WO2023246134A1 - 极片、电极组件、电池单体、电池及用电设备 - Google Patents

极片、电极组件、电池单体、电池及用电设备 Download PDF

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Publication number
WO2023246134A1
WO2023246134A1 PCT/CN2023/077463 CN2023077463W WO2023246134A1 WO 2023246134 A1 WO2023246134 A1 WO 2023246134A1 CN 2023077463 W CN2023077463 W CN 2023077463W WO 2023246134 A1 WO2023246134 A1 WO 2023246134A1
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WO
WIPO (PCT)
Prior art keywords
edge
current collector
electrode
along
active material
Prior art date
Application number
PCT/CN2023/077463
Other languages
English (en)
French (fr)
Inventor
黄玉平
喻鸿钢
马云建
Original Assignee
宁德时代新能源科技股份有限公司
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Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Publication of WO2023246134A1 publication Critical patent/WO2023246134A1/zh

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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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • 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
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/244—Secondary casings; Racks; Suspension devices; Carrying devices; Holders characterised by their mounting method
    • 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
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • 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
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • 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, specifically, to a pole piece, an electrode assembly, a battery cell, a battery and electrical equipment.
  • Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection.
  • battery technology is an important factor related to their development.
  • the purpose of this application is to provide a pole piece, electrode assembly, battery cell, battery and electrical equipment.
  • the battery cell composed of the pole piece has high safety.
  • the present application provides a pole piece, including: a current collector; an active material layer coated on the surface of the current collector; wherein the active material layer includes opposite electrodes along the width direction of the current collector. A first edge and a second edge, the first edge extending undulatingly along the length direction of the current collector.
  • the first edge is an edge of the active material layer in the width direction of the current collector, and the first edge extends undulatingly along the length direction of the current collector, so that one edge of the current collector in the width direction
  • the coating area of the active material layer on one edge in the width direction of the current collector is smaller, thereby reducing the probability of lithium precipitation during the use of the battery cell composed of the pole piece. Improved battery cell safety.
  • the first edge is wavy.
  • the shape of the first edge is wavy, which facilitates coating of the active material layer on the surface of the current collector and is simple to operate.
  • the second edge extends undulatingly along a length direction of the current collector.
  • the second edge extends undulatingly along the length direction of the current collector, so that the other edge of the current collector in the width direction has an empty foil area that is not coated with the active material layer, further reducing the battery cell composed of the pole piece.
  • the probability of lithium precipitation during use improves the safety of battery cells.
  • the second edge is wavy.
  • the shape of the second edge is wavy, which facilitates coating of the active material layer on the surface of the current collector and is simple to operate.
  • the first edge is symmetrical to the second edge.
  • the first edge and the second edge are symmetrical, which facilitates coating of the active material layer.
  • the current collector includes a body and a plurality of tabs, the body includes third edges and fourth edges oppositely arranged along the width direction of the current collector, and the tabs are formed from the A third edge extends out, the active material layer is coated on the surface of the body, the first edge is close to the third edge, and the second edge is close to the fourth edge.
  • the tab extends from the third edge, and the first edge is closer to the third edge than the second edge, so that the area of the active material layer coated on the area of the body close to the tab is smaller, reducing the composition of the pole piece. The probability of lithium precipitation occurring in a battery cell during use.
  • the third edge extends straight along the length direction of the current collector, and the maximum distance between the first edge and the third edge along the width direction of the current collector is D, the width of the current collector is W, satisfying 1/10 ⁇ D/W ⁇ 1/6.
  • the ratio between the maximum distance D between the first edge and the third edge and the width W of the current collector satisfies the above relationship, which can balance the energy density of the battery cell and the probability of lithium deposition.
  • the ratio of the maximum distance D between the first edge and the third edge to the width W of the current collector is less than 1/10, the probability of lithium deposition on the pole piece of the battery cell is greater; when the first edge and the third edge
  • the ratio between the maximum distance D and the width W of the current collector is greater than 1/6, the area of the active material layer coated by the current collector is smaller, resulting in a lower energy density of the battery cell.
  • the fourth edge extends undulatingly along the length direction of the current collector and at least partially coincides with the second edge.
  • the fourth edge relative to the fourth edge extending linearly along the length direction of the current collector, the fourth edge extends undulatingly along the length direction of the current collector and the fourth edge and the second edge at least partially overlap, so that the active material layer is on the body.
  • the coating area on the side away from the third edge is smaller, which reduces the coating area of the active material layer on the edge in the width direction of the current collector, thereby reducing the risk of lithium precipitation in the battery cell composed of the pole piece.
  • the fourth edge extends straight along a length direction of the current collector.
  • the fourth edge extends along a straight line to facilitate coating of the active material layer.
  • the first edge includes a plurality of protruding segments protruding toward the third edge, and the plurality of protruding segments are spaced apart along the length direction of the current collector, and the plurality of protruding segments are arranged at intervals along the length direction of the current collector.
  • the pole tabs are spaced apart along the length direction of the current collector, and each pole tab is located between two adjacent protruding sections.
  • the pole tabs correspond to two adjacent protruding segments to reduce the probability of lithium precipitation in the body at the position corresponding to the pole tabs.
  • the center line of each pole lug deviates from the symmetrical center line of the two protruding segments adjacent to the pole lug.
  • the present application provides an electrode assembly, including a positive electrode piece, a separator, and a negative electrode piece.
  • the positive electrode piece, the separator, and the negative electrode piece are stacked and rolled to form the electrode assembly, and the The positive electrode piece and the negative electrode piece are the electrode pieces described in the above embodiments.
  • the positive electrode piece and the negative electrode piece are the above-mentioned electrode pieces, which can reduce the risk of lithium precipitation in the battery cell composed of the electrode assembly and improve the safety of the battery cell.
  • the present application provides a battery cell, including the electrode assembly as described in the above embodiment.
  • the battery cell according to the embodiment of the present application adopts the above-mentioned electrode assembly and has high safety.
  • the battery cell further includes: a housing having an opening; an end cover closing the opening; a first electrode terminal and a second electrode terminal disposed on the end cover; a first set The current member and the second current collecting member; wherein, the electrode assembly is accommodated in the housing, the extension direction of the winding axis of the electrode assembly is perpendicular to the thickness direction of the end cap, and the positive electrode of the electrode assembly
  • the ears and the negative electrode tabs are respectively located on both sides of the electrode assembly in the extension direction of the winding axis.
  • the positive electrode tabs are electrically connected to the first electrode terminal through the first current collecting member, and the The negative electrode tab is electrically connected to the second electrode terminal through the second current collecting member.
  • the present application provides a battery, including the battery cell as described in the above embodiment.
  • the present application provides an electrical device, including the battery as described in the above embodiment.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Figure 2 is an exploded view of a battery provided by some embodiments of the present application.
  • Figure 3 is a cross-sectional view of a battery cell provided by some embodiments of the present application.
  • Figure 4 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 5 is a left view of Figure 4.
  • Figure 6 is a schematic structural diagram of the first edge of the pole piece provided by some embodiments of the present application.
  • Figure 7 is a schematic structural diagram of a pole piece provided by other embodiments of the present application.
  • Figure 8 is a left view of Figure 7;
  • Marking description 100-battery; 10-box; 11-first part; 12-second part; 20-battery cell; 21-casing; 22-end cover; 23-electrode assembly; 241-first electrode terminal ; 242-second electrode terminal; 251-first current collecting member; 252-second current collecting member; 30-pole piece; 31-current collector; 311-body; 3111-third edge; 3112-fourth edge; 312-pole tab; 312a-positive pole tab; 312b-negative pole tab; 32-active material layer; 321-first edge; 3211-first straight section; 3212-first curve section; 3213-protruding section; 322-the second edge; 3221-the second straight section; 3222-the second curve section; 200-controller; 300-motor; 1000-vehicle.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.
  • multiple refers to more than two (including two).
  • multiple groups refers to two or more groups (including two groups), and “multiple pieces” refers to means two or more pieces (including two pieces), unless otherwise clearly and specifically limited.
  • the battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • Batteries generally include a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly consists of a positive electrode plate, a negative electrode plate and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the positive electrode current collector that is not coated with the positive electrode active material layer protrudes from the positive electrode collector that is coated with the positive electrode active material layer. Fluid, the cathode current collector that is not coated with the cathode active material layer serves as the cathode tab.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode collector that is coated with the negative electrode active material layer.
  • Fluid, the negative electrode current collector that is not coated with the negative electrode active material layer serves as the negative electrode tab.
  • the material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon.
  • the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together.
  • the material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the negative electrode plate, positive electrode plate and separator in the electrode assembly of the lithium-ion battery cell can be rolled or folded and then compacted.
  • lithium ions are deintercalated from the positive electrode piece and embedded in the negative electrode piece.
