WO2025112348A1 - 电池单体、电池和用电设备 - Google Patents

电池单体、电池和用电设备 Download PDF

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Publication number
WO2025112348A1
WO2025112348A1 PCT/CN2024/094615 CN2024094615W WO2025112348A1 WO 2025112348 A1 WO2025112348 A1 WO 2025112348A1 CN 2024094615 W CN2024094615 W CN 2024094615W WO 2025112348 A1 WO2025112348 A1 WO 2025112348A1
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WO
WIPO (PCT)
Prior art keywords
segment
battery cell
extension
wall
pressure relief
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2024/094615
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English (en)
French (fr)
Inventor
王利钦
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Contemporary Amperex Technology Co Ltd
Original Assignee
Contemporary Amperex Technology Co Ltd
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Filing date
Publication date
Application filed by Contemporary Amperex Technology Co Ltd filed Critical Contemporary Amperex Technology Co Ltd
Publication of WO2025112348A1 publication Critical patent/WO2025112348A1/zh
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

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Classifications

    • 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
    • H01M50/342—Non-re-sealable arrangements
    • 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
    • H01M50/3425—Non-re-sealable arrangements in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
    • 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 battery technology, and in particular to a battery cell, a battery and an electrical device.
  • Batteries are widely used in portable electronic devices, electric vehicles, electric tools, drones, energy storage devices and other fields. During the use of batteries, reliability is an issue that cannot be ignored. Therefore, how to improve battery reliability is a technical problem that needs to be solved urgently in battery technology.
  • the present application provides a battery cell, a battery and an electrical device, which can reduce the degree of damage to the outer shell of the battery cell when the battery cell thermally runs away, reduce the impact on other battery cells, and thus improve the reliability of the battery.
  • an embodiment of the present application provides a battery cell, including a shell and a pressure relief notch, the shell including a first wall; the pressure relief notch is arranged on the first wall, the pressure relief notch includes an arc segment and a first extension segment, the arc segment has a first end, the first extension segment is connected to the first end and extends from the first end toward a direction close to the central axis of the arc segment.
  • the pressure relief notch includes an arc segment and a first extension segment.
  • the arc segment can reduce the stress concentration of the pressure relief notch during processing.
  • the first extension segment can guide the crack to approach the direction close to the central axis of the arc segment, so that the size of the torn part of the outer shell can be controlled.
  • the first extension segment can also make the tearing direction of the crack controllable.
  • the pressure relief notch further includes a second extension segment, the arc segment has a second end, the second extension segment is connected to the second end and extends from the second end toward the center axis.
  • the second extension segment can guide the crack toward the center axis of the arc segment, and the second extension segment and the first extension segment can make the crack have a convergence trend, so that the tearing direction and tearing range of the crack can be controlled, thereby realizing partial opening of the valve of the shell.
  • the first extension segment and the second extension segment are symmetrical about the central axis.
  • the extension length of the first extension segment is the same as the extension length of the second extension segment. If the first extension segment and the second extension segment are both straight lines, the angle between the extension line of the first extension segment and the central axis is the same as the angle between the extension line of the second extension segment and the central axis.
  • the tearing direction and tearing range of the cracks guided by the first extension segment and the second extension segment can be kept roughly consistent, reducing the probability of uncontrollable cracks, and further realizing stable partial valve opening of the shell.
  • the length of the first extension section is the same as the length of the second extension section.
  • the valve opening area of the crack at the first extension section is substantially the same as the valve opening area of the crack at the second extension section, and the subsequent valve opening area of the shell after the crack is guided by the first extension section and the subsequent valve opening area of the shell after the crack is guided by the second extension section are also substantially the same, thereby ensuring the stability of the tearing range of the crack and reducing the probability of uncontrollable cracks.
  • the first extension segment and the second extension segment are both straight segments.
  • the angle between the extension line of the first extension section and the central axis is the same as the angle between the extension line of the second extension section and the central axis.
  • the crack guided by the first extension section and the crack guided by the second extension section can intersect on the central axis, thereby realizing partial opening of the housing.
  • the length of the first extension section is less than the length of the second extension section.
  • the subsequent valve opening area of the shell after the crack is guided by the first extension section is larger than the subsequent valve opening area of the shell after the crack is guided by the second extension section, so that after the battery cell has thermal runaway, the high-pressure gas in the shell can be quickly discharged.
  • the first extension segment and the second extension segment are both straight segments, and the angle between the extension line of the first extension segment and the central axis is different from the angle between the extension line of the second extension segment and the central axis.
  • the subsequent valve opening area of the shell after the crack is guided by the first extension segment is different from the subsequent valve opening area of the shell after the crack is guided by the second extension segment, so that after the battery cell has thermal runaway, the high-pressure gas in the shell can be quickly discharged through the larger valve opening area on the shell.
  • the center angle of the arc segment is ⁇ , which satisfies: 180° ⁇ 360°.
  • ⁇ 180° the area enclosed by the arc segment is sufficient, so that when the battery cell has thermal runaway, the crack tears the shell along the arc segment, and the crack on the arc segment can quickly discharge the high-pressure gas in the shell;
  • the pressure relief notch is an unclosed annular structure, and the pressure relief notch has an opening, so that the crack can tear the shell along the direction of the opening, so that the tearing direction and tearing range of the crack can be controlled, thereby realizing the partial opening of the crack on the shell.
  • the crack range torn along the arc segment can be sufficient, the high-pressure gas in the shell can be quickly discharged, and at the same time, the pressure relief notch has an opening, which can guide the tearing direction and tearing range of the crack, and realize the partial opening of the crack on the shell.
  • 210° ⁇ 330° when ⁇ 210°, the area enclosed by the arc segment is further increased, so that when the battery cell has thermal runaway, the crack tears the shell along the arc segment, and the tearing range of the crack can make the high-pressure gas in the shell discharged more quickly;
  • the pressure relief notch is an unclosed annular structure, and the pressure relief notch has an opening and a larger opening range, so that the crack can tear the shell along the direction of the opening, not only the tearing direction and tearing range of the crack are controllable, but also the tearing range of the crack is larger, and thus the high-pressure gas in the shell can be discharged more quickly.
  • the discharge speed of the high-pressure gas in the shell can be further increased, and at the same time, the opening size on the arc segment is larger, so that the crack can be guided to a larger tearing range in the shell, so that the opening can not only guide the tearing direction and tearing range of the crack, but also further increase the discharge speed of the high-pressure gas in the shell.
  • the first extension segment is tangent to the arc segment; and/or the second extension segment is tangent to the arc segment.
  • the crack on the arc segment can be extended and torn very smoothly along the tangent at the first end of the arc segment, reducing the obstacles in the crack tearing process, making the crack tearing smoother and more controllable, and reducing the stress concentration in the tearing process; or/and the crack on the arc segment can be extended and torn very smoothly along the tangent at the second end of the arc segment, reducing the obstacles in the crack tearing process, making the crack tearing smoother and more controllable, and reducing the stress concentration in the tearing process.
  • the first extension segment is a straight segment; and/or the second extension segment is a straight segment.
  • the processing of the first extension segment can be easier, and on the other hand, the tearing process of the crack on the straight segment is smoother, or in other words, the straight segment can better guide the crack to tear along the preset direction, so that the tearing direction and tearing range of the crack are more controllable; and/or on the one hand, the processing of the second extension segment can be easier, and on the other hand, the tearing process of the crack on the straight segment is smoother, or in other words, the straight segment can better guide the crack to tear along the preset direction, so that the tearing direction and tearing range of the crack are more controllable.
  • the radius of the arc segment is R, which satisfies: 1mm ⁇ R ⁇ 20mm; the length of the straight line segment is L1, which satisfies: 0 ⁇ L1 ⁇ 20mm.
  • 3mm ⁇ R ⁇ 10mm, 1mm ⁇ L1 ⁇ 10mm 3mm ⁇ R ⁇ 10mm, 1mm ⁇ L1 ⁇ 10mm.
  • the pressure relief requirement of the battery cell during thermal runaway can be further met, and the range of the pressure relief notch can be not too large, so that the overall structural strength of the shell is further guaranteed.
  • 0 ⁇ L1/R ⁇ 2 is satisfied.
  • it can ensure that the straight line segment has sufficient length to guide the tearing direction and tearing range of the crack, and at the same time, it can alleviate the excessive negative impact on the structural strength of the shell caused by the excessive extension of the straight line segment resulting in an excessively large range of the pressure relief notch.
  • 0.1 ⁇ L1/R ⁇ 1 is satisfied.
  • it can ensure that the straight line segment has a sufficient length to guide the tearing direction and tearing range of the crack, and at the same time, it can further alleviate the excessive negative impact on the structural strength of the shell caused by the excessive extension of the straight line segment resulting in an excessively large range of the pressure relief notch.
  • the end of the first extension section away from the arc section and the end of the second extension section away from the arc section are spaced apart to form an opening.
  • the high-pressure gas will tear the pressure relief notch, and the crack can be torn along the direction of the opening toward the corner, so that the tearing direction of the crack can be adjusted by adjusting the direction of the opening.
  • the shell is flat, and the first wall is the wall of the shell in the thickness direction.
  • the pressure relief notch is not set on the small face, but on the large face of the shell. Therefore, the pressure relief notch is not constrained by the size of the small face, and the pressure relief notch can be designed to a suitable size as needed.
  • the pressure relief notch is set on the large face to reduce the processing difficulty of the pressure relief notch, so that the manufacturing cost of the pressure relief notch is reduced.
  • the pressure relief notch is arranged in the corner area of the first wall and the opening faces the corner of the first wall.
  • the pressure relief notch is arranged in the corner area of the first wall.
  • the crack tears the shell along the pressure relief notch, it can be torn along the direction of the opening, and the tearing direction of the crack is toward the corner of the first wall, thereby reducing the probability of the crack moving toward the middle area of the first wall and reducing the probability of the first wall being completely torn, so that the shell can be recycled.
  • the first wall includes a first edge and a second edge, and the first edge and the second edge intersect to form a corner of the first wall; the shortest distance between the center of the pressure relief notch and the first edge is L2, and the length of the second edge is L, satisfying: 0 ⁇ L2 ⁇ L/2; the shortest distance between the center of the pressure relief notch and the second edge is W1, and the length of the first edge is W, satisfying: 0 ⁇ W1 ⁇ W/2.
  • the center of the pressure relief notch is close to a corner defined by the first edge and the second edge. Therefore, the tearing area of the crack is also mainly concentrated in the corner area of the first wall, thereby reducing the probability of the crack damaging other areas of the first wall, making it possible to recycle the shell of the battery cell after thermal runaway occurs.
  • the shortest distance between one end of the first extension segment away from the arc segment and the first edge is L3, and the length of the second edge is L, satisfying: 0 ⁇ L3 ⁇ L/2; the shortest distance between one end of the second extension segment away from the arc segment and the second edge is W2, and the length of the first edge is W, satisfying: 0 ⁇ W2 ⁇ W/2.
  • the shortest distance between the end of the second extension section away from the arc section and the second edge and the length of the first edge meet the above conditions, so the opening is toward the corner defined by the first edge and the second edge.
  • the crack tears the shell along the pressure relief notch, it can tear along the direction of the opening, that is, the tearing direction of the crack is toward the corner of the first wall, thereby reducing the probability of the crack moving toward the middle area of the first wall, reducing the probability of the first wall being completely torn, and allowing the shell to be recycled.
  • the pressure relief notch is disposed in the central area of the first wall.
  • the pressure relief notch is disposed in the central area of the first wall, and because the pressure relief notch has an opening, when thermal runaway occurs in the battery cell, the crack will extend along the pressure relief notch and along the area toward which the opening is directed, so that the crack will not tear irregularly and will not destroy most areas of the first wall, but can be guided to a preset area.
  • the thickness of the first wall is T, which satisfies: 0.03mm ⁇ T ⁇ 0.6mm.
  • the thickness of the first wall can be ensured to be thin enough to increase the energy density of the battery cell in the thickness direction of the first wall, and on the other hand, the first wall can have sufficient structural strength to facilitate subsequent laser etching of pressure relief marks thereon.
  • T satisfies: 0.05mm ⁇ T ⁇ 0.2mm.
  • the thickness of the first wall can be ensured to be thin enough, further improving the energy density of the battery cell in the thickness direction of the first wall, and on the other hand, the structural strength of the first wall can be further ensured, making it convenient to laser-etch a pressure relief notch thereon later.
  • the outer shell includes a shell and a cover plate
  • the shell includes a bottom wall and a peripheral side wall, one end of the peripheral side wall is connected to the outer peripheral edge of the bottom wall, the other end of the peripheral side wall forms a first opening, and the cover plate closes the first opening; wherein the first wall is the cover plate or the bottom wall.
  • the shell is formed by two separate parts - the shell and the cover plate.
  • the shell and the cover plate can be metal parts, and the two can be fixed together by welding.
  • the first wall is the cover plate or the bottom wall, so the pressure relief notch is set on the cover plate or the bottom wall. For example, if the battery cell is flat, and the cover plate and the bottom wall are opposite in the thickness direction, the pressure relief notch is set on the large surface of the shell.
  • the embodiment of the present application provides a battery, including the above-mentioned battery cell.
  • the pressure relief notch can be torn when the battery cell is in thermal runaway, and the size and tearing direction of the torn part on the shell can be controlled, so that the valve is partially opened, and the probability of large-scale shell tearing is reduced.
  • an embodiment of the present application provides an electrical device, including the above-mentioned battery cell or the above-mentioned battery, wherein the battery cell or the above-mentioned battery is used to provide electrical energy.
  • the electrical device according to the embodiment of the present application is provided with the above-mentioned battery cell or battery, the safety of the electrical device is improved.
  • FIG1 is a schematic diagram of a vehicle provided in an embodiment of the present application.
  • FIG2 is an exploded view of a battery provided in an embodiment of the present application.
