空间用于容纳所述电极组件，所述端盖封闭所述开口。
第三方面，本申请实施例还提供了一种电池，所述电池包括箱体和上述的电 池单体，所述电池单体容纳于所述箱体内。
第四方面，本申请实施例还提供了一种用电设备，所述用电设备包括上述的电池，所述电池用于给所述用电设备提供电能。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本申请的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的爆炸图；
图3为本申请一些实施例提供的电池单体的爆炸图；
图4为本申请一些实施例提供的端盖组件的爆炸图；
图5为本申请另一些实施例提供的端盖组件的爆炸图；
图6为本申请一些实施例提供的端盖组件(刻痕槽为C形)的俯视示意图；
图7为本申请一些实施例提供的端盖组件(刻痕槽为双C形，且每个C形的开口朝向端盖的宽度方向)的俯视示意图；
图8为本申请一些实施例提供的端盖组件(刻痕槽为双C形，且每个C形的开口朝向端盖的长度方向)的俯视示意图；
图9为本申请一些实施例提供的端盖组件(刻痕槽为“王”字形)的俯视示意图；
图10为本申请一些实施例提供的端盖组件(刻痕槽呈O形)的俯视示意图；
图11为本申请一些实施例提供的端盖组件(刻痕槽为O-C组合)的俯视示意图；
图12为图6中A-A位置的剖视图；
图13为图9中B位置的放大图(刻痕槽的横截面呈矩形)；
图14为图9中B位置的放大图(刻痕槽的横截面呈梯形)；
图15为图9中B位置的放大图(刻痕槽的横截面呈三角形)。
图标：10-箱体；11-第一部分；12-第二部分；20-电池单体；21-端盖组件；211-端盖；2111-泄压孔；2112-第一平直面；2113-第二平直面；2114-第一圆弧面；2115-第二圆弧面；2116-凹槽；212-泄压机构；2121-刻痕槽；21211-第一段；21212-第二段；21213-第三段；21214-第四段；2122-泄压部；2123-凸部；2124-薄弱部；213-连接件；2131-卡槽；214-密封件；22-电极组件；23-壳体；100-电池；200-控制器；300-马达；1000-车辆。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本申请中在申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”、“附接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。
本申请中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本申请中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。应理解，附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸，以及集成装置的整体厚度、长宽等尺寸仅为示例性说明，而不应对本申请构成任何限定。
本申请中出现的“多个”指的是两个以上(包括两个)。
本申请中，电池单体可以包括锂离子二次电池单体、锂离子一次电池单体、锂硫电池单体、钠锂离子电池单体、钠离子电池单体或镁离子电池单体等，本申请实施例对此并不限定。电池单体可呈圆柱体、扁平体、长方体或其它形状等，本申请实施例对此也不限定。电池单体一般按封装的方式分成三种：柱形电池单体、方形电池单体和软包电池单体，本申请实施例对此也不限定。
本申请的实施例所提到的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。例如，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
电池单体包括电极组件和电解液，电极组件由正极片、负极片和隔离膜组成。电池单体主要依靠金属离子在正极片和负极片之间移动来工作。正极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂敷正极活性物质层的正极集流体凸出于已涂覆正极活性物质层的正极集流体，未涂敷正极活性物质层的正极集流体作为正极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂敷负极活性物质层的负极集流体凸出于已涂覆负极活性物质层的负极集流体，未涂敷负极活性物质层的负极集流体作为负极耳。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。为了保证通过大电流而不发生熔断，正极耳的数量为多个且层叠在一起，负极耳的数量为多个且层叠在一起。隔离膜的材质可以为PP(polypropylene，聚丙烯)或 PE(polyethylene，聚乙烯)等。此外，电极组件可以是卷绕式结构，也可以是叠片式结构，本申请实施例并不限于此。
目前，从市场形势的发展来看，电池的应用越加广泛。电池不仅被应用于水力、火力、风力和太阳能电站等储能电源系统，而且还被广泛应用于电动自行车、电动摩托车、电动汽车等电动交通工具，以及军事装备和航空航天等多个领域。随着电池应用领域的不断扩大，其市场的需求量也在不断地扩增。