  • some abnormal situations may occur, such as insufficient space for lithium insertion in the negative electrode piece, and the gap between the negative electrode piece and the positive electrode piece.
  • the distance is too large, the resistance of lithium ions to be inserted into the negative electrode piece is too great, or the lithium ions are deintercalated from the positive electrode piece too quickly.
  • the deintercalated lithium ions cannot be embedded in the negative active material layer of the negative electrode piece in equal amounts, and cannot be embedded in the negative electrode.
  • the lithium ions in the negative electrode can only gain electrons on the surface of the negative electrode, thus forming silvery white metallic lithium element. This is the phenomenon of lithium precipitation.
  • Lithium precipitation not only reduces the performance of lithium-ion battery cells and greatly shortens their cycle life, but also limits the fast charging capacity of lithium-ion battery cells.
  • the precipitated lithium metal is very active and can react with the electrolyte at a lower temperature, causing the battery cell to lower the starting temperature of self-heat generation and self-heat generation. The rate increases, seriously endangering the safety of battery cells.
  • the deintercalated lithium ions can form lithium crystals on the surface of the negative electrode piece, and the lithium crystals can easily pierce the separator, causing the risk of short circuit between adjacent positive electrode pieces and negative electrode pieces.
  • the inventors designed a pole piece after in-depth research.
  • the edge of the active material layer in the width direction of the current collector does not extend to the edge of the current collector, so that An empty foil area is formed near the edge of the current collector.
  • the risk of lithium precipitation in the electrode assembly composed of the pole piece can be reduced, making the battery cell highly safe.
  • the active material layer is coated to the edge of the current collector, and the edge of the active material layer is straight.
  • Linearly extended pole piece In the pole piece of the present application, the edge of the active material layer in the width direction of the current collector is not coated to the edge of the current collector, and the edge of the active material layer extends in an undulating shape, along the edge of the current collector. In the length direction, the distance between the edge of the active material layer and the edge of the current collector is unequal. The position of the current collector close to the edge forms an undulating empty foil area.
  • the battery cells disclosed in the embodiments of the present application can be used in, but are not limited to, vehicles, ships, aircraft, and other electrical equipment.
  • the power supply system of the electrical equipment can be composed of battery cells, batteries, etc. disclosed in this application.
  • Embodiments of the present application provide an electrical device that uses a battery as a power source.
  • the electrical device can be, but is not limited to, vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, electric tools, etc.
  • Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc.
  • spacecraft include aircraft, rockets, space shuttles, spaceships, etc.
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.
  • electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more.
  • the embodiments of this application impose no special restrictions on the above electrical equipment.
  • the following embodiments take the electrical equipment as a vehicle as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • the battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 .
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but can also be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • the battery 100 includes a case 10 and a plurality of battery cells 20 .
  • the plurality of battery cells 20 are disposed in the case 10 .
  • the box 10 is a component that accommodates the battery cells 20.
  • the box 10 provides a storage space for the battery cells 20.
  • the box 10 can adopt a variety of structures.
  • the box 10 may include a first part 11 and a second part 12 , and the first part 11 and the second part 12 cover each other to define an accommodation space for accommodating the battery cells 20 .
  • the first part 11 and the second part 12 may be in various shapes, such as cuboid, cylinder, etc.
  • the first part 11 may be a hollow structure open on one side, and the second part 12 may also be a hollow structure open on one side.
  • the open side of the second part 12 is covered with the open side of the first part 11 to form a box with accommodating space.
  • the first part 11 may be a hollow structure with one side open
  • the second part 12 may be a plate-like structure
  • the second part 12 covers the open side of the first part 11 to form a box 10 with an accommodation space.
  • the first part 11 and the second part 12 can be sealed by sealing elements, which can be sealing rings, sealants, etc.
  • multiple battery cells 20 can be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the multiple battery cells 20 are connected in series and in parallel. It can be that multiple battery cells 20 are connected in series or in parallel or mixed to form a battery.
  • Battery module multiple battery modules are connected in series, parallel or mixed to form a whole, and are accommodated in the box 10 . It is also possible that all the battery cells 20 are directly connected in series or in parallel or mixed together, and then the entire battery cell 20 is accommodated in the box 10 .
  • the battery 100 may further include a bus component, through which the multiple battery cells 20 may be electrically connected to achieve series, parallel, or mixed connection of the multiple battery cells 20 .
  • the bus component may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.
  • FIG. 3 is a cross-sectional view of a battery cell provided by some embodiments of the present application.
  • the battery cell 20 may include a case 21, an end cap 22, an electrode assembly 23, and an electrode terminal.
  • the housing 21 has an opening, and the end cover 22 and the housing 21 jointly define a sealed space.
  • the housing 21 may be a hollow structure with an opening formed at one end, or the housing 21 may be a hollow structure with openings formed at two opposite ends.
  • the housing 21 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
  • the end cap 22 is a component that closes the opening of the case 21 to isolate the internal environment of the battery cell 20 from the external environment.
  • the end cap 22 and the housing 21 jointly define a sealed space for accommodating the electrode assembly 23, electrolyte and other components.
  • the end cap 22 can be connected to the housing 21 by welding or crimping to close the opening of the housing 21 .
  • the shape of the end cap 22 can be adapted to the shape of the casing 21.
  • the casing 21 has a rectangular parallelepiped structure, and the end cap 22 has a rectangular plate structure matching the casing 21.
  • the casing 21 is a cylinder. body, and the end cover 22 is a circular plate-shaped structure that matches the housing 21.
  • the end cap 22 can also be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
  • the end cap 22 may be provided with electrode terminals, and the electrode terminals may include positive electrode terminals and negative electrode terminals.
  • the electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur.
  • the electrode assembly 23 may include a positive electrode piece, a negative electrode piece, and a separator.
  • the electrode assembly 23 may be a rolled structure formed by rolling a positive electrode piece, a separator, and a negative electrode piece.
  • the electrode assembly 23 has a positive electrode tab 312a and a negative electrode tab 312b.
  • the positive electrode tab 312a may be a portion of the positive electrode sheet that is not coated with a positive electrode active material layer
  • the negative electrode tab 312b may be a portion of the negative electrode sheet that is not coated with a negative electrode active material layer.
  • the positive electrode tab 312 a and the negative electrode tab 312 b may extend from both sides in the extension direction N of the winding axis of the electrode assembly 23 .
  • the electrode terminals are arranged on the end cover 22.
  • the number of electrode terminals is two.
  • the two electrode terminals are the first electrode terminal 241 and the second electrode terminal 242 respectively.
  • the positive electrode tab 312a is electrically connected to the first current collecting member 251 through the first current collecting member 251.
  • the electrode terminal 241 and the negative electrode tab 312b are electrically connected to the second electrode terminal 242 through the second current collection member 252 to form a current loop.
  • FIG. 4 is a schematic structural diagram of a pole piece provided by some embodiments of the present application
  • FIG. 5 is a left view of FIG. 4
  • the present application provides a pole piece 30 , which includes a current collector 31 and an active material layer 32 .
  • the active material layer 32 is coated on the surface of the current collector 31 .
  • the active material layer 32 includes a first edge 321 and a second edge 322 opposite along the width direction X of the current collector 31 .
  • the first edge 321 extends undulatingly along the length direction Y of the current collector 31 .
  • the direction indicated by the letter X is the width direction of the current collector 31
  • the direction indicated by the letter Y is the length direction of the current collector 31 .
  • the current collector 31 is a structure or component that collects current.
  • the current collector 31 is usually a metal foil, such as copper foil, aluminum foil, etc.
  • the active material layer 32 is a structure composed of active material materials, and the active material layer 32 may include active material materials, conductive agents, and adhesives.
  • the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate.
  • the negative active material can be carbon or silicon.
  • the active material layer 32 may be coated on one side of the current collector 31 in the thickness direction, or the active material layer 32 may be coated on two opposite surfaces of the current collector 31 in the thickness direction Z.
  • the direction indicated by the letter Z is the thickness direction of the current collector 31 .
  • the first edge 321 and the second edge 322 are two opposite edges of the active material layer 32 in the width direction X of the current collector 31 .
  • the first edge 321 and the second edge 322 define the width of the active material layer 32 in the current collector 31 Coating profile in direction X.
  • the first edge 321 Compared with the case where the first edge 321 has a linear structure and the first edge 321 is arranged parallel to the edge in the width direction X of the current collector 31 , the first edge 321 extends undulatingly along the length direction Y of the current collector 31 .
  • the distance between 321 and the edge in the width direction X of the current collector 31 changes along the length direction Y of the current collector 31 , that is, the first edge 321 is uneven.