  • FIG3 is an exploded view of a battery cell provided in an embodiment of the present application.
  • FIG4 is a schematic diagram of a first wall provided in an embodiment of the present application.
  • FIG5 is a partial enlarged schematic diagram of circle A in FIG4 ;
  • FIG6 is a schematic diagram of another first wall provided in an embodiment of the present application.
  • FIG7 is a partial cross-sectional view of the first wall of an embodiment of the present application.
  • FIG8 is a schematic diagram of another first wall provided in an embodiment of the present application.
  • FIG. 9 is a schematic diagram of yet another first wall provided in an embodiment of the present application.
  • Icon vehicle 1000, battery 100, controller 200, motor 300, box 10, battery cell 20, first sub-box 11, second sub-box 12, outer shell 21, electrode assembly 22, electrode terminal 25, shell 211, bottom wall 211a, peripheral side wall 211b, cover plate 212, first wall 212a, pressure relief notch 201, arc segment 201a, first extension segment 201b, second extension segment 201c, central axis 202, opening 203, first edge 204, second edge 205.
  • the terms “installed”, “connected”, “connected”, and “attached” should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements.
  • installed should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements.
  • a and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone.
  • the character "/" in this application generally indicates that the associated objects before and after are in an "or" relationship.
  • multiple refers to more than two (including two).
  • multiple groups refers to more than two groups (including two groups)
  • multiple sheets refers to more than two sheets (including two sheets).
  • the battery may be a battery module.
  • the multiple battery cells are arranged and fixed to form a battery module.
  • the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.
  • the box body can be used as a part of the chassis structure of the vehicle.
  • part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.
  • the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.
  • the battery cell may be a secondary battery.
  • a secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.
  • the battery cells may be, but are not limited to, lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel hydrogen batteries, nickel cadmium batteries, lead storage batteries, etc.
  • a battery cell generally includes an electrode assembly.
  • the electrode assembly includes a positive electrode, a negative electrode, and a separator.
  • active ions such as lithium ions
  • the separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.
  • the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.
  • the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc.
  • the composite current collector may include a polymer material base and a metal layer.
  • the composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
  • the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds.
  • the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.
  • the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used.
  • the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode active material is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode active material may be a negative electrode active material for a battery known in the art.
  • the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon-oxygen compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds and tin alloys.
  • the present application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.
  • the separator is a separator.
  • the present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.
  • the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.
  • the separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions.
  • the separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.
  • the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.
  • the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes.
  • the electrolyte can be liquid, gel or solid.
  • the liquid electrolyte includes an electrolyte salt and a solvent.
  • the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.
  • the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the solvent may also be an ether solvent.
  • the ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.
  • the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.
  • solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.
  • the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.
  • the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.
  • oxide solid electrolyte crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film
  • a sulfide solid electrolyte crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide)
  • a halide solid electrolyte a nitride solid electrolyt
  • the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.
  • the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.
  • the electrode assembly is a laminate structure.
  • the battery cell may include a housing.
  • the housing is used to encapsulate components such as the electrode assembly and the electrolyte.
  • the housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.
  • the housing includes an end cap and a shell, the shell is provided with an opening, and the end cap closes the opening to form a closed space for accommodating substances such as the electrode assembly and the electrolyte.
  • the shell may be provided with one or more openings.
  • One or more end caps may also be provided.
  • At least one electrode terminal is disposed on the housing, and the electrode terminal is electrically connected to the electrode tab of the electrode assembly.
  • the electrode terminal may be directly connected to the electrode tab, or may be indirectly connected to the electrode tab through an adapter.
  • the electrode terminal may be disposed on the end cap, or may be disposed on the housing.
  • an explosion-proof valve is provided on the housing, and the explosion-proof valve is used to release the internal pressure of the battery cell.
  • the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft pack battery cell, or a battery cell of other shapes.
  • the prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal prismatic batteries.
  • the polygonal prismatic batteries are, for example, hexagonal prismatic batteries, etc., and there is no particular limitation in the embodiments of the present application.
  • the battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery may be a battery module.
  • the multiple battery cells are arranged and fixed to form a battery module.
  • the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.
  • the box body can be used as a part of the chassis structure of the vehicle.
  • part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.
  • the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.
  • Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and small self-discharge coefficient. They are an important part of the development of new energy today.
  • the battery cells disclosed in the embodiments of the present application can be used, but not limited to, in electrical equipment such as vehicles, ships or aircraft.
  • the power supply system of the electrical equipment can be composed of the battery cells and batteries disclosed in the present application.
  • the embodiment of the present application provides an electric device using a battery cell as a power source
  • the electric device may be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, a spacecraft, etc.
  • the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc.
  • the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.
  • Vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle.
  • the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • a battery 100 is arranged inside the vehicle 1000, and the battery 100 can be arranged at the bottom, head or tail of the vehicle 1000.
  • the battery 100 can be used to power the vehicle 1000.
  • the battery 100 can be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, such as for the working power requirements during the startup, navigation and operation of the vehicle 1000.
  • the vehicle 1000 may further include a controller 200 and a motor 300 , wherein the controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .
  • the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve 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 a battery provided in the first embodiment of the present application.
  • the battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is contained in the box 10.
  • the box 10 is used to provide a storage space for the battery cell 20, and the box 10 can adopt a variety of structures.
  • the box 10 may include a first sub-box 11 and a second sub-box 12, and the first sub-box 11 and the second sub-box 12 cover each other, and the first sub-box 11 and the second sub-box 12 jointly define a storage space for accommodating the battery cell 20.
  • the second sub-box 12 may be a hollow structure with one end open, and the first sub-box 11 may be a plate-like structure, and the first sub-box 11 covers the open side of the second sub-box 12, so that the first sub-box 11 and the second sub-box 12 jointly define a storage space; the first sub-box 11 and the second sub-box 12 may also be hollow structures with one side open, and the open side of the first sub-box 11 covers the open side of the second sub-box 12.
  • the battery 100 there can be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection.
  • the mixed connection means that the multiple battery cells 20 are both connected in series and in parallel.
  • the multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 can also be a battery module formed by first connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and
  • the battery 100 is accommodated in the box 10 .
  • the battery 100 may also include other structures.
  • the battery 100 may also include a busbar component for realizing electrical connection between the plurality of battery cells 20 .
  • the battery cell 20 may be a secondary battery or a primary battery; the battery cell 20 may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto.
  • FIG. 3 is an exploded view of a battery cell provided in some embodiments of the present application.
  • a battery cell 20 includes a housing 21, an electrode assembly 22, and an electrode terminal 25.
  • the housing 21 includes a shell 211 and a cover plate 212, wherein the shell 211 has an opening, and the cover plate 212 closes the opening to isolate the internal environment of the battery cell 20 from the external environment.
  • the shell 211 is a component used to cooperate with the cover plate 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 22, the electrolyte and other components.
  • the shell 211 and the cover plate 212 can be independent components.
  • the shell 211 can be of various shapes and sizes. Specifically, the shape of the shell 211 can be determined according to the specific shape and size of the electrode assembly 22.
  • the material of the shell 211 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.
  • the cover plate 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment.
  • the shape of the cover plate 212 can be adapted to the shape of the shell 211 to match the shell 211.
  • the cover plate 212 can be made of a material with a certain hardness and strength (such as an aluminum alloy), so that the cover plate 212 is not easily deformed when it is squeezed and collided, so that the battery cell 20 can have a higher structural strength and reliability can also be improved.
  • Functional components such as electrode terminals can be provided on the cover plate 212. The electrode terminal can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy of the battery cell 20.
  • the material of the cover plate 212 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose special restrictions on this.
  • an insulating structure can also be provided on the inner side of the cover plate 212, and the insulating structure can be used to isolate the electrical connection components in the shell 211 from the cover plate 212 to reduce the risk of short circuit.
  • the insulating structure may be plastic, rubber, or the like.
  • the electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur.
  • One or more electrode assemblies 22 may be included in the housing 211.
  • the electrode assembly 22 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet, and the separator is used to separate the positive electrode sheet and the negative electrode sheet to avoid short circuits between the positive electrode sheet and the negative electrode sheet.
  • the parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a pole ear.
  • the positive pole ear and the negative pole ear may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the pole ears connect the electrode terminals to form a current loop.
  • the pressure relief notch is set on the shell of the battery cell.
  • the pressure relief notch is generally set on the side of the shell in the thickness direction, and does not penetrate the shell in the thickness direction of the shell, so that the structural strength of the part of the shell where the pressure relief notch is set is relatively low.
  • the pressure inside the shell increases rapidly in a short time, so the area where the pressure relief notch is located will be torn first.
  • the existing pressure relief notches do not have a guiding effect, so the tearing range and tearing direction of the pressure relief notches during the tearing process are uncontrollable; for example, the pressure relief notches are located in the central area of the shell side wall.
  • the cracks will not be guided to the preset position, but will extend irregularly in a direction away from the central area, and multiple cracks will diverge away from the central area, completely destroying most of the side wall where the pressure relief notches are located; or the pressure relief notches are set in the corner area of the shell side wall.
  • the cracks may extend toward the central area of the side wall, thereby destroying most of the side wall. Therefore, the existing pressure relief notches do not have a guiding effect, which will cause the cracks to cause large-scale damage to the shell, affecting the recycling of the shell.
  • the present application proposes a battery cell, on which the tearing direction or tearing range of the pressure relief notch can be controlled after thermal runaway of the battery occurs, thereby achieving partial valve opening.
  • the battery cell 20 may include a housing 21 and a pressure relief notch 201 .
  • the outer shell 21 can isolate the external environment and the internal environment of the battery cell 20.
  • the outer shell 21 can be a metal part, and of course, it can also be an insulating part.
  • the housing 21 may define a receiving space, in which the electrode assembly 22 and an electrolyte for soaking the electrode assembly may be accommodated.
  • the housing 21 may include a first wall 212a, which may be one of the walls of the housing 21.
  • the present application does not limit the specific position or specific function of the first wall 212a on the housing 21.
  • the first wall 212a may be a wall on the housing 21 where the electrode terminal is disposed, or the housing 21 may be a flat structure, and the first wall 212a is a wall on the housing 21 in the thickness direction.
  • the pressure relief score 201 is disposed on the first wall 212a.
  • the pressure relief score 201 is generally disposed on the side surface of the first wall 212a in the thickness direction.
  • the pressure relief score 201 can be disposed on the inner side surface and/or the outer side surface of the first wall 212a.
  • the pressure relief notch 201 may be formed on the first wall 212a by laser etching, and the pressure relief notch 201 does not penetrate the first wall 212a in the thickness direction of the first wall 212a.
  • the structural strength of the portion of the first wall where the pressure relief notch 201 is provided is lower than that of other portions. Therefore, after thermal runaway of the battery cell 20 occurs, the pressure relief notch will be torn first, thereby quickly discharging the high-pressure gas in the housing 21 .
  • the pressure relief notch 201 is generally a groove structure, and the cross-sectional shape of the pressure relief notch 201 may be semicircular, trapezoidal, or other shapes. The present application does not limit the specific shape of the cross-sectional shape of the pressure relief notch 201 .
  • the pressure relief notch 201 includes an arc segment 201a.
  • the arc segment 201a is not a complete circle, but an arc segment corresponding to the center angle of a circle. The center angle and radius of the arc segment 201a can be adjusted as needed.
  • the arc segment 201 a has a first end, which may be one end of the arc segment 201 a in the length direction.
  • the arc segment 201a may also have a second end, which may be the other end of the arc segment 201a in the length direction.
  • the pressure relief notch 201 further includes a first extension segment 201b.
  • the first extension segment 201b may be a straight line segment, an arc segment, or other special-shaped line segments (eg, a serpentine shape, etc.).
  • the specific type of the first extension segment 201b is not limited herein.
  • the first extension segment 201 b may be connected to the first end, and the first extension segment 201 b may extend from the first end toward a direction close to the central axis 202 of the arc segment 201 a.
  • the central axis 202 of the arc segment 201 a can divide the arc segment 201 a into two sub-arc segments, and the two sub-arc segments are symmetrical about the central axis 202 of the arc segment 201 a.
  • the extension line of the first extension segment 201 b extending in a direction away from the arc segment 201 a will eventually intersect with the central axis 202 of the arc segment 201 a .
  • the pressure relief notch 201 may further include a second extension segment 201c.
  • the second extension segment 201c may be a straight line segment, an arc segment, or other special-shaped line segments (eg, a serpentine shape, etc.).
  • the specific type of the second extension segment 201c is not limited herein.
  • the second extension segment 201c may be connected to the second end, and the second extension segment 201c may extend from the second end toward a direction close to the central axis 202 of the arc segment 201a.
  • extension line of the second extension segment 201c extending in the direction away from the arc segment 201a will eventually intersect with the central axis 202 of the arc segment 201a.
  • the first extension segment 201b and the second extension segment 201c may also be symmetrical about the central axis 202 of the arc segment 201a.
  • the first extension segment 201b and the second extension segment 201c may also be asymmetrical about the central axis 202 of the arc segment 201a, as long as the first extension segment 201b extends from the first end toward the direction close to the central axis 202 of the arc segment 201a, and the second extension segment 201c extends from the second end toward the direction close to the central axis 202 of the arc segment 201a.
  • the pressure relief notch may include an arc segment 201a and a first extension segment 201b.
  • the arc segment 201a can reduce the stress concentration of the pressure relief notch 201 during processing.
  • the first extension segment 201b can guide the crack to approach the direction close to the center axis 202 of the arc segment 201a, thereby making the size of the torn portion of the outer shell 21 controllable.
