WO2023221606A1 - 集流体、极片、电极组件、电池单体、电池及用电装置 - Google Patents

集流体、极片、电极组件、电池单体、电池及用电装置 Download PDF

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Publication number
WO2023221606A1
WO2023221606A1 PCT/CN2023/080133 CN2023080133W WO2023221606A1 WO 2023221606 A1 WO2023221606 A1 WO 2023221606A1 CN 2023080133 W CN2023080133 W CN 2023080133W WO 2023221606 A1 WO2023221606 A1 WO 2023221606A1
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WO
WIPO (PCT)
Prior art keywords
current collector
active material
material layer
body part
battery
Prior art date
Application number
PCT/CN2023/080133
Other languages
English (en)
French (fr)
Inventor
郭锁刚
付成华
叶永煌
常雯
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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Publication of WO2023221606A1 publication Critical patent/WO2023221606A1/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
    • H01M4/04—Processes of manufacture in general
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/043—Processes of manufacture in general involving compressing or compaction
    • H01M4/0435—Rolling or calendering
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • 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 current collector, a pole piece, an electrode assembly, a battery cell, a battery and an electrical device.
  • Embodiments of the present application provide a current collector, pole pieces, electrode components, battery cells, batteries and electrical devices, which can effectively improve the energy density and performance of the battery.
  • embodiments of the present application provide a current collector, including a body part and a reinforcing protrusion; along the thickness direction of the current collector, the body part has two coating surfaces oppositely arranged; the reinforcing protrusion Projecting on at least one of the two coating surfaces.
  • the current collector with this structure can increase the contact area between the active material layer of the pole piece and the current collector, which on the one hand is conducive to improving the bonding strength between the current collector and the active material layer to reduce the polarity.
  • the active material layer falling off during use of the sheet.
  • strengthening the protrusions can also increase the structural strength of the current collector itself and reduce the minimum thickness requirement of the current collector, so that while ensuring the structural strength of the current collector, for pole pieces with the same overall thickness, having this structure
  • the pole piece of the current collector can effectively increase the capacity of the active material layer and improve the ability of the pole piece to preserve the electrolyte, thereby helping to improve the energy density and performance of the battery cell.
  • the maximum size of the current collector is D 1
  • the minimum thickness of the body part is D 2 , satisfying D 1 -D 2 ⁇ 0.5 ⁇ m.
  • the current collector of this structure has a smaller equivalent thickness, so that when the current collector is provided with The side of the reinforced bulge has more space to accommodate the active material layer, thereby being able to accommodate more active material layers, thereby effectively increasing the capacity of the active material layer of the pole piece while ensuring the structural strength of the current collector. , which is conducive to improving the energy density of pole pieces with such current collectors.
  • the thickness of the body part is D 4 , satisfying 0.5 ⁇ m ⁇ D 4 ⁇ 10 ⁇ m.
  • the thickness of the body part between 0.5 ⁇ m and 10 ⁇ m, on the one hand, the risk of breakage of the current collector during use due to the too small thickness of the body part can be reduced, and on the other hand, the risk of the current collector being broken due to the body part being too small can be reduced.
  • the thickness of the part is too large, causing the current collector to take up too much space and take up too much weight.
  • the area of the end surface of the end of the reinforcing protrusion away from the body part is S 2
  • the area of the coating surface is S 1 , satisfying, 0.1 ⁇ (S 2 ⁇ n)/S 1 ⁇ 0.9; where n is the number of the reinforcing protrusions on the coated surface.
  • the reinforcing protrusions are strip structures extending along a straight trajectory, and the extending direction of the reinforcing protrusions is perpendicular to the thickness direction of the current collector.
  • the reinforcing protrusions of this structure are conducive to improving the mechanical strength and mechanical strength of the current collector. Structural strength.
  • the elongation at break of the current collector satisfies, 1.1% ⁇ e ⁇ 8%.
  • the breaking elongation of the current collector is set at 1.1% to 8% to ensure the mechanical strength of the current collector, thereby reducing the phenomenon of breakage or damage of the current collector during use, which is beneficial to improving the performance of the current collector.
  • the service life of the current collector is set at 1.1% to 8% to ensure the mechanical strength of the current collector, thereby reducing the phenomenon of breakage or damage of the current collector during use, which is beneficial to improving the performance of the current collector.
  • the coating surface is protruded with a plurality of the reinforcing protrusions.
  • the structural strength of the current collector can be further improved, which is beneficial to increasing the service life of the current collector, and on the other hand, the current collector can be further improved.
  • the contact area with the active material layer is conducive to reducing the contact resistance between the current collector and the active material layer, and is conducive to improving the connection stability between the current collector and the active material layer.
  • both of the coated surfaces are provided with the reinforcing protrusions.
  • reinforcing protrusions are provided on both coating surfaces of the body part, that is to say, reinforcing protrusions are protruded on both sides of the body part in the thickness direction of the current collector, so that on the one hand, there are It is conducive to further increasing the overall structural strength of the current collector. On the other hand, it can increase the contact area between both sides of the current collector and the active material layer, and can increase the capacity of the active material layers on both sides of the current collector, which is beneficial to improving the characteristics of the current collector. The overall performance of the pole piece of the current collector with this structure.
  • embodiments of the present application further provide a pole piece, including an active material layer and the above-mentioned current collector; the active material layer is coated on the coating surface.
  • the pole piece of this structure can effectively increase the contact area between the current collector and the active material layer, which is beneficial to improving the bonding strength and connection stability between the current collector and the active material layer, and has It is beneficial to reduce the contact resistance between the current collector and the active material layer.
  • it can effectively increase the capacity of the active material layer of the pole piece, and can improve the ability of the pole piece to preserve the electrolyte, thereby helping to increase the energy of the pole piece. Density to improve the performance of the pole pieces.
  • the body portion has a weak area and the active material layer covers the weak area.
  • a weak area is provided on the main body, and the weak area is covered with an active material layer, so that the weak area can play a certain role in preserving the electrolyte, which is beneficial to improving the preservation of the electrolyte by the electrode piece. ability to improve the performance of the pole piece.
  • embodiments of the present application further provide an electrode assembly, including the above-mentioned pole piece.
  • embodiments of the present application further provide a battery cell, including a casing and the above-mentioned electrode assembly; the electrode assembly is accommodated in the casing.
  • embodiments of the present application further provide a battery including a plurality of the above battery cells.
  • embodiments of the present application further provide an electrical device, including the above-mentioned battery.
  • embodiments of the present application also provide a method for manufacturing a pole piece, including: providing a current collector, the current collector includes a body part and a reinforcing protrusion, and along the thickness direction of the current collector, the body part has There are two opposite coating surfaces, and the reinforcing protrusions are protruding from at least one of the two coating surfaces; an active material layer is coated on the coating surfaces.
  • the manufacturing method of the pole piece further includes: cold pressing the active material layer to remove the active material layer.
  • the body part is partially pressed into the body part, and the body part forms a weak area at the position where the active material layer is partially pressed into.
  • 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 the structure of a battery provided by some embodiments of the present application.
  • Figure 3 is an exploded view of the structure of a battery cell provided by some embodiments of the present application.
  • Figure 4 is a cross-sectional view of an electrode assembly provided by some embodiments of the present application.
  • Figure 5 is a partial structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 6 is a top view of a current collector provided by some embodiments of the present application.
  • Figure 7 is a partial cross-sectional view of a current collector provided by some embodiments of the present application.
  • Figure 8 is a top view of a current collector provided by some embodiments of the present application.
  • Figure 9 is a top view of a current collector provided by some further embodiments of the present application.
  • Figure 10 is a partial cross-sectional view of a current collector provided by some further embodiments of the present application.
  • Figure 11 is a top view of a current collector provided by other embodiments of the present application.
  • Figure 12 is a cross-sectional view of a current collector provided by some embodiments of the present application in other embodiments;
  • Figure 13 is a schematic flowchart of the manufacturing method of the pole piece provided by some embodiments of the present application.
  • Icon 1000-vehicle; 100-battery; 10-box; 11-first box body; 12-second box body; 20-battery cell; 21-outer shell; 211-casing; 2111-opening; 212- End cap; 22-electrode assembly; 221-pole piece; 2211-current collector; 2211a-body part; 2211b-reinforcement protrusion; 2211c-coated surface; 2212-active material layer; 222-isolation film; 23-positive electrode Terminal; 24-negative electrode terminal; 25-pressure relief mechanism; 200-controller; 300-motor; X-thickness direction of current collector; Y-length direction of current collector; Z-width direction of current collector.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
  • connection should be understood in a broad sense.
  • connection can be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • connection can be a fixed connection
  • connection can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • connection can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • “Plural” appearing in this application means two or more (including two).