  • the active material layer 32 is coated on the edge of the current collector 31 in the width direction X, and the edge of the active material layer 32 extends linearly, in the pole piece 30 of the present application, the active material layer 32
  • the first edge 321 in the width direction X of the current collector 31 is not coated to the edge in the width direction Y, a undulating empty foil area is formed near the edge of the current collector 31 (the area of the current collector 31 that is not coated with the active material layer 32).
  • the coating area of the active material layer 32 on the edge of the pole piece 30 is smaller, and the risk of lithium precipitation on the edge of the pole piece 30 is reduced, thereby reducing the risk of lithium precipitation on the electrode assembly 23 and improving the battery cell efficiency. 20 for security.
  • the first edge 321 is wavy.
  • first edge 321 is wavy means that the first edge 321 may be a curved surface.
  • the projection of the first edge 321 on the current collector 31 is in a wavy form.
  • the shape of the first edge 321 is wavy, which facilitates coating of the active material layer 32 on the surface of the current collector 31 and is simple to operate.
  • FIG. 6 is a schematic structural diagram of the first edge of the pole piece provided by some embodiments of the present application.
  • the projection of the first edge 321 on the current collector 31 may include a first straight segment 3211 and a first curved segment 3212.
  • a straight section 3211 extends linearly along the length direction Y of the current collector 31 , and a first curved section 3212 protrudes from the first straight section 3211 along the width direction X of the current collector 31 . That is, the first curved section 3212 is formed by the first The straight section 3211 protrudes toward the edge of the current collector 31 .
  • the edge of the current collector 31 mentioned here refers to the edge close to the first edge 321 in the width direction X of the current collector 31 .
  • the distance between the first straight section 3211 and the edge of the current collector 31 can be the same along the length direction Y of the current collector 31 , or the distance between the first straight section 3211 and the edge of the current collector 31 can be along the length direction Y of the current collector 31 .
  • the length direction Y gradually decreases or gradually increases.
  • the shape of the first curve segment 3212 may be a triangle, a rectangle, a semicircle, a trapezoid, a special shape, etc.
  • the second edge 322 extends undulatingly along the length direction Y of the current collector 31 stretch.
  • the second edge 322 extends undulatingly along the length direction Y of the current collector 31 , and the distance between the second edge 322 and the edge in the width direction X of the current collector 31 changes along the length direction Y of the current collector 31 , that is, the The two edges 322 are uneven.
  • edge in the width direction X of the current collector 31 here refers to the edge in the width direction One edge is closer to the second edge 322.
  • the second edge 322 extends undulatingly along the length direction Y of the current collector 31 , so that the two edges of the current collector 31 in the width direction can have
  • the empty foil area that is not coated with the active material layer 32 further reduces the probability of lithium precipitation in the battery cell 20 composed of the pole piece 30 during use, and improves the safety of the battery cell 20 .
  • the second edge 322 is wavy.
  • the second edge 322 being wavy means that the second edge 322 may be a curved surface.
  • the projection of the second edge 322 on the current collector 31 is in a wavy form.
  • the shape of the second edge 322 is wavy, which facilitates coating of the active material layer 32 on the surface of the current collector 31 and is simple to operate.
  • the projection of the second edge 322 on the current collector 31 may include a second straight section 3221 and a second straight section 3221 .
  • Two curved sections 3222, the second straight section 3221 extends linearly along the length direction Y of the current collector 31, and the second curved section 3222 protrudes from the second straight section 3221 along the width direction X of the current collector 31, that is, the second The curved section 3222 protrudes from the second straight section 3221 toward the edge of the current collector 31 .
  • the edge of the current collector 31 mentioned here refers to the edge close to the second edge 322 in the width direction X of the current collector 31 .
  • the distance between the second straight section 3221 and the edge of the current collector 31 can be the same along the length direction Y of the current collector 31 , or the distance between the second straight section 3221 and the edge of the current collector 31 can be along the length direction Y of the current collector 31 .
  • the length direction Y gradually decreases or gradually increases.
  • the shape of the second curve segment 3222 may be a triangle, a rectangle, a semicircle, a trapezoid, a special shape, etc.
  • the first edge 321 is symmetrical to the second edge 322 .
  • the first edge 321 and the second edge 322 are symmetrical, which facilitates coating of the active material layer 32 .
  • the current collector 31 includes a body 311 and a plurality of tabs 312 .
  • the body 311 includes a third edge 3111 and a third edge 3111 that are oppositely arranged along the width direction X of the current collector 31 .
  • Four edges 3112, the tabs 312 extend from the third edge 3111, the active material layer 32 is coated on the surface of the body 311, the first edge 321 is close to the third edge 3111, and the second edge 322 is close to the fourth edge 3112.
  • the body 311 is a portion of the current collector 31 used for coating the active material layer 32 .
  • the third edge 3111 and the fourth edge 3112 are two edges of the body 311 that are oppositely arranged along the width direction X of the current collector 31 .
  • the third edge 3111 and the fourth edge 3112 define the body 311 in the width direction contour.
  • a plurality of tabs 312 are arranged at intervals along the length direction Y of the current collector 31 .
  • the tabs 312 can be formed by the current collector 31 . 31 is cut, and the third edge 3111 is the cutting edge.
  • the pole tab 312 extends from the third edge 3111 means that the pole tab 312 protrudes from the third edge 3111 in a direction away from the fourth edge 3112 along the width direction X of the current collector 31 .
  • the first edge 321 is close to the third edge 3111 means that the first edge 321 is close to the third edge 3111 relative to the second edge 322. In other words, along the width direction X of the current collector 31, the first edge 321 to the third edge 3111 The distance is greater than the distance from the second edge 322 to the third edge 3111.
  • the second edge 322 being close to the fourth edge 3112 means that the second edge 322 is close to the fourth edge 3112 relative to the first edge 321 .
  • the second edge 322 to the fourth edge 3112 The distance is greater than the distance from the first edge 321 to the fourth edge 3112.
  • the tab 312 extends from the third edge 3111.
  • the first edge 321 is adjacent to the third edge 3111.
  • the first edge 321 and the third edge 3111 define a first empty foil area, so that the area of the body 311 is close to the tab 312.
  • the area of the coated active material layer 32 is smaller, which reduces the probability of lithium precipitation in the edge area of the pole piece 30 close to the tab 312 .
  • the third edge 3111 extends linearly along the length direction Y of the current collector 31 , and along the width direction X of the current collector 31 , the distance between the first edge 321 and the third edge 3111 is The maximum distance is D, the width of the current collector 31 is W, and satisfies 1/10 ⁇ D/W ⁇ 1/6.
  • the third edge 3111 extends linearly along the length direction Y of the current collector 31 , that is, the edge of the body 311 is flush, which facilitates assembly between the pole piece 30 and other components.
  • the ratio between the maximum distance D between the first edge 321 and the third edge 3111 and the width W of the current collector 31 satisfies the above relationship, which can balance the energy density of the battery cell 20 and the probability of lithium deposition.
  • the ratio of the maximum distance D between the first edge 321 and the third edge 3111 to the width W of the current collector 31 is less than 1/10, the probability of lithium deposition in the pole piece 30 of the battery cell 20 is relatively high; when the first When the ratio of the maximum distance D between the edge 321 and the third edge 3111 to the width W of the current collector 31 is greater than 1/6, the area of the active material layer 32 coated by the current collector 31 is smaller, resulting in the energy loss of the battery cell 20 Density is lower.
  • Figure 7 is a schematic structural diagram of a pole piece provided by other embodiments of the present application
  • Figure 8 is a left view of Figure 7.
  • the fourth edge 3112 extends undulatingly along the length direction Y of the current collector 31 and at least partially coincides with the second edge 322 .
  • the fourth edge 3112 and the second edge 322 at least partially overlap means that the fourth edge 3112 and a part of the second edge 322 overlap, or the fourth edge 3112 and the second edge 322 completely overlap.
  • the fourth edge 3112 completely coincides with the second edge 322, which facilitates processing and manufacturing.
  • the fourth edge 3112 extends undulatingly along the length direction Y of the current collector 31 and the fourth edge 3112 and the second edge 322 at least partially overlap, so that the active material layer
  • the coating area of 32 on the side of the body 311 away from the third edge 3111 is smaller, which reduces the coating area of the active material layer 32 on the edge of the current collector 31 in the width direction X, thereby reducing the The risk of lithium precipitation from battery cells 20.
  • the fourth edge 3112 and the second edge 322 at least partially overlap, and the width of the current collector 31 is
  • the upward edge without the pole lug 312 can be die-cut to facilitate the forming and processing of the pole piece 30 .
  • the fourth edge 3112 extends straight along the length direction Y of the current collector 31 .
  • the fourth edge 3112 extends straight along the length direction Y of the current collector 31 , that is, the edge of the body 311 is flush, which facilitates assembly between the pole piece 30 and other components.