  • the first extension segment 201b can also make the tearing direction of the crack controllable. Therefore, after the battery cell 20 undergoes thermal runaway and the pressure relief notch 201 is torn, a local valve opening can be achieved, thereby reducing the probability of large-scale tearing of the outer shell 21. Both the tearing direction and the tearing range of the crack are controllable, thereby reducing the damage to the battery cell 20 due to the uncontrollable crack. the damage caused.
  • the pressure relief notch 201 includes an arc segment 201a, a first extension segment 201b and a second extension segment 201c.
  • the arc segment 201a can reduce the stress concentration of the pressure relief notch 201 during processing.
  • the first extension segment 201b and the second extension segment 201c can guide the crack to the central axis close to the arc segment 201a. 202, so that the first extension segment 201b and the second extension segment 201c can guide the crack on the outer shell 21 to gradually converge, so that the size of the torn portion of the outer shell 21 can be controlled.
  • the first extension segment 201b and the second extension segment 201c can also make the tearing direction of the crack controllable.
  • the tearing direction and tearing range of the crack are both controllable, reducing the damage to the battery cell 20 caused by the uncontrollable crack, and also reducing the disorderly discharge of high-pressure gas due to the uncontrollable crack and the impact on other battery cells 20.
  • the first extension section 201b and the second extension section 201c are symmetrical about the central axis 202.
  • the extension length of the first extension section 201b is the same as the extension length of the second extension section 201c. If the first extension section 201b and the second extension section 201c are both straight lines, the angle between the extension line of the first extension section 201b and the central axis 202 is the same as the angle between the extension line of the second extension section 201c and the central axis 202.
  • the tearing direction and tearing range of the cracks guided by the first extension section 201b and the second extension section 201c can be kept roughly consistent, reducing the uncontrollable probability of the cracks, and further realizing stable partial valve opening of the housing 21.
  • the length of the first extension segment 201b is the same as the length of the second extension segment 201c.
  • the first extension segment 201b and the second extension segment 201c can both be straight segments, or the first extension segment 201b and the second extension segment 201c can both be arc segments, or one of the first extension segment 201b and the second extension segment 201c is an arc segment and the other is a straight segment.
  • the length of the first extension segment 201b is the same as the length of the second extension segment 201c, it is within the protection scope of the present application.
  • valve opening area of the crack at the first extension section 201b is approximately the same as the valve opening area of the crack at the second extension section 201c, and the subsequent valve opening area of the crack on the outer shell 21 after being guided by the first extension section 201b and the subsequent valve opening area of the crack on the outer shell 21 after being guided by the second extension section 201c are also approximately the same, thereby ensuring the stability of the crack tearing range and reducing the probability of uncontrollable cracks.
  • the first extension segment 201b and the second extension segment 201c are both straight segments, and the angle between the extension line of the first extension segment 201b and the central axis 202 is the same as the angle between the extension line of the second extension segment 201c and the central axis 202.
  • the crack guided by the first extension segment 201b and the crack guided by the second extension segment 201c can intersect on the central axis 202, thereby realizing partial opening of the housing 21.
  • the length of the first extension section 201b is less than the length of the second extension section 201c. After the crack is guided by the first extension section 201b, it will continue to tear the shell 21. Similarly, after the crack is guided by the second extension section 201c, it will continue to tear the shell 21. Since the length of the first extension section 201b is less than the length of the second extension section 201c, the two cracks are not guided by the first extension section 201b and the second extension section 201c. The subsequent valve opening area of the shell 21 after the crack is guided by the first extension section 201b is larger than the subsequent valve opening area of the shell 21 after the crack is guided by the second extension section 201c. Therefore, after the battery cell 20 has thermal runaway, the high-pressure gas in the shell 21 can be quickly discharged.
  • the first extension section 201b and the second extension section 201c are both straight sections, and the angle between the extension line of the first extension section 201b and the central axis 202 is different from the angle between the extension line of the second extension section 201c and the central axis 202. Therefore, the subsequent valve opening area of the shell 21 after the crack passes through the first extension section 201b is different from the subsequent valve opening area of the shell 21 after the crack passes through the second extension section 201c.
  • the subsequent valve opening area of the shell 21 after the crack passes through the first extension section 201b and the subsequent valve opening area of the shell 21 after the crack passes through the second extension section 201c are at least larger, so that after the battery cell 20 has thermal runaway, the high-pressure gas in the shell 21 can be quickly discharged.
  • the center angle of the arc segment 201a is ⁇ , which satisfies: 180° ⁇ 360°.
  • the center angle may be 180°, 200°, 220°, 240°, 260°, 280°, 300°, 320°, 340°, 350°.
  • the present application does not limit the specific value of the center angle of the arc segment 201a, as long as the center angle of the arc segment 201a is It can be within the above range.
  • the pressure relief notch 201 is an unclosed annular structure, and the pressure relief notch 201 has an opening, so that the crack can tear the outer shell along the direction of the opening, so that the tearing direction and tearing range of the crack can be controlled, and then the crack can partially open the valve on the outer shell 21.
  • the crack range torn along the arc segment 201a is sufficient, and the high-pressure gas in the outer shell 21 can be quickly discharged.
  • the pressure relief notch 201 has an opening, which can guide the tearing direction and tearing range of the crack, and realize the partial opening of the valve on the outer shell 21.
  • the pressure relief notch 201 Since the central angle of the arc segment 201a satisfies the above range, the pressure relief notch 201 has a sufficient range and can be opened when the pressure in the shell 21 meets the preset conditions. At the same time, the circular pressure relief notch 201 will not extend irregularly after being torn.
  • the tangents at both ends of the arc segment 201a in the length direction can also be parallel or intersecting, so that the arc segment 201a itself can also guide the cracks at the first end and the cracks at the second end to extend toward each other, and the extension directions of the cracks on both sides are in a convergent state, so that the tearing direction and tearing range of the cracks can be controlled.
  • the central angle ⁇ of the arc segment 201a can be 210°, 240°, 245°, 250°, 255°, 260°, 265°, 270°, 275°, 280°, 285°, 290°, 295°, 300°, or 330°.
  • the pressure relief notch 201 is an unclosed annular structure, and the pressure relief notch 201 has an opening and a larger opening range, so that the crack can tear the outer shell along the direction of the opening, not only the tearing direction and tearing range of the crack are controllable, but also the tearing range of the crack is larger, and thus the high-pressure gas in the outer shell 21 can be discharged more quickly.
  • the discharge speed of the high-pressure gas in the outer shell 21 can be further increased, and at the same time, the opening size on the arc segment 201a is larger, so that the crack can be guided to a larger tearing range in the outer shell 21, so that the opening can not only guide the tearing direction and tearing range of the crack, but also further increase the discharge speed of the high-pressure gas in the outer shell 21.
  • the range of the pressure relief notch 201 is sufficient and can be opened when the pressure in the shell 21 meets the preset conditions.
  • the tangents at both ends of the arc segment 201a in the length direction can also intersect, so that the arc segment 201a itself can also guide the crack at the first end and the crack at the second end to extend in a direction close to each other, and the extension direction of the cracks on both sides is in a convergent state, so that the extension direction of the crack and the tearing range are controllable.
  • the first extension segment 201b may be tangent to the arc segment 201a. That is, the first extension segment 201b coincides with the tangent of the first end.
  • the crack on the arc segment 201a can extend and tear very smoothly along the tangent at the first end of the arc segment 201a, reducing obstacles in the crack tearing process, making the crack tearing smoother and more controllable, and reducing stress concentration during the tearing process.
  • first extension segment 201b can be an arc segment or a straight line segment.
  • the present application does not limit the segment type of the first extension segment 201b, as long as the first extension segment 201b is tangent to the arc segment 201a.
  • the second extension segment 201c may be tangent to the arc segment 201a. That is, the second extension segment 201c coincides with the tangent of the second end.
  • the crack on the arc segment 201a can smoothly extend and tear along the tangent at the second end of the arc segment 201a, reducing obstacles in the crack tearing process, making the crack tearing smoother and more controllable, and reducing stress concentration during the tearing process.
  • the second extension segment 201c can be an arc segment or a straight line segment.
  • the present application does not limit the segment type of the second extension segment 201c, as long as the second extension segment 201c is tangent to the arc segment 201a.
  • the first extension segment 201 b is an arc segment and the first extension segment 201 b may be tangent to the circular arc segment 201 a
  • the second extension segment 201 c is an arc segment and the second extension segment 201 c may be tangent to the circular arc segment 201 a .
  • the first extension segment 201b is a straight segment. Constructing the first extension segment 201b as a straight segment can, on the one hand, make the processing of the first extension segment 201b easier, and on the other hand, the tearing of the crack on the straight segment The process is smoother, or in other words, the straight line segment can better guide the crack to tear along the preset direction, so that the tearing direction and tearing range of the crack are more controllable.
  • the second extension segment 201c is a straight segment. Constructing the second extension segment 201c as a straight segment can, on the one hand, make the processing of the second extension segment 201c easier, and on the other hand, the tearing process of the crack on the straight segment is smoother, or in other words, the straight segment can better guide the crack to tear along a preset direction, so that the tearing direction and tearing range of the crack are more controllable.
  • the radius of the arc segment 201 a is R, satisfying: 1 mm ⁇ R ⁇ 20 mm.
  • the radius of the arc segment 201a can be 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, or 20 mm.
  • the present application does not limit the specific value of the radius of the arc segment 201a. As long as the radius of the arc segment 201a is within the above range, it is within the protection scope of the present application.
  • the length of the straight line segment is L1, which satisfies: 0 ⁇ L1 ⁇ 20mm.
  • the length of the straight line segment can be 1mm, 3mm, 5mm, 7mm, 9mm, 11mm, 13mm, 15mm, 17mm, 19mm, 20mm.
  • the length of the straight segment is the length when the first extension segment 201b is constructed as a straight line, or the length when the second extension segment 201c is a straight line.
  • 3mm ⁇ R ⁇ 10mm, 1mm ⁇ L1 ⁇ 10mm 3mm ⁇ R ⁇ 10mm, 1mm ⁇ L1 ⁇ 10mm.
  • the radius of the arc segment 201a can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm.
  • the present application does not limit the specific value of the radius of the arc segment 201a. As long as the radius of the arc segment 201a is within the above range, it is within the protection scope of the present application.
  • the length of the straight line segment can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm.
  • the length of the straight segment is the length when the first extension segment 201b is constructed as a straight line, or the length when the second extension segment 201c is a straight line.
  • the present application does not limit the length of the straight line segment. As long as the radius of the straight line segment is within the above range, it is within the protection scope of the present application.
  • the pressure relief requirement of the battery cell 20 in thermal runaway can be further met; when L1 ⁇ 10mm, the range of the straight line segment is not too large, so that the overall structural strength of the shell 21 can further meet the requirements.
  • the pressure relief requirement of the battery cell 20 in thermal runaway can be further met, and the range of the pressure relief notch 201 can also be not too large, and the overall structural strength of the shell 21 can further meet the requirements.
  • L1/R can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0.
  • L1/R is within the above range, it is within the protection scope of the present application.
  • L1/R represents the degree to which the straight line segment extends relative to the radius of the arc segment. The larger L1/R is, the more the straight line segment extends compared to the radius of the arc segment. The smaller L1/R is, the less the straight line segment extends compared to the radius of the arc segment.
  • the straight line segment can extend from one end of the arc segment, and the straight line segment can guide the crack to tear the shell 21. After the crack is torn along the straight line segment, it can meet the pressure relief requirements of the battery cell 20 during thermal runaway; when L1/R ⁇ 2, the length of the straight line segment is not too long, thereby controlling the range of the pressure relief notch 201, so that the overall structural strength of the shell 21 meets the requirements.
  • L1/R may be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.7, 0.8, 0.9, or 1.0.
  • the straight line segment can extend from one end of the arc segment, and the straight line segment can guide the crack to tear the shell 21. After the crack is torn along the straight line segment, it can further meet the pressure relief requirements of the battery cell 20 during thermal runaway; when L1/R ⁇ 1, the length of the straight line segment is not too long, thereby controlling the range of the pressure relief notch 201, so that the overall structural strength of the shell 21 further meets the requirements.
  • one end of the first extension segment 201b away from the arc segment 201a and one end of the second extension segment 201c away from the arc segment 201a are spaced apart to form an opening 203.
  • one end of the first extension segment 201b away from the arc segment 201a and one end of the second extension segment 201c away from the arc segment 201a are not connected to each other, thereby ensuring that the pressure relief notch 201 is in an unsealed state.
  • the orientation of the opening 203 directly affects the tearing direction of the crack. For example, if the opening 203 is toward the corner of the first wall 212a, then after the battery cell 20 thermally runs away, the high-pressure gas will tear the pressure relief notch 201, and the crack can be torn along the direction of the opening 203 toward the corner, so that the tearing direction of the crack can be adjusted by adjusting the orientation of the opening 203.
  • the housing 21 is flat, and the first wall 212a is a wall of the housing 21 in the thickness direction. That is, the pressure relief notch 201 in the embodiment of the present application is not arranged on the small face, but is arranged on the large face of the housing 21. Thus, the pressure relief notch 201 is not constrained by the size of the small face, and the pressure relief notch 201 can be designed to a suitable size as required. In addition, the pressure relief notch 201 is arranged on the large face, which can also reduce the processing difficulty of the pressure relief notch 201, so that the manufacturing cost of the pressure relief notch 201 is reduced.
  • the pressure relief notch 201 is disposed at the corner area of the first wall 212a.
  • the pressure relief notch 201 is disposed at the corner area of the first wall 212a.
  • the crack can tear the outer shell 21 under the guidance of the pressure relief notch 201. Since the pressure relief notch 201 is disposed at the corner area of the first wall 212a, the tearing area of the crack is also mainly concentrated in the corner area of the first wall 212a, thereby reducing the probability of the crack damaging other areas of the first wall 212a, making it possible to recycle the outer shell 21 after the battery cell 20 has thermal runaway.