电池技术的发展要同时考虑多方面的设计因素，例如，电池寿命、能量密度、放电容量、充放电倍率等性能参数。另外，还需要考虑电池的安全性。然而，目前的电池的安全性较差。
对于电池单体来说，为保证电池单体的安全性，可以在电池单体的端盖上设置泄压机构。在电池单体内部压力达到起爆压力时，泄压机构打开，以泄放电池单体内部的压力，以降低电池单体爆炸、起火的风险。
发明人注意到，受生产工艺的影响，外界水分可能经过泄压机构进入到电池单体内部，造成电池单体短路。电池单体内的水汽或电解液也可能经过泄压机构泄漏，造成了安全风险。
发明人进一步研究发现，可以通过采用高分子材料制成泄压机构，利用高分子材料透气阻水的性质，阻断水汽和电解液通过泄压机构向电池单体内外流通。但是，采用高分子材料制成的泄压机构在电池单体泄压时的爆破一致性差，也就是说很难把各个相同规格的电池单体的爆破压力控制在合理的波动范围内，而且高分子材料制成的泄压机构打开时，还会经常出现泄压机构发生变形但是不能及时打开泄压的情况。另外，在电池单体产气过程中，高分子材料制成的泄压机构容易受电池单体内部气压作用而出现小裂纹，气体可以通过小裂纹部分释放，使得泄压机构很难达到爆破压力，但是从小裂纹泄压的速度较慢，电池单体的内部压力不能及时释放，因此存在安全风险。简而言之，采用高分子材料制成泄压机构在电池单体泄压时，容易出现鼓胀(泄压机构变形而形成凸包)或开裂(泄压机构出现小裂纹)，导致泄压不畅，爆破一致性差，电池单体的安全性很不稳定。
鉴于此，本申请实施例提供一种端盖组件，该端盖组件的泄压机构采用高分子材料制成，泄压机构上设置有薄弱部，薄弱部被配置为在电池单体泄压时裂开。
由于高分子材料具有透气阻水的性质，采用高分子材料制成泄压机构，不但能够在电池单体泄压时稳定排出电池单体内的气体，还能够在电池单体正常使用时阻隔外界水分渗入电池单体内，阻断水汽和电解液通过泄压机构向电池单体内外流通，降低电池单体短路风险。
另外，通过在泄压机构设置薄弱部，薄弱部在电池单体泄压时能够裂开，形成供气体顺畅通过的开口，泄压机构不易出现变形、开裂、局部开口等问题导致泄压不畅，有利于提高电池单体的安全性。
本申请实施例描述的技术方案适用于电池以及使用电池的用电设备。
用电设备可以是车辆、手机、便携式设备、笔记本电脑、轮船、航天器、电动玩具和电动工具等等。航天器包括飞机、火箭、航天飞机和宇宙飞船等等；电动玩具包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等；电动工具包括金属切削电动工具、研磨电动工具、装配电动工具和铁道用电动工具，例如，电钻、电动砂轮机、电动扳手、电动螺丝刀、电锤、冲击电钻、混凝土振动器和电刨等等。本申请实施例对上述用电设备不做特殊限制。
以下实施例为了方便说明，以用电设备为车辆1000为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000可以为燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源。车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池100不仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2，图2为本申请一些实施例提供的电池100的爆炸图。电池100包括箱体10和电池单体20，电池单体20容纳于箱体10内。其中，箱体10用于为电池单体20提供容纳空间，箱体10可以采用多种结构。在一些实施例中，箱体10可以包括第一部分11和第二部分12，第一部分11与第二部分12相互盖合，第一部分11和第二部分12共同限定出用于容纳电池单体20的容纳空间。第二部分12可以为一端开口的空心结构，第一部分11可以为板状结构，第一部分11盖合于第二部分12的开口侧，以使第一部分11与第二部分12共同限定出容纳空间；第一部分11和第二部分12也可以是均为一侧开口的空心结构，第一部分11的开口侧盖合于第二部分12的开口侧。当然，第一部分11和第二部分12形成的箱体10可以是多种形状，比如，圆柱体、长方体等。
在电池100中，电池单体20可以是多个，多个电池单体20之间可串联或并联或混联，混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起，再将多个电池单体20构成的整体容纳于箱体10内；当然，电池100也可以是多个电池单体20先串联或并联或混联组成电池模块形式，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体10内。电池100还可以包括其他结构，例如，该电池100还可以包括汇流部件，用于实现多个电池单体20之间的电连接。
其中，每个电池单体20可以为二次电池单体或一次电池单体；还可以是锂硫电池单体、钠离子电池单体或镁离子电池单体，但不局限于此。电池单体20可呈圆柱体、扁平体、长方体或其它形状等。
请参照图3，图3为本申请一些实施例提供的电池单体20的分解结构示意图。电池单体20是指组成电池100的最小单元。如图3，电池单体20包括有端盖组件21、电极组件22以及壳体23。