  • the fourth edge 3112 extends along a straight line to facilitate coating of the active material layer 32 .
  • the first edge 321 includes a plurality of protruding segments 3213 protruding toward the third edge 3111 , and the plurality of protruding segments 3213 are spaced apart along the length direction Y of the current collector 31 , a plurality of pole tabs 312 are arranged at intervals along the length direction Y of the current collector 31 , and each pole tab 312 is located between two adjacent protruding sections 3213 .
  • the protruding section 3213 refers to the portion of the first edge 321 that is closer to the third edge 3111 relative to other portions.
  • the plurality of protruding sections 3213 are spaced apart along the length direction Y of the current collector 31 , so that the first edge 321 extends in an undulating manner along the length direction Y of the current collector 31 .
  • a recessed section is formed between two adjacent protruding sections 3213, and the recessed section is recessed toward the fourth edge 3112.
  • the pole tab 312 corresponds to the two adjacent protruding sections 3213 to reduce the risk of lithium precipitation at the position of the body 311 corresponding to the pole tab 312. Probability.
  • the centerline P1 of each pole tab 312 deviates from the symmetrical centerline P2 of the two protruding segments 3213 adjacent to the pole tab 312 .
  • the plurality of protruding segments 3213 are arranged at intervals along the length direction Y of the current collector 31 .
  • the plurality of protruding segments 3213 may have the same structural form.
  • Two adjacent protruding segments 3213 have a symmetrical centerline P2 .
  • the present application provides an electrode assembly 23.
  • the electrode assembly 23 includes a positive electrode piece, a separator, and a negative electrode piece.
  • the positive electrode piece, the separator, and the negative electrode piece are stacked and rolled to form the electrode assembly 23.
  • the positive electrode piece and the negative electrode piece are the electrode pieces 30 provided in the above embodiment.
  • the positive electrode piece and the negative electrode piece are the above-mentioned electrode pieces 30, which can reduce the risk of lithium precipitation in the battery cell 20 composed of the electrode assembly 23 and improve the safety of the battery cell 20. .
  • the present application provides a battery cell 20.
  • the battery cell 20 includes the electrode assembly 23 provided in the above embodiment.
  • the battery cell 20 according to the embodiment of the present application adopts the above-mentioned electrode assembly 23 and has high safety.
  • the battery cell 20 further includes a case 21, an end cover 22, a first electrode terminal 241, a second electrode terminal 242, a first current collecting member 251 and a second current collecting member.
  • the housing 21 has an opening; the end cap 22 closes the opening.
  • the first electrode terminal 241 and the second electrode terminal 242 are provided on the end cap 22 .
  • the electrode assembly 23 is accommodated in the casing 21 .
  • the extension direction of the winding axis of the electrode assembly 23 is perpendicular to the thickness direction M of the end cover 22 .
  • the positive electrode tab 312 a and the negative electrode tab 312 b of the electrode assembly 23 are respectively located on the electrode assembly 23 On both sides in the extension direction N of the winding axis, the positive electrode tab 312a is electrically connected to the first electrode terminal 241 through the first current collecting member 251, and the negative electrode tab 312b is electrically connected to the second electrode through the second current collecting member 252. Terminal 242.
  • Both the first electrode terminal 241 and the second electrode terminal 242 are conductive components for connecting the battery cells 20 export of electrical energy.
  • the direction indicated by letter M is the thickness direction of the end cap 22
  • the direction indicated by letter N is the extension direction of the winding axis of the electrode assembly 23 .
  • the extension direction N of the winding axis of the electrode assembly 23 is parallel to the width direction X of the current collector 31 .
  • the positive electrode tab 312a and the negative electrode tab 312b extend from both sides of the extension direction N of the winding axis of the electrode assembly 23 to facilitate the assembly of the electrode assembly 23 and reduce the risk of contact short circuit between the positive electrode tab 312a and the negative electrode tab 312b.
  • Both the first current collecting member 251 and the second current collecting member 252 are conductive parts with good conductive properties.
  • the material of the first current collecting member 251 and the second current collecting member 252 can be metal, such as aluminum, nickel or Its alloys etc.
  • the present application provides a battery 100 including the battery cell 20 as described in the above embodiments.
  • the present application provides an electrical device, including the battery 100 as described in the above embodiments.
  • the battery 100 is used to provide electrical energy for the electrical device.
  • the powered device can be any of the above-mentioned devices or systems that use batteries.
  • the present application provides a rectangular battery cell, which includes a casing 21, an end cover 22, an electrode assembly 23, a first electrode terminal 241, and a third Two electrode terminals 242, a first current collecting member 251 and a second current collecting member 252.
  • the housing 21 has an opening, and the end cover 22 closes the opening to define a sealed space with the housing 21 .
  • the first electrode terminal 241 and the second electrode terminal 242 are provided on the end cap 22 .
  • the electrode assembly 23 is accommodated in the housing 21 .
  • the electrode assembly 23 includes a positive electrode piece, a separator, and a negative electrode piece. The positive electrode piece, the separator, and the negative electrode piece are stacked and rolled to form the electrode assembly 23.
  • the positive electrode piece and the negative electrode piece are the electrode pieces 30 provided in the above embodiment.
  • the extension direction N of the winding axis of the electrode assembly 23 is perpendicular to the thickness direction M of the end cap 22 .
  • the positive tab 312 a and the negative tab 312 b of the electrode assembly 23 are respectively located on both sides of the electrode assembly 23 in the extension direction N of the winding axis.
  • the positive electrode tab 312a is electrically connected to the first electrode terminal 241 through the first current collecting member 251
  • the negative electrode tab 312b is electrically connected to the second electrode terminal 242 through the second current collecting member 252.
  • the pole piece 30 includes a current collector 31 and an active material layer 32 .
  • the current collector 31 includes a body 311 and a plurality of tabs 312 .
  • the body 311 includes third edges that are oppositely arranged along the thickness direction Z of the current collector 31 . 3111 and the fourth edge 3112, the tab 312 extends from the third edge 3111, and the active material layer 32 is coated on the two opposite sides of the body 311 in the thickness direction.
  • the third edge 3111 extends linearly along the length direction Y of the current collector 31
  • the fourth edge 3112 extends in an undulating manner along the length direction Y of the current collector 31 .
  • the active material layer 32 includes a first edge 321 and a second edge 322 opposite along the width direction , the second edge 322 is close to the fourth edge 3112, and the second edge 322 coincides with the fourth edge 3112.
  • the second edge 322 is symmetrically arranged with the first edge 321 .
  • the first edge 321 of the active material layer 32 of the positive electrode piece corresponds to the second edge 322 of the active material layer 32 of the negative electrode piece
  • the second edge 322 of the active material layer 32 of the positive electrode piece corresponds to the second edge 322 of the active material layer 32 of the negative electrode piece. corresponds to the first edge 321 of the active material layer 32 of the sheet.
  • the edge of the winding axis of the electrode assembly 23 in the extension direction N has less active material layer 32 , which reduces the power of the rectangular battery cells.
  • the risk of lithium precipitation makes the square battery cells highly safe.

