WO2023221109A1 - 极片、电池单体、电池、用电设备及极片的制造方法 - Google Patents

极片、电池单体、电池、用电设备及极片的制造方法 Download PDF

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Publication number
WO2023221109A1
WO2023221109A1 PCT/CN2022/094185 CN2022094185W WO2023221109A1 WO 2023221109 A1 WO2023221109 A1 WO 2023221109A1 CN 2022094185 W CN2022094185 W CN 2022094185W WO 2023221109 A1 WO2023221109 A1 WO 2023221109A1
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WO
WIPO (PCT)
Prior art keywords
pole piece
main body
current collector
end portion
transition
Prior art date
Application number
PCT/CN2022/094185
Other languages
English (en)
French (fr)
Inventor
王慢慢
刘锋
葛销明
Original Assignee
宁德时代新能源科技股份有限公司
Priority date (The priority date 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 date listed.)
Filing date
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Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to CN202280045615.9A priority Critical patent/CN117642876A/zh
Priority to PCT/CN2022/094185 priority patent/WO2023221109A1/zh
Priority to EP22942148.2A priority patent/EP4386878A1/en
Priority to CN202321265897.1U priority patent/CN220774411U/zh
Publication of WO2023221109A1 publication Critical patent/WO2023221109A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • 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 pole piece, a battery cell, a battery, an electrical device, and a method for manufacturing the pole piece.
  • 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 pole piece is an important part of the battery cell.
  • the pole piece includes a current collector.
  • a porous current collector is used as the current collector, due to the porous structure of the porous current collector and the weak mechanical strength of the porous current collector, the porous current collector cannot weld other components.
  • the purpose of this application is to provide a method for manufacturing pole pieces, battery cells, batteries, electrical equipment and pole pieces.
  • the end of the pole piece has high mechanical strength and can be welded to other components.
  • the present application provides a pole piece, which includes a porous current collector.
  • the porous current collector includes an integrally formed main body and an end.
  • the unit area weight of the end is greater than the unit area weight of the main body.
  • the thickness of the end portion is smaller than the thickness of the main body portion, the thickness of the end portion is D1, and satisfies 5 ⁇ m ⁇ D1 ⁇ 100 ⁇ m.
  • the weight per unit area of the end is greater than the weight per unit area of the main body, and the thickness of the end is smaller than the thickness of the main body.
  • the end can be a compressed part of the porous current collector, and has high mechanical strength. It can be used as the tab of the pole piece to facilitate welding with other components; at the same time, the thickness of the end meets the above range. On the one hand, it meets the requirements for die cutting and is easy to process. On the other hand, the current distribution at the end is concentrated and the cycle performance is relatively good. good.
  • 5 ⁇ m ⁇ D1 ⁇ 50 ⁇ m is satisfied.
  • 10 ⁇ m ⁇ D1 ⁇ 20 ⁇ m is satisfied.
  • the thickness of the main body part is D2, satisfying 10% ⁇ D1/D2 ⁇ 15%.
  • the thickness of the main part when the thickness of the main part is consistent, the thickness of the end part and the thickness of the main part satisfy the above relationship, the end part has better processing performance, and the current distribution at the end part is ensured to be concentrated.
  • the end portion and the main body portion are arranged along the first direction, and the size of the end portion in the first direction is B, satisfying 5 mm ⁇ B ⁇ 20 mm.
  • the size of the end portion in the first direction meets the above range, so that the end portion can have a larger connection area with other components.
  • 6mm ⁇ B ⁇ 9mm is satisfied.
  • the end portion and the main body portion are arranged along a first direction, the size of the porous current collector in the first direction is A, and the end portion is in the first direction.
  • the upward dimension is B, satisfying 5% ⁇ B/A ⁇ 20%.
  • the size of the porous current collector in the first direction when the size of the porous current collector in the first direction is constant, the size of the end in the first direction and the size of the porous current collector in the first direction satisfy the above relationship.
  • the end It has a larger connection area with other components.
  • it ensures that the main body part has a larger size in the first direction, so that the porous current collector has more metal ion deposition sites.
  • the porosity of the end portion is 50-80%.
  • the porosity of the end portion is 62.5-75%.
  • the areal density of the end portion is 300-500g/m 2 .
  • the areal density of the end portion meets the above range, which makes the structure of the end portion dense and improves the strength and cutting performance of the end portion.
  • the areal density of the end portion is 350-450g/m 2 .
  • the main body portion has an oppositely arranged first surface and a third surface
  • the end portion has an oppositely arranged second surface and a fourth surface
  • the second surface and the fourth surface are both located between the plane of the first surface and the plane of the third surface.
  • the end portion is located between the first surface and the third surface, which can reduce stress concentration at the transition between the end portion and the main body portion and reduce the probability of end portion breakage.
  • the porous current collector further includes a transition portion connecting the main body portion and the end portion, and the thickness of the transition portion is connected by one side connecting the main body portion.
  • the end tapers off on one side.
  • the transition part connects the main part and the end part, which facilitates processing and shaping and reduces the difficulty of processing.
  • the main body part has a first surface
  • the end part has a second surface
  • the transition part has a first transition surface
  • the first transition surface connects the first surface and the The second surface
  • the first transition surface is an arc surface tangent to the second surface
  • the first transition surface is tangent to the second surface, which makes the processing mold structure simple and facilitates the preparation of the pole piece.
  • the radius of curvature of the first transition surface is R, satisfying 15mm ⁇ R ⁇ 25mm.
  • the curvature radius of the first transition surface meets the above range, which facilitates the processing of the pole piece.
  • the main body portion has a third surface disposed opposite to the first surface
  • the end portion has a fourth surface disposed opposite to the second surface
  • the transition portion has a third surface disposed opposite to the first surface.
  • a second transition surface is provided opposite to the first transition surface. The second transition surface connects the third surface and the fourth surface. The second transition surface is an arc tangent to the fourth surface. noodle.
  • the second transition surface connects the third surface and the fourth surface, and the second transition surface is tangent to the fourth surface, which facilitates the manufacturing of the pole piece.
  • the second transition surface is arranged symmetrically with the first transition surface.
  • the end is extruded by porous current collectors on opposite sides to facilitate pole piece processing and ensure concentrated current distribution at the end.
  • the end portion, the transition portion and the main body portion are arranged along the first direction, and the size of the transition portion in the first direction is C, satisfying 0.5mm ⁇ C ⁇ 2mm.
  • the size of the transition part in the first direction meets the above range, which facilitates the processing and shaping of the end part.
  • the pole piece further includes an active material layer, and the active material layer is disposed on the surface of the main body part.
  • the active material layer is disposed on the surface of the main body part so that the pole piece has more active material capacity.
  • the porous current collector is foam metal.
  • foam metal has better mechanical properties.
  • the present application provides a battery cell, including: a case assembly including an electrode lead-out portion; an electrode assembly accommodated in the case assembly, the electrode assembly including a first pole piece with opposite polarity and a second pole piece, at least one of the first pole piece and the second pole piece is the pole piece provided in the above embodiment, and the end portion is electrically connected to the electrode lead-out portion.
  • At least one of the first pole piece and the second pole piece is the above-mentioned pole piece, and the end of the pole piece has high mechanical strength to facilitate the realization of the electrode assembly and the electrode lead-out part. electrical connection.
  • the present application provides a battery, including a box and a plurality of battery cells provided in the above embodiments, and the plurality of battery cells are accommodated in the box.
  • the present application provides an electrical device, including the battery cell provided in the above embodiment, where the battery cell is used to provide electric energy.
  • the present application provides a method for manufacturing a pole piece, which includes: providing a porous current collector; extruding the ends of the porous current collector from both sides in the thickness direction of the porous current collector to make the porous current collector The thickness of the end portion is compressed to 5-100 ⁇ m.
  • the preparation process is simple.
  • the end of the prepared pole piece has high mechanical strength, meets the die-cutting requirements, and is easy to process.
  • the current distribution at the end is concentrated and the cycle performance is relatively good. good.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Figure 2 is a schematic structural diagram of a battery provided by some embodiments of the present application.
  • Figure 3 is a schematic structural diagram of a battery cell provided by some embodiments of the present application.
  • Figure 4 is a perspective view of a pole piece provided by some embodiments of the present application.
  • Figure 5 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 6 is a schematic structural diagram of a porous current collector provided by some embodiments of the present application.
  • Figure 7 is a schematic structural diagram of a porous current collector provided by other embodiments of the present application.
  • Figure 8 is a schematic structural diagram of a pole piece provided by other embodiments of the present application.
  • Figure 9 shows a schematic flow chart of the manufacturing method of the pole piece provided by some embodiments of the present application.
  • Figure 10 is a schematic diagram of the manufacturing equipment of the pole piece provided by some embodiments of the present application.
  • Marking description 100-battery; 10-box; 11-first part; 12-second part; 20-battery cell; 21-end cover; 21a-electrode terminal; 22-casing; 23-electrode assembly; 23a -pole ear; 30-pole piece; 31-porous current collector; 311-main body; 3111-first surface; 3112-third surface; 312-end; 3121-second surface; 3122-fourth surface; 313 -Transition part; 3131-first transition surface; 3132-second transition surface; 32-active material layer; 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 It is more than two pieces (including two pieces).
  • the battery mentioned refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack.
  • 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 current collector without the positive electrode active material layer is used as a positive electrode 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.