端盖组件21包括端盖211和泄压机构212。其中，端盖211是指盖合于壳体23的开口处以将电池单体20的内部环境隔绝于外部环境的部件。不限地，端盖211的形状可以与壳体23的形状相适应以配合壳体23。可选地，端盖211可以由具有一定硬度和强度的材质(如铝合金)制成，这样，端盖211在受挤压碰撞时就不易发生形变，使电池单体20能够具备更高的结构强度，安全性能也可以有所提高。端盖211的材质也可以是多种的，比如，铜、铁、铝、不锈钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。端盖组件21还可以包括电极端子(图中未示出)，电极端子设置于端盖211。电极端子可以用于与电极组件22电连接，以用于输出或输入电池单体20的电能。泄压机构212设置于端盖211，泄压机构212用于在电池单体20的内部压力或温度达到起爆压力时打开，以泄放电池单体20的内部压力。
壳体23是用于配合端盖211以形成电池单体20的内部环境的组件，其中，形成的内部环境可以用于容纳电极组件22、电解液以及其他部件。壳体23和端盖211可以是独立的部件，可以于壳体23上设置开口，通过在开口处使端盖211盖合开口以形成电池单体20的内部环境。不限地，也可以使端盖211和壳体23一体化，具体地，端盖211和壳体23可以在其他部件入壳前先形成一个共同的连接面，当需要封装壳体23的内部时，再使端盖211盖合壳体23。壳体23可以是多种形状和多种尺寸的，例如长方体形、圆柱体形、六棱柱形等。具体地，壳体23的形状可以根据电极组件22的具体形状和尺寸大小来确定。壳体23的材质可以是多种，比如，铜、铁、铝、不锈钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。
电极组件22是电池单体20中发生电化学反应的部件。壳体23内可以包含一个或更多个电极组件22。电极组件22主要由正极片和负极片卷绕或层叠放置形成，并且通常在正极片与负极片之间设有隔离膜。正极片和负极片具有活性物质的部分构成电极组件22的本体部，正极片和负极片不具有活性物质的部分各自构成极耳。正极极耳和负极极耳可以共同位于本体部的一端或是分别位于本体部的两端。在电池100的充放电过程中，正极活性物质和负极活性物质与电解液发生反应，极耳连接电极端子以形成电流回路。
请参照图4，图4为本申请一些实施例提供的端盖组件21的爆炸图。本申请实施例提供了一种端盖组件21，用于电池单体20。端盖组件21包括端盖211和泄压机构212，端盖211具有泄压孔2111，泄压机构212覆盖泄压孔2111。其中，泄压机构212为高分子材料。泄压机构212设有薄弱部2124(在图13、图14和图15中示出)，薄弱部2124被配置为在电池单体20泄压时裂开。
泄压孔2111是贯穿端盖211厚度方向两个表面的通孔。泄压机构212覆盖泄压孔2111，以在电池单体20正常使用时将电池单体20内部与外部隔绝，避免外界杂质进入到电池单体20内或者电池单体20内的电解液泄漏。泄压孔2111的形状不受限制，例如，泄压孔2111可以为圆孔、方孔、椭圆孔等。高分子材料也称为聚合物材料，是以高分子化合物为基体，再配有其他添加剂(助剂)所构成的材料。高分子材料按来源分为天然高分子材料和合成高分子材料。天然高分子是存在于动物、植物及生物体内的高分子物质，可分为天然纤维、天然树脂、天然橡胶、动物胶等。合成高分子材料主要是指塑料、合成橡胶和合成纤维三大合成材料，此外还包括胶黏剂、涂料以及各种功能性高分子材料。合成高分子材料具有天然高分子材料所没有的或较为优越的性能——较小的密度、较高的力学、耐磨性、耐腐蚀性、电绝缘性等。
薄弱部2124(在图13、图14和图15中示出)是泄压机构212上强度较低的部分，在电池单体20内部压力达到起爆压力时，薄弱部2124在压力作用下打开，泄放电池单体20内部的压力，以降低电池单体20爆炸、起火的风险。需要说明的是，图13、图14和图15中虚线是为了标识出薄弱部2124的范围，不代表实际结构。
“电池单体20泄压时”是指电池单体20内部的压力达到起爆压力时。由于泄压机构212是由高分子材料制成的，而高分子材料具有透气阻水的性质，在电池单体20正常使用时，由此性质产生的气体进出电池单体20不能称为“泄压时”。
由于高分子材料具有透气阻水的性质，采用高分子材料制成泄压机构212，不但能够在电池单体20泄压时稳定排出电池单体20内的气体，还能够在电池单体20正常使用时阻隔外界水分渗入电池单体20内，阻断水汽和电解液通过泄压机构212向电池单体20内外流通，降低电池单体20短路风险。另外，通过在泄压机构212设置薄弱部2124，薄弱部2124在电池单体20泄压时裂开，形成供气体顺畅通过的开口， 泄压机构212不易出现变形、开裂、局部开口等问题导致泄压不畅，有利于提高电池单体20的安全性。
请参照图4，在一些实施例中，泄压机构212可以是粘接于端盖211。为了便于泄压机构212与端盖211粘接，可以在泄压孔2111外周设置凸起，将泄压机构212粘接于凸起上。
请参照图5，图5为本申请另一些实施例提供的端盖组件21的爆炸图。在一些实施例中，端盖组件21包括连接件213，连接件213连接于端盖211，泄压机构212设置于连接件213。可选地，连接件213焊接于端盖211。连接件213上开设有卡槽2131，泄压机构212的边缘设置有凸部2123，凸部2123与卡槽2131卡接配合。
在一些实施例中，连接件213为环状结构，其中间的通孔可以供电池单体20内部的气体流向泄压机构212。