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Abstract

本申请涉及一种极片、电极组件、电池单体、电池及用电设备，属于电池技术领域。极片包括：集流体；活性物质层，涂覆于所述集流体的表面；其中，所述活性物质层包括沿所述集流体的宽度方向相对的第一边缘和第二边缘，所述第一边缘沿所述集流体的长度方向起伏地延伸。由该极片构成的电池单体具有较高的安全性。

Description

极片、电极组件、电池单体、电池及用电设备
相关申请的交叉引用
本申请要求享有于2022年06月20日提交的名称为“极片、电极组件、电池单体、电池及用电设备”的中国专利申请CN202221547191.X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，涉及一种极片、电极组件、电池单体、电池及用电设备。
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。
在电池技术的发展中，除了提高电池的能量密度外，安全性也是一个不可忽视的问题。因此，如何提高电池的安全性，是电池技术一个亟需解决的技术问题。
发明内容
本申请的目的在于提供一种极片、电极组件、电池单体、电池及用电设备。由该极片构成的电池单体具有较高的安全性。
本申请是通过如下技术方案实现的：
第一方面，本申请提供了一种极片，包括：集流体；活性物质层，涂覆于所述集流体的表面；其中，所述活性物质层包括沿所述集流体的宽度方向相对的第一边缘和第二边缘，所述第一边缘沿所述集流体的长度方向起伏地延伸。
根据本申请实施例的极片，第一边缘为活性物质层的在集流体的宽度方向上的边缘，第一边缘沿集流体的长度方向起伏地延伸，使得集流体在宽度方向上的一个边缘具有未涂覆活性物质层的空箔区，活性物质层在集流体的宽度方向的一个边缘的涂覆面积较小，从而降低极片构成的电池单体在使过程中出现析锂的概率，提高了电池单体的安全性。
根据本申请的一些实施例，所述第一边缘呈波浪形。
在上述方案中，第一边缘的形状呈波浪形，便于实现活性物质层在集流体的表面的涂覆，操作简单。
根据本申请的一些实施例，所述第二边缘沿所述集流体的长度方向起伏地延伸。
在上述方案中，第二边缘沿集流体的长度方向起伏地延伸，使得集流体在其宽度方向的另一个边缘具有未涂覆活性物质层的空箔区，进一步降低极片构成的电池单体在使用过程中出现析锂的概率，提高电池单体的安全性。
根据本申请的一些实施例，所述第二边缘呈波浪形。
在上述方案中，第二边缘的形状呈波浪形，便于实现活性物质层在集流体的表面的涂覆，操作简单。
根据本申请的一些实施例，所述第一边缘与所述第二边缘对称。
在上述方案中，第一边缘与第二边缘对称，便于实现活性物质层的涂覆。
根据本申请的一些实施例，所述集流体包括本体和多个极耳，所述本体包括沿所述集流体的宽度方向相对设置的第三边缘和第四边缘，所述极耳从所述第三边缘延伸出，所述活性物质层涂覆于所述本体的表面，所述第一边缘靠近所述第三边缘，所述第二边缘靠近所述第四边缘。
在上述方案中，极耳从第三边缘延伸出，第一边缘相对于第二边缘靠近第三边缘，使得本体的靠近极耳的区域涂覆的活性物质层的面积较小，降低极片构成的电池单体在使用过程中出现析锂的概率。
根据本申请的一些实施例，所述第三边缘沿所述集流体的长度方向直线延伸，沿所述集流体的宽度方向，所述第一边缘与所述第三边缘之间的最大距离为D，所述集流体的宽度为W，满足1/10≤D/W≤1/6。
在上述方案中，第一边缘与第三边缘之间的最大距离D和集流体的宽度W的比例满足上述关系，能够平衡电池单体的能量密度和析锂的概率。当第一边缘与第三边缘之间的最大距离D和集流体的宽度W的比例小于1/10时，电池单体的极片出现析锂的概率较大；当第一边缘与第三边缘之间的最大距离D和集流体的宽度W的比例大于1/6时，集流体涂覆的活性物质层的面积较小，导致电池单体的能量密度较低。
根据本申请的一些实施例，所述第四边缘沿所述集流体的长度方向起伏地延伸且与所述第二边缘至少部分重合。
在上述方案中，相对于第四边缘沿集流体的长度方向直线延伸，第四边缘沿集流体的长度方向起伏地延伸且第四边缘与第二边缘至少部分重合，使得活性物质层在本体的背离第三边缘的一侧的涂覆面积较小，降低了活性物质层在集流体的宽度方向边缘的涂覆面积，进而降低了由该极片构成的电池单体析锂的风险。
根据本申请的一些实施例，所述第四边缘沿所述集流体的长度方向直线延伸。
在上述方案中，第四边缘沿直线延伸，便于实现活性物质层的涂覆。
根据本申请的一些实施例，所述第一边缘包括多个朝向所述第三边缘凸出的凸出段，多个所述凸出段沿所述集流体的长度方向间隔设置，多个所述极耳沿所述集流体的长度方向间隔设置，每个所述极耳位于相邻两个所述凸出段之间。
在上述方案中，极耳与相邻的两个凸出段对应，以降低本体在与极耳对应位置处析锂的概率。
根据本申请的一些实施例，每个所述极耳的中心线偏离与该极耳相邻的两个所述凸出段的对称中心线。
第二方面，本申请提供了一种电极组件，包括正极极片、隔膜及负极极片，所述正极极片、所述隔膜及所述负极极片层叠卷绕形成所述电极组件，所述正极极片和所述负极极片为如上述实施例所述的极片。
根据本申请实施例的电极组件，正极极片和负极极片为上述的极片，能够降低由该电极组件构成的电池单体的析锂风险，提高电池单体的安全性。
第三方面，本申请提供了一种电池单体，包括如上述实施例所述的电极组件。
根据本申请实施例的电池单体，采用上述的电极组件，具有较高的安全性。
根据本申请的一些实施例，所述电池单体还包括：壳体，具有开口；端盖，封闭所述开口；第一电极端子和第二电极端子，设置于所述端盖；第一集流构件和第二集流构件；其中，所述电极组件容纳于所述壳体内，所述电极组件的卷绕轴线的延伸方向与所述端盖的厚度方向垂直，所述电极组件的正极极耳和负极极耳分别位于所述电极组件在所述卷绕轴线的延伸方向上的两侧，所述正极极耳通过所述第一集流构件电连接于所述第一电极端子，所述负极极耳通过所述第二集流构件电连接于所述第二电极端子。
在上述方案中，由于电极组件的卷绕方向与端盖的厚度方向垂直，并且正极极耳和负极极耳分别位于卷绕方向上的两侧，由于正极集流体的宽度方向的边缘具有空箔区和负极集流体的宽度方向的边缘具有空箔区，在电池工作过程中，能够降低电极组件析锂的概率。
第四方面，本申请提供了一种电池，包括如上述实施例所述的电池单体。
第五方面，本申请提供了一种用电设备，包括如上述实施例所述的电池。
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为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的爆炸图；
图3为本申请一些实施例提供的电池单体的剖视图；
图4为本申请一些实施例提供的极片的结构示意图；
图5为图4的左视图；
图6为本申请一些实施例提供的极片的第一边缘的结构示意图；
图7为本申请另一些实施例提供的极片的结构示意图；
图8为图7的左视图；
在附图中，附图并未按照实际的比例绘制。
标记说明：100-电池；10-箱体；11-第一部分；12-第二部分；20-电池单体；21-壳体；22-端盖；23-电极组件；241-第一电极端子；242-第二电极端子；251-第一集流构件；252-第二集流构件；30-极片；31-集流体；311-本体；3111-第三边缘；3112-第四边缘；312-极耳；312a-正极极耳；312b-负极极耳；32-活性物质层；321-第一边缘；3211-第一平直段；3212-第一曲线段；3213-凸出段；322-第二边缘；3221-第二平直段；3222-第二曲线段；200-控制器；300-马达；1000-车辆。
具体实施方式
下面将结合附图对本申请技术方案的实施例进行详细的描述。以下实施例仅用于更加清楚地说明本申请的技术方案，因此只作为示例，而不能以此来限制本申请的保护范围。
除非另有定义，本文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；本文中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。
在本申请实施例的描述中，技术术语“第一”“第二”等仅用于区别不同对象，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量、特定顺序或主次关系。
在本文中提及“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，本文所描述的实施例可以与其它实施例相结合。
在本申请实施例的描述中，术语“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)，除非另有明确具体的限定。
在本申请实施例的描述中，技术术语“中心”“纵向”“横向”“长度”“宽度”“厚度”“上”“下”“前”“后”“左”“右”“竖直”“水平”“顶”“底”“内”“外”“顺时针”“逆时针”“轴向”“径向”“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请实施例和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请实施例的限制。