  • the material of the negative electrode current collector may be copper, and the negative electrode current collector is not coated with an active material.
  • 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 active material may be carbon or silicon.
  • the material of the isolation film can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the current collector can be a porous current collector, such as metal foam; porous current collectors have higher porosity and more metal ion deposition sites, especially in lithium-ion batteries, which can effectively inhibit lithium
  • the growth of dendrites and the mitigation of volume changes allow it to significantly improve the deposition behavior and electrochemical performance of metallic lithium.
  • other components such as electrode terminals, housings, adapters, etc.
  • the present application provides a pole piece, which compresses the end of a porous current collector to form a pole ear, which has high mechanical strength. At the same time, the thickness of the end is compressed to 5 ⁇ m ⁇ D1 ⁇ 100 ⁇ m. On the one hand, it meets the requirements of die-cutting and facilitates processing. On the other hand, the current distribution at the end is concentrated and the cycle performance is better.
  • 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, a mobile phone, a tablet computer, a laptop, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, Spacecraft and more.
  • electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc.
  • spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.
  • an electrical device is a vehicle 1000 as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application.
  • the vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • the battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 100 can be used to power the vehicle 1000 .
  • the battery 100 can be used as an operating power source for the vehicle 1000 and for the circuit system of the vehicle 1000 , such as for the starting, navigation and operating power requirements of the vehicle 1000 .
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • FIG. 2 is a schematic structural diagram of a battery 100 provided by some embodiments of the present application.
  • the battery 100 includes a case 10 and battery cells 20 , and the battery cells 20 are accommodated in the case 10 .
  • the box 10 is used to provide an accommodation space for the battery cells 20, and the box 10 can adopt a variety of structures.
  • the box 10 may include a first part 11 and a second part 12 , the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a space for accommodating the battery cells 20 of accommodation space.
  • the second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure.
  • the first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define a receiving space.
  • the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 is covered with the open side of the second part 12.
  • the battery 100 there may be a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the plurality of battery cells 20 are connected in series and in parallel.
  • the plurality of battery cells 20 can be directly connected in series or in parallel or mixed together, and then the whole composed of the plurality of battery cells 20 can be accommodated in the box 10 ; of course, the battery 100 can also be a plurality of battery cells 20 First, the battery modules are connected in series, parallel, or mixed to form a battery module, and then multiple battery modules are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 10 .
  • the battery 100 may also include other structures.
  • the battery 100 may further include a bus component for realizing electrical connections between multiple battery cells 20 .
  • Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto.
  • FIG. 3 is a schematic structural diagram of a battery cell 20 provided in some embodiments of the present application.
  • the battery cell 20 refers to the smallest unit that constitutes the battery.
  • the battery cell 20 includes a case assembly, an electrode assembly 23 and other functional components.
  • the housing assembly includes an end cover 21 and a housing 22. At least one of the end cover 21 and the housing 22 is provided with an electrode lead-out portion.
  • the end cap 21 refers to a component that covers the opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment.
  • the shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22 .
  • the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 21 is less likely to deform when subjected to extrusion and collision, so that the battery cell 20 can have higher durability. Structural strength and safety performance can also be improved.
  • the end cap 21 may be provided with an electrode lead-out part (electrode terminal 21 a ), and the electrode terminal 21 a may be used to electrically connect with the electrode assembly 23 for outputting or inputting electric energy of the battery cell 20 .
  • the end cap 21 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold.
  • the end cap 21 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application.
  • an insulating member may also be provided inside the end cover 21 , and the insulating member may be used to isolate the electrical connection components in the housing 22 from the end cover 21 to reduce the risk of short circuit.
  • the insulating member may be plastic, rubber, etc.
  • the housing 22 is a component used to cooperate with the end cover 21 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 23 , electrolyte, and other components.
  • the housing 22 and the end cover 21 may be independent components, and an opening may be provided on the housing 22.
  • the end cover 21 covers the opening at the opening to form the internal environment of the battery cell 20.
  • the end cover 21 and the housing 22 can also be integrated.
  • the end cover 21 and the housing 22 can form a common connection surface before other components are put into the housing. When it is necessary to encapsulate the inside of the housing 22 At this time, the end cover 21 covers the housing 22 again.
  • the housing 22 can be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23 .
  • the housing 22 may be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiments of the present application.
  • the housing 22 may be provided with an electrode lead-out portion, which is used to electrically connect with the tab for outputting or inputting electric energy of the battery cell 20 .
  • the electrode assembly 23 is a component in the battery cell 100 where electrochemical reactions occur.
  • One or more electrode assemblies 23 may be contained within the housing 22 .
  • the electrode assembly 23 is mainly formed by winding or stacking a positive electrode piece and a negative electrode piece, and is usually provided with an isolation film between the positive electrode piece and the negative electrode piece. The isolation film is used to separate the positive electrode piece and the negative electrode piece. Avoid internal short circuit between positive and negative electrode pieces.
  • the ends of the positive electrode piece and the negative electrode piece respectively protrude from the tabs 23a.
  • the positive electrode tab and the negative electrode tab can be located together at one end of the electrode assembly 23 or respectively located at both ends of the electrode assembly 23 .
  • the positive active material and the negative active material react with the electrolyte, and the tab 23a is connected to the electrode lead-out part through the adapter 24 to form a current loop.
  • Figure 4 is a perspective view of the pole piece 30 provided by some embodiments of the present application
  • Figure 5 is a schematic structural diagram of the pole piece 30 provided by some embodiments of the present application.
  • the pole piece 30 includes a porous current collector 31.
  • the porous current collector 31 includes an integrally formed main body part 311 and an end part 312.
  • the unit area weight of the end part 312 is greater than that of the main body part 311.
  • the thickness of the end part 312 is smaller than the main body part 311.
  • the thickness of the end 312 is D1, which satisfies 5 ⁇ m ⁇ D1 ⁇ 100 ⁇ m.
  • the porous current collector 31 may be a metal conductor, and the porous current collector 31 may have a porous structure, which may be a porous structure formed by the material itself having voids, or may be a porous structure formed by processing.
  • the direction indicated by the letter Z is the thickness direction of the porous current collector 31
  • the thickness D1 of the end portion 312 is the size of the end portion 312 in the thickness direction Z
  • the thickness of the main body is the size of the main body in the thickness direction Z.
  • the main body portion 311 and the end portion 312 are components of the porous current collector 31 , and the end portion 312 is a portion of the porous current collector 31 with a smaller thickness.
  • the main body part 311 is the part of the positive electrode piece used for coating the positive electrode active material.
  • the main body part 311 is the part opposite to the main body part 311 of the positive electrode piece; specifically, when the surface of the negative electrode piece is not coated with active material, the main body part 311 is a metal used to receive the positive active material.
  • the main part 311 is the part of the negative electrode sheet used to coat the negative electrode active material when the active material is coated on the surface of the negative electrode sheet.
  • the end portion 312 is located at one end of the main body portion 311.
  • the end portion 312 and the main body portion 311 may be arranged along a preset direction.
  • the weight per unit area of the end portion 312 is greater than the weight per unit area of the main body portion 311 , and the thickness of the end portion 312 is smaller than the thickness of the main body portion 311 .
  • the end portion 312 may be formed by compressing the porous current collector 31 .
  • the thickness D1 of the end 312 When the thickness D1 of the end 312 satisfies 5 ⁇ m ⁇ D1 ⁇ 100 ⁇ m, the thickness D1 of the end 312 may be 5 ⁇ m, 10 ⁇ m, 20 ⁇ m, 30 ⁇ m, 40 ⁇ m, 50 ⁇ m, 60 ⁇ m, 70 ⁇ m, 75 ⁇ m, 80 ⁇ m, 90 ⁇ m, 100 ⁇ m, etc.
  • the end portion 312 When the thickness D1 of the end portion 312 is less than 5 ⁇ m, and the end portion 312 is compressed and formed by the porous current collector 31, the end portion 312 is easily torn, so that the end portion 312 does not meet the die-cutting requirements, and the end portion 312 cannot be used as the tab 23a; when When the thickness D1 of the end portion 312 is greater than 100 ⁇ m, the current distribution of the end portion 312 is dispersed and the cycle performance is poor.
  • the end portion 312 can be a compressed part of the porous current collector 31.
  • the end portion 312 has high mechanical strength.
  • the end portion 312 can serve as the tab 23a of the pole piece 30 to facilitate connection with other components.
  • Components such as electrode terminal 21a, housing 22 or adapter 24, etc.
  • the thickness of the end 312 meets the above range. On the one hand, it meets the die-cutting requirements and facilitates processing.
  • the end 312 The current distribution of 312 is concentrated and the cycle performance is better.
  • end portion 312 serves as the tab 23a of the pole piece 30 and can be directly connected to the electrode terminal 21a, the housing 22 or the adapter 24.
  • 5 ⁇ m ⁇ D1 ⁇ 50 ⁇ m is satisfied.
  • the thickness D1 of the end portion 312 may be 5 ⁇ m, 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 30 ⁇ m, 40 ⁇ m, 50 ⁇ m, etc.
  • the weight per unit area of the end portion 312 is larger and the mechanical strength is higher.
  • 10 ⁇ m ⁇ D1 ⁇ 20 ⁇ m is satisfied.
  • the unit area weight of the end portion 312 is larger and the mechanical strength is higher.