  • the opening 203 on the pressure relief score 201 faces the corner of the first wall 212a. Therefore, when the crack tears the shell 21 along the pressure relief score 201, it can tear along the direction of the opening 203, and the tearing direction of the crack faces the corner of the first wall 212a, thereby reducing the probability of the crack moving toward the middle area of the first wall 212a, reducing the probability of the first wall 212a being completely torn, and allowing the shell 21 to be recycled.
  • the first wall 212 a includes a first edge 204 and a second edge 205 , and the first edge 204 and the second edge 205 intersect to form a corner of the first wall 212 a .
  • the shortest distance between the center of the pressure relief notch 201 and the first edge 204 is L2, and the length of the second edge 205 is L, satisfying: 0 ⁇ L2 ⁇ L/2;
  • the shortest distance between the center of the pressure relief notch 201 and the second edge 205 is W1, and the length of the first edge 204 is W, satisfying: 0 ⁇ W1 ⁇ W/2.
  • the center of the pressure relief notch 201 is close to a corner defined by the first edge 204 and the second edge 205. Therefore, the tearing area of the crack is also mainly concentrated in the corner area of the first wall 212a, thereby reducing the probability of the crack damaging other areas of the first wall 212a, making it possible to recycle the housing 21 after the battery cell 20 has thermal runaway.
  • the shortest distance between the end of the first extension segment 201b away from the arc segment 201a and the first edge 204 is L3, and the length of the second edge 205 is L, satisfying: 0 ⁇ L3 ⁇ L/2; the shortest distance between the end of the second extension segment 201c away from the arc segment 201a and the second edge 205 is W2, and the length of the first edge 204 is W, satisfying: 0 ⁇ W2 ⁇ W/2.
  • One end of the first extension segment 201b away from the arc segment 201a is spaced apart from one end of the second extension segment 201c away from the arc segment 201a to form an opening 203. Since the shortest distance between one end of the first extension segment 201b away from the arc segment 201a and the first edge 204 and the length of the second edge 205 meet the above conditions, the shortest distance between one end of the second extension segment 201c away from the arc segment 201a and the second edge 205 and the length of the first edge 204 meet the above conditions, the opening 203 faces the corner defined by the first edge 204 and the second edge 205.
  • the crack tears the outer shell 21 along the pressure relief notch 201, it can be torn along the direction of the opening 203, that is, the tearing direction of the crack is toward the corner of the first wall 212a, thereby reducing the probability of the crack moving toward the middle area of the first wall 212a, reducing the probability of the first wall 212a being completely torn, and allowing the outer shell 21 to be recycled.
  • the pressure relief notch is annular and located in the center area of the first wall. Since there is no opening on the pressure relief notch, when the battery cell experiences thermal runaway, the cracks will not be guided to the preset position, but will extend irregularly in a direction away from the center area. Multiple cracks diverge away from the center area, completely destroying most of the first wall.
  • the pressure relief notch 201 is disposed in the central area of the first wall 212a. It is understood that the center of the pressure relief notch 201 can be disposed in the central area of the first wall 212a, or the area surrounded by the pressure relief notch 201 can be located in the central area of the first wall 212a.
  • the pressure relief notch 201 is arranged in the central area of the first wall 212a. At the same time, since the pressure relief notch 201 has an opening 203, when the battery cell 20 has thermal runaway, the crack will extend along the pressure relief notch 201 and along the area toward which the opening 203 is directed. Therefore, the crack will not tear irregularly and will not destroy most of the first wall 212a, but can be guided to a preset area.
  • the thickness of the first wall 212a is T, which satisfies: 0.03 mm ⁇ T ⁇ 0.6 mm.
  • the thickness of the first wall 212a provided with the pressure relief notch 201 may be 0.03 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, or 0.6 mm.
  • the present application does not limit the specific value of the thickness of the first wall 212a, and as long as the thickness of the first wall 212a satisfies the above range, it is within the protection scope of the present application.
  • the first wall 212a When T ⁇ 0.03mm, the first wall 212a can be guaranteed to have sufficient structural strength, which is convenient for laser etching of the pressure relief notch 201 thereon later; when T ⁇ 0.6mm, the first wall 212a can be made thin enough to increase the energy density of the battery cell 20 in the thickness direction of the first wall 212a. When 0.03mm ⁇ T ⁇ 0.6mm, the thickness of the first wall 212a can be guaranteed to be thin enough to increase the energy density of the battery cell 20 in the thickness direction of the first wall 212a, and the first wall 212a can also have sufficient structural strength, which is convenient for laser etching of the pressure relief notch 201 thereon later.
  • the first wall 212a is provided with a pressure relief notch 201, and the thickness of the first wall 212a is T, which satisfies: 0.05mm ⁇ T ⁇ 0.2mm.
  • the thickness of the first wall 212a provided with the pressure relief notch 201 can be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm.
  • the present application does not limit the specific value of the thickness of the first wall 212a, as long as the thickness of the first wall 212a meets the above range, it is within the protection scope of the present application.
  • the first wall 212a has sufficient structural strength, which is convenient for subsequent laser etching of the pressure relief notch 201 thereon; when T ⁇ 0.2mm, the first wall 212a can be made thin enough to further improve the energy density of the battery cell 20 in the thickness direction of the first wall 212a.
  • T ⁇ 0.05mm it can further ensure that the first wall 212a has sufficient structural strength, which is convenient for subsequent laser etching of the pressure relief notch 201 thereon; when T ⁇ 0.2mm, the first wall 212a can be made thin enough to further improve the energy density of the battery cell 20 in the thickness direction of the first wall 212a.
  • 0.03mm ⁇ T ⁇ 0.6mm it can ensure that the thickness of the first wall 212a is thin enough to further improve the energy density of the battery cell 20 in the thickness direction of the first wall 212a, and it can also make the first wall 212a thinner.
  • the first step has sufficient structural strength to facilitate subsequent laser etching of a pressure relief notch 201 thereon.