在一些实施例中，端盖211上开设有凹槽2116，凹槽2116用于容纳连接件213的至少一部分，以减小泄压机构212凸出于端盖211的高度。
在一些实施例中，端盖组件21包括密封件214，密封件214设置于连接件213与端盖211之间，以将连接件213与端盖211密封。连接件213可以将密封件214压迫于端盖211上，密封件214能够阻止外界的水汽从连接件213与端盖211之间进入到电池单体20的内部。
在一些实施例中，密封件214为密封圈，其中间的通孔可以供电池单体20内部的气体流向泄压机构212。
在一些实施例中，薄弱部2124由在泄压机构212上设置刻痕槽2121形成。
刻痕槽2121可以是从泄压机构212的表面沿端盖211的厚度方向凹陷的槽体。刻痕槽2121可以设置于泄压机构212面向于端盖211的表面，也可以设置于泄压机构212背离端盖211的表面。以泄压机构212为长方形平板结构为例，泄压机构212在端盖211的厚度方向具有相对的第一表面和第二表面，第一表面面向端盖211，第二表面背离端盖211。刻痕槽2121可以是设置于泄压机构212的第一表面，也可以是设置于泄压机构212的第二表面。
通过在泄压机构212上设置刻痕槽2121，以形成薄弱部2124，简单方便，易于加工，生产成本较低。
请参照图5，在一些实施例中，泄压机构212具有泄压部2122，刻痕槽2121沿着泄压部2122的边缘延伸。泄压部2122被配置为在电池单体20泄压时以刻痕槽2121为边界打开。
泄压部2122可以看作是刻痕槽2121的内侧面界定出来的部分。以刻痕槽2121的内侧面为长方形为例，泄压部2122为泄压机构212由刻痕槽2121的内侧面界定出来的长方形部分。刻痕槽2121也可以是沿弯折轨迹延伸的线形槽，比如，弯折轨迹为U形轨迹，泄压部2122则为泄压机构212由弯折轨迹界定出来的U形部分。再如，弯折轨迹为长方形轨迹，泄压部2122则为泄压机构212由弯折轨迹界定出来的长方形部分。若刻痕槽2121为沿弯折轨迹延伸的线形槽，在电池单体20内部压力达到起爆压力时，泄压部2122可以是以刻痕槽2121为边界打开，以泄放电池单体20内部的压力。
由于刻痕沿着泄压部2122的边缘设置，因此在电池单体20泄压时，泄压部2122会沿着边缘打开，以提供较大的供气体通过的开口。
在另一些实施例中，泄压机构212具有泄压部2122，泄压部2122为泄压机构212设置刻痕槽2121后剩余的部分。泄压机构212被配置为在电池单体20泄压时 从泄压部2122打开。
请参照图4和图6，图6为本申请一些实施例提供的端盖组件21(刻痕槽2121为C形)的俯视示意图。在一些实施例中，刻痕槽2121为沿非封闭轨迹延伸的非封闭结构。
需要说明的是，图6中虚线表示的是泄压孔2111的位置。
非封闭轨迹的两端存在距离，非封闭轨迹可以是U形轨迹、C形轨迹、圆弧轨迹、抛物线轨迹等。刻痕槽2121沿着两端存在距离的非封闭轨迹延伸，因此，刻痕槽2121也可以为U形槽、C形槽、圆弧槽、抛物线形槽等。
非封闭轨迹的两端存在距离，也即沿非封闭轨迹延伸的刻痕槽2121的两端之间存在距离，这样，在电池单体20泄压时，刻痕槽2121的两端之间的部分可以作为转动轴，泄压部2122绕着这个转动轴翻转打开，有利于提升泄压部2122的打开效率，使得泄压部2122不易出现变形、开裂、局部开口等问题导致泄压不畅，有利于提高电池单体20的安全性。
在一些实施例中，刻痕槽2121包括依次连接的第一段21211、第二段21212和第三段21213，第一段21211和第三段21213相对设置。
第一段21211和第三段21213是刻痕槽2121中相对设置的两个槽段，第二段21212是刻痕槽2121中连接第一段21211和第三段21213的槽段。第一段21211的远离第二段21212的一端与第三段21213的远离第二段21212的一端存在间隔，以形成非封闭结构。由于第一段21211和第三段21213是相对设置的，因此，整个刻痕槽2121是非直线结构。换句话说，第一段21211、第二段21212和第三段21213中至少两个的延伸方向不在同一直线上。
当电池单体20泄压时，泄压部2122以第一段21211、第二段21212和第三段21213为边界打开，并且，第一段21211远离第二段21212的一端与第三段21213远离第二段21212的一端的连线作为泄压部2122转动的转动轴，以便于泄压部2122打开。
请参照图4和图6，在一些实施例中，第二段21212为直线形，第一段21211和第三段21213关于第二段21212的中垂线对称。
第二段21212沿着直线轨迹延伸。第二段21212的中垂线是指经过第二段21212的中点，并且垂直于第二段21212的直线。第二段21212的中垂线也可以称为第二段21212的垂直平分线。第一段21211和第三段21213关于第二段21212的中垂线轴对称设置。
将第一段21211和第三段21213关于第二段21212的中垂线对称设置，使得泄压部2122在打开时受力较为均匀，有利于提升泄压部2122的打开效率。
请参照图4和图6，在一些实施例中，第一段21211和第三段21213为圆弧形。
第一段21211和第三段21213分别沿着圆弧轨迹延伸，第一段21211和第三段21213的沿着互相远离的方向弯曲，使得第一段21211和第三段21213的圆心均位于泄压部2122内。