  • the thickness D1 of the end portion 312 may be 10 ⁇ m, 12 ⁇ m, 15 ⁇ m, 18 ⁇ m, 20 ⁇ m, etc.
  • the thickness of the main body part 311 is D2, which satisfies 10% ⁇ D1/D2 ⁇ 15%.
  • D1/D2 is less than 10%, the thickness D1 of the end 312 is small, the processing of the end 312 is more difficult, and the end 312 is prone to cracks; if D1/D2 is greater than 15%, the thickness D1 of the end 312 is relatively small. Large, the current distribution at end 312 is relatively dispersed, and the cycle performance is poor.
  • the thickness D1 of the main body part 311 is constant, the thickness of the end part 312 and the thickness of the main body part 311 satisfy 10% ⁇ D1/D2 ⁇ 15%, the end part 312 has better processing performance, and Ensure that the current distribution at end 312 is concentrated.
  • the end portion 312 and the main body portion 311 are arranged along the first direction X, and the size of the end portion 312 in the first direction X is B, satisfying 5 mm ⁇ B ⁇ 20 mm.
  • the first direction X is perpendicular to the thickness direction Z.
  • the end portion 312 and the main body portion 311 are arranged along the first direction X" means that the end portion 312 is located on one side of the main body portion 311 in the first direction X.
  • the dimension B of the end 312 in the first direction is greater than 20 mm.
  • the main body 311 serves as the attachment site of the active material. The size of the main body 311 is small, so that the active material capacity of the pole piece 30 is small, so that the energy density of the battery cell is low.
  • the size B of the end portion 312 in the first direction Active material capacity is the size B of the end portion 312 in the first direction Active material capacity.
  • 6mm ⁇ B ⁇ 9mm is satisfied.
  • the larger connection area can also ensure that the main body 311 has a larger size in the first direction X, ensuring that the pole piece 30 can have a higher active material capacity.
  • the dimension B in the first direction X may be 6mm, 7mm, 8mm, 9mm, etc.
  • the end portion 312 and the main body portion 311 are arranged along the first direction X, the size of the porous current collector 31 in the first direction X is A, and the end portion 312 is in the first direction
  • the dimension on X is B, satisfying 5% ⁇ B/A ⁇ 20%.
  • the size A of the porous current collector 31 in the first direction X is constant, if B/A is less than 5%, the size of the end portion 312 in the first direction The area is smaller; if B/A is greater than 20%, the size of the end portion 312 in the first direction X is larger, correspondingly, the size of the main body portion 311 in the first direction
  • the portion of 30 where the active material is provided reduces the capacity of the active material of the pole piece 30 and affects the energy density of the battery cell 20 .
  • the dimension B of the end portion 312 in the first direction X and the dimension A of the porous current collector 31 in the first direction X satisfy 5% ⁇ B/A ⁇ 20%.
  • the components have a large connection area.
  • the main body part 311 has a large size in the first direction X, so that the porous current collector 31 has more metal ion deposition sites and the main body part 311 can be attached.
  • the pole piece 30 can have more active material capacity, and the energy density of the battery cell 20 is higher.
  • the dimension B of the end portion 312 in the first direction X and the dimension A of the porous current collector 31 in the first direction X satisfy 5% ⁇ B/A ⁇ 10%.
  • the size of the portion 312 in the first direction X is smaller, so that the size of the main body portion 311 in the first direction X is larger, so that the pole piece 30 can have more active material capacity.
  • the porosity of the end portion 312 is less than the porosity of the main body portion 311 , which has a porosity of 95%.
  • the porosity of end 312 is 50-80%.
  • Porosity (1-(mass of porous material [g]/(volume of porous material [cm 3 ] ⁇ material density))) ⁇ 100[%].
  • the porosity of end 312 is 62.5-75%.
  • the porosity of end 312 may be 62.5%, 65%, 70%, 75%, etc.
  • the end portion 312 has an areal density of 300-500 g/m 2 .
  • the areal density of the end portion 312 meets the above range, so that the structure of the end portion 312 is dense and the strength and cutting performance of the end portion 312 are improved.
  • the areal density of the end portion 312 is 350-450 g/m 2 .
  • the areal density of the end portion 312 may be 350g/m 2 , 375g/m 2 , 400g/m 2 , 425g/m 2 , 450g/m 2 , etc.
  • Figure 6 is a schematic structural diagram of a porous current collector 31 provided by some embodiments of the present application
  • Figure 7 is a schematic structural diagram of a porous current collector 31 provided by other embodiments of the present application.
  • the main portion 311 has a first surface 3111 and a third surface 3112 that are oppositely arranged
  • the end portion 312 has a second surface 3121 and a fourth surface that are oppositely arranged.
  • 3122, the second surface 3121 and the fourth surface 3122 are both located between the plane where the first surface 3111 is located and the plane where the third surface 3112 is located.
  • the main part 311 and the end part 312 are integrally formed.
  • the second surface 3121 and the fourth surface 3122 are located between the plane where the first surface 3111 is located and the plane where the third surface 3112 is located.
  • the porous current collector 31 in the thickness direction Z are compressed to form the end portion 312 , which can reduce the stress concentration at the transition between the end portion 312 and the main body portion 311 and reduce the probability of the end portion 312 breaking.
  • the fourth surface 3122 may be coplanar with the third surface 3112 , that is, the end 312 is formed by rolling the porous current collector 31 from one side of the porous current collector 31 .
  • the porous current collector 31 also includes a transition portion 313, which connects the main body portion 311 and the end portion 312.
  • the thickness of the transition portion 313 is determined by One side gradually decreases toward the side connecting the end portion 312 .
  • the transition portion 313 is a portion of the porous current collector 31 used to connect the main body portion 311 and the end portion 312 so that the end portion 312 is roll-formed by the porous current collector 31 .
  • the transition part 313 connects the main part 311 and the end part 312, which facilitates the processing and shaping of the pole piece 30 and reduces the difficulty of processing.
  • the main part 311 has a first surface 3111
  • the end part 312 has a second surface 3121
  • the transition part 313 has a first transition surface 3131
  • the first transition surface 3131 Connecting the first surface 3111 and the second surface 3121, the first transition surface 3131 is an arc surface tangent to the second surface 3121.
  • the first transition surface 3131 is an arc surface tangent to the second surface 3121.
  • the first transition surface 3131 is tangent to the second surface 3121, which makes the processing mold structure simple and facilitates the preparation of the pole piece 30.
  • the radius of curvature of the first transition surface 3131 is R, satisfying 15mm ⁇ R ⁇ 25mm.
  • the cross section of the first transition surface 3131 along the thickness direction Z is an arc surface, and the curvature radius R of the first transition surface 3131 refers to the radius of the arc surface.
  • the curvature radius of the first transition surface 3131 meets the above range, which facilitates the processing of the pole piece 30 .
  • the main part 311 has a third surface 3112 arranged opposite to the first surface 3111
  • the end part 312 has a fourth surface 3122 arranged opposite to the second surface 3121
  • the transition part 313 has a second transition surface 3132 opposite to the first transition surface 3131.
  • the second transition surface 3132 connects the third surface 3112 and the fourth surface 3122.
  • the second transition surface 3132 is an arc surface tangent to the fourth surface 3122.
  • the second transition surface 3132 is an arc surface tangent to the fourth surface 3122.
  • the porous current collector 31 can be rolled from both sides in the thickness direction Z of the porous current collector 31. .
  • the second transition surface 3132 connects the third surface 3112 and the fourth surface 3122, and the second transition surface 3132 is tangent to the fourth surface 3122, which facilitates the manufacturing of the pole piece 30.
  • the second transition surface 3132 is symmetrically arranged with the first transition surface 3131 .
  • the second transition surface 3132 is arranged symmetrically with the first transition surface 3131.
  • the end portion 312 is located in the middle of the main body portion 311.
  • two identical pressure rollers can be used to roll the porous current collector 31 on both sides of the porous current collector 31 in the thickness direction Z to ensure that the force on the porous current collector 31 is balanced and convenient. Shaping of end 312.
  • the end portion 312 can be extruded by the porous current collector 31 on opposite sides to facilitate the processing of the pole piece 30 and ensure that the current distribution of the end portion 312 is concentrated.
  • the end portion 312, the transition portion 313 and the main body portion 311 are arranged along the first direction X, and the size of the transition portion 313 in the first direction X is C, satisfying 0.5mm ⁇ C ⁇ 2mm.
  • the end portion 312 , the transition portion 313 and the main body portion 311 are arranged along the first direction X.
  • the porous current collector 31 forms the end portion 312
  • the porous current collector 31 is rolled at one end of the porous current collector 31 in the first direction X.
  • the size of the transition portion 313 in the first direction X meets the above range, which facilitates the processing and shaping of the end portion 312 .
  • FIG. 8 is a schematic structural diagram of the pole piece 30 provided in other embodiments of the present application.
  • the pole piece 30 further includes an active material layer 32, and the active material layer 32 is disposed on the surface of the main body part 311.
  • the fact that the active material layer 32 is provided on the surface of the main body part 311 means that the active material layer 32 is provided on one or both sides of the main body part 311 in the thickness direction Z.
  • the active material layer 32 is disposed on the surface of the main body 311 so that the pole piece 30 has a larger active material capacity.
  • the porous current collector 31 is foam metal or metal mesh.