  • the housing 21 includes a shell 211 and a cover plate 212
  • the shell 211 includes a bottom wall 211a and a peripheral side wall 211b
  • one end of the peripheral side wall 211b is connected to the outer periphery of the bottom wall 211a
  • the other end of the peripheral side wall 211b forms a first opening
  • the cover plate 212 closes the first opening, wherein the first wall 212a is the cover plate 212 or the bottom wall 211a.
  • the housing 21 is formed by two separate parts, the housing 211 and the cover plate 212.
  • the housing 211 and the cover plate 212 can be metal parts, and the two can be fixed together by welding.
  • the first wall 212a is the cover plate 212 or the bottom wall 211a, so the pressure relief notch 201 is set on the cover plate 212 or the bottom wall 211a.
  • the pressure relief notch 201 is set on the large surface of the housing 21.
  • the housing 21 is made of stainless steel, and the pressure relief notch 201 can be formed by laser etching.
  • the pressure relief notch 201 can also be formed by stamping, and the present application does not limit the forming method of the pressure relief notch 201.
  • the cross-sectional shape of the pressure relief notch 201 may be a trapezoid, the longer of the two parallel sides of the trapezoid being located at the opening 203 of the groove of the pressure relief notch 201, the shorter of the two parallel sides having a length of 0.05 mm to 1.0 mm, and the bottom angle of the trapezoid (the angle between the bottom wall and the surrounding wall of the trapezoidal groove) may be 30° to 60°.
  • the cross section of the pressure relief notch 201 is a trapezoid, which has better consistency and less stress concentration.
  • the cross section of the pressure relief notch 201 can also be a triangle, an arc or a rectangle.
  • the battery according to the embodiment of the present application includes the battery cell 20 of the above-mentioned embodiment. Since the battery according to the embodiment of the present application is provided with the above-mentioned battery cell 20, the pressure relief notch 201 can be torn when the battery cell 20 thermally runs away, and the size and tearing direction of the torn portion on the outer shell 21 are controllable, thereby realizing local valve opening and reducing the probability of large-scale tearing of the outer shell 21.
  • the electric device according to the embodiment of the present application includes the above-mentioned battery. Since the electric device according to the embodiment of the present application is provided with the above-mentioned battery, the safety of the electric device is improved, and the negative impact of the battery cell 20 on the electric device when thermal runaway occurs is reduced.

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  • Sealing Battery Cases Or Jackets (AREA)

Abstract

本申请公开一种电池单体、电池和用电设备，本申请涉及电池技术领域。电池单体包括外壳和泄压刻痕，外壳包括第一壁；泄压刻痕设置于第一壁，泄压刻痕包括圆弧段和第一延长段，圆弧段具有第一端，第一延长段连接于第一端并从第一端向靠近圆弧段的中轴线的方向延伸。根据本申请实施例的电池单体，外壳上被撕裂的部位的撕裂范围和撕裂方向可控，在电池单体发生热失控且泄压刻痕被撕裂后，可以实现局部开阀，降低了大范围撕裂外壳的几率，减少了由于裂痕的不可控对电池单体造成的损害。

Description

电池单体、电池和用电设备
相关申请的交叉引用
本申请要求享有于2023年11月30日提交的名称为“电池单体、电池和用电设备”的中国专利申请2023116416764的优先权，该申请的全部内容通过引用并入本文中。
技术领域
本申请涉及电池技术领域，具体而言，涉及一种电池单体、电池和用电设备。
背景技术
节能减排是汽车产业可持续发展的关键，电动车辆由于其节能环保的优势成为汽车产业可持续发展的重要组成部分。对于电动车辆而言，电池技术又是关乎其发展的一项重要因素。
电池广泛应用于便携式电子设备、电动交通工具、电动工具、无人机、储能设备等领域。电池的使用过程中，可靠性是一个不可忽视的问题。因此，如何提高电池的可靠性是电池技术中一个亟需解决的技术问题。
发明内容
本申请提供一种电池单体、电池和用电设备，可以减少电池单体热失控时外壳的受损程度，降低对其他电池单体的影响，从而提高电池的可靠性。
本申请是通过下述技术方案实现的：
第一方面，本申请实施例提供一种电池单体，包括外壳和泄压刻痕，外壳包括第一壁；泄压刻痕设置于第一壁，泄压刻痕包括圆弧段和第一延长段，圆弧段具有第一端，第一延长段连接于所述第一端并从第一端向靠近圆弧段的中轴线的方向延伸。
根据本申请实施例的电池单体，泄压刻痕包括圆弧段和第一延长段，通过将第一延长段从第一端向靠近圆弧段的中轴线的方向延伸，从而圆弧段可以减少泄压刻痕在加工时的应力集中，在电池单体发生热失控、且内部高压气体将泄压刻痕撕裂时，第一延长段可以引导裂痕向靠近圆弧段的中轴线的方向靠近，从而使得外壳上被撕裂的部位的尺寸可控，当然第一延长段还可以使得裂痕的撕裂方向可控，由此在电池单体发生热失控且泄压刻痕被撕裂后，可以实现局部开阀，降低了大范围撕裂外壳的几率，裂痕的撕裂方向和撕裂范围均可控，减少了由于裂痕的不可控对电池单体造成的损害。
根据本申请的一些实施例，所述泄压刻痕还包括第二延长段，所述圆弧段具有第二端，所述第二延长段连接于所述第二端并从所述第二端向靠近所述中轴线的方向延伸。在上述方案中，第二延长段可以引导裂痕向靠近圆弧段的中轴线的方向靠近，第二延长段和第一延长段可以使得裂痕具有收敛的趋势，从而裂痕的撕裂方向和撕裂范围可控，实现对外壳的局部开阀。
根据本申请的一些实施例，所述第一延长段和所述第二延长段关于所述中轴线对称。在上述方案中，第一延长段的延伸长度和第二延长段的延伸长度相同，若第一延长段和第二延长段均为直线，则第一延长段的延长线和中轴线的角度与第二延长段的延长线与中轴线的角度相同。由此，第一延长段和第二延长段引导的裂痕的撕裂方向和撕裂范围可以保持大体一致，降低裂痕的不可控几率，进一步实现对外壳稳定地局部开阀。
根据本申请的一些实施例，所述第一延长段的长度与所述第二延长段的长度相同。在上述方案中，第一延长段处的裂痕的开阀面积与第二延长段处的裂痕的开阀面积大致相同，且裂痕经过第一延长段引导后对外壳后续的开阀面积和裂痕经过第二延长段引导后对外壳后续的开阀面积也大体相同，从而保证了裂痕撕裂范围的稳定性，降低裂痕的不可控几率。
根据本申请的一些实施例，所述第一延长段和所述第二延长段均为直线段，所述第一延长段 的延长线和所述中轴线的夹角与所述第二延长段的延长线和所述中轴线的夹角相同。在上述方案中，第一延长段引导的裂痕和第二延长段引导的裂痕可以在中轴线上交汇，从而实现对外壳的局部开阀。
根据本申请的一些实施例，所述第一延长段的长度小于所述第二延长段的长度。在上述方案中，裂痕经过第一延长段引导后对外壳后续的开阀面积相较于裂痕经过第二延长段引导后对外壳后续的开阀面积要更大，从而在电池单体发生热失控后，外壳内的高压气体能够快速地排出。
根据本申请的一些实施例，所述第一延长段和所述第二延长段均为直线段，所述第一延长段的延长线和所述中轴线的夹角与所述第二延长段的延长线和所述中轴线的夹角不相同。在上述方案中，裂痕经过第一延长段引导后对外壳后续的开阀面积与裂痕经过第二延长段引导后对外壳后续的开阀面积不相同，从而在电池单体发生热失控后，外壳内的高压气体可以经过外壳上较大面积的开阀区域快速排出。
根据本申请的一些实施例，所述圆弧段的圆心角为α，满足：180°≤α＜360°。在上述方案中，当α≥180°时，圆弧段围设的面积足够，从而在电池单体发生热失控时，裂痕沿着圆弧段撕裂外壳，在圆弧段上的裂痕可以使外壳内的高压气体快速排出；当α＜360°时，泄压刻痕为未封闭的环形结构，泄压刻痕上具有开口，从而裂痕可以沿着开口的朝向撕裂外壳，使得裂痕的撕裂方向和撕裂范围可控，进而实现裂痕在外壳上局部开阀。当180°≤α＜360°时，既可以使沿着圆弧段撕裂的裂痕范围足够、外壳内的高压气体能够快速排出，同时泄压刻痕上具有开口，可以引导裂痕的撕裂方向和撕裂范围，实现裂痕在外壳上局部开阀。
根据本申请的一些实施例，210°≤α≤330°。在上述方案中，当α≥210°时，圆弧段的围设的面积进一步提升，从而在电池单体发生热失控时，裂痕沿着圆弧段撕裂外壳，裂痕的撕裂范围可以使外壳内的高压气体更加快速地排出；当α≤330°时，泄压刻痕为未封闭的环形结构，泄压刻痕上具有开口且开口范围更大，从而裂痕可以沿着开口的朝向撕裂外壳，不仅裂痕的撕裂方向和撕裂范围可控，且裂痕的撕裂范围更大，进而外壳内的高压气体可以更加快速地排出。当210°≤α≤330°时，可以进一步提升外壳内的高压气体的排出速度，同时圆弧段上具有的开口尺寸更大，从而可以引导裂痕在外壳的撕裂范围更大，从而开口不仅可以引导裂痕的撕裂方向和撕裂范围，也进一步提升外壳内的高压气体的排出速度。
根据本申请的一些实施例，所述第一延长段与所述圆弧段相切；和/或所述第二延长段与所述圆弧段相切。在上述方案中，圆弧段上的裂痕可以非常顺畅地沿着圆弧段的第一端处的切线延伸、撕裂，减少裂痕撕裂过程的阻碍，使得裂痕撕裂更加顺畅、可控，减少撕裂过程中的应力集中；或/和圆弧段上的裂痕可以非常顺畅的沿着圆弧段的第二端处的切线延伸、撕裂，减少裂痕撕裂过程的阻碍，使得裂痕撕裂更加顺畅、可控，减少撕裂过程中的应力集中。
根据本申请的一些实施例，所述第一延长段为直线段；和/或所述第二延长段为直线段。在上述方案中，一方面可以第一延长段的加工更加容易，另一方面，裂痕在直线段上的撕裂过程更加顺畅，或者说，直线段可以更好地引导裂痕沿预设方向撕裂，从而使得裂痕的撕裂方向和撕裂范围更加可控；和/或一方面可以第二延长段的加工更加容易，另一方面，裂痕在直线段上的撕裂过程更加顺畅，或者说，直线段可以更好地引导裂痕沿预设方向撕裂，从而使得裂痕的撕裂方向和撕裂范围更加可控。
根据本申请的一些实施例，所述圆弧段的半径为R，满足：1mm≤R≤20mm；所述直线段的长度为L1，满足：0＜L1≤20mm。在上述方案中，一方面可以满足电池单体在热失控时的泄压需求，另外也可以使得泄压刻痕的范围不至于过大影响外壳整体的结构强度。
根据本申请的一些实施例，3mm≤R≤10mm，1mm≤L1≤10mm。在上述方案中，可以进一步满足电池单体在热失控时的泄压需求，另外也可以使得泄压刻痕的范围不至于过大、使得外壳整体的结构强度进一步得到保证。
根据本申请的一些实施例，满足：0＜L1/R≤2。在上述方案中，既可以保证直线段具有足够的长度来引导裂痕的撕裂方向和撕裂范围，同时也缓解了由于直线段延伸的过长导致泄压刻痕的范围过大而对外壳的结构强度产生过多的负面影响。
根据本申请的一些实施例，满足：0.1≤L1/R≤1。在上述方案中，既可以保证直线段具有足够的长度来引导裂痕的撕裂方向和撕裂范围，同时也进一步缓解了由于直线段延伸的过长导致泄压刻痕的范围过大而对外壳的结构强度产生过多的负面影响。
根据本申请的一些实施例，所述第一延长段远离所述圆弧段的一端和所述第二延长段远离所述圆弧段的一端间隔开以形成开口。在上述方案中，在电池单体热失控后、高压气体会撕裂泄压刻痕，且裂痕可以沿着开口朝向边角的方向撕裂，从而可以调整开口的朝向来调整裂痕的撕裂方向。
根据本申请的一些实施例，所述外壳呈扁平状，所述第一壁为所述外壳在厚度方向上的壁。在上述方案中，泄压刻痕不会设置于小面上，而是设置于外壳的大面上。从而，泄压刻痕不会受到小面尺寸的约束，泄压刻痕可以根据需要设计为合适的尺寸。另外，泄压刻痕设置于大面上还可以降低泄压刻痕的加工难度，使得泄压刻痕的制造成本得到降低。
根据本申请的一些实施例，所述泄压刻痕设置于所述第一壁的边角区域且所述开口朝向所述第一壁的边角。在上述方案中，将泄压刻痕设置于第一壁的边角区域，在电池单体发生热失控时，裂痕可以在泄压刻痕的引导下撕裂外壳，由于泄压刻痕设置于第一壁的边角区域，因此裂痕的撕裂区域也主要集中在第一壁的边角区域，从而可以减少裂痕对第一壁的其他区域的破坏几率，使得电池单体在发生热失控后，外壳的回收成为可能。
裂痕在沿着泄压刻痕撕裂外壳时，可以沿着开口的朝向撕裂，及裂痕的撕裂方向朝向第一壁的边角，从而降低了裂痕朝向第一壁的中间区域移动的几率，降低了第一壁被完全撕裂的几率，使得外壳可以被回收利用。
根据本申请的一些实施例，所述第一壁包括第一边缘和第二边缘，所述第一边缘和所述第二边缘相交以形成所述第一壁的一个所述边角；所述泄压刻痕的中心与所述第一边缘之间的最短距离为L2，所述第二边缘的长度为L，满足：0＜L2＜L/2；所述泄压刻痕的中心与所述第二边缘之间的最短距离为W1，所述第一边缘的长度为W，满足：0＜W1＜W/2。