在本申请实施例的描述中，除非另有明确的规定和限定，技术术语“安装”“相连”“连接”“固定”等术语应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或成一体；也可以是机械连接，也可以是电连接；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或两个元件的相互作用关系。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实施例中的具体含义。
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。电池一般包括用于封装一个或多个电池单体的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
电池单体包括电极组件和电解液，电极组件由正极极片、负极极片和隔膜组成。电池单体主要依靠金属离子在正极极片和负极极片之间移动来工作。正极极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂覆正极活性物质层的正极集流体凸出于已涂覆正极活性物质层的正极集流体，未涂覆正极活性物质层的正极集流体作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂覆负极活性物质层的负极集流体凸出于已涂覆负极活性物质层的负极集流体，未涂覆负极活性物质层的负极集流体作为负极极耳。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。为了保证通过大电流而不发生熔断，正极极耳的数量为多个且层叠在一起，负极极耳的数量为多个且层叠在一起。隔膜的材质可以为PP(polypropylene，聚丙烯)或PE(polyethylene，聚乙烯)等。
为使得锂离子电池单体体积更小，能量密度更高，锂离子电池单体的电极组件中的负极极片、正极极片和隔膜可以进行卷绕或折叠，然后压实。
锂离子电池单体在充电时，锂离子从正极极片脱嵌并嵌入负极极片，但是可能会发生一些异常情况，例如，负极极片嵌锂空间不足、负极极片与正极极片之间的距离过大、锂离子嵌入负极极片阻力太大或锂离子过快的从正极极片脱嵌，脱嵌的锂离子无法等量的嵌入负极极片的负极活性物质层，无法嵌入负极极片的锂离子只能在负极极片表面得电子，从而形成银白色的金属锂单质，这就是析锂现象。析锂不仅使锂离子电池单体性能下降，循环寿命大幅缩短，还限制了锂离子电池单体的快充容量。除此之外，锂离子电池发生析锂时，析出来的锂金属非常活泼，在较低的温度下便可以与电解液发生反应，造成电池单体自产热起始温度降低和自产热速率增大，严重危害电池单体的安全。再者，析锂严重时，脱嵌的锂离子可以在负极极片表面形成锂结晶，而锂结晶容易刺破隔膜，造成相邻的正极极片和负极极片具有短路的风险。
现有的电池经常出现析锂的问题，导致电池的安全性较差。发明人发现，现有技术中，为了使得极片具有较多的活性物质容量，活性物质层通常涂覆至集流体的宽度方向的边缘，在锂离子电池中，电极组件的边缘容易出现析锂现象，尤其是电极组件为卷绕式结构时，极片的边缘更容易出现析锂现象。例如，在方壳式的电池单体中，当极耳从电极组件的两侧延伸出时，电极组件的边缘处电解液浸润效果较差，电池单体使用过程中，极片的边缘容易出现析锂。
鉴于此，为了降低析锂以提高电池单体的安全性，发明人经过深入研究，设计了一种极片，活性物质层在集流体的宽度方向的边缘并未延伸至集流体的边缘，使得集流体的靠近边缘的位置形成有空箔区，在电池单体使用过程中，能够降低由该极片构成的电极组件出现析锂的风险，使得电池单体具有较高的安全性。
相对于现有技术的活性物质层涂覆至集流体的边缘、且活性物质层的边缘呈直 线式延伸的极片，本申请的极片中，活性物质层在集流体的宽度方向的边缘并未涂覆至集流体的边缘，并且活性物质层的边缘呈起伏状延伸，沿集流体的长度方向，活性物质层的边缘与集流体的边缘之间的距离大小不等，集流体的靠近边缘的位置形成起伏状的空箔区，在由该极片构成的电池单体中，由于空箔区的存在，极片的边缘的活性物质层较少，极片的边缘出现析锂的风险降低，从而降低了电极组件出现析锂的风险，提高了电池单体的安全性。
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作为电源的用电设备，用电设备可以为但不限于车辆、手机、便携式设备、笔记本电脑、轮船、航天器、电动玩具和电动工具等等。车辆可以是燃油汽车、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；航天器包括飞机、火箭、航天飞机和宇宙飞船等等；电动玩具包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等；电动工具包括金属切削电动工具、研磨电动工具、装配电动工具和铁道用电动工具，例如，电钻、电动砂轮机、电动扳手、电动螺丝刀、电锤、冲击电钻、混凝土振动器和电刨等等。本申请实施例对上述用电设备不做特殊限制。
以下实施例为了方便说明，以用电设备为车辆为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆的结构示意图。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源。
车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池100不仅仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2，图2为本申请一些实施例提供的电池的爆炸图。电池100包括箱体10和多个电池单体20，多个电池单体20设置于箱体10内。
其中，箱体10是容纳电池单体20的部件，箱体10为电池单体20提供容纳空间，箱体10可以采用多种结构。在一些实施例中，箱体10可以包括第一部分11和第二部分12，第一部分11与第二部分12相互盖合，以限定出用于容纳电池单体20的容纳空间。第一部分11和第二部分12可以是多种形状，例如，长方体、圆柱体等。第一部分11可以是一侧开放的空心结构，第二部分12也可以是一侧开放的空心结构，第二部分12的开放侧盖合于第一部分11的开放侧，则形成具有容纳空间的箱体10。也可以是第一部分11为一侧开放的空心结构，第二部分12为板状结构，第二部分12盖合于第一部分11的开放侧，则形成具有容纳空间的箱体10。第一部分11与第二部分12可以通过密封元件来实现密封，密封元件可以是密封圈、密封胶等。
在电池100中，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。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，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。也可以是所有电池单体20之间直接串联或并联或混联在一起，再将所有电池单体20构成的整体容纳于箱体10内。
在一些实施例中，电池100还可以包括汇流部件，多个电池单体20之间可通过汇流部件实现电连接，以实现多个电池单体20的串联或并联或混联。汇流部件可以是金属导体，例如，铜、铁、铝、不锈钢、铝合金等。
请参照图3，图3为本申请一些实施例提供的电池单体的剖视图。电池单体20可以包括壳体21、端盖22、电极组件23和电极端子。壳体21具有开口，端盖22与壳体21共同限定出密封空间。
其中，壳体21可以是一端形成开口的空心结构，壳体21也可以是相对的两端形成开口的空心结构。壳体21的材质可以是多种，例如，铜、铁、铝、钢、铝合金等。
端盖22是封闭壳体21的开口以将电池单体20的内部环境与外部环境隔绝的部件。端盖22与壳体21共同限定出用于容纳电极组件23、电解液以及其他部件的密封空间。端盖22可以通过焊接或卷封的方式连接于壳体21，以封闭壳体21的开口。端盖22的形状可以与壳体21的形状相适配，例如，壳体21为长方体结构，端盖22为与壳体21相适配的矩形板状结构，再如，壳体21为圆柱体，端盖22为与壳体21相适配的圆形板状结构。端盖22的材质也可以是多种，例如，铜、铁、铝、钢、铝合金等。端盖22上可以设置有电极端子，电极端子可以包括正极电极端子和负极电极端子。
电极组件23是电池单体20中发生电化学反应的部件。电极组件23可以包括正极极片、负极极片和隔膜。电极组件23可以是由正极极片、隔膜和负极极片通过卷绕形成的卷绕式结构。电极组件23具有正极极耳312a和负极极耳312b，正极极耳312a可以是正极片上未涂覆正极活性物质层的部分，负极极耳312b可以是负极极片上未涂覆负极活性物质层的部分。正极极耳312a和负极极耳312b可以从电极组件23的卷绕轴线的延伸方向N的两侧延伸出。
电极端子设置于端盖22，电极端子的数量为两个，两个电极端子分别为第一电极端子241和第二电极端子242，正极极耳312a通过第一集流构件251电连接于第一电极端子241，负极极耳312b通过第二集流构件252电连接于第二电极端子242，以形成电流回路。
根据本申请的一些实施例，参照图4，图4为本申请一些实施例提供的极片的结构示意图，图5为图4的左视图。本申请提供了一种极片30，该极片30包括集流体31和活性物质层32。活性物质层32涂覆于集流体31的表面。其中，活性物质层32包括沿集流体31的宽度方向X相对的第一边缘321和第二边缘322，第一边缘321沿集流体31的长度方向Y起伏地延伸。
图中，字母X所指示的方向为集流体31的宽度方向，字母Y所指示的方向为集流体31的长度方向。