  • the battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium-sulfur batteries, sodium lithium ion batteries, sodium ion batteries or magnesium ion batteries, etc., which are not limited in the embodiments of this application.
  • the battery cell may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes, and the embodiments of the present application are not limited to this.
  • Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application are not limited to this.
  • the battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack.
  • Batteries generally include a box for packaging one or more battery cells or multiple battery modules. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • the battery cell includes a casing, an electrode assembly and an electrolyte.
  • the casing is used to accommodate the electrode assembly and the electrolyte.
  • the electrode assembly consists of a positive electrode piece, a negative electrode piece and an isolation film. 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 part of the positive electrode current collector that is not coated with the positive electrode active material layer serves as a positive electrode tab to realize the operation through the positive electrode tab.
  • the electrical energy input or output of the positive pole piece is a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate.
  • 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 part of the negative electrode current collector that is not coated with the negative electrode active material layer serves as a negative electrode tab to realize the realization of 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. In order to ensure that large currents can pass through without melting, 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 isolation film can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the electrode assembly may have a rolled structure or a laminated structure, and the embodiments of the present application are not limited thereto.
  • Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and small self-discharge coefficient. They are an important part of the development of new energy today.
  • the battery cell is composed of a positive electrode plate, a negative electrode plate and a separator film which are assembled into an electrode assembly (bare cell) by winding or laminating, and then put into the case, then covered with an end cap, and finally injected with electrolyte. obtained later.
  • higher requirements have been put forward for the energy density and performance of batteries.
  • the electrode assembly is composed of two pole pieces with opposite polarities (positive pole piece and negative pole piece) and an isolation film.
  • the pole piece is composed of a current collector and a current collector coated on the current collector. consists of a layer of active material on the surface.
  • current collectors are usually made of metal conductive materials such as copper foil and aluminum foil, which have a high density and have a great impact on the quality of the electrode assembly.
  • the current collector does not have a flat sheet structure on both sides. If it is necessary to ensure To increase the strength of the current collector, it is necessary to increase the thickness of the current collector.
  • the contact area between the active material layer of the pole piece and the current collector is small, and the contact resistance is large, and The bonding strength is low, and there is a risk that the active material layer will fall off easily.
  • the above problems lead to high capacity density and poor performance of the electrode assembly.
  • the current collector is improved by providing a rough conductive coating on the surface of the current collector to increase the contact area between the current collector and the active material layer.
  • this kind of current collector improves the bonding strength of the active material layer and reduces the contact resistance between the two
  • the current collector with this structure has the risk of easy detachment of the conductive coating during use, resulting in The active material layer is very easy to fall off, which is not conducive to improving the cycle life of the battery cell.
  • it is easy to increase the thickness of the current collector resulting in a larger space occupied by the current collector, which is not conducive to improving the energy density of the battery cell.
  • the structural strength of the current collector cannot be effectively improved, which leads to poor performance of the battery cells and is not conducive to reducing the production cost of the battery cells.
  • the inventor has designed a current collector after in-depth research, including a body part and reinforcing protrusions along the thickness direction of the current collector.
  • the body part has two oppositely arranged coating surfaces, and the reinforcing protrusions are protruding on at least one of the two coating surfaces.
  • reinforcing protrusions are provided on at least one side of the coating surface of the body part to increase the contact area between the active material layer of the pole piece and the current collector, which is beneficial on the one hand. Improve the bonding strength between the current collector and the active material layer to reduce the risk of the active material layer falling off during use. On the other hand, it will help reduce the contact resistance between the current collector and the active material layer, which can effectively improve The cycle life of the battery cells.
  • strengthening the protrusions can also increase the structural strength of the current collector itself and reduce the minimum thickness requirement of the current collector, so that while ensuring the structural strength of the current collector, for pole pieces with the same overall thickness, the structure of this structure
  • the current collector can effectively increase the capacity of the active material layer of the pole piece, and can improve the pole piece's ability to preserve the electrolyte, thereby helping to improve the energy density and performance of the battery cell.
  • the current collector disclosed in the embodiment of the present application can be used in, but is not limited to, electrical devices such as vehicles, ships, or aircrafts.
  • the power supply system of the electrical device can be composed of the pole pieces, electrode assemblies, battery cells, etc. disclosed in this application. In this way, the performance and service life of the battery cells can be effectively improved, and the manufacturing cost of the battery cells can be reduced.
  • Embodiments of the present application provide an electrical device that uses a battery as a power source.
  • the electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc.
  • 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 electric device 1000 according to an embodiment of the present application is used as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application.
  • the vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • the battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 .
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • FIG. 2 is an exploded view of the structure of the battery 100 provided by some embodiments of the present application.
  • the battery 100 includes a case 10 and battery cells 20 , and the battery cells 20 are used to be accommodated in the case 10 .
  • the box 10 is used to provide an assembly space for the battery cells 20, and the box 10 can adopt a variety of structures.
  • the box body 10 may include a first box body 11 and a second box body 12 .
  • the first box body 11 and the second box body 12 cover each other.
  • the first box body 11 and the second box body 12 share a common
  • An assembly space for accommodating the battery cells 20 is defined.
  • the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure.
  • the first box body 11 is covered with the open side of the second box body 12 so that the first box body 11 and the second box body 11 can be connected to each other.
  • the two box bodies 12 jointly define an assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side cover of the first box body 11 is closed with the second box body 12 Open side.
  • the box 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a rectangular parallelepiped, etc.
  • the battery 100 there may be a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the plurality of battery cells 20 are connected in series and in parallel.
  • the plurality of battery cells 20 can be directly connected in series or in parallel or mixed together, and then the whole composed of the plurality of battery cells 20 can be accommodated in the box 10 ; of course, the battery 100 can also be a plurality of battery cells 20 First, the battery modules are connected in series, parallel, or mixed to form a battery module, and then multiple battery modules are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 10 .
  • the battery 100 may also include other structures.
  • the battery 100 may further include a bus component for realizing electrical connections between multiple battery cells 20 .
  • Each battery cell 20 may be a secondary battery 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.
  • the battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes. For example, in FIG. 2 , the battery cell 20 has a rectangular parallelepiped structure.
  • FIG. 3 is an exploded view of the structure of the battery cell 20 provided in some embodiments of the present application.
  • the battery cell 20 includes a casing 21 and an electrode assembly 22.
  • the casing 21 is used to accommodate the electrode assembly 22.
  • the housing 21 can also be used to contain electrolyte, such as electrolyte.
  • the shell 21 can be of various structural shapes Mode.
  • the housing 21 may include a housing 211 and an end cover 212.
  • the housing 211 is a hollow structure with an opening 2111 on one side.
  • the end cover 212 is used to cover the opening 2111 of the housing 211 and form a sealed connection. To form a sealed space for accommodating the electrode assembly 22 and the electrolyte.
  • the electrode assembly 22 When assembling the battery cell 20 , the electrode assembly 22 can be first placed into the casing 211 , the electrolyte is filled into the casing 211 , and then the end cap 212 is closed with the opening 2111 of the casing 211 .
  • the housing 211 can be in various shapes, such as cylinder, cuboid, etc.
  • the shape of the housing 211 can be determined according to the specific shape of the electrode assembly 22 .
  • a cylindrical shell can be selected; if the electrode assembly 22 has a rectangular parallelepiped structure, a rectangular parallelepiped shell can be selected.
  • the end cap 212 can also have a variety of structures.
  • the end cap 212 has a plate-like structure, a hollow structure with an opening 2111 at one end, etc. For example, in FIG.
  • the electrode assembly 22 has a rectangular parallelepiped structure, correspondingly, the housing 211 has a rectangular parallelepiped structure, and the end cover 212 has a rectangular plate-like structure.
  • the end cover 212 covers the opening 2111 of the housing 211 .
  • the battery cell 20 may also include a positive electrode terminal 23 , a negative electrode terminal 24 and a pressure relief mechanism 25 .
  • the positive electrode terminal 23 , the negative electrode terminal 24 and the pressure relief mechanism 25 are all installed on the end cover 212 . Both the positive electrode terminal 23 and the negative electrode terminal 24 are used to electrically connect with the electrode assembly 22 to realize the input and output of electric energy of the battery cell 20 .
  • the pressure relief mechanism 25 is used to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.
  • the pressure relief mechanism 25 is located between the positive electrode terminal 23 and the negative electrode terminal 24 .
  • the pressure relief mechanism 25 may be a component such as an explosion-proof valve, explosion-proof disc, air valve, pressure relief valve or safety valve.
  • the housing 21 is not limited to the above structure, and the housing 21 can also be of other structures.
  • the housing 21 includes a housing 211 and two end caps 212.
  • the housing 211 is a hollow structure with openings 2111 on opposite sides.