在上述方案中，泄压刻痕的中心靠近第一边缘和第二边缘限定出的一个边角。从而裂痕的撕裂区域也主要集中在第一壁的边角区域，从而可以减少裂痕对第一壁的其他区域的破坏几率，使得电池单体在发生热失控后，外壳的回收成为可能。
根据本申请的一些实施例，所述第一延长段远离所述圆弧段的一端与所述第一边缘之间的最短距离为L3，所述第二边缘的长度为L，满足：0＜L3＜L/2；所述第二延长段远离所述圆弧段的一端与所述第二边缘之间的最短距离为W2，所述第一边缘的长度为W，满足：0＜W2＜W/2。
在上述方案中，第二延长段远离圆弧段的一端与第二边缘之间的最短距离与第一边缘的长度满足上述条件，因此开口朝向第一边缘和第二边缘限定出的边角。裂痕在沿着泄压刻痕撕裂外壳时，可以沿着开口的朝向撕裂，即裂痕的撕裂方向朝向第一壁的边角，从而降低了裂痕朝向第一壁的中间区域移动的几率，降低了第一壁被完全撕裂的几率，使得外壳可以被回收利用。
根据本申请的一些实施例，所述泄压刻痕设置于所述第一壁的中心区域。在上述方案中，泄压刻痕设置于第一壁的中心区域，同时由于泄压刻痕具有开口，因此在电池单体发生热失控时，裂痕会沿着泄压刻痕延伸且沿着开口朝向的区域延伸，从而裂痕不会无规律的撕裂，不会将第一壁的大部分区域破坏，而是可以被引导到预设区域。
根据本申请的一些实施例，所述第一壁的壁厚为T，满足：0.03mm≤T≤0.6mm。在上述方案中，一方面，可以保证第一壁的厚度足够薄，提升电池单体在第一壁厚度方向上的能量密度，另外还可以使得第一壁具有足够的结构强度，方便后续可以在其上激光蚀刻出泄压刻痕。
根据本申请的一些实施例，所述T满足：0.05mm≤T≤0.2mm。在上述方案中，一方面，可以保证第一壁的厚度足够薄，进一步提升电池单体在第一壁厚度方向上的能量密度，另外还可以使第一壁的结构强度进一步得到了保证，方便后续可以在其上激光蚀刻出泄压刻痕。
根据本申请的一些实施例，所述外壳包括壳体和盖板，所述壳体包括底壁和周侧壁，所述周侧壁的一端与所述底壁的外周沿连接，所述周侧壁的另一端围成第一开口，所述盖板封闭所述第一开口；其中所述第一壁为所述盖板或所述底壁。
在上述方案中，外壳由两个分体部件-壳体和盖板共同形成，壳体和盖板可以为金属件，二者可以通过焊接的方式固定在一起。第一壁为盖板或底壁，因此泄压刻痕设置于盖板或底壁上，例如若电池单体为扁平状，且盖板和底壁在厚度方向上相对，因此泄压刻痕设置于外壳的大面上。
第二方面，本申请实施例提供一种电池，包括上述的电池单体。在上述方案中，由于根据本申请实施例的电池设置有上述的电池单体，泄压刻痕在电池单体热失控时可以被撕裂，外壳上被撕裂的部位的尺寸和撕裂方向可控，实现局部开阀，降低了大范围撕裂外壳的几率。
第三方面，本申请实施例提供一种用电设备，包括上述的电池单体或上述的电池，所述电池单体或所述电池用于提供电能。在上述方案中，由于根据本申请实施例的用电设备设置有上述的电池单体或电池，因此该用电设备的安全性得到了提升。
本申请的附加方面和优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本申请的实践了解到。
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为本申请实施例提供的车辆的示意图；
图2为本申请实施例提供的电池的爆炸图；
图3为本申请实施例提供的电池单体的爆炸图；
图4为本申请实施例提供的第一壁的示意图；
图5为图4圈示A的局部放大示意图；
图6为本申请实施例提供的另一个第一壁的示意图；
图7为本申请实施例的第一壁的局部剖视图；
图8为本申请实施例提供的再一个第一壁的示意图；
图9为本申请实施例提供的再一个第一壁的示意图。
图标：车辆1000，电池100，控制器200，马达300，箱体10，电池单体20，第一子箱体11，第二子箱体12，外壳21，电极组件22，电极端子25，壳体211，底壁211a，周侧壁211b，盖板212，第一壁212a，泄压刻痕201，圆弧段201a，第一延长段201b，第二延长段201c，中轴线202，开口203，第一边缘204，第二边缘205。
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、完整地描述，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做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，不是旨在于限定本申请；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。本领域技术人员显式地和隐式地理解的是，本申请所描述的实施例可以与其它实施例相结合。
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。
本申请中出现的“多个”指的是两个以上(包括两个)，同理，“多组”指的是两组以上(包括两组)，“多片”指的是两片以上(包括两片)。
在一些实施例中，电池可以为电池模块，电池单体有多个时，多个电池单体排列并固定形成一个电池模块。
在一些实施例中，电池可以为电池包，电池包包括箱体和电池单体，电池单体或电池模块容纳于箱体中。
在一些实施例中，箱体可以作为车辆的底盘结构的一部分。例如，箱体的部分可以成为车辆的地板的至少一部分，或者，箱体的部分可以成为车辆的横梁和纵梁的至少一部分。
在一些实施例中，电池可以为储能装置。储能装置包括储能集装箱、储能电柜等。
本申请实施例中，电池单体可以为二次电池，二次电池是指在电池单体放电后可通过充电的方式使活性材料激活而继续使用的电池单体。
电池单体可以但不限于为锂离子电池、钠离子电池、钠锂离子电池、锂金属电池、钠金属电池、锂硫电池、镁离子电池、镍氢电池、镍镉电池、铅蓄电池等。
电池单体一般包括电极组件。电极组件包括正极、负极以及隔离件。在电池单体充放电过程中，活性离子(例如锂离子)在正极和负极之间往返嵌入和脱出。隔离件设置在正极和负极之间，可以起到防止正负极短路的作用，同时可以使活性离子通过。
在一些实施例中，正极可以为正极片，正极片可以包括正极集流体以及设置在正极集流体至少一个表面的正极活性材料。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极活性材料设置在正极集流体相对的两个表面的任意一者或两者上。
作为示例，正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用表面镀银处理的铝、表面镀银处理的不锈钢、不锈钢、铜、铝、镍、炭精电极、碳、镍或钛等。复合集流体可包括高分子材料基层和金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚苯乙烯、聚乙烯等的基材)上而形成。
作为示例，正极活性材料可包括以下材料中的至少一种：含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。
在一些实施例中，负极可以为负极片，负极片可以包括负极集流体。
作为示例，负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用表面镀银处理的铝、表面镀银处理的不锈钢、不锈钢、铜、铝、镍、炭精电极、用碳、镍或钛等。
在一些实施例中，负极集流体具有在其自身厚度方向相对的两个表面，负极活性材料设置在负极集流体相对的两个表面中的任意一者或两者上。
作为示例，负极活性材料可采用本领域公知的用于电池的负极活性材料。作为示例，负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一 种。锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施方式中，隔离件为隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
作为示例，隔离膜的主要材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯，陶瓷中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。隔离件可以是单独的一个部件位于正负极之间，也可以附着在正负极的表面。
在一些实施方式中，隔离件为固态电解质。固态电解质设于正极和负极之间，同时起到传输离子和隔离正负极的作用。
在一些实施方式中，电池单体还包括电解质，电解质在正、负极之间起到传导离子的作用。电解质可以是液态的、凝胶态的或固态的。其中，液态电解质包括电解质盐和溶剂。
在一些实施方式中，电解质盐可以包括六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。
在一些实施方式中，溶剂可以包括碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。溶剂也可选醚类溶剂。醚类溶剂可以包括乙二醇二甲醚、乙二醇二乙醚、二乙二醇二甲醚、三乙二醇二甲醚、四乙二醇二甲醚、1,3-二氧戊环、四氢呋喃、甲基四氢呋喃、二苯醚及冠醚中的一种或多种。
其中，凝胶态电解质包括以聚合物作为电解质的骨架网络，搭配离子液体-锂盐。
其中，固态电解质包括聚合物固态电解质、无机固态电解质、复合固态电解质。
作为示例，聚合物固态电解质可以为聚醚(聚氧化乙烯)、聚硅氧烷、聚碳酸酯、聚丙烯腈、聚偏氟乙烯、聚甲基丙烯酸甲酯、单离子聚合物、聚离子液体-锂盐、纤维素等。
作为示例，无机固态电解质可以包括氧化物固体电解质(晶态的钙钛矿、钠超导离子导体、石榴石、非晶态的LiPON薄膜)、硫化物固体电解质(晶态的锂超离子导体(锂锗磷硫、硫银锗矿)、非晶体硫化物)以及卤化物固体电解质、氮化物固体电解质及氢化物固体电解质中的一种或多种。
作为示例，复合固态电解质通过在聚合物固体电解质中增加无机固态电解质填料形成。
在一些实施方式中，电极组件为卷绕结构。正极片、负极片卷绕成卷绕结构。
在一些实施方式中，电极组件为叠片结构。
在一些实施方式中，电池单体可以包括外壳。外壳用于封装电极组件及电解质等部件。外壳可以为钢壳、铝壳、塑料壳(如聚丙烯)、复合金属壳(如铜铝复合外壳)或铝塑膜等。
在一些实施方式中，外壳包括端盖和壳体，壳体设有开口，端盖封闭开口以形成用于容纳电极组件和电解质等物质的密闭空间。壳体可设有一个或多个开口。端盖也可设置一个或者多个。
在一些实施方式中，外壳上设置有至少一个电极端子，电极端子与电极组件的极耳电连接。电极端子可以与极耳直接连接，也可以通过转接件与极耳间接连接。电极端子可以设置于端盖上，也可以设置在壳体上。
在一些实施方式中，外壳上设置有防爆阀。防爆阀用于泄放电池单体的内部压力。
作为示例，电池单体可以为圆柱形电池单体、棱柱电池单体、软包电池单体或其它形状的电 池单体，棱柱电池单体包括方壳电池单体、刀片形电池单体、多棱柱电池，多棱柱电池例如为六棱柱电池等，本申请实施例没有特别的限制。
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。
在一些实施例中，电池可以为电池模块，电池单体有多个时，多个电池单体排列并固定形成一个电池模块。
在一些实施例中，电池可以为电池包，电池包包括箱体和电池单体，电池单体或电池模块容纳于箱体中。
在一些实施例中，箱体可以作为车辆的底盘结构的一部分。例如，箱体的部分可以成为车辆的地板的至少一部分，或者，箱体的部分可以成为车辆的横梁和纵梁的至少一部分。
在一些实施例中，电池可以为储能装置。储能装置包括储能集装箱、储能电柜等。
电池具有能量密度高、环境污染小、功率密度大、使用寿命长、适应范围广、自放电系数小等突出的优点，是现今新能源发展的重要组成部分。
电池技术的发展要同时考虑多方面的设计因素，例如，能量密度、放电容量、充放电倍率等性能参数，另外，还需要考虑电池的装配效率。
本申请实施例公开的电池单体可以但不限用于车辆、船舶或飞行器等用电设备中。可以使用具备本申请公开的电池单体、电池等组成该用电设备的电源系统。
本申请实施例提供一种使用电池单体作为电源的用电设备，用电设备可以为但不限于手机、平板电脑、笔记本电脑、电动玩具、电动工具、电动自行车、电动摩托车、电动汽车、轮船、航天器等等。其中，电动玩具可以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，航天器可以包括飞机、火箭、航天飞机和宇宙飞船等等。
以下实施例为了方便说明，以本申请一实施例的一种用电设备为车辆1000为例进行说明。
请参照图1，图1为本申请第一实施例提供的车辆的示意图。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，用于车辆1000的电路系统，例如用于车辆1000的启动、导航和运行时的工作用电需求。
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为本申请第一实施例提供的电池的爆炸图。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可以包括第一子箱体11和第二子箱体12，第一子箱体11与第二子箱体12相互盖合，第一子箱体11和第二子箱体12共同限定出用于容纳电池单体20的容纳空间。第二子箱体12可以为一端开口的空心结构，第一子箱体11可以为板状结构，第一子箱体11盖合于第二子箱体12的开口侧，以使第一子箱体11与第二子箱体12共同限定出容纳空间；第一子箱体11和第二子箱体12也可以是均为一侧开口的空心结构，第一子箱体11的开口侧盖合于第二子箱体12的开口侧。
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，电池单体20可以为二次电池或一次电池；电池单体20还可以是锂硫电池、钠离子电池或镁离子电池，但不局限于此。
请参照图3，图3为本申请一些实施例提供的电池单体的爆炸图。如图3所示，电池单体20包括外壳21、电极组件22及电极端子25。外壳21包括壳体211和盖板212，壳体211具有开口，盖板212封闭开口，以将电池单体20的内部环境与外部环境隔绝。
壳体211是用于配合盖板212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211和盖板212可以是独立的部件。壳体211可以是多种形状和多种尺寸的。具体地，壳体211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211的材质可以是多种，比如，铜、铁、铝、不锈钢、铝合金、塑胶等。
盖板212是指盖合于壳体211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，盖板212的形状可以与壳体211的形状相适应以配合壳体211。可选地，盖板212可以由具有一定硬度和强度的材质(如铝合金)制成，这样，盖板212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，可靠性也可以有所提高。盖板212上可以设置有如电极端子等的功能性部件。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。盖板212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。在一些实施例中，在盖板212的内侧还可以设置有绝缘结构，绝缘结构可以用于隔离壳体211内的电连接部件与盖板212，以降低短路的风险。示例性的，绝缘结构可以是塑料、橡胶等。
电极组件22是电池单体20中发生电化学反应的部件。壳体211内可以包含一个或更多个电极组件22。电极组件22主要由正极极片和负极极片卷绕或层叠放置形成，并且通常在正极极片与负极极片之间设有隔离膜，隔离膜用于分隔正极极片和负极极片，以避免正极极片和负极极片内接短路。正极极片和负极极片具有活性物质的部分构成电极组件的主体部，正极极片和负极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主体部的一端或是分别位于主体部的两端。在电池的充放电过程中，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。