集流体31为汇集电流的结构或部件，在锂离子中，集流体31通常为金属箔，如铜箔、铝箔等。
活性物质层32为活性物质材料构成的结构，活性物质层32可以包括活性物质材料、导电剂和粘接剂。正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极活性物质可以为碳或硅等。
活性物质层32可以涂覆于集流体31的厚度方向的一面，或者，活性物质层32也可以涂覆于集流体31的厚度方向Z的相对的两面。图中，字母Z所指示的方向为集流体31的厚度方向。
第一边缘321和第二边缘322为活性物质层32在集流体31的宽度方向X上相对的两个边缘，第一边缘321和第二边缘322限定出活性物质层32在集流体31的宽度方向X上的涂覆轮廓。
相对于第一边缘321呈直线式结构、且第一边缘321与集流体31的宽度方向X的边缘平行设置的情况，第一边缘321沿集流体31的长度方向Y起伏地延伸，第一边缘321与集流体31的宽度方向X的边缘之间的距离沿着集流体31的长度方向Y是变化的，也即第一边缘321参差不齐。
相对于现有技术的活性物质层32涂覆至集流体31的宽度方向X的边缘、且活性物质层32的边缘呈直线式延伸的极片，本申请的极片30中，活性物质层32在集流体31的宽度方向X的第一边缘321并未涂覆至集流体31的宽度方向X的边缘，并且活性物质层32的第一边缘321呈起伏状延伸，沿集流体31的长度方向Y，集流体31的靠近边缘的位置形成起伏状的空箔区(集流体31的未涂覆活性物质层32的区域)，在由该极片30构成的电池单体20中，由于空箔区的存在，极片30的边缘的活性物质层32的涂覆面积较少，极片30的边缘出现析锂的风险降低，从而降低了电极组件23出现析锂的风险，提高了电池单体20的安全性。
根据本申请的一些实施例，如图4所示，第一边缘321呈波浪形。
第一边缘321呈波浪形是指，第一边缘321可以为曲面，例如，沿集流体31的厚度方向Z，第一边缘321在集流体31上的投影呈波浪形的形式。
在上述方案中，第一边缘321的形状呈波浪形，便于实现活性物质层32在集流体31的表面的涂覆，操作简单。
请参见图6，图6为本申请一些实施例提供的极片的第一边缘的结构示意图。根据本申请的一些实施例，沿集流体31的厚度方向Z(请参见图5)，第一边缘321在集流体31上的投影可以包括第一平直段3211和第一曲线段3212，第一平直段3211沿集流体31的长度方向Y直线延伸，第一曲线段3212沿集流体31的宽度方向X凸出于第一平直段3211，也即，第一曲线段3212由第一平直段3211朝向集流体31的边缘凸出。需要指出的是，这里提及的集流体31的边缘是指集流体31的宽度方向X上的、靠近第一边缘321的边缘。
第一平直段3211与集流体31的边缘之间的距离沿集流体31的长度方向Y可以相同，或者，第一平直段3211与集流体31的边缘之间的距离沿集流体31的长度方向Y逐渐减小或者逐渐增大。
第一曲线段3212的形状可以三角形、矩形、半圆形、梯形或者异形等。
根据本申请的一些实施例，第二边缘322沿集流体31的长度方向Y起伏地延 伸。
第二边缘322沿集流体31的长度方向Y起伏地延伸，第二边缘322与集流体31的宽度方向X的边缘之间的距离沿着集流体31的长度方向Y是变化的，也即第二边缘322参差不齐。
需要指出的是，这里的集流体31的宽度方向X的边缘是指集流体31的宽度方向X上的、靠近第二边缘322的边缘，该边缘相对于集流体31的宽度方向X上的另一边缘更靠近第二边缘322。
在第一边缘321沿集流体31的长度方向Y起伏地延伸的基础上，第二边缘322沿集流体31的长度方向Y起伏地延伸，使得集流体31在其宽度方向的两个边缘能够具有未涂覆活性物质层32的空箔区，进一步降低极片30构成的电池单体20在使用过程中出现析锂的概率，提高电池单体20的安全性。
根据本申请的一些实施例，如图4所示，第二边缘322呈波浪形。
第二边缘322呈波浪形是指，第二边缘322可以为曲面，例如，沿集流体31的厚度方向Z，第二边缘322在集流体31上的投影呈波浪形的形式。
在上述方案中，第二边缘322的形状呈波浪形，便于实现活性物质层32在集流体31的表面的涂覆，操作简单。
根据本申请的一些实施例，如图6所示，沿集流体31的厚度方向Z(请参见图5)，第二边缘322在集流体31上的投影可以包括第二平直段3221和第二曲线段3222，第二平直段3221沿集流体31的长度方向Y直线延伸，第二曲线段3222沿集流体31的宽度方向X凸出于第二平直段3221，也即，第二曲线段3222由第二平直段3221朝向集流体31的边缘凸出。需要指出的是，这里提及的集流体31的边缘是指集流体31的宽度方向X上的、靠近第二边缘322的边缘。
第二平直段3221与集流体31的边缘之间的距离沿集流体31的长度方向Y可以相同，或者，第二平直段3221与集流体31的边缘之间的距离沿集流体31的长度方向Y逐渐减小或者逐渐增大。
第二曲线段3222的形状可以三角形、矩形、半圆形、梯形或者异形等。
根据本申请的一些实施例，如图4和图6所示，第一边缘321与第二边缘322对称。
在上述方案中，第一边缘321与第二边缘322对称，便于实现活性物质层32的涂覆。
根据本申请的一些实施例，如图4至图6所示，集流体31包括本体311和多个极耳312，本体311包括沿集流体31的宽度方向X相对设置的第三边缘3111和第四边缘3112，极耳312从第三边缘3111延伸出，活性物质层32涂覆于本体311的表面，第一边缘321靠近第三边缘3111，第二边缘322靠近第四边缘3112。
本体311为集流体31的用于涂覆活性物质层32的部位。第三边缘3111和第四边缘3112为本体311的沿集流体31的宽度方向X相对设置的两个边缘，第三边缘3111和第四边缘3112在集流体31的宽度方向X上限定本体311的轮廓。
多个极耳312沿集流体31的长度方向Y间隔设置，极耳312可以由集流体 31裁切而成，第三边缘3111为裁切边缘。
极耳312从第三边缘3111延伸出是指，极耳312沿集流体31的宽度方向X由第三边缘3111超背离第四边缘3112的方向凸出。
第一边缘321靠近第三边缘3111是指，第一边缘321相对于第二边缘322靠近第三边缘3111，换句话说，沿集流体31的宽度方向X，第一边缘321到第三边缘3111的距离大于第二边缘322到第三边缘3111的距离。
第二边缘322靠近第四边缘3112是指，第二边缘322相对于第一边缘321靠近第四边缘3112，换句话说，沿集流体31的宽度方向X，第二边缘322到第四边缘3112的距离大于第一边缘321到第四边缘3112的距离。
极耳312从第三边缘3111延伸出，第一边缘321与第三边缘3111相邻，第一边缘321和第三边缘3111限定出第一空箔区，使得本体311的靠近极耳312的区域涂覆的活性物质层32的面积较小，降低极片30在靠近极耳312的边缘区域出现析锂的概率。
根据本申请的一些实施例，如图4所示，第三边缘3111沿集流体31的长度方向Y直线延伸，沿集流体31的宽度方向X，第一边缘321与第三边缘3111之间的最大距离为D，集流体31的宽度为W，满足1/10≤D/W≤1/6。
第三边缘3111沿集流体31的长度方向Y直线延伸，也即本体311边缘平齐，便于极片30与其他部件之间的装配。
第一边缘321与第三边缘3111之间的最大距离D和集流体31的宽度W的比例满足上述关系，能够平衡电池单体20的能量密度和析锂的概率。当第一边缘321与第三边缘3111之间的最大距离D和集流体31的宽度W的比例小于1/10时，电池单体20的极片30出现析锂的概率较大；当第一边缘321与第三边缘3111之间的最大距离D和集流体31的宽度W的比例大于1/6时，集流体31涂覆的活性物质层32的面积较小，导致电池单体20的能量密度较低。
可选地，第一边缘321与第三边缘3111之间的最大距离D和集流体31的宽度W的比例关系满足D/W＝1/8。
请参见图7和图8，图7为本申请另一些实施例提供的极片的结构示意图，图8为图7的左视图。根据本申请的一些实施例，第四边缘3112沿集流体31的长度方向Y起伏地延伸且与第二边缘322至少部分重合。
第四边缘3112与第二边缘322至少部分重合是指，第四边缘3112与第二边缘322的一部分重合，或者，第四边缘3112与第二边缘322完全重合。可选地，如图7和图8所示，第四边缘3112与第二边缘322完全重合，便于加工制造。
相对于第四边缘3112沿集流体31的长度方向Y直线延伸，第四边缘3112沿集流体31的长度方向Y起伏地延伸且第四边缘3112与第二边缘322至少部分重合，使得活性物质层32在本体311的背离第三边缘3111的一侧的涂覆面积较小，降低了活性物质层32在集流体31的宽度方向X边缘的涂覆面积，进而降低了由该极片30构成的电池单体20析锂的风险。
同时，第四边缘3112与第二边缘322至少部分重合，集流体31的在宽度方 向上未设置极耳312的边缘可以进行模切，便于极片30成型加工。
根据本申请的一些实施例，如图4和图6所示，第四边缘3112沿集流体31的长度方向Y直线延伸。
第四边缘3112沿集流体31的长度方向Y直线延伸，也即本体311边缘平齐，便于极片30与其他部件之间的装配。
同时，第四边缘3112沿直线延伸，便于实现活性物质层32的涂覆。
根据本申请的一些实施例，如图4所示，第一边缘321包括多个朝向第三边缘3111凸出的凸出段3213，多个凸出段3213沿集流体31的长度方向Y间隔设置，多个极耳312沿集流体31的长度方向Y间隔设置，每个极耳312位于相邻两个凸出段3213之间。