  • an end cap 212 correspondingly covers an opening 2111 of the housing 211 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.
  • the positive electrode terminal 23 and the negative electrode terminal 24 can be installed on the same end cover 212, or they can be installed on different end covers 212; the pressure relief mechanism 25 can be installed on one end cover 212, It is also possible that pressure relief mechanisms 25 are installed on both end caps 212 .
  • the electrode assembly 22 is a component that causes an electrochemical reaction in the battery cell 20 .
  • FIG. 4 is a cross-sectional view of the electrode assembly 22 provided in some embodiments of the present application.
  • the electrode assembly 22 may include a pole piece 221 and an isolation film 222.
  • the pole piece 221 and the isolation film 222 are superimposed.
  • the electrode assembly 22 may be a rolled structure formed by winding the pole piece 221 and the isolation film 222, or may be a stacked structure formed by a stacked arrangement of the pole piece 221 and the isolation film 222.
  • the electrode assembly 22 is a rolled structure formed by rolling the pole piece 221 and the isolation film 222 .
  • the electrode assembly 22 includes two pole pieces 221 with opposite polarity (positive pole piece and negative pole piece).
  • the two pole pieces 221 with opposite polarity (positive pole piece and negative pole piece) and the isolation film 222 are wound around each other.
  • the isolation film 222 is arranged between two pole pieces 221 (positive pole piece and negative pole piece) with opposite polarity.
  • the isolation film 222 is used to separate the two pole pieces 221 (positive pole piece and negative pole piece) with opposite polarity. piece).
  • FIG. 5 is a partial structural diagram of the pole piece 221 provided by some embodiments of the present application.
  • the pole piece 221 includes a current collector 2211 and an active material layer 2212. Along the thickness direction of the current collector 2211, active material layers 2212 are provided on both sides of the current collector 2211.
  • the pole piece 221 may also have a structure, for example, along the thickness direction of the current collector 2211, the active material layer 2212 is provided only on one side of the current collector 2211.
  • Figure 6 is a top view of the current collector 2211 provided by some embodiments of the present application, that is, the current collector 2211 is in its own thickness direction.
  • 7 is a partial cross-sectional view of the current collector 2211 provided by some embodiments of the present application.
  • the present application provides a current collector 2211.
  • the current collector 2211 includes a body part 2211a and a reinforcing protrusion 2211b. Thickness along current collector In the direction X, the body portion 2211a has two coating surfaces 2211c arranged oppositely.
  • the reinforcing protrusion 2211b is protruding from at least one coating surface 2211c of the two coating surfaces 2211c.
  • the main body 2211a has coating surfaces 2211c on both sides in the thickness direction It should be noted that the coating surface 2211c is used to coat the active material, and the coating surface 2211c is provided with reinforcing protrusions 2211b. Coating the active material on the coating surface 2211c means having the coating surface 2211c on the body part 2211a.
  • the active material is coated on one side of the current collector 2211 to form an active material layer 2212 on one side of the current collector 2211, so that the active material can cover the coating surface 2211c and accommodate the reinforcing protrusions 2211b in the active material layer 2212.
  • a plurality of reinforcing protrusions 2211b are provided on the coating surface 2211c, and the reinforcing protrusions 2211b are strip-shaped structures extending along a straight line.
  • the reinforcing protrusions 2211b may also be cylindrical protrusions or wavy strip structures.
  • both coating surfaces 2211c on both sides of the body part 2211a are provided with reinforcing protrusions 2211b.
  • the reinforcing protrusions 2211b may also be provided only on the coating surface 2211c on one side of the body part 2211a.
  • the current collector 2211 can be used for the positive electrode piece or the negative electrode piece.
  • the body part 2211a and the reinforcing protrusion 2211b have an integrated structure, and the current collector 2211 can be made of a variety of materials.
  • the current collector 2211 can be made of copper, nickel, or aluminum.
  • the current collector 2211 can be used for the negative electrode piece.
  • the current collector 2211 can be made by electrolysis or corrosion to form a reinforcing protrusion 2211b on one side of the body part 2211a; when the current collector 2211 When 2211 is made of aluminum, the current collector 2211 can be used for the positive electrode piece.
  • the current collector 2211 can be made by electrolysis or corrosion.
  • the current collector 2211 made of aluminum has a soft texture
  • the current collector 2211 It can also be made by rolling or stamping methods to form reinforcing protrusions 2211b on one side of the body part 2211a. That is to say, the current collector 2211 is formed with a reinforcing protrusion 2211b on at least one side in its thickness direction.
  • the reinforcing protrusion 2211b may be a protruding structure processed on one side of the current collector 2211 to form the reinforcing protrusion 2211b, or it may be A groove is provided on one side of the current collector 2211 to form a reinforcing protrusion 2211b.
  • the current collector 2211 with this structure can increase the contact area between the active material layer 2212 of the pole piece 221 and the current collector 2211, which on the one hand is beneficial to improving the contact between the current collector 2211 and the active material layer 2212.
  • the bonding strength can reduce the risk of the active material layer 2212 falling off during use of the pole piece 221.
  • the structural strength of the current collector 2211 itself can be increased and the minimum thickness requirement of the current collector 2211 can be reduced, so that while ensuring the structural strength of the current collector 2211, for pole pieces 221 with the same overall thickness,
  • the pole piece 221 of the current collector 2211 with such a structure can effectively increase the capacity of the active material layer 2212, and can improve the electrolyte preservation ability of the pole piece 221, thereby conducive to improving the energy density and use of the battery cell 20 performance.
  • the maximum size of the current collector 2211 is D 1 , that is, the maximum thickness occupied by the current collector 2211 is D 1 in the thickness direction Minimum thickness in thickness direction X.
  • the difference between the maximum dimension of the current collector 2211 in the thickness direction and the minimum thickness of the body part 2211a is ensured, thereby A structure that can alleviate the current collector 2211 caused by insufficient size of the reinforcing protrusion 2211b.
  • the phenomenon of insufficient strength is ensured.
  • the area of the coating surface 2211c is the area of the projected area of the main body 2211a in the thickness direction X of the current collector.
  • the equivalent thickness of the current collector 2211 is the overall mass m of the current collector 2211 divided by the product of the actual density ⁇ of the current collector 2211 and the surface area S 1 on one side of the body part 2211a. That is to say, the equivalent thickness of the current collector 2211 In order to re-melt the current collector 2211 to form a planar current collector with an area of S 1 on one side, such that compared to the planar current collector structure in the prior art, the current collector 2211 has a portion in its thickness.
  • the thickened area and the partially thinned area that is, the minimum thickness of the current collector 2211 is smaller than the thickness of the flat current collector, and the maximum thickness of the current collector 2211 is larger than the thickness of the flat current collector, so that the final equivalent thickness is smaller and at least A current collector 2211 with a concave and convex structure is formed on one side.
  • the current collector 2211 of this structure has a smaller equivalent thickness, so that when the reinforcing protrusions are provided, One side of 2211b has more space to accommodate the active material layer 2212, thereby being able to accommodate more active material layers 2212, thus ensuring the structural strength of the current collector 2211 while effectively improving the active material layer 2212 of the pole piece 221.
  • the accommodation capacity is conducive to improving the energy density of the pole piece 221 with such a current collector 2211.
  • the thickness of the body portion 2211a is D 4 , satisfying 0.5 ⁇ m ⁇ D 4 ⁇ 10 ⁇ m.
  • the thickness D4 of the main body part 2211a is the average thickness of the main body part 2211a.
  • the thickness of the main body part 2211a By setting the thickness of the main body part 2211a to 0.5 ⁇ m to 10 ⁇ m, on the one hand, the risk of breakage of the current collector 2211 during use due to the too small thickness of the main body part 2211a can be reduced, and on the other hand, the risk of breakage of the main body part 2211a can be reduced. Excessive thickness will cause the current collector 2211 to occupy too much space and take up too much weight.
  • one end of the reinforcing protrusion 2211b is connected to the body part 2211a in the thickness direction
  • the number of protrusions 2211b that is, the total area of the end surface of the end of the reinforcing protrusion 2211b away from the body part 2211a accounts for 10% to 90% of the area of a coating surface 2211c.
  • the area of the coating surface 2211c is the area of the projected area of the main body 2211a in the thickness direction X of the current collector.
  • the ratio of the total area of the end surface of the end of the reinforcing protrusion 2211b away from the body part 2211a to the area of the coated surface 2211c of the body part 2211a at 0.1 to 0.9, on the one hand, the total area of the end surface of the reinforcing protrusion 2211b can be reduced.
  • the area occupied by the coated surface 2211c is too small, resulting in low bonding strength and insufficient contact area between the current collector 2211 and the active material layer 2212.