  • Foam metal can be copper foam, aluminum foam, nickel foam, copper-tin alloy foam, etc.
  • the metal mesh can be copper mesh, aluminum mesh, stainless steel mesh, etc.
  • the foam metal can be nickel foam or copper foam, which has high electronic conductivity and low density.
  • foam metal has better mechanical properties.
  • Lithium batteries that use foam metal as the current collector can be lithium-ion batteries.
  • the surface of the foam metal needs to be coated with active material.
  • the active material can be graphite, silicon, etc.
  • foam metal current collectors can also be used in lithium metal batteries.
  • foam copper current collectors can be used as negative electrode current collectors for lithium metal batteries.
  • the surface of the foam copper current collectors can be coated with active substances, or the copper foam current collectors can be directly used. Used as negative electrode.
  • the present application provides a battery cell 20.
  • the battery cell 20 includes a case assembly and an electrode assembly 23.
  • the case assembly includes an electrode lead-out portion; the electrode assembly 23 accommodates In the housing assembly, the electrode assembly 23 includes a first pole piece and a second pole piece with opposite polarities. At least one of the first pole piece and the second pole piece is the pole piece 30 provided by any of the above solutions.
  • the end portion 312 Electrically connected to the electrode lead-out part.
  • the housing assembly includes an end cover 21 and a housing 22. At least one of the end cover 21 and the housing 22 is provided with an electrode lead-out portion.
  • the end cap 21 refers to a component that covers the opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment.
  • the housing 22 is a component used to cooperate with the end cover 21 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 23 , electrolyte, and other components.
  • the electrode lead-out portion is a portion of the battery cell 20 used to draw out electric energy, and is used to achieve electrical connection between the battery cell 20 and other components (such as bus components, battery cells).
  • the electrode lead-out part may be the electrode terminal 21a, and the end part 312 may be electrically connected to the electrode terminal 21a through the adapter 24, or the end part 312 may be directly electrically connected to the electrode terminal 21a.
  • the electrode lead-out part may also be the case 22, and the end part 312 may be directly electrically connected to the case 22, or the end part 312 may be connected to the case 22 through an intermediate piece.
  • At least one of the first pole piece and the second pole piece is the above-mentioned pole piece 30, and the end 312 of the pole piece 30 has high mechanical strength to facilitate the implementation of the electrode assembly. Electrical connection to the electrode lead-out.
  • the present application provides a battery, which includes a box and a plurality of battery cells 20 provided in the above embodiments, and the plurality of battery cells 20 are accommodated in the box.
  • the present application provides an electrical device.
  • the electrical device includes the battery cell 20 provided in the above embodiment, and the battery cell 20 is used to provide electric energy.
  • the electrical device may be any of the above-mentioned devices or systems using the battery cell 20 .
  • the present application provides a pole piece 30.
  • the pole piece 30 includes a porous current collector 31.
  • the porous current collector 31 includes an integrally formed main body part 311 and a transition part 313. and the end portion 312, the unit area weight of the end portion 312 is greater than the unit area weight of the main body portion 311, the thickness of the end portion 312 is smaller than the thickness of the main body portion 311, the transition portion 313 connects the main body portion 311 and the end portion 312, the thickness of the transition portion 313 It gradually decreases from the side connecting the main body part 311 to the side connecting the end part 312.
  • the thickness of the end part 312 is D1 and satisfies 5 ⁇ m ⁇ D1 ⁇ 100 ⁇ m.
  • the end 312 of the porous current collector 31 is compressed, and the end has high mechanical strength.
  • the end 312 can be used as the tab 23a of the pole piece 30 to facilitate connection with other components (such as The electrode terminal 21a, the housing 22 or the adapter 24) are welded; at the same time, the thickness of the end 312 meets the above range. On the one hand, it meets the die-cutting requirements and facilitates processing. On the other hand, the current distribution of the end 312 is concentrated and circulates. Better performance.
  • Figure 9 shows a schematic flow chart of a pole piece manufacturing method 400 provided by some embodiments of the present application.
  • the manufacturing method 400 of the pole piece may include:
  • end portion 312 is located in the middle of the thickness direction of the main body portion 311 so that the forces on both sides of the thickness direction Z of the porous current collector 31 are balanced during rolling.
  • the preparation process is simple.
  • the prepared pole piece 30 meets the die-cutting requirements and is easy to process.
  • the current distribution at the end 312 is concentrated and the cycle performance is better.
  • FIG. 10 is a schematic diagram of a pole piece manufacturing equipment 500 provided by some embodiments of the present application.
  • the present application provides a pole piece manufacturing equipment 500.
  • the pole piece manufacturing equipment 500 includes at least a pair of pressure rollers 50, and a rolling space is formed between each pair of pressure rollers 50. Fluid 31 is contained within the rolling space.
  • Each pair of pressing rollers 50 is used to roll the end portion 312 of the porous current collector 31 on both sides of the thickness direction Z of the porous current collector 31 so that the thickness D1 of the end portion 312 satisfies 5 ⁇ m ⁇ D1 ⁇ 100 ⁇ m.
  • the end portion 312 is located in the middle of the thickness direction of the main body 311 so that the forces on both sides of the porous current collector 31 in the thickness direction Z are balanced during rolling.
  • the manufacturing method of the pole piece also includes a die-cutting process of die-cutting the end 312 of the compressed porous current collector 31 to cut out pole tabs 23a with good thickness and width consistency.
  • the copper foam raw material with a length of 200mm and a width of 100mm is pre-pressed into a 120 ⁇ m thick copper foam.
  • Embodiment 2 The difference between Embodiment 2 and Embodiment 1 is that the end portion 312 is compressed to a thickness of 10 ⁇ m.
  • Embodiment 3 The difference between Embodiment 3 and Embodiment 1 is that the end portion 312 is compressed to a thickness of 20 ⁇ m.
  • Embodiment 4 The difference between Embodiment 4 and Embodiment 1 is that the end portion 312 is compressed to a thickness of 50 ⁇ m.
  • Embodiment 5 The difference between Embodiment 5 and Embodiment 1 is that the end portion 312 is compressed to a thickness of 75 ⁇ m.
  • Embodiment 6 The difference between Embodiment 6 and Embodiment 1 is that the end portion 312 is compressed to a thickness of 100 ⁇ m.
  • the copper foam raw material with a length of 200 mm and a width of 100 mm is pre-pressed into a 120 ⁇ m thick copper foam, and then the tabs 23a are directly die-cut without rolling the end 312.
  • the width and length of the tabs 23a are the same as in Example 6. .
  • the copper foam raw material with a length of 200mm and a width of 100mm is pre-pressed into a 120 ⁇ m thick copper foam foil.
  • the thickness of the end of the copper foam current collector is pressed to 3 ⁇ m using the above manufacturing method of the pole piece, and the length of the compressed area is 8 mm. After compression, the pole tab 23a is easily broken, making it difficult to obtain data.
  • Tensile measurement The samples prepared in Examples 1-6 and Comparative Example 1 were measured by a tensile testing machine. The end of the pole piece opposite to the pole lug 23a was fixed, and the pole lug 23a was stretched to obtain the pull-off time. Displays the pulling force value.
  • Welding tensile test Test the welding strength of the pole tab 23a and the adapter 24 of the samples prepared in Examples 1-6 and Comparative Example 1.
  • the test method is: combine the pole tab 23a of Examples 1-6 and Comparative Document 1 with aluminum
  • the strip (adapter 24) is welded, and a tensile testing machine is used to test the welding tension between the aluminum strip and the tab 23a.
  • the tab 23a formed by rolling has higher tensile strength than the tab directly die-cut from foam metal, and its strength is also improved accordingly after welding with the adapter 24.
  • the thickness of the end is less than 5 ⁇ m, the end is easy to tear and has low mechanical strength and cannot be used as the tab 23a; when the thickness of the end is greater than 100 ⁇ m, the tensile strength of the end is low and it is welded to the adapter 24 Its strength is also lower afterwards.