特殊地，第一段21211和第三段21213可以为半圆形。这样，第一段21211、第二段21212和第三段21213连接形成的刻痕槽2121呈C形。
将第一段21211和第三段21213设置为圆弧形，有利于圈出较大的范围，使得泄压部2122的面积较大。这样泄压部2122打开后形成的供气体通过的开口较大，便于顺畅泄压。
请参照图4和图6，在一些实施例中，泄压孔2111的孔壁面包括第一平直面2112、第二平直面2113、第一圆弧面2114和第二圆弧面2115。第一平直面2112、第一圆弧面2114、第二平直面2113和第二圆弧面2115首尾依次连接。第一圆弧面2114和第一段21211同轴设置，第二圆弧面2115和第三段21213同轴设置。
第一平直面2112和第二平直面2113均为平面。第一圆弧面2114和第二圆弧面2115均为曲面，且第一圆弧面2114和第二圆弧面2115沿着圆弧轨迹延伸。第一平直面2112、第一圆弧面2114、第二平直面2113和第二圆弧面2115共同限定出泄压孔2111。
“第一圆弧面2114和第一段21211同轴设置”是指第一圆弧面2114的轴线经过第一段21211的圆心。“第二圆弧面2115和第三段21213同轴设置”是指第二圆弧面2115的轴线经过第三段21213的圆心。
在本实施例中，泄压孔2111为第一平直面2112、第二平直面2113、第一圆弧面2114和第二圆弧面2115围成的O形结构。与之相应地，泄压部2122也呈O形。这样，泄压孔2111的形状与泄压部2122的形状相同，以便于在电池单体20泄压时从刻痕槽2121的位置裂开。
泄压机构212的形状与泄压孔2111的形状相匹配，以在对泄压孔2111具有较好的覆盖效果的同时，减少泄压机构212的材料消耗。
在另一些实施例中，泄压孔2111的也可以为矩形、椭圆形等。这样，泄压孔2111的形状与泄压部2122的形状相似，同样便于在电池单体20泄压时从刻痕槽2121的位置裂开。
请参照图7和图8，图7为本申请一些实施例提供的端盖组件21(刻痕槽2121为双C形，且每个C形的开口朝向端盖211的宽度方向)的俯视示意图。图8为本申请一些实施例提供的端盖组件21(刻痕槽2121为双C形，且每个C形的开口朝向端盖211的长度方向)的俯视示意图。需要说明的是，图7和图8中虚线表示的是泄压孔2111的位置。在一些实施例中，泄压机构212设置有两个刻痕槽2121，两个刻痕槽2121背对设置。
刻痕槽2121是沿两端存在距离的非封闭轨迹延伸的非封闭结构。刻痕槽2121形成的图形中具有开口端。两个刻痕槽2121背对设置是指两个刻痕槽2121的开口端的朝向相反。
请参照图7，在另一些实施例中，两个刻痕槽2121均为C形槽。两个刻痕槽2121的开口端朝向端盖211的宽度方向。请参照图8，在又一些实施例中，两个刻痕槽2121均为C形槽。两个刻痕槽2121的开口端朝向端盖211的长度方向。
通过在泄压机构212上设置两个刻痕槽2121，对应形成两个泄压部2122，在电池单体20泄压时，两个泄压部2122分别从两个刻痕槽2121所在的位置裂开，打开两个开口泄压。泄压机构212不易出现变形、开裂、局部开口等问题导致泄压不畅，具有较好的泄压效果，有利于提高电池单体20的安全性。
请参照图7和图8，在一些实施例中，两个刻痕槽2121部分重合。
每个刻痕槽2121可以包括依次连接的第一段21211、第二段21212和第三段21213，第一段21211和第三段21213相对设置。第一段21211和第三段21213为圆弧形，第二段21212为直线形，第一段21211和第三段21213关于第二段21212的中垂线对称。两个刻痕槽2121的第二段21212可以重合设置。
需要说明的是，这里两个刻痕槽2121部分重合可以是两个刻痕槽2121相交设置，也可以是两个刻痕槽2121相切设置。
两个刻痕槽2121重合的部分开裂时，可以同时打开两个开口，有利于提升泄压机构212的打开效率。
请参照图9，图9为本申请一些实施例提供的端盖组件21(刻痕槽2121为“王”字形)的俯视示意图。在一些实施例中，泄压机构212设置有多个刻痕槽2121，多个刻痕槽2121中至少有两个相交设置。
请参照图9，图9中泄压机构212包括4个刻痕槽2121，4个刻痕槽2121相交设置，形成“王”字形结构。
在一些实施例中，泄压部2122的面积为S1，泄压孔2111的面积为S2，满足：0.3＜S1/S2≤1。
S1/S2表示的是泄压部2122的面积与泄压孔2111的面积之比。泄压部2122的面积与泄压孔2111的面积之比可以为：S1/S2＝0.35、0.4、0.5、0.6、0.7、0.8、0.9、1等。
通过使泄压部2122的面积与泄压孔2111的面积之比大于0.3且小于或等于1，以保证泄压部2122具有较大的面积，使得泄压部2122在打开后形成较大的供气体通过的开口，从而使电池单体20泄压顺畅。
在一些实施例中，刻痕槽2121包括依次连接的第一段21211、第二段21212和第三段21213，第一段21211和第三段21213相对设置。第一段21211和第三段21213为半圆形，第二段21212为直线形，第一段21211和第三段21213关于第二段21212的中垂线对称。第二段21212的长度为L，第一段21211和第三段21213的半径均为r，满足：S1＝πr 2+2rL。