  • it can alleviate the total area occupied by the end surface of the reinforcement protrusion 2211b. Too much covering surface 2211c results in too little space for accommodating the active material layer 2212, which is beneficial to ensuring the capacity of the current collector 2211 for the active material layer 2212.
  • the reinforcing protrusions 2211b are strip structures extending along a straight trajectory, and the extending direction of the reinforcing protrusions 2211b is perpendicular to the thickness direction X of the current collector.
  • the reinforcing protrusion 2211b is a strip structure extending along a straight track, that is, the reinforcing protrusion 2211b is a straight Linear strip protrusions, and the extending direction of the reinforcing protrusions 2211b is perpendicular to the thickness direction 2211b can extend along the length direction Y of the current collector, or can also extend along the width direction Z of the current collector.
  • the extension direction of the reinforcing protrusion 2211b is the length direction Y of the current collector, that is, the body portion 2211a length direction.
  • FIG. 8 which is a top view of the current collector 2211 provided in some embodiments of the present application, the extension direction of the reinforcing protrusion 2211b can also be at an angle with the length direction Y of the current collector. layout.
  • the reinforcing protrusion 2211b is a strip structure with a rectangular cross-section.
  • the cross-section of the reinforcing protrusion 2211b can have various shapes.
  • Figure 9 is a top view of the current collector 2211 provided by some embodiments of the present application
  • Figure 10 is a partial cross-sectional view of the current collector 2211 provided by some further embodiments of the present application.
  • the cross-section of the reinforcing protrusion 2211b can also be a trapezoidal structure. , and the end with a larger area of the reinforcing protrusion 2211b is connected to the body part 2211a.
  • the reinforcing protrusions 2211b are beneficial to improving the mechanical strength and structure of the current collector 2211 strength.
  • the elongation at break of the current collector 2211 satisfies, 1.1% ⁇ e ⁇ 8%.
  • the elongation at break of the current collector 2211 refers to the ratio of the elongation length of the current collector 2211 before and after stretching to the length before stretching when the current collector 2211 is pulled apart by an external force, which is called the elongation at break.
  • the measurement method of the fracture elongation of the current collector 2211 may be measured using a stretching machine.
  • the stretching machine has a first chuck and a second chuck arranged at intervals.
  • the current collector 2211 is cut into a rectangular block structure of a predetermined size, and then the two ends of the cut current collector 2211 in the length direction are clamped by the first chuck and the second chuck respectively, and then through the first chuck.
  • the chuck and the second chuck stretch the current collector 2211 at a constant speed, and stop the stretching machine when the current collector 2211 is broken.
  • the stretched length of the current collector 2211 is measured, and the stretched length of the current collector 2211 is divided by the distance between the first chuck and the second chuck to obtain the fracture elongation rate of the current collector 2211.
  • the mechanical strength of the current collector 2211 is ensured, thereby reducing the occurrence of breakage or damage of the current collector 2211 during use, which is beneficial to improving the current collector 2211 service life.
  • the coating surface 2211c is provided with a plurality of reinforcing protrusions 2211b.
  • a plurality of reinforcing protrusions 2211b are arranged at intervals along the width direction Z of the current collector.
  • the plurality of reinforcing protrusions 2211b can be arranged in various ways.
  • the plurality of reinforcing protrusions 2211b can also be arranged at intervals along the length direction Y of the current collector, or arranged at an angle with the length direction Y of the current collector.
  • Directionally spaced arrangement the arrangement of the multiple reinforcing protrusions 2211b is not limited to this. In some embodiments, as shown in FIG.
  • protrusions 2211b can also be arranged to cross each other, so that the plurality of reinforcing protrusions 2211b form a grid-like structure.
  • the structural strength of the current collector 2211 can be further improved, which is beneficial to increasing the service life of the current collector 2211, and on the other hand, the current collector 2211 can be further improved.
  • the contact area with the active material layer 2212 is conducive to reducing the contact resistance between the current collector 2211 and the active material layer 2212, and is conducive to improving the connection stability between the current collector 2211 and the active material layer 2212.
  • both coating surfaces 2211c are provided with reinforcing protrusions 2211b.
  • both coating surfaces 2211c are provided with reinforcing protrusions 2211b, that is, the thickness of the current collector 2211 is Reinforcement protrusions 2211b are provided on both sides in the direction, thereby forming a current collector 2211 with concave and convex structures on both sides.
  • the reinforcing protrusions 2211b provided on both sides of the body part 2211a along the thickness direction X of the current collector may be arranged symmetrically or asymmetrically.
  • the reinforcing protrusions 2211b provided on both sides of the body part 2211a along the thickness direction X of the current collector are symmetrically arranged on both sides of the body part 2211a.
  • FIG. 12 which is a cross-sectional view of the current collector 2211 provided in some embodiments of the present application in other embodiments, and is disposed on both sides of the body part 2211a along the thickness direction X of the current collector.
  • the reinforcing protrusions 2211b are staggered and arranged on both sides of the body part 2211a, thereby forming an asymmetrically arranged structure.
  • the body part 2211a is provided with reinforcing protrusions 2211b on both coating surfaces 2211c of the body part 2211a, that is to say, the body part 2211a is provided with reinforcing protrusions 2211b on both sides in the thickness direction X of the current collector, so that on the one hand there are It is beneficial to further increase the overall structural strength of the current collector 2211. On the other hand, it can increase the contact area between both sides of the current collector 2211 and the active material layer 2212, and can increase the accommodation capacity of the active material layers 2212 on both sides of the current collector 2211, thus It is beneficial to improve the overall performance of the pole piece 221 of the current collector 2211 with this structure.
  • the embodiments of the present application also provide a pole piece 221, including an active material layer 2212 and a current collector 2211 of any of the above solutions.
  • the active material layer 2212 is coated on the coating surface of the body part 2211a. 2211c on.
  • pole piece 221 can be a positive pole piece or a negative pole piece, which is not limited in the embodiment of the present application.
  • the pole piece 221 with this structure can effectively increase the contact area between the current collector 2211 and the active material layer 2212, which is beneficial to improving the bonding strength and connection stability between the current collector 2211 and the active material layer 2212, and is beneficial to Reducing the contact resistance between the current collector 2211 and the active material layer 2212 can effectively increase the capacity of the active material layer 2212 of the pole piece 221, and improve the electrolyte preservation ability of the pole piece 221, thereby conducive to improving the The energy density of the pole piece 221 is improved to improve the performance of the pole piece 221.
  • the body portion 2211a has a weak area, and the active material layer 2212 covers the weak area.
  • the active material layer 2212 is cold-pressed so that the particles of the active material layer 2212 can squeeze the main body 2211a, so that the particles of the active material layer 2212 can press the main body 2211a.
  • the part 2211a causes certain damage or damage, thereby forming a weak area on the body part 2211a, and the weak area can accommodate part of the active material layer 2212, that is, part of the particles of the active material layer 2212.
  • the weak area formed on the body part 2211a may be a crack or a groove. That is to say, when the active material layer 2212 is cold pressed, some particles of the active material layer 2212 can squeeze the body part 2211a and Cracks or grooves are formed so that the cracks or grooves can accommodate part of the particles of the active material layer 2212, that is, a weak area formed on the body portion 2211a.
  • grooves or cracks before coating the active material layer 2212 on the current collector 2211, grooves or cracks can also be pre-processed on the body portion 2211a of the current collector 2211 as weak areas, and then the active material layer can be coated. 2212.
  • the weak area By arranging a weak area on the body part 2211a and covering the weak area with the active material layer 2212, the weak area can play a certain role in preserving the electrolyte, which is beneficial to improving the ability of the pole piece 221 to preserve the electrolyte. Improve the performance of pole piece 221.
  • embodiments of the present application also provide an electrode assembly 22, including the pole piece 221 of any of the above solutions.
  • embodiments of the present application also provide a battery cell 20, including a casing 21 and an electrode assembly 22 of any of the above solutions.
  • the electrode assembly 22 is accommodated in the casing 21.
  • embodiments of the present application also provide a battery 100, including a plurality of battery cells 20 of any of the above solutions, and the plurality of battery cells 20 are connected in series or in parallel.
  • embodiments of the present application also provide an electrical device, including the battery 100 of any of the above solutions, and the battery 100 is used to provide electrical energy for the electrical device.
  • the power-consuming device may be any of the aforementioned devices or systems using the battery 100 .
  • the present application provides a current collector 2211.
  • the current collector 2211 includes a body portion 2211a and a reinforcing protrusion 2211b.
  • the body portion 2211a has two coating surfaces 2211c arranged oppositely.
  • a plurality of reinforcing protrusions 2211b are protruding from the two coating surfaces 2211c.