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  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请实施例提供一种极片、电池单体、电池、用电设备及极片的制造方法。极片包括多孔集流体，所述多孔集流体包括一体成型的主体部和端部，所述端部的单位面积重量大于所述主体部的单位面积重量，所述端部的厚度小于所述主体部的厚度，所述端部的厚度为D1，满足5μm≤D1≤100μm。该极片，制造工艺较为简单，便于加工。

Description

极片、电池单体、电池、用电设备及极片的制造方法 技术领域
本申请涉及电池技术领域，特别是涉及一种极片、电池单体、电池、用电设备及极片的制造方法。
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。
极片是电池单体的重要组成部分。极片包括集流体，集流体采用多孔集流体时，由于多孔集流体的多孔结构，并且多孔集流体的机械强度较弱，导致多孔集流体无法焊接其他部件。
发明内容
本申请的目的在于提供一种极片、电池单体、电池、用电设备及极片的制造方法。该极片，端部具有较高的机械强度，能够与其他部件焊接。
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，包括多孔集流体，所述多孔集流体包括一体成型的主体部和端部，所述端部的单位面积重量大于所述主体部的单位面积重量，所述端部的厚度小于所述主体部的厚度，所述端部的厚度为D1，满足5μm≤D1≤100μm。
根据本申请实施例提供的极片，端部的单位面积重量大于主体部的单位面积重量、且端部的厚度小于主体部的厚度，端部可以为多孔集流体的压缩部位，机械强度高，能够作为极片的极耳，以便于与其他部件焊接；同时，端部的厚度满足上述范围，一方面，符合模切需求，便于加工，另一方面，端部的电流分布集中，循环性能较佳。
根据本申请的一些实施例，满足5μm≤D1≤50μm。
根据本申请的一些实施例，满足10μm≤D1≤20μm。
根据本申请的一些实施例，所述主体部的厚度为D2，满足10％≤D1/D2≤15％。
在上述方案中，在主体部的厚度一致的情况下，端部的厚度与主体部的厚度满足上述关系，端部具有较好的加工性能，并且保证端部的电流分布集中。
根据本申请的一些实施例，所述端部和所述主体部沿第一方向排列，所述端部在所述第一方向上的尺寸为B，满足5mm≤B≤20mm。
在上述方案中，端部在第一方向上的尺寸满足上述范围，使得端部能够与其他部件具有较大的连接面积。
根据本申请的一些实施例，满足6mm≤B≤9mm。
根据本申请的一些实施例，所述端部和所述主体部沿第一方向排列，所述多孔集流体在所述第一方向上的尺寸为A，所述端部在所述第一方向上的尺寸为B，满足5％≤B/A≤20％。
在上述方案中，在多孔集流体在第一方向上的尺寸恒定的情况下，端部在第一方向上的尺寸与多孔集流体在第一方向上的尺寸满足上述关系，一方面，端部与其他部件具有较大的连接面积，另一方面，保证主体部在第一方向上具有较大的尺寸，以使得多孔集流体具有较多的金属离子沉积位点。
根据本申请的一些实施例，满足5％≤B/A≤10％。
根据本申请的一些实施例，所述端部的孔隙率为50-80％。
根据本申请的一些实施例，所述端部的孔隙率为62.5-75％。
根据本申请的一些实施例，所述端部的面密度为300-500g/m 2。
在上述方案中，端部的面密度满足上述范围，使得端部的结构致密，提高端部的强度和切割性能。
根据本申请的一些实施例，所述端部的面密度为350-450g/m 2。
根据本申请的一些实施例，沿所述多孔集流体的厚度方向，所述主体部具有相对设置的第一表面和第三表面，所述端部具有相对设置的第二表面和第四表面，所述第二表面和所述第四表面均位于所述第一表面所在的平面和所述第三表面所在的平面之间。
在上述方案中，沿厚度方向，端部位于第一表面和第三表面之间，能够减少端部与主体部的过渡处的应力集中，减少端部断裂的概率。
根据本申请的一些实施例，所述多孔集流体还包括过渡部，所述过渡部连接所述主体部和所述端部，所述过渡部的厚度由连接所述主体部的一侧向连接所述端部的一侧逐渐减小。
在上述方案中，过渡部连接主体部和端部，便于加工成型，降低加工难度。
根据本申请的一些实施例，所述主体部具有第一表面，所述端部具有第二表面，所述过渡部具有第一过渡面，所述第一过渡面连接所述第一表面和所述第二表面，所述第一过渡面为与所述第二表面相切的弧面。
在上述方案中，第一过渡面与第二表面相切，使得加工模具结构简单，便于极片的制备。
根据本申请的一些实施例，所述第一过渡面的曲率半径为R，满足15mm≤R≤25mm。
在上述方案中，第一过渡面的曲率半径满足上述范围，便于极片的加工。
根据本申请的一些实施例，所述主体部具有与所述第一表面相对设置的第三表面，所述端部具有与所述第二表面相对设置的第四表面，所述过渡部具有与所述第一过渡面相对设置的第二过渡面，所述第二过渡面连接所述第三表面和所述第四表面，所述第二过渡面为与所述第四表面相切的弧面。
在上述方案中，第二过渡面连接第三表面和第四表面、且第二过渡面与第四表 面相切，便于实现极片的制造。
根据本申请的一些实施例，所述第二过渡面与所述第一过渡面对称设置。
在上述方案中，端部由多孔集流体在相对的两侧挤压成型，便于实现极片加工，保证端部的电流分布集中。
根据本申请的一些实施例，所述端部、所述过渡部和所述主体部沿第一方向排列，所述过渡部在所述第一方向上的尺寸为C，满足0.5mm≤C≤2mm。
在上述方案中，过渡部在第一方向上的尺寸满足上述范围，便于实现端部的加工成型。
根据本申请的一些实施例，所述极片还包括活性物质层，所述活性物质层设置于所述主体部的表面。
在上述方案中，活性物质层设置于主体部的表面，以使极片具有较多的活性物质容量。
根据本申请的一些实施例，所述多孔集流体为泡沫金属。
在上述方案中，泡沫金属具有较好的机械性能。
第二方面，本申请提供了一种电池单体，包括：壳体组件，包括电极引出部；电极组件，容纳于所述壳体组件内，所述电极组件包括极性相反的第一极片和第二极片，所述第一极片和所述第二极片中至少一者为上述实施例提供的极片，所述端部与所述电极引出部电连接。
根据本申请实施例的电池单体，第一极片和第二极片中至少一者为上述的极片，极片的端部具有较高的机械强度，以便于实现电极组件与电极引出部的电连接。
第三方面，本申请提供了一种电池，包括箱体和多个上述实施例提供的电池单体，多个所述电池单体容纳于所述箱体内。
第四方面，本申请提供了一种用电设备，包括上述实施例提供的电池单体，所述电池单体用于提供电能。
第五方面，本申请提供了一种极片的制造方法，包括：提供多孔集流体；从所述多孔集流体厚度方向上的两侧对所述多孔集流体的端部进行挤压，使所述端部的厚度被压缩至5-100μm。
根据本申请实施例的极片的制造方法，制备工艺简单，制备的极片的端部具有较高的机械强度，满足模切需求，便于加工，同时，端部的电流分布集中，循环性能较佳。
上述说明仅是本申请技术方案的概述，为了能够更清楚了解本申请的技术手段，而可依照说明书的内容予以实施，并且为了让本申请的上述和其它目的、特征和优点能够更明显易懂，以下特举本申请的具体实施方式。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施 例，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，还可以根据附图获得其他的附图。
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结构示意图；
图3为本申请一些实施例提供的电池单体的结构示意图；
图4为本申请一些实施例提供的极片的立体图；
图5为本申请一些实施例提供的极片的结构示意图；
图6为本申请一些实施例提供的多孔集流体的结构示意图；
图7为本申请另一些实施例提供的多孔集流体的结构示意图；
图8为本申请另一些实施例提供的极片的结构示意图；
图9示出了本申请一些实施例提供的极片的制造方法的示意性流程图；
图10为本申请一些实施例提供的极片的制造设备的简要示意图；
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-端盖；21a-电极端子；22-壳体；23-电极组件；23a-极耳；30-极片；31-多孔集流体；311-主体部；3111-第一表面；3112-第三表面；312-端部；3121-第二表面；3122-第四表面；313-过渡部；3131-第一过渡面；3132-第二过渡面；32-活性物质层；200-控制器；300-马达；1000-车辆。
具体实施方式
下面结合附图和实施例对本申请的实施方式作进一步详细描述。以下实施例的详细描述和附图用于示例性地说明本申请的原理，但不能用来限制本申请的范围，即本申请不限于所描述的实施例。
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。在本申请实施例的描述中，“多个”的含义是两个以上，除非另有明确具体的限定。
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“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：存在A，同时存在A和B，存 在B这三种情况。另外，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
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)。
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。
在本申请中，所提及的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。例如，本申请中所提及的电池可以包括电池模块或电池包等。
电池单体包括电极组件和电解液，电极组件由正极极片、负极极片和隔离膜组成。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，未涂敷正极活性物质层的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。一些实施例中，负极极片包括负极集流体，负极集流体的材料可以为铜，负极集流体不涂覆活性物质。一些实施例中，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，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。隔离膜的材质可以为PP(polypropylene，聚丙烯)或PE(polyethylene，聚乙烯)等。