将第一段21211和第三段21213设置为半圆形，有利于圈出较大的范围，使得泄压部2122的面积较大，这样泄压部2122打开后形成的供气体通过的开口较大，便于顺畅泄压。将第一段21211和第三段21213关于第二段21212的中垂线对称设置，使得泄压部2122在打开时受力较为均匀，有利于提升泄压部2122的打开效率。此时，泄压部2122包括第一段21211、第二段21212、第三段21213以及第一段21211远离第二段21212的一端和第三段21213远离第二段21212的一端的连线共同限定出的区域，泄压部2122的面积为：S1＝πr 2+2rL。
请参照图10，图10为本申请一些实施例提供的端盖组件21(刻痕槽2121呈O形)的俯视示意图。在一些实施例中，刻痕槽2121为沿着封闭轨迹延伸的封闭结构。
“封闭轨迹”是指首尾两端连接在一起的轨迹。封闭轨迹可以为圆形轨迹、椭圆轨迹、多边形轨迹等。刻痕槽2121沿着封闭轨迹延伸，因此，刻痕槽2121也可以为圆形槽、椭圆槽、多边形槽等。
将刻痕槽2121设置为沿着封闭轨迹延伸的封闭结构，以便于泄压机构212泄压时沿着刻痕槽2121裂开，形成供气体通过的开口。
在一些实施例中，刻痕槽2121包括首尾依次连接的第一段21211、第二段21212、第三段21213和第四段21214，第一段21211和第三段21213相对布置，第二段21212和第四段21214相对布置。第一段21211和第三段21213为圆弧形，第二段21212和第四段21214为直线形。
第一段21211和第三段21213可以向相同的方向弯曲，也可以向相反的方向弯曲。第一段21211和第三段21213可以向彼此靠近的方向弯曲，使得第一段21211的圆心和第三段21213的圆心位于泄压部2122外。第一段21211和第三段21213也可以向彼此远离的方向弯曲，第一段21211的圆心和第三段21213的圆心位于泄压部 2122内。
示例性的，在图10中，第一段21211和第三段21213向彼此远离的方向弯曲，第二段21212和第四段21214为沿端盖211长度方向延伸的直线槽，第二段21212和第四段21214均与第一段21211相切，且第二段21212和第四段21214均与第三段21213相切，使得第一段21211、第二段21212、第三段21213和第四段21214形成的刻痕槽2121呈O形。
第一段21211和第三段21213为圆弧槽，泄压机构212在第一段21211的中间位置和第三段21213的中间位置形成薄弱位置，薄弱位置为泄压部2122的最先开启位置，使得泄压部2122在电池单体20内部达到起爆压力时能够及时打开。第二段21212和第四段21214均为沿端盖211的长度方向延伸的直线槽，使得第二段21212和第四段21214平行设置，泄压部2122沿着第一段21211和第三段21213裂开后，能够更为容易地沿着第二段21212和第四段21214打开，提高泄压部2122的打开速率，实现快速泄压。
请参照图11，图11为本申请一些实施例提供的端盖组件21(刻痕槽2121为O-C组合)的俯视示意图。在一些实施例中，泄压机构212包括多个刻痕槽2121，其中一些刻痕槽2121为沿非封闭轨迹延伸的非封闭结构。另一些刻痕槽2121为沿封闭轨迹延伸的封闭结构。多个刻痕槽2121相交设置。
在图11中，泄压机构212包括3个刻痕槽2121，其中，两个刻痕槽2121均为C形槽。两个刻痕槽2121的开口端朝向端盖211的宽度方向。另一个刻痕槽2121为O形槽，两个C形的刻痕槽2121位于O形的刻痕槽2121内部，且两个C形的刻痕槽2121的开口端均被O形的刻痕槽2121封闭。
请参照图12、图13、图14、和图15，图12为图5中A-A位置的剖视图。图13为图9中B位置的放大图(刻痕槽2121的横截面呈矩形)。图14为图9中B位置的放大图(刻痕槽2121的横截面呈梯形)。图15为图9中B位置的放大图(刻痕槽2121的横截面呈三角形)。在一些实施例中，刻痕槽2121的宽度为W，泄压机构212的厚度为T，满足：0＜W/T≤1。
刻痕槽2121的横截面的形状不受限制。例如，请参照图13，在图13所示的实施例中，刻痕槽2121的横截面的形状呈矩形。请参照图14，在图14所示的实施例中，刻痕槽2121的横截面的形状呈梯形。请参照图15，在图15所示的实施例中，刻痕槽2121的横截面的形状呈三角形。
刻痕槽2121的宽度是指刻痕槽2121的横截面上，刻痕槽2121的槽口的宽度。
刻痕槽2121在不同位置的宽度可以不同，也可以相同。但是刻痕槽2121在任何位置的宽度与泄压机构212的厚度之比应该大于0且小于等于1。刻痕槽2121的宽度与泄压机构212的厚度之比可以为：W/T＝1、0.9、0.8、0.7、0.6、0.5、0.4、0.3、0.2、0.1等。
刻痕槽2121的宽度与泄压机构212的厚度的比值大于0且小于或等于1。刻痕槽2121的宽度不宜过宽，否则在电池单体20泄压时，刻痕槽2121所在的位置不易受到剪力作用，而是容易出现拉伸应变，导致泄压机构212不易从刻痕槽2121位置裂开。当W/T＞1时，相比于0＜W/T≤1的情况，泄压机构212从刻痕槽2121位置裂开的难度更大。
在一些实施例中，还满足：0.004mm≤W≤0.018mm；和/或，0.01mm≤T≤10mm。