  • the reinforcing protrusions 2211b are strip structures extending along a straight trajectory. The extending direction of the reinforcing protrusions 2211b is perpendicular to the thickness direction X of the current collector.
  • the thickness of the body part 2211a is D 4 , which satisfies 0.5 ⁇ m ⁇ D 4 ⁇ 10 ⁇ m
  • the equivalent thickness of the current collector 2211 is D 3 , which satisfies 1 ⁇ m ⁇ D 3 ⁇ 20 ⁇ m
  • D 3 m/( ⁇ S 1 )
  • the mass of the current collector 2211 is m
  • the density of the current collector 2211 is ⁇
  • the area of the coating surface 2211c is S 1 .
  • the embodiment of the present application also provides a method for manufacturing the pole piece 221.
  • Figure 13 is a schematic flow chart of the manufacturing method of the pole piece 221 provided by some embodiments of the present application.
  • the manufacturing method includes:
  • the current collector 2211 includes a body part 2211a and a reinforcing protrusion 2211b. Along the thickness direction at least one coating surface 2211c among the coating surfaces 2211c;
  • pole piece 221 manufactured by the manufacturing method provided in the above embodiments can be referred to the pole piece 221 provided in the above embodiments, and will not be described again here.
  • step S200 coating the active material layer 2212 on the coating surface 2211c
  • the manufacturing method of the pole piece 221 further includes:
  • S300 Cold-press the active material layer 2212 to press part of the active material layer 2212 into the body part 2211a.
  • the body part 2211a forms a weak area at the position where the part of the active material layer 2212 is pressed.
  • the particles of the active material layer 2212 can be squeezed against the coating surface 2211c of the main body 2211a, so that the active material layer 2212 can be activated.
  • the particles of the material layer 2212 can cause certain damage or damage to the body part 2211a, thereby forming a weak area on the body part 2211a.
  • the body part 2211a forms a weak area at the position where it is pressed in by part of the active material layer 2212. That is to say, the weak area formed by the damaged area of the body part 2211a can accommodate the part of the active material layer 2212, that is, the part of the active material layer 2212. Particles.
  • the weak area formed on the body part 2211a may be a crack or a groove. That is to say, when the active material layer 2212 is cold pressed, some particles of the active material layer 2212 can squeeze the body part 2211a and Cracks or grooves are formed so that the cracks or grooves can accommodate part of the particles of the active material layer 2212, that is, a weak area formed on the body portion 2211a.
  • some particles of the active material layer 2212 can be pressed into the body part 2211a to form a weak area on the body part 2211a, thereby enabling the weak area to It plays a certain role in preserving the electrolyte, which is beneficial to improving the ability of the pole piece 221 to preserve the electrolyte.

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Abstract

本申请提供了一种集流体、极片、电极组件、电池单体、电池及用电装置，属于电池技术领域。其中，集流体包括本体部和加强凸起。沿集流体的厚度方向，本体部具有相对设置的两个涂覆表面。加强凸起凸设于两个涂覆表面中的至少一个涂覆表面。在具有这种集流体的极片中，这种集流体能够增加活性物质层与集流体之间的接触面积，从而一方面有利于提高集流体与活性物质层的粘接强度，且有利于降低集流体与活性物质层之间的接触电阻，另一方面还能够增加集流体的结构强度，降低集流体的最小厚度需求，使得在保证集流体的结构强度的同时，对于整体厚度相同的极片中，这种集流体能够有效增加极片的活性物质层的容纳量，且能够提高极片对电解液的保存能力。

Description

集流体、极片、电极组件、电池单体、电池及用电装置
相关申请的交叉引用
本申请要求享有于2022年5月20日提交的名称为“集流体、极片、电极组件、电池单体、电池及用电装置”的中国专利申请202210551576.1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，涉及一种集流体、极片、电极组件、电池单体、电池及用电装置。
背景技术
近些年，新能源汽车有了飞跃式的发展，在电动汽车领域，动力电池作为电动汽车的动力源，起着不可替代的重要作用。随着新能源汽车的大力推广，对动力电池产品的需求也日益增长，其中，电池作为新能源汽车核心零部件不论在循环使用寿命或使用性能等方面都有着较高的要求。电池的电池单体是由正极极片、负极极片和隔离膜通过卷绕或者叠片等方式组装成电极组件(裸电芯)，之后装入外壳，再注入电解液后得到的。但是，现有技术中的电池在使用过程中存在能量密度难以有效提升、使用性能较差的问题。
发明内容
本申请实施例提供一种集流体、极片、电极组件、电池单体、电池及用电装置，能够有效提升电池的能量密度和使用性能。
第一方面，本申请实施例提供一种集流体，包括本体部和加强凸起；沿所述集流体的厚度方向，所述本体部具有相对设置的两个涂覆表面；所述加强凸起凸设于两个所述涂覆表面中的至少一个所述涂覆表面。
在上述技术方案中，通过在本体部的至少一侧的涂覆表面上设置加强凸起，也就是说，集流体用于涂覆活性物质层的一侧形成有凹凸结构，使得在具有这种集流体的极片中，这种结构的集流体能够增加极片的活性物质层与集流体之间的接触面积，从而一方面有利于提高集流体与活性物质层的粘接强度，以降低极片在使用过程中出现活性物质层脱落的风险，另一方面有利于降低集流体与活性物质层之间的接触电阻，进而能够有效提升电池单体的循环使用寿命。此外，通过加强凸起还能够增加集流体自身的结构强度，降低集流体的最小厚度需求，使得在保证集流体的结构强度的同时，对于在整体厚度相同的极片中，具有这种结构的集流体的极片能够有效增加对活性物质层的容纳量，且能够提高极片对电解液的保存能力，从而有利于提升电池单体的能量密度和使用性能。