凸出段3213是指第一边缘321的相对于其他部位靠近第三边缘3111的部位。
多个凸出段3213沿集流体31的长度方向Y间隔设置，使得第一边缘321沿集流体31的长度方向Y起伏地延伸。
相邻的两个凸出段3213之间形成凹陷段，凹陷段朝向第四边缘3112凹陷。
由于本体311的与极耳312对应的位置处出现析锂的概率较大，极耳312与相邻的两个凸出段3213对应，以降低本体311在与极耳312对应位置处析锂的概率。
根据本申请的一些实施例，如图4所示，每个极耳312的中心线P1偏离与该极耳312相邻的两个凸出段3213的对称中心线P2。
多个凸出段3213沿集流体31的长度方向Y间隔设置，多个凸出段3213的结构形式可以相同，相邻两个凸出段3213具有对称中心线P2。
根据本申请的一些实施例，本申请提供了一种电极组件23，该电极组件23包括正极极片、隔膜及负极极片，正极极片、隔膜及负极极片层叠卷绕形成电极组件23，正极极片和负极极片为如上述实施例提供的极片30。
根据本申请实施例的电极组件23，正极极片和负极极片为上述的极片30，能够降低由该电极组件23构成的电池单体20的析锂风险，提高电池单体20的安全性。
根据本申请的一些实施例，本申请提供了一种电池单体20，该电池单体20包括如上述实施例提供的电极组件23。
根据本申请实施例的电池单体20，采用上述的电极组件23，具有较高的安全性。
根据本申请的一些实施例，如图3所示，电池单体20还包括壳体21、端盖22、第一电极端子241、第二电极端子242、第一集流构件251和第二集流构件252。壳体21具有开口；端盖22封闭开口。第一电极端子241和第二电极端子242设置于端盖22。其中，电极组件23容纳于壳体21内，电极组件23的卷绕轴线的延伸方向与端盖22的厚度方向M垂直，电极组件23的正极极耳312a和负极极耳312b分别位于电极组件23在卷绕轴线的延伸方向N上的两侧，正极极耳312a通过第一集流构件251电连接于第一电极端子241，负极极耳312b通过第二集流构件252电连接于第二电极端子242。
第一电极端子241和第二电极端子242均为导电部件，用于将电池单体20 的电能导出。
图中，字母M所指示的方向为端盖22的厚度方向，字母N所指示的方向为电极组件23的卷绕轴线的延伸方向。
电极组件23的卷绕轴线的延伸方向N与集流体31的宽度方向X平行。
正极极耳312a和负极极耳312b从电极组件23的卷绕轴线的延伸方向N的两侧延伸出，以便于电极组件23的装配，降低正极极耳312a和负极极耳312b接触短路的风险。
第一集流构件251和第二集流构件252均为导电件，具有较好的导电性能，第一集流构件251和第二集流构件252的材质可以为金属，例如，铝、镍或者其合金等。
在上述方案中，由于电极组件23的卷绕方向与端盖22的厚度方向M垂直，并且正极极耳312a和负极极耳312b分别位于卷绕方向上的两侧，由于正极集流体31的宽度方向X的边缘和负极集流体31的宽度方向X的边缘均具有空箔区，在电池工作过程中，能够降低电极组件23析锂的概率。
根据本申请的一些实施例，本申请提供了一种电池100，包括如上述实施例所述的电池单体20。
根据本申请的一些实施例，本申请提供了一种用电设备，包括如上述实施例所述的电池100，电池100用于为用电设备提供电能。
用电设备可以为上述任一应用电池的设备或系统。
根据本申请的一些实施例，参见图3，本申请提供了一种方体电池单体，该方体电池单体包括壳体21、端盖22、电极组件23、第一电极端子241、第二电极端子242、第一集流构件251和第二集流构件252。壳体21具有开口，端盖22封闭开口，以与壳体21限定密封空间。第一电极端子241和第二电极端子242设置于端盖22。电极组件23容纳于壳体21内。电极组件23包括正极极片、隔膜及负极极片，正极极片、隔膜及负极极片层叠卷绕形成电极组件23，正极极片和负极极片为上述实施例提供的极片30。电极组件23的卷绕轴线的延伸方向N与端盖22的厚度方向M垂直，电极组件23的正极极耳312a和负极极耳312b分别位于电极组件23在卷绕轴线的延伸方向N上的两侧，正极极耳312a通过第一集流构件251电连接于第一电极端子241，负极极耳312b通过第二集流构件252电连接于第二电极端子242。
其中，请参见图7，极片30包括集流体31和活性物质层32，集流体31包括本体311和多个极耳312，本体311包括沿集流体31的厚度方向Z相对设置的第三边缘3111和第四边缘3112，极耳312从第三边缘3111延伸出，活性物质层32涂覆于本体311的厚度方向的相对的两面。第三边缘3111沿集流体31的长度方向Y直线延伸，第四边缘3112沿集流体31的长度方向Y起伏地延伸。活性物质层32包括沿集流体31的宽度方向X相对的第一边缘321和第二边缘322，第一边缘321沿集流体31的长度方向Y起伏地延伸，第一边缘321靠近第三边缘3111，第二边缘322靠近第四边缘3112，且第二边缘322与第四边缘3112重合。第二边缘322与第一边缘321对称设置。
电极组件23中，正极极片的活性物质层32的第一边缘321与负极极片的活性物质层32的第二边缘322对应，正极极片的活性物质层32的第二边缘322与负极极片的活性物质层32的第一边缘321对应。
相对于活性物质层32涂覆至集流体31的边缘，该电极组件23中，电极组件23的卷绕轴线的延伸方向N的边缘具有较少的活性物质层32，降低了方体电池单体析锂的风险，使得方体电池单体具有较高的安全性。
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 (16)

  1. 一种极片，包括：
    集流体；
    活性物质层，涂覆于所述集流体的表面；
    其中，所述活性物质层包括沿所述集流体的宽度方向相对的第一边缘和第二边缘，所述第一边缘沿所述集流体的长度方向起伏地延伸。
  2. 根据权利要求1所述的极片，其中，所述第一边缘呈波浪形。
  3. 根据权利要求1或2所述的极片，其中，所述第二边缘沿所述集流体的长度方向起伏地延伸。
  4. 根据权利要求3所述的极片，其中，所述第二边缘呈波浪形。
  5. 根据权利要求3或4所述的极片，其中，所述第一边缘与所述第二边缘对称。
  6. 根据权利要求1-5中任一项所述的极片，其中，所述集流体包括本体和多个极耳，所述本体包括沿所述集流体的宽度方向相对设置的第三边缘和第四边缘，所述极耳从所述第三边缘延伸出，所述活性物质层涂覆于所述本体的表面，所述第一边缘靠近所述第三边缘，所述第二边缘靠近所述第四边缘。
  7. 根据权利要求6所述的极片，其中，所述第三边缘沿所述集流体的长度方向直线延伸，沿所述集流体的宽度方向，所述第一边缘与所述第三边缘之间的最大距离为D，所述集流体的宽度为W，满足1/10≤D/W≤1/6。
  8. 根据权利要求6所述的极片，其中，所述第四边缘沿所述集流体的长度方向起伏地延伸且与所述第二边缘至少部分重合。
  9. 根据权利要求6所述的极片，其中，所述第四边缘沿所述集流体的长度方向直线延伸。
  10. 根据权利要求6所述的极片，其中，所述第一边缘包括多个朝向所述第三边缘凸出的凸出段，多个所述凸出段沿所述集流体的长度方向间隔设置，多个所述极耳沿所述集流体的长度方向间隔设置，每个所述极耳位于相邻两个所述凸出段之间。
  11. 根据权利要求10所述的极片，其中，每个所述极耳的中心线偏离与该极耳相邻的两个所述凸出段的对称中心线。
  12. 一种电极组件，包括正极极片、隔膜及负极极片，所述正极极片、所述隔膜及所述负极极片层叠卷绕形成所述电极组件，所述正极极片和所述负极极片为如权利要求1-11中任一项所述的极片。
  13. 一种电池单体，包括如权利要求12所述的电极组件。
  14. 根据权利要求13所述的电池单体，其中，所述电池单体还包括：
    壳体，具有开口；
    端盖，封闭所述开口；
    第一电极端子和第二电极端子，设置于所述端盖；
    第一集流构件和第二集流构件；
    其中，所述电极组件容纳于所述壳体内，所述电极组件的卷绕轴线的延伸方向与 所述端盖的厚度方向垂直，所述电极组件的正极极耳和负极极耳分别位于所述电极组件在所述卷绕轴线的延伸方向上的两侧，所述正极极耳通过所述第一集流构件电连接于所述第一电极端子，所述负极极耳通过所述第二集流构件电连接于所述第二电极端子。
  15. 一种电池，包括如权利要求13或14所述的电池单体。
  16. 一种用电设备，包括如权利要求15所述的电池。
PCT/CN2023/077463 2022-06-20 2023-02-21 极片、电极组件、电池单体、电池及用电设备 WO2023246134A1 (zh)

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CN117637990A (zh) * 2024-01-26 2024-03-01 宁德新能源科技有限公司 极片、电极组件及电池
CN117638254A (zh) * 2024-01-26 2024-03-01 宁德新能源科技有限公司 一种电极组件及电池

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CN117638254A (zh) * 2024-01-26 2024-03-01 宁德新能源科技有限公司 一种电极组件及电池
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