刻痕槽2121的宽度在0.004～0.018mm范围内，泄压机构212较为容易在电池单体20泄压时沿着刻痕槽2121开裂。泄压机构212的厚度在0.01～10mm内，不但能够在电池单体20泄压时稳定排出电池单体20内的气体，还能够在电池单体20正常使用时阻隔外界水分渗入电池单体20内，降低电池单体20短路风险。
在一些实施例中，刻痕槽2121的深度为H，单位为mm。电池单体20的起爆压力为P，单位为MPa。泄压机构212的厚度为T，单位为mm。满足：H＝K(-0.181P+T-0.246)，K∈[0.1，5]。
若刻痕槽2121从泄压机构212的背离端盖211的表面沿着端盖211的厚度方向朝向端盖211凹陷，则刻痕槽2121的深度是刻痕槽2121的槽底在端盖211的厚度方向上与泄压机构212的背离端盖211的表面之间的最大距离。
起爆压力是指能使泄压机构212打开的气压值。当电池单体20内的压力达到起爆压力时，泄压机构212打开泄压。
沿着端盖211的厚度方向，泄压机构212具有相对的第一表面和第二表面，泄压机构212的厚度是指第一表面沿端盖211的厚度方向与第二表面的距离。
其中，K为系数。0.1≤K≤5。
若已知电池单体20的起爆压力和泄压机构212的厚度，即可根据公式得到刻痕槽2121应该刻痕的深度范围。
在一些实施例中，高分子材料包括氟化乙烯丙烯共聚物和聚氯三氟乙烯中的至少一种。
氟化乙烯丙烯共聚物和聚氯三氟乙烯的透气性和阻水性的平衡性能较好，采用氟化乙烯丙烯共聚物和聚氯三氟乙烯中的至少一种制成泄压机构212，不但能够在电池单体20泄压时稳定排出电池单体20内的气体，还能够在电池单体20正常使用时阻隔外界水分渗入电池单体20内，降低电池单体20短路风险。
本申请实施例还提供了一种电池单体20，电池单体20包括电极组件22、壳体23和上述的端盖组件21，壳体23具有至少一端开口的容纳空间，容纳空间用于容纳电极组件22，端盖211封闭开口。
本申请实施例还提供了一种电池100，电池100包括箱体10和上述的电池单体20，电池单体20容纳于箱体10内。
本申请实施例还提供了一种用电设备，用电设备包括上述的电池100，电池100用于给用电设备提供电能。
根据本申请的一些实施例，请参照图4～图15。
本申请实施例提供了一种端盖组件21，用于电池单体20。端盖组件21包括端盖211和泄压机构212，端盖211具有泄压孔2111，泄压机构212覆盖泄压孔2111。其中，泄压机构212为高分子材料。泄压机构212设有薄弱部2124，薄弱部2124被配置为在电池单体20泄压时裂开。薄弱部2124由在泄压机构212上设置刻痕槽2121形成。泄压机构212具有泄压部2122，刻痕槽2121沿着泄压部2122的边缘延伸，泄压部2122被配置为在电池单体20泄压时以刻痕槽2121为边界打开。刻痕槽2121为沿两端存在距离的非封闭轨迹延伸的非封闭结构。
由于高分子材料具有透气阻水的性质，采用高分子材料制成泄压机构212，不但能够在电池单体20泄压时稳定排出电池单体20内的气体，还能够在电池单体20正常使用时阻隔外界水分渗入电池单体20内，阻断水汽和电解液通过泄压机构212向电池单体20内外流通，降低电池单体20短路风险。另外，通过在泄压机构212设置刻痕槽2121，以在泄压机构212上形成薄弱部2124，保证在电池单体20泄压时泄压 机构212能够从刻痕槽2121所在位置撕裂，形成供气体顺畅通过的开口，泄压机构212不易出现变形、开裂、局部开口等问题导致泄压不畅，有利于提高电池单体20的安全性。由于刻痕沿着泄压部2122的边缘设置，因此在电池单体20泄压时，泄压部2122会沿着边缘打开，以提供较大的供气体通过的开口。刻痕槽2121的两端之间存在距离，这样，在电池单体20泄压时，刻痕槽2121的两端之间的部分可以作为转动轴，泄压部2122绕着这个转动轴翻转打开，有利于提升泄压部2122的打开效率，使得泄压部2122不易出现变形、开裂、局部开口等问题导致泄压不畅，有利于提高电池单体20的安全性。
刻痕槽2121包括依次连接的第一段21211、第二段21212和第三段21213，第一段21211和第三段21213相对设置。第一段21211和第三段21213为圆弧形，第二段21212为直线形，第一段21211和第三段21213关于第二段21212的中垂线对称。当电池单体20泄压时，泄压部2122以第一段21211、第二段21212和第三段21213为边界打开，并且，第一段21211远离第二段21212的一端与第三段21213远离第二段21212的一端的连线作为泄压部2122转动的转动轴，以便于泄压部2122打开。
泄压部2122的面积为S1，泄压孔2111的面积为S2，满足：0.3＜S1/S2≤1。通过使泄压部2122的面积与泄压孔2111的面积之比大于0.3且小于或等于1，以保证泄压部2122具有较大的面积，使得泄压部2122在打开后形成较大的供气体通过的开口，从而使电池单体20泄压顺畅。
刻痕槽2121的宽度为W，泄压机构212的厚度为T，满足：0＜W/T≤1。刻痕槽2121的宽度与泄压机构212的厚度的比值大于0且小于或等于1。刻痕槽2121的宽度不宜过宽，否则在电池单体20泄压时，刻痕槽2121所在的位置不易受到剪力作用，而是容易出现拉伸应变，导致泄压机构212不易从刻痕槽2121位置裂开。当W/T＞1时，相比于0＜W/T≤1的情况，泄压机构212从刻痕槽2121位置裂开的难度更大。