在一些实施例中，沿所述集流体的厚度方向，所述集流体的最大尺寸为D1，所述本体部的最小厚度为D2，满足，D1-D2≥0.5μm。
在上述技术方案中，通过将集流体在其厚度方向上的最大尺寸与本体部的最小厚度的差值设置为大于0.5μm，以保证加强凸起凸出于本体部的涂覆表面的尺寸，从而能够缓解因加强凸起的尺寸不够而造成集流体的结构强度达不到的现象。
在一些实施例中，所述集流体的等效厚度为D3，满足，1μm≤D3≤20μm；其中，D3＝m/(ρ×S1)，所述集流体的质量为m，所述集流体的密度为ρ，所述涂覆表面的面积为S1。
在上述技术方案中，通过将集流体的等效厚度设置在1μm到20μm，也就是说，在同等厚度的极片中，这种结构的集流体具有更小的等效厚度，使得在设置有加强凸起的一侧具有更多的空间对活性物质层进行容纳，从而能够容纳更多的活性物质层，进而在保证集流体的结构强度的同时能够有效提升极片的活性物质层的容纳量，有利于提升具有这种集流体的极片的能量密度。
在一些实施例中，所述本体部的厚度为D4，满足，0.5μm≤D4≤10μm。
在上述技术方案中，通过将本体部的厚度设置在0.5μm到10μm，一方面能够降低因本体部的厚度过小而导致集流体在使用过程中存在断裂的风险，另一方面能够减少因本体部的厚度过大而造成集流体占用空间过多和占用重量过大的现象。
在一些实施例中，沿所述集流体的厚度方向，所述加强凸起背离所述本体部的一端的端面的面积为S2，所述涂覆表面的面积为S1，满足，0.1≤(S2×n)/S1≤0.9；其中，n为所述涂覆表面上的所述加强凸起的数量。
在上述技术方案中，通过将加强凸起远离本体部的一端的端面的总面积与本体部的涂覆表面的面积之比设置在0.1到0.9，从而一方面能够降低因加强凸起的端面的总面积占用涂覆表面过少而导致集流体与活性物质层之间的粘接强度较低且接触面积不够的风险，另一方面能够缓解因加强凸起的端面的总面积占用涂覆表面过多而造成用于容纳活性物质层的空间过少的现象，从而有利于保证集流体对活性物质层的容纳量。
在一些实施例中，所述加强凸起为沿直线轨迹延伸的条状结构，所述加强凸起的延伸方向垂直于所述集流体的厚度方向。
在上述技术方案中，通过将加强凸起设置为条状结构，且加强凸起沿垂直于集流体的厚度方向的方向延伸，使得这种结构的加强凸起有利于提升集流体的机械强度和结构强度。
在一些实施例中，所述集流体的断裂伸长率为e，满足，1.1％≤e≤8％。
在上述技术方案中，通过将集流体的断裂伸长率设置在1.1％到8％，以保证集流体的机械强度，从而能够减少集流体在使用过程中出现断裂或损坏的现象，有利于提升集流体的使用寿命。
在一些实施例中，所述涂覆表面凸设有多个所述加强凸起。
在上述技术方案中，通过在本体部的涂覆表面设置多个加强凸起，从而一方面能够进一步提升集流体的结构强度，有利于提升集流体的使用寿命，另一方面能够进一步提升集流体与活性物质层之间的接触面积，有利于降低集流体与活性物质层之间接触电阻，且有利于提升集流体与活性物质层之间的连接稳定性。
在一些实施例中，两个所述涂覆表面均凸设有所述加强凸起。
在上述技术方案中，通过在本体部的两个涂覆表面均设置加强凸起，也就是说，本体部在集流体的厚度方向上的两侧均凸设有加强凸起，从而一方面有利于进一步增加集流体的整体结构强度，另一方面能够提升集流体的两侧与活性物质层的接触面积，且能够提升集流体的两侧的活性物质层的容纳量，进而有利于提升具有这种结构的集流体的极片的整体使用性能。
第二方面，本申请实施例还提供一种极片，包括活性物质层和上述的集流体；所述活性物质层涂覆于所述涂覆表面上。
在上述技术方案中，这种结构的极片一方面能够有效增加集流体与活性物质层之间的接触面积，从而有利于提高集流体与活性物质层的粘接强度和连接稳定性，且有利于降低集流体与活性物质层之间的接触电阻，另一方面能够有效增加极片的活性物质层的容纳量，且能够提高极片对电解液的保存能力，从而有利于提升极片的能量 密度，以提升极片的使用性能。
在一些实施例中，所述本体部具有薄弱区，所述活性物质层覆盖所述薄弱区。
在上述技术方案中，通过在本体部上设置薄弱区，且薄弱区覆盖有活性物质层，从而使得薄弱区能够对电解液起到一定的保存作用，进而有利于提升极片对电解液的保存能力，以改善极片的使用性能。
第三方面，本申请实施例还提供一种电极组件，包括上述的极片。
第四方面，本申请实施例还提供一种电池单体，包括外壳和上述的电极组件；所述电极组件容纳于所述外壳内。
第五方面，本申请实施例还提供一种电池，包括多个上述的电池单体。
第六方面，本申请实施例还提供一种用电装置，包括上述的电池。
第七方面，本申请实施例还提供一种极片的制造方法，包括：提供集流体，所述集流体包括本体部和加强凸起，沿所述集流体的厚度方向，所述本体部具有相对设置的两个涂覆表面，所述加强凸起凸设于两个所述涂覆表面中的至少一个所述涂覆表面；将活性物质层涂覆于所述涂覆表面上。
在一些实施例中，在所述将活性物质层涂覆于所述涂覆表面上之后，所述极片的制造方法还包括：冷压所述活性物质层，以将所述活性物质层的部分压入所述本体部内，所述本体部在被所述活性物质层的部分压入的位置形成薄弱区。
在上述技术方案中，通过对设置于涂覆表面上的活性物质层进行冷压，从而能够将活性物质层的部分颗粒压入本体部内，以在本体部上形成薄弱区，进而使得薄弱区能够对电解液起到一定的保存作用，有利于提升极片对电解液的保存能力。
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结构***图；
图3为本申请一些实施例提供的电池单体的结构***图；
图4为本申请一些实施例提供的电极组件的剖视图；
图5为本申请一些实施例提供的极片的局部结构示意图；
图6为本申请一些实施例提供的集流体的俯视图；
图7为本申请一些实施例提供的集流体的局部剖视图；
图8为本申请又一些实施例提供的集流体的俯视图；
图9为本申请再一些实施例提供的集流体的俯视图；
图10为本申请再一些实施例提供的集流体的局部剖视图；
图11为本申请另一些实施例提供的集流体的俯视图；
图12为本申请一些实施例提供的集流体在其他实施例中的剖视图；
图13为本申请一些实施例提供的极片的制造方法的流程示意图。
图标：1000-车辆；100-电池；10-箱体；11-第一箱本体；12-第二箱本体；20-电池单体；21-外壳；211-壳体；2111-开口；212-端盖；22-电极组件；221-极片；2211-集流体；2211a-本体部；2211b-加强凸起；2211c-涂覆表面；2212-活性物质层；222-隔离膜；23-正极电极端子；24-负极电极端子；25-泄压机构；200-控制器；300-马达；X-集流体的厚度方向；Y-集流体的长度方向；Z-集流体的宽度方向。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本申请中在申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”、“附接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。
本申请中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本申请中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。应理解，附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸，以及集成装置的整体厚度、长宽等尺寸仅为示例性说明，而不应对本申请构成任何限定。
本申请中出现的“多个”指的是两个以上(包括两个)。
本申请中，电池单体可以包括锂离子二次电池、锂离子一次电池、锂硫电池、钠锂离子电池、钠离子电池或镁离子电池等，本申请实施例对此并不限定。电池单体可呈圆柱体、扁平体、长方体或其它形状等，本申请实施例对此也不限定。电池单体一般按封装的方式分成三种：柱形电池单体、方形电池单体和软包电池单体，本申请实施例对此也不限定。
本申请的实施例所提到的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。例如，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体或多个电池模块的箱体。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。
电池单体包括壳体、电极组件和电解液，壳体用于容纳电极组件和电解液。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正极集流体的部分作为正极极耳，以通过正极极耳实现正极极片的电能输入或输出。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，未涂敷负极活性物质层的负极集流体的部分作为负极极耳，以通过负极极耳实现负极极片的电能输入或输出。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。
隔离膜的材质可以为PP(polypropylene，聚丙烯)或PE(polyethylene，聚乙烯)等。此外，电极组件可以是卷绕式结构，也可以是叠片式结构，本申请实施例并不限于此。
电池具有能量密度高、环境污染小、功率密度大、使用寿命长、适应范围广、自放电系数小等突出的优点，是现今新能源发展的重要组成部分。电池的电池单体是由正极极片、负极极片和隔离膜通过卷绕或者叠片等方式组装成电极组件(裸电芯)，之后装入壳体，再盖上端盖，最后注入电解液后得到的。但是，随着电池技术的不断发展，对电池的能量密度和使用性能等也提出了更高的要求。
对于一般的电极组件而言，电极组件是由极性相反的两种极片(正极极片和负极极片)和隔离膜组成，通常情况下，极片是由集流体和涂覆于集流体的表面上的活性物质层构成。