现有技术中，集流体可以为多孔集流体，例如泡沫金属；多孔集流体具有较高的孔隙率，具有较多的金属离子沉积位点，尤其是在锂离子电池中，能够有效地抑制锂枝晶的生长和缓解体积变化，使其显著改善金属锂的沉积行为和电化学性能。但是，由于多孔集流体孔隙率较大，机械强度较低，不能直接将其他部件(例如，电极端子、壳体和转接件等)焊接到多孔集流体上。
鉴于此，本申请提供了一种极片，将多孔集流体的端部压缩后形成极耳，机械强度高，。同时，端部的厚度压缩至5μm≤D1≤100μm，一方面，符合模切需求，便于加工，另一方面，端部的电流分布集中，循环性能较佳。
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为本申请一些实施例提供的车辆1000的结构示意图。车辆1000可以为燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源，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为本申请一些实施例提供的电池100的结构示意图。电池100包括箱体10和电池单体20，电池单体20容纳于箱体10内。其中，箱体10用于为电池单体20提供容纳空间，箱体10可以采用多种结构。在一些实施例中，箱体10可以包括第一部分11和第二部分12，第一部分11与第二部分12相互盖合，第一部分11和第二部分12共同限定出用于容纳电池单体20的容纳空间。第二部分12可以为一端开口的空心结构，第一部分11可以为板状结构，第一部分11盖合于第二部分12的开口侧，以使第一部分11与第二部分12共同限定出容纳空间；第一部分11和第二部分12也可以是均为一侧开口的空心结构，第一部分11的开口侧盖合于第二部分12的开口侧。
在电池100中，电池单体20可以是多个，多个电池单体20之间可串联或并联或混联，混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起，再将多个电池单体20构成的整体容纳于箱体10内；当然，电池100也可以是多个电池单体20先串联或并联或混联组成电池模块形式，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体10内。电池100还可以包括其他结构，例如，该电池100还可以包括汇流部件，用于实现多个电池单体20之间的电连接。
其中，每个电池单体20可以为二次电池或一次电池；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20的结构示意图。电池单体20是指组成电池的最小单元。如图3，电池单体20包括有壳体组件、电极组件 23以及其他的功能性部件。壳体组件包括端盖21和壳体22，端盖21和壳体22中至少一者设置有电极引出部。
端盖21是指盖合于壳体22的开口处以将电池单体20的内部环境隔绝于外部环境的部件。不限地，端盖21的形状可以与壳体22的形状相适应以配合壳体22。可选地，端盖21可以由具有一定硬度和强度的材质(如铝合金)制成，这样，端盖21在受挤压碰撞时就不易发生形变，使电池单体20能够具备更高的结构强度，安全性能也可以有所提高。端盖21上可以设置有电极引出部(电极端子21a)，电极端子21a可以用于与电极组件23电连接，以用于输出或输入电池单体20的电能。在一些实施例中，端盖21上还可以设置有用于在电池单体20的内部压力或温度达到阈值时泄放内部压力的泄压机构。端盖21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，在端盖21的内侧还可以设置有绝缘件，绝缘件可以用于隔离壳体22内的电连接部件与端盖21，以降低短路的风险。示例性的，绝缘件可以是塑料、橡胶等。
壳体22是用于配合端盖21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23、电解液以及其他部件。壳体22和端盖21可以是独立的部件，可以于壳体22上设置开口，通过在开口处使端盖21盖合开口以形成电池单体20的内部环境。不限地，也可以使端盖21和壳体22一体化，具体地，端盖21和壳体22可以在其他部件入壳前先形成一个共同的连接面，当需要封装壳体22的内部时，再使端盖21盖合壳体22。壳体22可以是多种形状和多种尺寸的，例如长方体形、圆柱体形、六棱柱形等。具体地，壳体22的形状可以根据电极组件23的具体形状和尺寸大小来确定。壳体22的材质可以是多种，比如，铜、铁、铝、不锈钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。壳体22上可以设置有电极引出部，电极引出部用于与极耳电连接，以用于输出或输入电池单体20的电能。
电极组件23是电池单体100中发生电化学反应的部件。壳体22内可以包含一个或更多个电极组件23。电极组件23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的端部各自伸出极耳23a。正极极耳和负极极耳可以共同位于电极组件23的一端或是分别位于电极组件23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23a通过转接件24连接电极引出部以形成电流回路。
根据本申请的一些实施例，参照图4和图5，图4为本申请一些实施例提供的极片30的立体图，图5为本申请一些实施例提供的极片30的结构示意图。本申请提供了一种极片30。极片30包括多孔集流体31，多孔集流体31包括一体成型的主体部311和端部312，端部312的单位面积重量大于主体部311的单位面积重量，端部312的厚度小于主体部311的厚度，端部312的厚度为D1，满足5μm≤D1≤100μm。
多孔集流体31可以是金属导体，多孔集流体31为多孔结构，其可以是材质本身具有空隙形成的多孔结构，也可以是通过加工成型形成的多孔结构。
图中，字母Z所指示的方向为多孔集流体31的厚度方向，端部312的厚度D1 为端部312在厚度方向Z上的尺寸，主体部的厚度为主体部在厚度方向Z上的尺寸。
主体部311和端部312为多孔集流体31的组成部分，端部312为多孔集流体31的厚度较小的部位。
对于正极极片来说，主体部311是正极极片用于涂覆正极活性物质的部分。对于负极极片来说，主体部311是与正极极片的主体部311相对的部分；具体来说，在负极极片表面不涂活性物质时，主体部311是用于接收正极活性物质的金属离子的部分，在负极极片表面涂活性物质时，主体部311是负极极片用于涂覆负极活性物质的部分。
端部312位于主体部311的一端，例如，端部312和主体部311可以沿预设方向排列。
端部312的单位面积重量大于主体部311的单位面积重量、且端部312的厚度小于主体部311的厚度。端部312可以由多孔集流体31被压缩形成。
端部312的厚度D1满足5μm≤D1≤100μm时，端部312的厚度D1可以为5μm、10μm、20μm、30μm、40μm、50μm、60μm、70μm、75μm、80μm、90μm、100μm等
当端部312的厚度D1小于5μm时，端部312由多孔集流体31压缩形成时，端部312容易撕裂，使得端部312不符合模切需求，端部312无法作为极耳23a；当端部312的厚度D1大于100μm时，端部312的电流分布分散，循环性能较差。
根据本申请实施例的极片30，端部312可以为多孔集流体31的压缩部位，端部312具有较高的机械强度，端部312能够作为极片30的极耳23a，以便于与其他部件(如电极端子21a、壳体22或转接件24等)焊接实现电能输出；同时，端部312的厚度满足上述范围，一方面，符合模切需求，便于加工，另一方面，端部312的电流分布集中，循环性能较佳。
需要指出的是，端部312作为极片30的极耳23a，可以直接连接电极端子21a、壳体22或转接件24。
根据本申请的一些实施例，满足5μm≤D1≤50μm。
可选地，端部312的厚度D1可以为5μm、10μm、15μm、20μm、30μm、40μm、50μm等。
相对于端部312的厚度D1满足50μm＜D1≤100μm，端部312的厚度D1满足5μm≤D1≤50μm时，端部312的单位面积重量较大，机械强度较高。
根据本申请的一些实施例，满足10μm≤D1≤20μm。
相对于端部312的厚度D1满足5μm≤D1＜10μm，端部312的厚度D1满足10μm≤D1≤20μm时，端部312的单位面积重量较大，机械强度较高。
可选地，端部312的厚度D1可以为10μm、12μm、15μm、18μm、20μm等。
根据本申请的一些实施例，如图5所示，主体部311的厚度为D2，满足10％≤D1/D2≤15％。
如果D1/D2小于10％，则端部312的厚度D1较小，端部312的加工难度较大，端部312容易产生裂纹；如果D1/D2大于15％，则端部312的厚度D1较大，端 部312的电流分布较为分散，循环性能较差。
在上述方案中，在主体部311的厚度D1恒定的情况下，端部312的厚度与主体部311的厚度满足10％≤D1/D2≤15％，端部312具有较好的加工性能，并且保证端部312的电流分布集中。
根据本申请的一些实施例，如图5所示，端部312和主体部311沿第一方向X排列，端部312在第一方向X上的尺寸为B，满足5mm≤B≤20mm。
第一方向X与厚度方向Z垂直。
“端部312和主体部311沿第一方向X排列”是指，端部312位于主体部311在第一方向X的一侧。
如果端部312在第一方向X上的尺寸B小于5mm，则端部312与其他部件之间具有较小的连接面积，不利于端部312与其他部件的连接；如果端部312在第一方向X上的尺寸B大于20mm，在第一方向X上，端部312占有较大的尺寸，导致主体部311的尺寸较小，多孔集流体31具有较少的金属离子沉积点位，并且，主体部311作为活性物质的附着部位，主体部311的尺寸较小，使得极片30的活性物质容量较少，使得电池单体的能量密度较低。
在上述方案中，端部312在第一方向X上的尺寸B满足5mm≤B≤20mm，使得端部312能够与其他部件具有较大的连接面积，并且保证极片30能够具有较高的承载活性物质容量。