现有的技术方案中，泄压刻痕设置在电池单体的外壳上，泄压刻痕一般为设置于外壳在厚度方向上的侧面上，且不会在外壳的厚度方向上贯通外壳，从而使得外壳上设置有泄压刻痕的部分的结构强度相对较低。在电池单体发生热失控时，由于外壳内部的压力在短时间内迅速增大，因此泄压刻痕所在的区域会率先发生撕裂。
然而，现有的泄压刻痕由于不存在引导的效果，因此泄压刻痕在撕裂的过程中裂痕的撕裂范围和撕裂方向都不可控；例如，泄压刻痕位于外壳侧壁的中心区域，在电池单体发生热失控时，裂痕不会被引导到预设位置，而是无规律地朝向远离中心区域的方向延伸，多个裂痕成发散形地远离中心区域，将泄压刻痕所在的侧壁的大部分区域全部破坏；或者泄压刻痕设置于外壳侧壁的边角区域，在电池单体发生热失控时，裂痕有可能朝向侧壁的中心区域延伸，从而将侧壁的大部分区域破坏。因此，现有的泄压刻痕由于不存在引导的效果，会使得裂痕对外壳产生大范围的损伤，影响外壳的回收利用。
另外，由于裂痕的撕裂范围和撕裂方向不可控，高压气体会从裂痕处无序排出，从而可能对其他的电池单体造成损伤。
为此，本申请提出了一种电池单体，该电池单体上的泄压刻痕在电池发生热失控后，泄压刻痕的撕裂方向或撕裂范围可控，从而可以实现局部开阀。
如图4和如图6所示，根据本申请实施例的电池单体20可以包括外壳21和泄压刻痕201。
外壳21可以将电池单体20的外部环境和内部环境隔离，外壳21可以为金属件，当然也可以为绝缘件。
外壳21可以限定出容纳空间，容纳空间内可以容置有电极组件22以及用于浸润电极组件的电解液。
外壳21可以包括第一壁212a，第一壁212a可以为外壳21的其中一个壁，本申请不对第一壁212a在外壳21上的具体位置或者具体功能进行限定。例如，第一壁212a可以为外壳21上设置有电极端子的壁，或者外壳21可以为扁平状结构，第一壁212a为外壳21上在厚度方向上的一个壁。
泄压刻痕201设置于第一壁212a，泄压刻痕201一般设置于第一壁212a在厚度方向上的侧面上，例如，泄压刻痕201可以设置于第一壁212a的内侧面或/和外侧面。
泄压刻痕201可以通过激光蚀刻的方式成型在第一壁212a上，泄压刻痕201在第一壁212a的厚度方向上不贯通第一壁212a。
第一壁上设置泄压刻痕201部分的结构强度相较于其他部分的结构强度要小，因此在电池单体20发生热失控后，泄压刻痕会率先撕裂，从而将外壳21内的高压气体迅速排除。
泄压刻痕201一般为凹槽结构，泄压刻痕201的横截面形状可以为半圆形、梯形或者其他形状，本申请不对泄压刻痕201的横截面的具体形状进行限定。
泄压刻痕201包括圆弧段201a，顾名思义，圆弧段201a不是一个完整的圆，而是某一圆的圆心角对应的弧线段。圆弧段201a的圆心角以及半径可以根据需要进行调整。
圆弧段201a具有第一端，第一端可以为圆弧段201a在长度方向上的一端。
圆弧段201a还可以具有第二端，第二端可以为圆弧段201a在长度方向上的另一端。
泄压刻痕201还包括第一延长段201b，第一延长段201b可以为直线段、弧线段或者其他异形线段(例如，蛇形等)，此处不对第一延长段201b的具体类型进行限定。
第一延长段201b可以与第一端连接，且第一延长段201b可以从第一端向靠近圆弧段201a的中轴线202的方向延伸。
需要说明的是，圆弧段201a的中轴线202可以将圆弧段201a分为两个子圆弧段，且两个子圆弧段关于圆弧段201a的中轴线202对称。
由此，第一延长段201b朝向远离圆弧段201a的方向延伸的延长线会最终与圆弧段201a的中轴线202相交。
泄压刻痕201还可以包括第二延长段201c，第二延长段201c可以为直线段、弧线段或者其他异形线段(例如，蛇形等)，此处不对第二延长段201c的具体类型进行限定。
第二延长段201c可以与第二端连接，且第二延长段201c可以从第二端向靠近圆弧段201a的中轴线202的方向延伸。
由此，第二延长段201c朝向远离圆弧段201a的方向延伸的延长线会最终与圆弧段201a的中轴线202相交。
第一延长段201b和第二延长段201c也可以关于圆弧段201a的中轴线202对称，当然第一延长段201b和第二延长段201c也可以关于圆弧段201a的中轴线202不对称，只要保证第一延长段201b从第一端向靠近圆弧段201a的中轴线202的方向延伸、第二延长段201c从第二端向靠近圆弧段201a的中轴线202的方向延伸即可。
根据本申请实施例的电池单体，如图9所示，泄压刻痕可以包括圆弧段201a和第一延长段201b，通过将第一延长段201b从第一端向靠近圆弧段的中轴线202的方向延伸，从而圆弧段201a可以减少泄压刻痕201在加工时的应力集中，在电池单体20发生热失控、且内部高压气体将泄压刻痕201撕裂时，第一延长段201b可以引导裂痕向靠近圆弧段201a的中轴线202的方向靠近，从而使得外壳21上被撕裂的部位的尺寸可控，当然第一延长段201b还可以使得裂痕的撕裂方向可控，由此在电池单体20发生热失控且泄压刻痕201被撕裂后，可以实现局部开阀，降低了大范围撕裂外壳21的几率，裂痕的撕裂方向和撕裂范围均可控，减少了由于裂痕的不可控对电池单体20 造成的损害。
根据本申请实施例的电池单体20，泄压刻痕201包括圆弧段201a、第一延长段201b和第二延长段201c，通过将第一延长段201b从第一端向靠近圆弧段201a的中轴线202的方向延伸、第二延长段201c从第二端向靠近圆弧段201a的中轴线202的方向延伸，从而圆弧段201a可以减少泄压刻痕201在加工时的应力集中，在电池单体20发生热失控、且内部高压气体将泄压刻痕201撕裂时，第一延长段201b和第二延长段201c可以引导裂痕向靠近圆弧段201a的中轴线202的方向靠近，从而第一延长段201b和第二延长段201c可以引导外壳21上的裂痕逐渐收敛，使得外壳21上被撕裂的部位的尺寸可控，当然第一延长段201b和第二延长段201c还可以使得裂痕的撕裂方向可控，由此在电池单体20发生热失控且泄压刻痕201被撕裂后，可以实现局部开阀，降低了大范围撕裂外壳21的几率，裂痕的撕裂方向和撕裂范围均可控，减少了由于裂痕的不可控对电池单体20造成的损害，也减少由于裂痕不可控导致高压气体无序排出、对其他电池单体20造成的影响。
根据本申请的一些实施例，第一延长段201b和第二延长段201c关于中轴线202对称。例如，第一延长段201b的延伸长度和第二延长段201c的延伸长度相同，若第一延长段201b和第二延长段201c均为直线，则第一延长段201b的延长线和中轴线202的角度与第二延长段201c的延长线与中轴线202的角度相同。由此，第一延长段201b和第二延长段201c引导的裂痕的撕裂方向和撕裂范围可以保持大体一致，降低裂痕的不可控几率，进一步实现对外壳21稳定地局部开阀。
根据本申请的一些实施例，第一延长段201b的长度与第二延长段201c的长度相同。需要说明的是，第一延长段201b与第二延长段201c可以均为直线段，或者第一延长段201b与第二延长段201c可以均为弧线段，或者第一延长段201b与第二延长段201c中的一个为弧线段，另一个为直线段。只要，第一延长段201b的长度与第二延长段201c的长度相同，就在本申请的保护范围内。
由此，第一延长段201b处的裂痕的开阀面积与第二延长段201c处的裂痕的开阀面积大致相同，且裂痕经过第一延长段201b引导后对外壳21后续的开阀面积和裂痕经过第二延长段201c引导后对外壳21后续的开阀面积也大体相同，从而保证了裂痕撕裂范围的稳定性，降低裂痕的不可控几率。
根据本申请的一些实施例，第一延长段201b和第二延长段201c均为直线段，第一延长段201b的延长线和中轴线202的夹角与第二延长段201c的延长线和中轴线202的夹角相同。由此，第一延长段201b引导的裂痕和第二延长段201c引导的裂痕可以在中轴线202上交汇，从而实现对外壳21的局部开阀。
根据本申请的一些实施例，第一延长段201b的长度小于第二延长段201c的长度。裂痕经过第一延长段201b引导后会继续撕裂外壳21，同样的，裂痕经过第二延长段201c引导后会继续撕裂外壳21；由于一延长段201b的长度小于第二延长段201c的长度，因此两处裂痕没有了第一延长段201b和第二延长段201c的引导，裂痕经过第一延长段201b引导后对外壳21后续的开阀面积相较于裂痕经过第二延长段201c引导后对外壳21后续的开阀面积要更大，从而在电池单体20发生热失控后，外壳21内的高压气体能够快速地排出。
根据本申请的一些实施例，第一延长段201b和第二延长段201c均为直线段，第一延长段201b的延长线和中轴线202的夹角与第二延长段201c的延长线和中轴线202的夹角不相同。由此，裂痕经过第一延长段201b引导后对外壳21后续的开阀面积与裂痕经过第二延长段201c引导后对外壳21后续的开阀面积不相同，裂痕经过第一延长段201b引导后对外壳21后续的开阀面积与裂痕经过第二延长段201c引导后对外壳21后续的开阀面积至少有一处较大，从而在电池单体20发生热失控后，外壳21内的高压气体可以快速排出。
在本申请的一些实施例中，如图4所示，圆弧段201a的圆心角为α，满足：180°≤α＜360°。例如，圆心角可以为180°、200°、220°、240°、260°、280°、300°、320°、340°、350°。
本申请不对圆弧段201a的圆心角的具体数值进行限定，只要保证圆弧段201a的圆心角位 于上述范围内即可。
当α≥180°时，圆弧段201a围设的面积足够，从而在电池单体20发生热失控时，裂痕沿着圆弧段201a撕裂外壳21，在圆弧段201a上的裂痕可以使外壳21内的高压气体快速排出；当α＜360°时，泄压刻痕201为未封闭的环形结构，泄压刻痕201上具有开口，从而裂痕可以沿着开口的朝向撕裂外壳，使得裂痕的撕裂方向和撕裂范围可控，进而实现裂痕在外壳21上局部开阀。当180°≤α＜360°时，既可以使沿着圆弧段201a撕裂的裂痕范围足够、外壳21内的高压气体能够快速排出，同时泄压刻痕201上具有开口，可以引导裂痕的撕裂方向和撕裂范围，实现裂痕在外壳21上局部开阀。
由于圆弧段201a的圆心角满足上述范围，因此使得泄压刻痕201的范围足够、可以在外壳21内的压力满足预设条件时被开启，同时也不会出现圆形的泄压刻痕201在被撕裂后裂痕无规则延伸的情况。
另外，圆弧段201a在长度方向的两端的切线也可以平行或者相交，从而圆弧段201a自身也可以引导第一端处的裂痕和第二端处的裂痕朝向靠近彼此的方向延伸，两侧裂痕的延伸方向处于收敛状态，从而使得裂痕的撕裂方向和撕裂范围可控。
在本申请的一些实施例中，210°≤α≤330°例如，圆弧段201a的圆心角为α可以为210°、240°、245°、250°、255°、260°、265°、270°、275°、280°、285°、290°、295°、300°、330°。
当α≥210°时，圆弧段201a的围设的面积进一步提升，从而在电池单体20发生热失控时，裂痕沿着圆弧段201a撕裂外壳21，裂痕的撕裂范围可以使外壳21内的高压气体更加快速地排出；当α≤330°时，泄压刻痕201为未封闭的环形结构，泄压刻痕201上具有开口且开口范围更大，从而裂痕可以沿着开口的朝向撕裂外壳，不仅裂痕的撕裂方向和撕裂范围可控，且裂痕的撕裂范围更大，进而外壳21内的高压气体可以更加快速地排出。当210°≤α≤330°时，可以进一步提升外壳21内的高压气体的排出速度，同时圆弧段201a上具有的开口尺寸更大，从而可以引导裂痕在外壳21的撕裂范围更大，从而开口不仅可以引导裂痕的撕裂方向和撕裂范围，也进一步提升外壳21内的高压气体的排出速度。
由于圆弧段201a的圆心角满足上述范围，因此使得泄压刻痕201的范围足够、可以在外壳21内的压力满足预设条件时被开启，同时圆弧段201a在长度方向的两端的切线也可以相交，从而圆弧段201a自身也可以引导第一端处的裂痕和第二端处的裂痕朝向靠近彼此的方向延伸，两侧裂痕的延伸方向处于收敛状态，从而使得裂痕的延伸方向和撕裂范围可控。
在本申请的一些实施例中，第一延长段201b可以与圆弧段201a相切。也就是说，第一延长段201b与第一端的切线重合。由此，圆弧段201a上的裂痕可以非常顺畅地沿着圆弧段201a的第一端处的切线延伸、撕裂，减少裂痕撕裂过程的阻碍，使得裂痕撕裂更加顺畅、可控，减少撕裂过程中的应力集中。
可以理解的是，第一延长段201b可以弧线段、也可以为直线段，本申请不对第一延长段201b的线段类型进行限定，只要保证第一延长段201b与圆弧段201a相切即可。
在本申请的一些实施例中，如图5所示，第二延长段201c可以与圆弧段201a相切。也就是说，第二延长段201c与第二端的切线重合。由此，圆弧段201a上的裂痕可以非常顺畅的沿着圆弧段201a的第二端处的切线延伸、撕裂，减少裂痕撕裂过程的阻碍，使得裂痕撕裂更加顺畅、可控，减少撕裂过程中的应力集中。
可以理解的是，第二延长段201c可以弧线段、也可以为直线段，本申请不对第二延长段201c的线段类型进行限定，只要保证第二延长段201c与圆弧段201a相切即可。
如图8所示，第一延长段201b为弧线段且第一延长段201b可以与圆弧段201a相切，第二延长段201c为弧线段且第二延长段201c可以与圆弧段201a相切。
根据本申请的一些实施例，如图5所示，第一延长段201b为直线段。将第一延长段201b构造为直线段，一方面可以第一延长段201b的加工更加容易，另一方面，裂痕在直线段上的撕裂 过程更加顺畅，或者说，直线段可以更好地引导裂痕沿预设方向撕裂，从而使得裂痕的撕裂方向和撕裂范围更加可控。
根据本申请的一些实施例，第二延长段201c为直线段。将第二延长段201c构造为直线段，一方面可以第二延长段201c的加工更加容易，另一方面，裂痕在直线段上的撕裂过程更加顺畅，或者说，直线段可以更好地引导裂痕沿预设方向撕裂，从而使得裂痕的撕裂方向和撕裂范围更加可控。
在本申请的一些实施例中，如图4所示，圆弧段201a的半径为R，满足：1mm≤R≤20mm。
例如，圆弧段201a的半径可以为1mm、3mm、5mm、7mm、9mm、11mm、13mm、15mm、17mm、19mm、20mm。
本申请不对圆弧段201a的半径的具体数值进行限定，只要圆弧段201a的半径处于上述范围内，均在本申请的保护范围内。
当R≥1mm时，裂痕沿圆弧段201撕裂后，能够满足电池单体20在热失控时的泄压需求；当R≤20mm时，圆弧段201的范围不至于过大，从而使得外壳21的整体的结构强度满足要求。当1mm≤R≤20mm，既可以满足电池单体20在热失控时的泄压需求，另外也可以使得泄压刻痕201的范围不至于过大、外壳21整体的结构强度符合要求。
在本申请的一些实施例中，如图4所示，直线段的长度为L1，满足：0＜L1≤20mm。例如，直线段的长度可以为1mm、3mm、5mm、7mm、9mm、11mm、13mm、15mm、17mm、19mm、20mm。
需要说明的是，直线段的长度即为第一延长段201b构造为直线时的长度、或者第二延长段201c为直线时的长度。
本申请不对直线段的长度进行限定，只要直线段的半径处于上述范围内，均在本申请的保护范围内。
当L1＞0时，裂痕沿直线段撕裂后，能够满足电池单体20在热失控时的泄压需求；当L1≤20mm时，直线段的范围不至于过大，从而使得外壳21的整体的结构强度满足要求。当0＜L1≤20mm，既可以满足电池单体20在热失控时的泄压需求，另外也可以使得泄压刻痕201的范围不至于过大影响外壳21整体的结构强度。
根据本申请的一些实施例，3mm≤R≤10mm，1mm≤L1≤10mm。
例如，圆弧段201a的半径可以为3mm、4mm、5mm、6mm、7mm、8mm、9mm、10mm。
本申请不对圆弧段201a的半径的具体数值进行限定，只要圆弧段201a的半径处于上述范围内，均在本申请的保护范围内。
当R≥3mm时，裂痕沿圆弧段201撕裂后，能够进一步满足电池单体20在热失控时的泄压需求；当R≤10mm时，圆弧段201的范围不至于过大，从而使得外壳21的整体的结构强度可以进一步满足要求。当3mm≤R≤10mm，既可以进一步满足电池单体20在热失控时的泄压需求，另外也可以使得泄压刻痕201的范围不至于过大、外壳21整体的结构强度可以进一步符合要求。
例如，直线段的长度可以为1mm、2mm、3mm、4mm、5mm、6mm、7mm、8mm、9mm、10mm。
需要说明的是，直线段的长度即为第一延长段201b构造为直线时的长度、或者第二延长段201c为直线时的长度。
本申请不对直线段的长度进行限定，只要直线段的半径处于上述范围内，均在本申请的保护范围内。