发明人发现，集流体通常为铜箔、铝箔等金属导电材质，密度较高，对电极组件的质量影响较大，且通常情况下，集流体未两面均为平面的片状结构，如果需要保证集流体的强度，那么就需要提高集流体的厚度，并且，平面结构的集流体在涂覆活性物质层后，极片的活性物质层与集流体之间接触面积小，接触电阻较大，且粘接强度较低，活性物质层存在容易脱落的风险。上述问题导致电极组件的能力密度较大和使用性能不佳。
为了解决上述技术问题，在现有技术中，通过对集流体进行了改进，在集流体的表面设置一层粗糙的导电涂层，以增加集流体与活性物质层之间的接触面积。虽然这种集流体提升了活性物质层的粘接强度，并降低了两者之间的接触电阻，但是，这种结构的集流体一方面在使用过程中存在导电涂层容易脱离的风险，导致活性物质层极容易脱落，从而不利于提升电池单体的循环使用寿命，另一方面容易造成集流体的厚度增加，导致集流体的占地空间较大，不利于提升电池单体的能量密度，且集流体的结构强度无法得到有效提升，进而导致电池单体的使用性能较差，且不利于降低电池单体的生产成本。
基于上述考虑，为了解决电池单体存在循环使用寿命较短且使用性能较差的问题，发明人经过深入研究，设计了一种集流体，包括本体部和加强凸起，沿集流体的厚度方向，本体部具有相对设置的两个涂覆表面，加强凸起凸设于两个涂覆表面中的至少一个涂覆表面上。
在具有上述集流体的极片中，通过在本体部的至少一侧的涂覆表面上设置加强凸起，以增加极片的活性物质层与集流体之间的接触面积，从而一方面有利于提高集流体与活性物质层的粘接强度，以降低极片在使用过程中出现活性物质层脱落的风险，另一方面有利于降低集流体与活性物质层之间的接触电阻，进而能够有效提升电池单体的循环使用寿命。
此外，通过加强凸起还能够增加集流体自身的结构强度，降低集流体的最小厚度需求，使得在保证集流体的结构强度的同时，对于在具有相同整体厚度的极片中，这种结构的集流体能够有效增加极片的活性物质层的容纳量，且能够提高极片对电解液的保存能力，从而有利于提升电池单体的能量密度和使用性能。
本申请实施例公开的集流体可以但不限用于车辆、船舶或飞行器等用电装置中。可以使用具备本申请公开的极片、电极组件、电池单体等组成该用电装置的电源***，这样，能够有效提升电池单体的使用性能和使用寿命，并降低电池单体的制造成本。
本申请实施例提供一种使用电池作为电源的用电装置，用电装置可以为但不限于手机、平板、笔记本电脑、电动玩具、电动工具、电瓶车、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装置为车辆1000为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000可以为燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源。车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池100不仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2，图2为本申请一些实施例提供的电池100的结构***图。电池100包括箱体10和电池单体20，电池单体20用于容纳于箱体10内。其中，箱体10用于为电池单体20提供装配空间，箱体10可以采用多种结构。在一些实施例中，箱体10可以包括第一箱本体11和第二箱本体12，第一箱本体11与第二箱本体12相互盖合，第一箱本体11和第二箱本体12共同限定出用于容纳电池单体20的装配空间。第二箱本体12可以为一端开放的空心结构，第一箱本体11可以为板状结构，第一箱本体11盖合于第二箱本体12的开放侧，以使第一箱本体11与第二箱本体12共同限定出装配空间；第一箱本体11和第二箱本体12也可以是均为一侧开放的空心结构，第一箱本体11的开放侧盖合于第二箱本体12的开放侧。当然，第一箱本体11和第二箱本体12形成的箱体10可以是多种形状，比如，圆柱体、长方体等。
在电池100中，电池单体20可以是多个，多个电池单体20之间可串联或并联或混联，混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起，再将多个电池单体20构成的整体容纳于箱体10内；当然，电池100也可以是多个电池单体20先串联或并联或混联组成电池模块形式，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体10内。电池100还可以包括其他结构，例如，该电池100还可以包括汇流部件，用于实现多个电池单体20之间的电连接。
其中，每个电池单体20可以为二次电池或一次电池；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。电池单体20可呈圆柱体、扁平体、长方体或其它形状等。示例性的，在图2中，电池单体20为长方体结构。
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***图。电池单体20包括外壳21和电极组件22，外壳21用于容纳电极组件22。
其中，外壳21还可用于容纳电解质，例如电解液。外壳21可以是多种结构形 式。
在一些实施例中，外壳21可以包括壳体211和端盖212，壳体211为一侧开口2111的空心结构，端盖212用于盖合于壳体211的开口2111处并形成密封连接，以形成用于容纳电极组件22和电解质的密封空间。
在组装电池单体20时，可先将电极组件22放入壳体211内，并向壳体211内填充电解质，再将端盖212盖合于壳体211的开口2111。
壳体211可以是多种形状，比如，圆柱体、长方体等。壳体211的形状可根据电极组件22的具体形状来确定。比如，若电极组件22为圆柱体结构，则可选用为圆柱体壳体；若电极组件22为长方体结构，则可选用长方体壳体。当然，端盖212也可以是多种结构，比如，端盖212为板状结构、一端开口2111的空心结构等。示例性的，在图3中，电极组件22为长方体结构，对应的，壳体211为长方体结构，端盖212为长方形板状结构，端盖212盖合于壳体211的开口2111处。
在一些实施例中，电池单体20还可以包括正极电极端子23、负极电极端子24和泄压机构25，正极电极端子23、负极电极端子24和泄压机构25均安装于端盖212上。正极电极端子23和负极电极端子24均用于与电极组件22电连接，以实现电池单体20的电能的输入和输出。泄压机构25用于在电池单体20的内部压力或温度达到预定值时泄放电池单体20内部的压力。
示例性的，如图3所示，泄压机构25位于正极电极端子23和负极电极端子24之间。泄压机构25可以是诸如防爆阀、防爆片、气阀、泄压阀或安全阀等部件。
可理解的，外壳21并不仅仅局限于上述结构，外壳21也可以是其他结构，比如，外壳21包括壳体211和两个端盖212，壳体211为相对的两侧开口2111的空心结构，一个端盖212对应盖合于壳体211的一个开口2111处并形成密封连接，以形成用于容纳电极组件22和电解质的密封空间。在这种结构中，正极电极端子23和负极电极端子24可安装在同一个端盖212上，也可以安装在不同的端盖212上；可以是一个端盖212上安装有泄压机构25，也可以是两个端盖212上均安装有泄压机构25。
在本申请实施例中，容纳于外壳21内的电极组件22可以是一个，也可以是多个。示例性的，在图3中，电极组件22为两个，两个电极组件22堆叠布置。
需要说明的是，电极组件22是电池单体20中发生电化学反应的部件。请参照图4，图4为本申请一些实施例提供的电极组件22的剖视图。电极组件22可以包括极片221和隔离膜222，极片221与隔离膜222叠加设置。电极组件22可以是由极片221和隔离膜222通过卷绕形成的卷绕式结构，也可以是由极片221和隔离膜222通过层叠布置形成的层叠式结构。示例性的，在图4中，电极组件22为由极片221和隔离膜222通过卷绕形成的卷绕式结构。其中，电极组件22包括极性相反的两种极片221(正极极片和负极极片)，极性相反的两种极片221(正极极片和负极极片)和隔离膜222相互卷绕设置，隔离膜222设置于极性相反的两种极片221(正极极片和负极极片)之间，隔离膜222用于分隔极性相反的两种极片221(正极极片和负极极片)。
请参照图5，图5为本申请一些实施例提供的极片221的局部结构示意图。极片221包括集流体2211和活性物质层2212，沿集流体2211的厚度方向，集流体2211的两侧均设置有活性物质层2212。当然，在一些实施例中，极片221还可以是结构，比如，沿集流体2211的厚度方向，只在集流体2211的一侧均设置活性物质层2212。
根据本申请的一些实施例，参照图4和图5，并请进一步参照图6和图7，图6为本申请一些实施例提供的集流体2211的俯视图，即集流体2211在其自身厚度方向上的视图，图7为本申请一些实施例提供的集流体2211的局部剖视图。本申请提供了一种集流体2211，集流体2211包括本体部2211a和加强凸起2211b。沿集流体的厚度 方向X，本体部2211a具有相对设置的两个涂覆表面2211c。加强凸起2211b凸设于两个涂覆表面2211c中的至少一个涂覆表面2211c。
其中，本体部2211a在集流体的厚度方向X上的两侧具有涂覆表面2211c，涂覆表面2211c用于涂覆活性物质，以在本体部2211a的两侧形成活性物质层2212。需要说明的是，涂覆表面2211c用于涂覆活性物质，且涂覆表面2211c上凸设有加强凸起2211b，在涂覆表面2211c上涂覆活性物质指在本体部2211a具有涂覆表面2211c的一侧上涂覆活性物质，以在集流体2211的一侧形成活性物质层2212，使得活性物质能够覆盖于涂覆表面2211c上，并将加强凸起2211b容纳于活性物质层2212内。
示例性的，在图6中，涂覆表面2211c上设置有多个加强凸起2211b，且加强凸起2211b为沿直线延伸的条状结构。当然，在一些实施例中，加强凸起2211b也可以为圆柱形凸起或波浪形条状结构等。