根据本申请的一些实施例，满足6mm≤B≤9mm。
相对于端部312在第一方向X上的尺寸B满足5mm≤B≤20m，端部312在第一方向X上的尺寸B满足6mm≤B≤9mm，既能保证端部312与其他部件具有较大的连接面积，还能够保证主体部311在第一方向X上具有较大的尺寸，保证极片30能够具有较高的活性物质容量。
可选地，第一方向X上的尺寸B可以为6mm、7mm、8mm、9mm等。
根据本申请的一些实施例，如图5所示，端部312和主体部311沿第一方向X排列，多孔集流体31在第一方向X上的尺寸为A，端部312在第一方向X上的尺寸为B，满足5％≤B/A≤20％。
在多孔集流体31在第一方向X上的尺寸A恒定的情况下，如果B/A小于5％，则端部312在第一方向X上的尺寸较小，端部312与其他部件的连接面积较小；如果B/A大于20％，则端部312在第一方向X的尺寸较大，对应地，主体部311在第一方向X上的尺寸较小，而主体部311为极片30的设置活性物质的部分，使得极片30的活性物质的容量减小，影响电池单体20的能量密度。
在上述方案中，端部312在第一方向X上的尺寸B与多孔集流体31在第一方向X上的尺寸A满足5％≤B/A≤20％，一方面，端部312与其他部件具有较大的连接面积，另一方面，保证主体部311在第一方向X上具有较大的尺寸，以使得多孔集流体31具有较多的金属离子沉积位点，同时主体部311能够附着较多的活性物质，极片30能够具有较多的活性物质容量，电池单体20的能量密度较高。
根据本申请的一些实施例，满足5％≤B/A≤10％。
相对于5％≤B/A≤20％，端部312在第一方向X上的尺寸B与多孔集流体31在第一方向X上的尺寸A满足5％≤B/A≤10％，端部312在第一方向X上的尺寸较小，使得主体部311在第一方向X上的尺寸较大，以使极片30能够具有较多的活性物质容量。
根据本申请的一些实施例，端部312的孔隙率小于主体部311的孔隙率，主体部311的孔隙率为95％。
根据本申请的一些实施例，端部312的孔隙率为50-80％。
孔隙率＝(1-(多孔材料的质量[g]/(多孔材料的体积[cm 3]×材料密度)))×100[％]。
根据本申请的一些实施例，端部312的孔隙率为62.5-75％。
可选地，端部312的孔隙率可以为62.5％、65％、70％、75％等。
根据本申请的一些实施例，端部312的面密度为300-500g/m 2。
面密度ρ A可以由公式ρ A＝ρ V L＝mL/V得知，其中，ρ V为材料的体积密度，L为材料长度，m为材料质量，V为材料体积。
在上述方案中，端部312的面密度满足上述范围，使得端部312的结构致密，提高端部312的强度和切割性能。
根据本申请的一些实施例，端部312的面密度为350-450g/m 2。
可选地，端部312的面密度可以为350g/m 2、375g/m 2、400g/m 2、425g/m 2、450g/m 2等。
请参照图6和图7，图6为本申请一些实施例提供的多孔集流体31的结构示意图，图7为本申请另一些实施例提供的多孔集流体31的结构示意图。根据本申请的一些实施例，沿多孔集流体31的厚度方向Z，主体部311具有相对设置的第一表面3111和第三表面3112，端部312具有相对设置的第二表面3121和第四表面3122，第二表面3121和第四表面3122均位于第一表面3111所在的平面和第三表面3112所在的平面之间。
主体部311和端部312一体成型，在厚度方向Z上，第二表面3121和第四表面3122均位于第一表面3111所在的平面和第三表面3112所在的平面之间，换句话说，从多孔集流体31的厚度方向Z的两侧压缩多孔集流体31形成端部312，能够减少端部312与主体部311的过渡处的应力集中，减少端部312断裂的概率。
在一些实施例中，如图6所示，第四表面3122可以与第三表面3112共面，也即，从多孔集流体31的一侧辊压多孔集流体31形成端部312。
根据本申请的一些实施例，如图6和图7所示，多孔集流体31还包括过渡部313，过渡部313连接主体部311和端部312，过渡部313的厚度由连接主体部311的一侧向连接端部312的一侧逐渐减小。
过渡部313为多孔集流体31的用于连接主体部311和端部312的部位，以便于端部312由多孔集流体31辊压成型。
在上述方案中，过渡部313连接主体部311和端部312，便于极片30加工成型，降低加工难度。
根据本申请的一些实施例，如图6和图7所示，主体部311具有第一表面3111，端部312具有第二表面3121，过渡部313具有第一过渡面3131，第一过渡面3131连接第一表面3111和第二表面3121，第一过渡面3131为与第二表面3121相切的弧面。
第一过渡面3131为与第二表面3121相切的弧面，在多孔集流体31辊压成型端部312时，辊压多孔集流体31的模具可以压辊。
在上述方案中，第一过渡面3131与第二表面3121相切，使得加工模具结构简单，便于极片30的制备。
根据本申请的一些实施例，如图5所示，第一过渡面3131的曲率半径为R，满足15mm≤R≤25mm。
第一过渡面3131的沿厚度方向Z的截面为弧面，第一过渡面3131的曲率半径R是指该弧面的半径。
在上述方案中，第一过渡面3131的曲率半径满足上述范围，便于极片30的加工。
根据本申请的一些实施例，如图7所示，主体部311具有与第一表面3111相对设置的第三表面3112，端部312具有与第二表面3121相对设置的第四表面3122，过渡部313具有与第一过渡面3131相对设置的第二过渡面3132，第二过渡面3132连接第三表面3112和第四表面3122，第二过渡面3132为与第四表面3122相切的弧面。
第二过渡面3132为与第四表面3122相切的弧面，在多孔集流体31辊压成型端部312时，可以从多孔集流体31的厚度方向Z的两侧对多孔集流体31辊压。
在上述方案中，第二过渡面3132连接第三表面3112和第四表面3122、且第二过渡面3132与第四表面3122相切，便于实现极片30的制造。
根据本申请的一些实施例，如图7所示，第二过渡面3132与第一过渡面3131对称设置。
第二过渡面3132与第一过渡面3131对称设置，换句话说，沿厚度方向Z，端部312位于主体部311的中部。在多孔集流体31辊压成型端部312时，可以使用两个相同的压辊在多孔集流体31的厚度方向Z的两侧辊压多孔集流体31，保证多孔集流体31受力均衡，便于端部312的成型。
在上述方案中，端部312可以由多孔集流体31在相对的两侧挤压成型，便于实现极片30加工，保证端部312的电流分布集中。
根据本申请的一些实施例，如图5所示，端部312、过渡部313和主体部311沿第一方向X排列，过渡部313在第一方向X上的尺寸为C，满足0.5mm≤C≤2mm。
端部312、过渡部313和主体部311沿第一方向X排列，在多孔集流体31成型端部312时，在多孔集流体31的第一方向X的一端辊压多孔集流体31。
在上述方案中，过渡部313在第一方向X上的尺寸满足上述范围，便于实现端部312的加工成型。
请参照图8，图8为本申请另一些实施例提供的极片30的结构示意图。根据 本申请的一些实施例，极片30还包括活性物质层32，活性物质层32设置于主体部311的表面。
活性物质层32设置于主体部311的表面，是指活性物质层32设置于主体部311的厚度方向Z的一侧或两侧。
在上述方案中，活性物质层32设置于主体部311的表面，以使极片30具有较多的活性物质容量。
根据本申请的一些实施例，多孔集流体31为泡沫金属、金属网。
泡沫金属可以为泡沫铜、泡沫铝、泡沫镍、泡沫铜锡合金等。金属网可以为铜网、铝网、不锈钢网等。
可选地，泡沫金属可以为泡沫镍或泡沫铜，具有较高的电子电导率，密度较小。
在上述方案中，泡沫金属具有较好的机械性能。
使用泡沫金属作为集流体的锂电池可以为锂离子电池，此时，泡沫金属的表面需涂布活性物质，如负极集流体使用泡沫铜时，活性物质可以为石墨、硅等。同时，泡沫金属集流体还可以运用于锂金属电池，如泡沫铜集流体作为锂金属电池的负极集流体，此时，泡沫铜集流体的表面可以涂布活性物质，也可以泡沫铜集流体直接作为负极使用。
根据本申请的一些实施例，请参照图3，本申请提供了一种电池单体20，该电池单体20包括壳体组件和电极组件23，壳体组件包括电极引出部；电极组件23容纳于壳体组件内，电极组件23包括极性相反的第一极片和第二极片，第一极片和第二极片中至少一者为上述任意方案提供的极片30，端部312与电极引出部电连接。
壳体组件包括端盖21和壳体22，端盖21和壳体22中至少一者设置有电极引出部。端盖21是指盖合于壳体22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。壳体22是用于配合端盖21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23、电解液以及其他部件。
电极引出部为电池单体20的用于将电能引出的部位，用于实现该电池单体20与其他部件(如汇流构件、电池单体)的电连接。
电极引出部可以为电极端子21a，端部312可以通过转接件24与电极端子21a电连接，端部312也可以直接与电极端子21a电连接。电极引出部也可以为壳体22，端部312可以直接与壳体22电连接，端部312也可以通过中间件与壳体22连接。
根据本申请实施例的电池单体20，第一极片和第二极片中至少一者为上述的极片30，极片30的端部312具有较高的机械强度，以便于实现电极组件与电极引出部的电连接。
根据本申请的一些实施例，本申请提供了一种电池，该电池包括箱体和多个上述实施例提供的电池单体20，多个电池单体20容纳于箱体内。
根据本申请的一些实施例，本申请提供了一种用电设备，该用电设备包括上述实施例提供的电池单体20，电池单体20用于提供电能。
用电设备可以为上述任一应用电池单体20的设备或系统。
根据本申请的一些实施例，参见图4至图8，本申请提供了一种极片30，该极片30包括多孔集流体31，多孔集流体31包括一体成型的主体部311、过渡部313和端部312，端部312的单位面积重量大于主体部311的单位面积重量，端部312的厚度小于主体部311的厚度，过渡部313连接主体部311和端部312，过渡部313的厚度由连接主体部311的一侧向连接端部312的一侧逐渐减小，端部312的厚度为D1，满足5μm≤D1≤100μm。