刻痕槽2121的深度为H，单位为mm，电池单体20的起爆压力为P，单位为MPa，泄压机构212的厚度为T，单位为mm，满足：H＝-0.181P+T-0.246。若已知电池单体20的起爆压力和泄压机构212的厚度，即可根据公式得到刻痕槽2121应该刻痕的深度。
以上所述仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (21)

  1. 一种端盖组件，用于电池单体，其中，包括：
    端盖，具有泄压孔；
    泄压机构，覆盖所述泄压孔；
    所述泄压机构为高分子材料，所述泄压机构设有薄弱部，所述薄弱部被配置为在所述电池单体泄压时裂开。
  2. 如权利要求1所述端盖组件，其中，所述薄弱部由在所述泄压机构上设置刻痕槽形成。
  3. 如权利要求2所述端盖组件，其中，所述泄压机构具有泄压部，所述刻痕槽沿着所述泄压部的边缘延伸，所述泄压部被配置为在所述电池单体泄压时以所述刻痕槽为边界打开。
  4. 如权利要求3所述端盖组件，其中，所述刻痕槽为沿非封闭轨迹延伸的非封闭结构。
  5. 如权利要求4所述端盖组件，其中，所述刻痕槽包括依次连接的第一段、第二段和第三段，所述第一段和所述第三段相对设置。
  6. 如权利要求5所述端盖组件，其中，所述第二段为直线形，所述第一段和所述第三段关于所述第二段的中垂线对称。
  7. 如权利要求6所述端盖组件，其中，所述第一段和所述第三段为圆弧形。
  8. 如权利要求6或7所述端盖组件，其中，所述泄压孔的孔壁面包括第一平直面、第二平直面、第一圆弧面和第二圆弧面，所述第一平直面、所述第一圆弧面、所述第二平直面和所述第二圆弧面首尾依次连接；
    所述第一圆弧面和所述第一段同轴设置，所述第二圆弧面和所述第三段同轴设置。
  9. 如权利要求4所述端盖组件，其中，所述泄压机构设置有两个所述刻痕槽，两个所述刻痕槽背对设置。
  10. 如权利要求9所述端盖组件，其中，两个所述刻痕槽部分重合。
  11. 如权利要求3-10任一项所述端盖组件，其中，所述泄压部的面积为S1，所述泄压孔的面积为S2，满足：0.3＜S1/S2≤1。
  12. 如权利要求11所述端盖组件，其中，所述刻痕槽包括依次连接的第一段、第二段和第三段，所述第一段和所述第三段相对设置，所述第一段和所述第三段为半圆形，所述第二段为直线形，所述第一段和所述第三段关于所述第二段的中垂线对称；
    所述第二段的长度为L，所述第一段和所述第三段的半径均为r，满足：S1＝πr 2+2rL。
  13. 如权利要求2或3所述端盖组件，其中，所述刻痕槽为沿着封闭轨迹延伸的封闭结构。
  14. 如权利要求13所述端盖组件，其中，所述刻痕槽包括首尾依次连接的第一段、第二段、第三段和第四段，所述第一段和所述第三段相对布置，所述第二段和所述第四段相对布置，所述第一段和所述第三段为圆弧形，所述第二段和所述第四段为直线形。
  15. 如权利要求2-14任一项所述端盖组件，其中，所述刻痕槽的宽度为W，所述泄压机构的厚度为T，满足：0＜W/T≤1。
  16. 如权利要求15所述端盖组件，其中，还满足：0.004mm≤W≤0.018mm；和/或，0.01mm≤T≤10mm。
  17. 如权利要求2-16任一项所述端盖组件，其中，所述刻痕槽的深度为H，单位为mm，所述电池单体的起爆压力为P，单位为MPa，所述泄压机构的厚度为T，单位为mm，满足：H＝K(-0.181P+T-0.246)，K∈[0.1，5]。
  18. 如权利要求1-17任一项所述端盖组件，其中，所述高分子材料包括氟化乙烯丙烯共聚物和聚氯三氟乙烯中的至少一种。
  19. 一种电池单体，其中，包括：
    电极组件；
    壳体，具有至少一端开口的容纳空间，所述容纳空间用于容纳所述电极组件；
    如权利要求1-18任一项所述的端盖组件，所述端盖封闭所述开口。
  20. 一种电池，其中，包括：
    箱体；
    如权利要求19所述的电池单体，所述电池单体容纳于所述箱体内。
  21. 一种用电设备，其中，包括如权利要求20所述的电池，所述电池用于给所述用电设备提供电能。
PCT/CN2022/114899 2022-08-25 2022-08-25 端盖组件、电池单体、电池及用电设备 WO2024040532A1 (zh)

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CN215989098U (zh) * 2021-07-21 2022-03-08 宁德时代新能源科技股份有限公司 电池单体、电池以及用电装置
WO2022105140A1 (zh) * 2020-11-19 2022-05-27 常州瑞德丰精密技术有限公司 二次电池顶盖组件以及二次电池
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WO2022105140A1 (zh) * 2020-11-19 2022-05-27 常州瑞德丰精密技术有限公司 二次电池顶盖组件以及二次电池
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