当L1≥1mm时，裂痕沿直线段撕裂后，能够进一步满足电池单体20在热失控时的泄压需求；当L1≤10mm时，直线段的范围不至于过大，从而使得外壳21的整体的结构强度进一步满足要求。当1mm≤L1≤20mm，既可以进一步满足电池单体20在热失控时的泄压需求，另外也可以使得泄压刻痕201的范围不至于过大，外壳21整体的结构强度可以进一步满足需求。
在本申请的一些实施例中，0＜L1/R≤2。例如，L1/R可以为0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8、0.9、1.0、1.1、1.2、1.3、1.4、1.5、1.6、1.7、1.8、1.9、2.0。
本申请不对L1/R的具体数值进行限定，只要L1/R处于上述范围，均在本申请的保护范围内。
L1/R表征直线段相对于弧线段的半径延伸的程度，L1/R越大，则表示直线段相较于弧线段的半径延伸的越多，L1/R越小，则表示直线段相较于弧线段的半径延伸的越小。
当L1/R＞0时，直线段可以从弧线段的一端延伸，直线段可以引导裂痕撕裂外壳21，裂痕沿直线段撕裂后，能够满足电池单体20在热失控时的泄压需求；当L1/R≤2，从而直线段的长度不至于过长，从而控制泄压刻痕201的范围，使得外壳21的整体的结构强度满足要求。当0＜L1/R≤0.6时，既可以保证直线段具有足够的长度来引导裂痕的撕裂方向和撕裂范围，同时也缓解了由于直线段延伸的过长导致泄压刻痕201的范围过大而对外壳21的结构强度产生过多的负面影响。
在本申请的一些实施例中，0.1≤L1/R≤1。例如，L1/R可以为0.05、0.1、0.15、0.2、0.25、0.3、0.35、0.4、0.45、0.5、0.55、0.6、0.7、0.8、0.9、1.0。
当L1/R≥0.1时，直线段可以从弧线段的一端延伸，直线段可以引导裂痕撕裂外壳21，裂痕沿直线段撕裂后，能够进一步满足电池单体20在热失控时的泄压需求；当L1/R≤1，从而直线段的长度不至于过长，从而控制泄压刻痕201的范围，使得外壳21的整体的结构强度进一步满足要求。当0＜L1/R≤0.6时，既可以保证直线段具有足够的长度来引导裂痕的撕裂方向和撕裂范围，同时也进一步缓解了由于直线段延伸的过长导致泄压刻痕201的范围过大而对外壳21的结构强度产生过多的负面影响。
在本申请的一些实施例中，如图4和图5所示，第一延长段201b远离圆弧段201a的一端和第二延长段201c远离圆弧段201a的一端间隔开以形成开口203。也就是说，第一延长段201b远离圆弧段201a的一端和第二延长段201c远离圆弧段201a的一端彼此不连接，从而确保泄压刻痕201为未封闭的状态。
一般来说，开口203的朝向直接影响裂痕的撕裂方向，例如，若开口203朝向第一壁212a的边角，那么在电池单体20热失控后、高压气体会撕裂泄压刻痕201，且裂痕可以沿着开口203朝向边角的方向撕裂，从而可以调整开口203的朝向来调整裂痕的撕裂方向。
在本申请的一些实施例中，如图3所示，外壳21呈扁平状，第一壁212a为外壳21在厚度方向上的壁。也就是说，本申请实施例中的泄压刻痕201不会设置于小面上，而是设置于外壳21的大面上。从而，泄压刻痕201不会受到小面尺寸的约束，泄压刻痕201可以根据需要设计为合适的尺寸。另外，泄压刻痕201设置于大面上还可以降低泄压刻痕201的加工难度，使得泄压刻痕201的制造成本得到降低。
在本申请的一些实施例中，如图6所示，泄压刻痕201设置于第一壁212a的边角区域。将泄压刻痕201设置于第一壁212a的边角区域，在电池单体20发生热失控时，裂痕可以在泄压刻痕201的引导下撕裂外壳21，由于泄压刻痕201设置于第一壁212a的边角区域，因此裂痕的撕裂区域也主要集中在第一壁212a的边角区域，从而可以减少裂痕对第一壁212a的其他区域的破坏几率，使得电池单体20在发生热失控后，外壳21的回收成为可能。
在本申请的一些实施例中，泄压刻痕201上的开口203朝向第一壁212a的边角。由此，裂痕在沿着泄压刻痕201撕裂外壳21时，可以沿着开口203的朝向撕裂，及裂痕的撕裂方向朝向第一壁212a的边角，从而降低了裂痕朝向第一壁212a的中间区域移动的几率，降低了第一壁212a被完全撕裂的几率，使得外壳21可以被回收利用。
根据本申请的一些实施例，如图6所示，第一壁212a包括第一边缘204和第二边缘205，第一边缘204和第二边缘205相交以形成第一壁212a的一个边角。
泄压刻痕201的中心与第一边缘204之间的最短距离为L2，第二边缘205的长度为L，满足：0＜L2＜L/2；
泄压刻痕201的中心与第二边缘205之间的最短距离为W1，第一边缘204的长度为W，满足：0＜W1＜W/2。
由此，泄压刻痕201的中心靠近第一边缘204和第二边缘205限定出的一个边角。从而裂痕的撕裂区域也主要集中在第一壁212a的边角区域，从而可以减少裂痕对第一壁212a的其他区域的破坏几率，使得电池单体20在发生热失控后，外壳21的回收成为可能。
在本申请的一些实施例中，如图6所示，第一延长段201b远离圆弧段201a的一端与第一边缘204之间的最短距离为L3，第二边缘205的长度为L，满足：0＜L3＜L/2；第二延长段201c远离圆弧段201a的一端与第二边缘205之间的最短距离为W2，第一边缘204的长度为W，满足：0＜W2＜W/2。
第一延长段201b远离圆弧段201a的一端与第二延长段201c远离圆弧段201a的一端间隔开从而形成开口203，由于第一延长段201b远离圆弧段201a的一端与第一边缘204之间的最短距离与第二边缘205的长度满足上述条件，第二延长段201c远离圆弧段201a的一端与第二边缘205之间的最短距离与第一边缘204的长度满足上述条件，因此开口203朝向第一边缘204和第二边缘205限定出的边角。
从而，裂痕在沿着泄压刻痕201撕裂外壳21时，可以沿着开口203的朝向撕裂，即裂痕的撕裂方向朝向第一壁212a的边角，从而降低了裂痕朝向第一壁212a的中间区域移动的几率，降低了第一壁212a被完全撕裂的几率，使得外壳21可以被回收利用。
相关技术中，泄压刻痕构造为环形且位于第一壁的中心区域，由于泄压刻痕上不具备开口，因此在电池单体发生热失控时，裂痕不会被引导到预设位置，而是无规律地朝向远离中心区域的方向延伸。多个裂痕成发散形地远离中心区域，将第一壁的大部分区域全部破坏。
在本申请的一些实施例中，如图4所示，泄压刻痕201设置于第一壁212a的中心区域。可以理解的是，泄压刻痕201的中心可以设置于第一壁212a的中心区域，或者泄压刻痕201围设出的区域可以位于第一壁212a的中心区域。
泄压刻痕201设置于第一壁212a的中心区域，同时由于泄压刻痕201具有开口203，因此在电池单体20发生热失控时，裂痕会沿着泄压刻痕201延伸且沿着开口203朝向的区域延伸，从而裂痕不会无规律的撕裂，不会将第一壁212a的大部分区域破坏，而是可以被引导到预设区域。
在本申请的一些实施例中，如图7所示，第一壁212a的厚度为T，满足：0.03mm≤T≤0.6mm。例如，设置有泄压刻痕201的第一壁212a的厚度可以为0.03mm、0.05mm、0.1mm、0.15mm、0.2mm、0.25mm、0.3mm、0.35mm、0.4mm、0.45mm、0.5mm、0.55mm、0.6mm。本申请不对第一壁212a的厚度的具体数值进行限定，只要第一壁212a的厚度满足上述范围均在本申请的保护范围内。
当T≥0.03mm时，可以保证第一壁212a具有足够的结构强度，方便后续在其上激光蚀刻出泄压刻痕201；当T≤0.6mm时，可以使得第一壁212a足够薄，提升电池单体20在第一壁212a厚度方向上的能量密度。当0.03mm≤T≤0.6mm，既可以保证第一壁212a的厚度足够薄，提升电池单体20在第一壁212a厚度方向上的能量密度，另外还可以使得第一壁212a具有足够的结构强度，方便后续可以在其上激光蚀刻出泄压刻痕201。
在本申请的一些实施例中，如图7所示，第一壁212a设置有泄压刻痕201，第一壁212a的厚度为T，满足：0.05mm≤T≤0.2mm。例如，设置有泄压刻痕201的第一壁212a的厚度可以为0.05mm、0.06mm、0.07mm、0.08mm、0.09mm、0.1mm、0.11mm、0.12mm、0.13mm、0.14mm、0.15mm、0.16mm、0.17mm、0.18mm、0.19mm、0.2mm。本申请不对第一壁212a的厚度的具体数值进行限定，只要第一壁212a的厚度满足上述范围均在本申请的保护范围内。
当T≥0.05mm时，可以进一步保证第一壁212a具有足够的结构强度，方便后续在其上激光蚀刻出泄压刻痕201；当T≤0.2mm时，可以使得第一壁212a足够薄，进一步提升电池单体20在第一壁212a厚度方向上的能量密度。当0.03mm≤T≤0.6mm，既可以保证第一壁212a的厚度足够薄，进一步提升电池单体20在第一壁212a厚度方向上的能量密度，另外还可以使第一壁212a进 一步具有足够的结构强度，方便后续可以在其上激光蚀刻出泄压刻痕201。
在本申请的一些实施例中，外壳21包括壳体211和盖板212，壳体211包括底壁211a和周侧壁211b，周侧壁211b的一端与底壁211a的外周沿连接，周侧壁211b的另一端围成第一开口，盖板212封闭第一开口，其中第一壁212a为盖板212或者底壁211a。
也就是说，外壳21由两个分体部件-壳体211和盖板212共同形成，壳体211和盖板212可以为金属件，二者可以通过焊接的方式固定在一起。第一壁212a为盖板212或底壁211a，因此泄压刻痕201设置于盖板212或底壁211a上，例如若电池单体20为扁平状，且盖板212和底壁211a在厚度方向上相对，因此泄压刻痕201设置于外壳21的大面上。
在本申请的一些实施例中，外壳21为不锈钢材质，泄压刻痕201可以通过激光蚀刻的方式加工成型。当然，泄压刻痕201也可以通过冲压的方式成型，本申请不对泄压刻痕201的成型方式进行限定。
在本申请的一些实施例中，泄压刻痕201的横截面的形状可以为梯形，梯形的平行的两个边中较长的边位于泄压刻痕201的凹槽的开口203处，平行的两个边中较短的边的边长可以为0.05mm-1.0mm，梯形的底部角度(梯形凹槽的底壁与周壁之间的角度)可以为30°-60°。
泄压刻痕201的横截面为梯形，一致性更好，应力集中会小。当然，泄压刻痕201的横截面还可以为三角形、圆弧形或者矩形。
下面简单描述本申请实施例的电池。
根据本申请实施例的电池包括上述实施例的电池单体20，由于根据本申请实施例的电池设置有上述的电池单体20，泄压刻痕201在电池单体20热失控时可以被撕裂，外壳21上被撕裂的部位的尺寸和撕裂方向可控，实现局部开阀，降低了大范围撕裂外壳21的几率。
下面简单描述本申请实施例的用电设备。
根据本申请实施例的用电设备包括上述的电池，由于根据本申请实施例的用电设备设置有上述的电池，因此该用电设备的安全性得到了提升，降低了电池单体20在发生热失控时对用电设备的负面影响。
虽然已经参考优选实施例对本申请进行了描述，但在不脱离本申请的范围的情况下，可以对其进行各种改进并且可以用等效物替换其中的部件。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (26)

  1. 一种电池单体，其特征在于，包括：
    外壳，包括第一壁；
    泄压刻痕，设置于所述第一壁，所述泄压刻痕包括圆弧段和第一延长段，所述圆弧段具有第一端，所述第一延长段连接于所述第一端并从所述第一端向靠近所述圆弧段的中轴线的方向延伸。
  2. 根据权利要求1所述的电池单体，其特征在于，所述泄压刻痕还包括第二延长段，所述圆弧段具有第二端，所述第二延长段连接于所述第二端并从所述第二端向靠近所述中轴线的方向延伸。
  3. 根据权利要求2所述的电池单体，其特征在于，所述第一延长段和所述第二延长段关于所述中轴线对称。
  4. 根据权利要求2或3所述的电池单体，其特征在于，所述第一延长段的长度与所述第二延长段的长度相同。
  5. 根据权利要求2-4中任一项所述的电池单体，其特征在于，所述第一延长段和所述第二延长段均为直线段，所述第一延长段的延长线和所述中轴线的夹角与所述第二延长段的延长线和所述中轴线的夹角相同。
  6. 根据权利要求2-5中任一项所述的电池单体，其特征在于，所述第一延长段的长度小于所述第二延长段的长度。
  7. 根据权利要求2-6中任一项所述的电池单体，其特征在于，所述第一延长段和所述第二延长段均为直线段，所述第一延长段的延长线和所述中轴线的夹角与所述第二延长段的延长线和所述中轴线的夹角不相同。
  8. 根据权利要求1-7中任一项所述的电池单体，其特征在于，所述圆弧段的圆心角为α，满足：180°≤α＜360°。
  9. 根据权利要求8所述的电池单体，其特征在于，210°≤α≤330°。
  10. 根据权利要求1-9中任一项所述的电池单体，其特征在于，所述第一延长段与所述圆弧段相切；和/或所述第二延长段与所述圆弧段相切。
  11. 根据权利要求1-10中任一项所述的电池单体，其特征在于，所述第一延长段为直线段；和/或所述第二延长段为直线段。
  12. 根据权利要求11所述的电池单体，其特征在于，所述圆弧段的半径为R，满足：1mm≤R≤20mm；
    所述直线段的长度为L1，满足：0＜L1≤20mm。
  13. 根据权利要求12所述的电池单体，其特征在于，3mm≤R≤10mm，1mm≤L1≤10mm。
  14. 根据权利要求11-13中任一项所述的电池单体，其特征在于，满足：0＜L1/R≤2。
  15. 根据权利要求14所述的电池单体，其特征在于，满足：0.1≤L1/R≤1。
  16. 根据权利要求1-15中任一项所述的电池单体，其特征在于，所述第一延长段远离所述圆弧段的一端和所述第二延长段远离所述圆弧段的一端间隔开以形成开口。
  17. 根据权利要求16所述的电池单体，其特征在于，所述外壳呈扁平状，所述第一壁为所述外壳在厚度方向上的壁。
  18. 根据权利要求17所述的电池单体，其特征在于，所述泄压刻痕设置于所述第一壁的边角区域且所述开口朝向所述第一壁的边角。
  19. 根据权利要求17或18所述的电池单体，其特征在于，所述第一壁包括第一边缘和第二边缘，所述第一边缘和所述第二边缘相交以形成所述第一壁的一个所述边角；
    所述泄压刻痕的中心与所述第一边缘之间的最短距离为L2，所述第二边缘的长度为L，满足：0＜L2＜L/2；
    所述泄压刻痕的中心与所述第二边缘之间的最短距离为W1，所述第一边缘的长度为W，满足：0＜W1＜W/2。
  20. 根据权利要求17-19中任一项所述的电池单体，其特征在于，所述第一延长段远离所述圆弧段的一端与所述第一边缘之间的最短距离为L3，所述第二边缘的长度为L，满足：0＜L3＜L/2；
    所述第二延长段远离所述圆弧段的一端与所述第二边缘之间的最短距离为W2，所述第一边缘 的长度为W，满足：0＜W2＜W/2。
  21. 根据权利要求17-20中任一项所述的电池单体，其特征在于，所述泄压刻痕设置于所述第一壁的中心区域。
  22. 根据权利要求1-21中任一项所述的电池单体，其特征在于，所述第一壁的壁厚为T，满足：0.03mm≤T≤0.6mm。
  23. 根据权利要求22所述的电池单体，其特征在于，所述T满足：0.05mm≤T≤0.2mm。
  24. 根据权利要求1-23中任一项所述的电池单体，其特征在于，所述外壳包括壳体和盖板，所述壳体包括底壁和周侧壁，所述周侧壁的一端与所述底壁的外周沿连接，所述周侧壁的另一端围成第一开口，所述盖板封闭所述第一开口；其中所述第一壁为所述盖板或所述底壁。
  25. 一种电池，其特征在于，包括权利要求1-24中任一项所述的电池单体。
  26. 一种用电设备，其特征在于，包括如权利要求1-24任一项所述的电池单体或如权利要求25所述的电池，所述电池单体或所述电池用于提供电能。
PCT/CN2024/094615 2023-11-30 2024-05-22 电池单体、电池和用电设备 Pending WO2025112348A1 (zh)

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US20070202393A1 (en) * 2006-02-27 2007-08-30 Hwail Hu Secondary battery
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