根据本申请实施例的极片30，多孔集流体31的端部312被压缩，端部具有较高的机械强度，端部312能够作为极片30的极耳23a，以便于与其他部件(如电极端子21a、壳体22或转接件24)焊接；同时，端部312的厚度满足上述范围，一方面，符合模切需求，便于加工，另一方面，端部312的电流分布集中，循环性能较佳。
图9示出了本申请一些实施例提供的极片的制造方法400的示意性流程图。如图9所示，该极片的制造方法400可以包括：
401，提供多孔集流体31；
402，从多孔集流体31厚度方向Z上的两侧对多孔集流体31的端部312进行挤压，使端部312的厚度被压缩至5-100μm。
需要指出的是，端部312位于主体部311的厚度方向的中间，以使多孔集流体31在辊压时厚度方向Z的两侧受力均衡。
根据本申请实施例的极片的制造方法400，制备工艺简单，制备的极片30满足模切需求，便于加工，同时，端部312的电流分布集中，循环性能较佳。
请参见图10，图10为本申请一些实施例提供的极片的制造设备500的简要示意图。根据本申请的一些实施例，本申请提供了一种极片的制造设备500，该极片的制造设备500包括至少一对压辊50，每对压辊50之间形成辊压空间，多孔集流体31被容纳于辊压空间内。每对压辊50用于在多孔集流体31的厚度方向Z的两侧辊压多孔集流体31的端部312，以使端部312的厚度D1满足5μm≤D1≤100μm。
如图10所示，多孔集流体31辊压后，端部312位于主体部311的厚度方向的中间，以使多孔集流体31在辊压时厚度方向Z的两侧受力均衡。
根据本申请的一些实施例，极片的制造方法还包括模切工序，对压缩后的多孔集流体31的端部312进行模切，切出厚度、宽度一致性较好的极耳23a。
接下来参照下面的示例更详细地描述一个或多个实施例。当然，这些示例并不限制一个或多个实施例的范围。
实施例1
以泡沫铜金属集流体为例进行介绍，将长度为200mm，宽度为100mm的泡沫铜原材料预压至120μm厚的泡沫铜。以上述极片的制造方法将泡沫铜集流体的端部312辊压至5μm厚，且压缩区域长度为8mm，压缩之后，将端部312进行模切，切出极耳23a，即得泡沫金属极片。
实施例2
实施例2与实施例1的区别在于，端部312被压缩至10μm厚。
实施例3
实施3与实施例1的区别在于，端部312被压缩至20μm厚。
实施例4
实施例4与实施例1的区别在于，端部312被压缩至50μm厚。
实施例5
实施例5与实施例1的区别在于，端部312被压缩至75μm厚。
实施例6
实施例6与实施例1的区别在于，端部312被压缩至100μm厚。
对比例1
将长度为200mm，宽度为100mm的泡沫铜原材料预压至120μm厚的泡沫铜，然后直接模切出极耳23a，不对端部312进行辊压，极耳23a的宽度和长度与实施例6相同。
对比例2
将长度为200mm，宽度为100mm的泡沫铜原材料预压至120μm厚的泡沫铜箔。以上述极片的制造方法将泡沫铜集流体的端部的厚度压至3μm，且压缩区域长度为8mm，压缩之后极耳23a易破裂，难以得到数据。
测试方法
拉伸测量：将实施例1-6和对比例1制备得到的样品通过拉力试验机进行测量，将极片的与极耳23a相对的一端固定，对极耳23a进行拉伸，得到拉断时显示拉力数值。
焊接拉力测试：测试实施例1-6和对比例1制备得到的样品的极耳23a与转接件24焊接强度，测试方法为：将实施例1-6及对比文件1的极耳23a与铝带(转接件24)进行焊接，利用拉力试验机测试铝带与极耳23a间的焊接拉力。
其中，实施例1至实施例6以及对比例1所涉及实验参数及测试结果请参见表1。
表1
序号 端部厚度/μm 拉力/N 焊接拉力/N
实施例1 5 17 20
实施例2 10 21 25
实施例3 20 19 18
实施例4 50 16 17
实施例5 75 14 16
实施例6 100 11 13
对比例1 120 8 10
由表1可知，通过辊压方式形成的极耳23a相比泡沫金属直接模切出的极耳的抗拉强度更高，与转接件24焊接后其强度也得到相应改善。当端部的厚度小于5μ m时，端部容易撕裂，机械强度低，无法作为极耳23a；当端部的厚度大于100μm时，端部的抗拉强度较低，与转接件24焊接后其强度也较低。
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 (25)

  1. 一种极片，包括多孔集流体，所述多孔集流体包括一体成型的主体部和端部，所述端部的单位体积重量大于所述主体部的单位体积重量，所述端部的厚度小于所述主体部的厚度，所述端部的厚度为D1，满足5μm≤D1≤100μm。
  2. 根据权利要求1所述的极片，其中，满足5μm≤D1≤50μm。
  3. 根据权利要求1或2所述的极片，其中，满足10μm≤D1≤20μm。
  4. 根据权利要求1-3中任一项所述的极片，其中，所述主体部的厚度为D2，满足10％≤D1/D2≤15％。
  5. 根据权利要求1-4中任一项所述的极片，其中，所述端部和所述主体部沿第一方向排列，所述端部在所述第一方向上的尺寸为B，满足5mm≤B≤20mm。
  6. 根据权利要求5所述的极片，其中，满足6mm≤B≤9mm。
  7. 根据权利要求1-6中任一项所述的极片，其中，所述端部和所述主体部沿第一方向排列，所述多孔集流体在所述第一方向上的尺寸为A，所述端部在所述第一方向上的尺寸为B，满足5％≤B/A≤20％。
  8. 根据权利要求7所述的极片，其中，满足5％≤B/A≤10％。
  9. 根据权利要求1-8中任一项所述的极片，其中，所述端部的孔隙率为50-80％。
  10. 根据权利要求9所述的极片，其中，所述端部的孔隙率为62.5-75％。
  11. 根据权利要求1-10中任一项所述的极片，其中，所述端部的面密度为300-500g/m 2。
  12. 根据权利要求11所述的极片，其中，所述端部的面密度为350-450g/m 2。
  13. 根据权利要求1-12中任一项所述的极片，其中，沿所述多孔集流体的厚度方向，所述主体部具有相对设置的第一表面和第三表面，所述端部具有相对设置的第二表面和第四表面，所述第二表面和所述第四表面均位于所述第一表面所在的平面和所述第三表面所在的平面之间。
  14. 根据权利要求1-13中任一项所述的极片，其中，所述多孔集流体还包括过渡部，所述过渡部连接所述主体部和所述端部，所述过渡部的厚度由连接所述主体部的一侧向连接所述端部的一侧逐渐减小。
  15. 根据权利要求14所述的极片，其中，所述主体部具有第一表面，所述端部具有第二表面，所述过渡部具有第一过渡面，所述第一过渡面连接所述第一表面和所述第二表面，所述第一过渡面为与所述第二表面相切的弧面。
  16. 根据权利要求15所述的极片，其中，所述第一过渡面的曲率半径为R，满足15mm≤R≤25mm。
  17. 根据权利要求15或16所述的极片，其中，所述主体部具有与所述第一表面相对设置的第三表面，所述端部具有与所述第二表面相对设置的第四表面，所述过渡部具有与所述第一过渡面相对设置的第二过渡面，所述第二过渡面连接所述第三表面和所述第四表面，所述第二过渡面为与所述第四表面相切的弧面。
  18. 根据权利要求17所述的极片，其中，所述第二过渡面与所述第一过渡面对称设置。
  19. 根据权利要求14所述的极片，其中，所述端部、所述过渡部和所述主体部沿第一方向排列，所述过渡部在所述第一方向上的尺寸为C，满足0.5mm≤C≤2mm。
  20. 根据权利要求1-19中任一项所述的极片，其中，所述极片还包括活性物质层，所述活性物质层设置于所述主体部的表面。
  21. 根据权利要求1-20中任一项所述的极片，其中，所述多孔集流体为泡沫金属。
  22. 一种电池单体，包括：
    壳体组件，包括电极引出部；
    电极组件，容纳于所述壳体组件内，所述电极组件包括极性相反的第一极片和第二极片，所述第一极片和所述第二极片中至少一者为如权利要求1-21中任一项所述的极片，所述端部与所述电极引出部电连接。
  23. 一种电池，包括箱体和多个如权利要求22所述的电池单体，多个所述电池单体容纳于所述箱体内。
  24. 一种用电设备，包括如权利要求22所述的电池单体，所述电池单体用于提供电能。
  25. 一种极片的制造方法，包括：
    提供多孔集流体；
    从所述多孔集流体厚度方向上的两侧对所述多孔集流体的端部进行挤压，使所述端部的厚度被压缩至5～100μm。
PCT/CN2022/094185 2022-05-20 2022-05-20 极片、电池单体、电池、用电设备及极片的制造方法 WO2023221109A1 (zh)

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JP2015222685A (ja) * 2014-05-23 2015-12-10 トヨタ自動車株式会社 二次電池用の電極
CN110061182A (zh) * 2019-05-21 2019-07-26 宁德新能源科技有限公司 电池极片及电芯
CN113224261A (zh) * 2021-04-30 2021-08-06 珠海冠宇电池股份有限公司 极片和电池
CN108713271B (zh) * 2016-06-27 2021-09-21 宁德时代新能源科技股份有限公司 电芯以及使用此电芯的电池

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CN108713271B (zh) * 2016-06-27 2021-09-21 宁德时代新能源科技股份有限公司 电芯以及使用此电芯的电池
CN110061182A (zh) * 2019-05-21 2019-07-26 宁德新能源科技有限公司 电池极片及电芯
CN113224261A (zh) * 2021-04-30 2021-08-06 珠海冠宇电池股份有限公司 极片和电池

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Publication number Priority date Publication date Assignee Title
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
CN117637990B (zh) * 2024-01-26 2024-04-26 宁德新能源科技有限公司 极片、电极组件及电池

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