示例性的，在图7中，本体部2211a的两侧的两个涂覆表面2211c均设置有加强凸起2211b。当然，在其他实施例中，也可以只在本体部2211a的一侧的涂覆表面2211c设置加强凸起2211b。
需要说明的是，集流体2211可以用于正极极片，也可以用于负极极片。其中，本体部2211a与加强凸起2211b为一体式结构，集流体2211的材质可以是多种，比如，集流体2211的材质可以为铜、镍或铝等。当集流体2211的材质为铜时，集流体2211可以用于负极极片，集流体2211可以采用电解或腐蚀等方法制成，以在本体部2211a的一侧形成加强凸起2211b；当集流体2211的材质为铝时，集流体2211可以用于正极极片，集流体2211可以采用电解或腐蚀等方法制成，当然，由于材质为铝的集流体2211的质地较软，因此，集流体2211还可以采用辊压或冲压等方法制成，以在本体部2211a的一侧形成加强凸起2211b。也就是说，集流体2211在其厚度方向上的至少一侧形成有加强凸起2211b，加强凸起2211b可以是在集流体2211的一侧加工凸起结构，以形成加强凸起2211b，也可以是在集流体2211的一侧设置凹槽，以形成加强凸起2211b。
通过在本体部2211a的至少一侧的涂覆表面2211c上设置加强凸起2211b，也就是说，集流体2211用于涂覆活性物质层2212的一侧形成有凹凸结构，使得在具有这种集流体2211的极片221中，这种结构的集流体2211能够增加极片221的活性物质层2212与集流体2211之间的接触面积，从而一方面有利于提高集流体2211与活性物质层2212的粘接强度，以降低极片221在使用过程中出现活性物质层2212脱落的风险，另一方面有利于降低集流体2211与活性物质层2212之间的接触电阻，进而能够有效提升电池单体20的循环使用寿命。此外，通过加强凸起2211b还能够增加集流体2211自身的结构强度，降低集流体2211的最小厚度需求，使得在保证集流体2211的结构强度的同时，对于在整体厚度相同的极片221中，具有这种结构的集流体2211的极片221能够有效增加对活性物质层2212的容纳量，且能够提高极片221对电解液的保存能力，从而有利于提升电池单体20的能量密度和使用性能。
根据本申请的一些实施例，参见图7所示，沿集流体的厚度方向X，集流体2211的最大尺寸为D1，本体部2211a的最小厚度为D2，满足，D1-D2≥0.5μm。
其中，集流体2211的最大尺寸为D1，即在集流体的厚度方向X，集流体2211占用的最大厚度为D1；本体部2211a的最小厚度为D2，即本体部2211a在集流体的厚度方向X上的最小厚度。
通过将集流体2211在其厚度方向上的最大尺寸与本体部2211a的最小厚度的差值设置为大于0.5μm，以保证加强凸起2211b凸出于本体部2211a的涂覆表面2211c的尺寸，从而能够缓解因加强凸起2211b的尺寸不够而造成集流体2211的结构 强度达不到的现象。
根据本申请的一些实施例，集流体2211的等效厚度为D3，满足，1μm≤D3≤20μm。其中，D3＝m/(ρ×S1)，集流体2211的质量为m，集流体2211的密度为ρ，涂覆表面2211c的面积为S1。
涂覆表面2211c的面积，即为本体部2211a在集流体的厚度方向X上的投影区域的面积。
其中，集流体2211的等效厚度为集流体2211的整体质量m除以集流体2211的实际密度ρ与本体部2211a一侧的表面积S1的积，也就是说，集流体2211的等效厚度为将集流体2211重新熔化后形成单侧的面积为S1的平面型集流体的厚度，使得在相较于现有技术中的平面型集流体结构中，集流体2211在其厚度上存在部分加厚的区域和部分减薄的区域，即集流体2211的最小厚度比平面型集流体厚度小，集流体2211的最大厚度比平面型集流体厚度大，从而最终得到等效厚度较小且至少一侧形成凹凸结构的集流体2211。
通过将集流体2211的等效厚度设置在1μm到20μm，也就是说，在同等厚度的极片221中，这种结构的集流体2211具有更小的等效厚度，使得在设置有加强凸起2211b的一侧具有更多的空间对活性物质层2212进行容纳，从而能够容纳更多的活性物质层2212，进而在保证集流体2211的结构强度的同时能够有效提升极片221的活性物质层2212的容纳量，有利于提升具有这种集流体2211的极片221的能量密度。
根据本申请的一些实施例，请参见图7所示，本体部2211a的厚度为D4，满足，0.5μm≤D4≤10μm。
其中，本体部2211a的厚度D4为本体部2211a的平均厚度。
通过将本体部2211a的厚度设置在0.5μm到10μm，一方面能够降低因本体部2211a的厚度过小而导致集流体2211在使用过程中存在断裂的风险，另一方面能够减少因本体部2211a的厚度过大而造成集流体2211占用空间过多、占用重量过大的现象。
根据本申请的一些实施例，参照图7所示，沿集流体的厚度方向X，加强凸起2211b背离本体部2211a的一端的端面的面积为S2，涂覆表面2211c的面积为S1，满足，0.1≤(S2×n)/S1≤0.9；其中，n为涂覆表面2211c上的加强凸起2211b的数量。
其中，加强凸起2211b在集流体的厚度方向X的一端连接于本体部2211a，另一端的端面的面积即为S1，n为本体部2211a的一侧的涂覆表面2211c上设置的加强凸起2211b的数量，也就是说，加强凸起2211b背离本体部2211a的一端的端面的总面积占一个涂覆表面2211c的面积的10％到90％。
涂覆表面2211c的面积，即为本体部2211a在集流体的厚度方向X上的投影区域的面积。
通过将加强凸起2211b远离本体部2211a的一端的端面的总面积与本体部2211a的涂覆表面2211c的面积之比设置在0.1到0.9，从而一方面能够降低因加强凸起2211b的端面的总面积占用涂覆表面2211c过少而导致集流体2211与活性物质层2212之间的粘接强度较低且接触面积不够的风险，另一方面能够缓解因加强凸起2211b的端面的总面积占用涂覆表面2211c过多而造成用于容纳活性物质层2212的空间过少的现象，从而有利于保证集流体2211对活性物质层2212的容纳量。
根据本申请的一些实施例，请参见图6和图7所示，加强凸起2211b为沿直线轨迹延伸的条状结构，加强凸起2211b的延伸方向垂直于集流体的厚度方向X。
其中，加强凸起2211b为沿直线轨迹延伸的条状结构，即加强凸起2211b为直 线型的条状凸起，且加强凸起2211b的延伸方向垂直于集流体的厚度方向X，也就是说，加强凸起2211b的延伸方向平行于本体部2211a的涂覆表面2211c，加强凸起2211b可以沿集流体的长度方向Y延伸，也可以沿集流体的宽度方向Z延伸，示例性的，在图6中，加强凸起2211b的延伸方向为集流体的长度方向Y，即本体部2211a的长度方向。当然，在其他实施例中，参照图8所示，图8为本申请又一些实施例提供的集流体2211的俯视图，加强凸起2211b的延伸方向也可以与集流体的长度方向Y呈夹角布置。
示例性的，在图7中，加强凸起2211b为横截面为矩形的条状结构，在其他实施例中，加强凸起2211b的横截面的形状可以是多种，比如，在图9和图10中，图9为本申请再一些实施例提供的集流体2211的俯视图，图10为本申请再一些实施例提供的集流体2211的局部剖视图，加强凸起2211b的横截面还可以为梯形结构，且加强凸起2211b面积较大的一端连接于本体部2211a。
通过将加强凸起2211b设置为条状结构，且加强凸起2211b沿垂直于集流体的厚度方向X的方向延伸，使得这种结构的加强凸起2211b有利于提升集流体2211的机械强度和结构强度。
根据本申请的一些实施例，集流体2211的断裂伸长率为e，满足，1.1％≤e≤8％。
其中，集流体2211的断裂伸长率为e指集流体2211在外力作用至拉断时，集流体2211在拉伸前后的伸长长度与拉伸前长度的比值称断裂伸长率。
示例性的，集流体2211的断裂伸出率的测量方法可以是采用拉伸机进行测量，拉伸机具有间隔布置的第一夹头和第二夹头。首先将集流体2211裁切为预设尺寸的矩形块状结构，然后通过第一夹头和第二夹头分别夹持裁切后的集流体2211在长度方向上的两端，之后通过第一夹头和第二夹头对集流体2211进行匀速拉伸，当集流体2211被拉断时停止拉伸机。此时，测量集流体2211被拉伸长度，将集流体2211被拉伸的长度除以第一夹头和第二夹头之间的距离，得出集流体2211的断裂伸出率。
通过将集流体2211的断裂伸长率设置在1.1％到8％，以保证集流体2211的机械强度，从而能够减少集流体2211在使用过程中出现断裂或损坏的现象，有利于提升集流体2211的使用寿命。
根据本申请的一些实施例，参照图6和图7所示，涂覆表面2211c凸设有多个加强凸起2211b。
示例性的，在图6中，多个加强凸起2211b沿集流体的宽度方向Z间隔排布。其中，多个加强凸起2211b的布置方式有多种，比如，多个加强凸起2211b还可以沿集流体的长度方向Y间隔排布，或沿与集流体的长度方向Y呈夹角设置的方向间隔排布。当然，多个加强凸起2211b的排布方式并不局限于此，在一些实施例中，参照图11所示，图11为本申请另一些实施例提供的集流体2211的俯视图，多个加强凸起2211b还可以呈相互交叉布置，以使多个加强凸起2211b形成网格状的结构。
通过在本体部2211a的涂覆表面2211c设置多个加强凸起2211b，从而一方面能够进一步提升集流体2211的结构强度，有利于提升集流体2211的使用寿命，另一方面能够进一步提升集流体2211与活性物质层2212之间的接触面积，有利于降低集流体2211与活性物质层2212之间接触电阻，且有利于提升集流体2211与活性物质层2212之间的连接稳定性。
根据本申请的一些实施例，参见图7所示，两个涂覆表面2211c均凸设有加强凸起2211b。
其中，两个涂覆表面2211c均凸设有加强凸起2211b，即集流体2211在其厚度 方向上的两侧均设置有加强凸起2211b，从而形成两侧均具有凹凸结构的集流体2211。
可选地，沿集流体的厚度方向X设置于本体部2211a的两侧的加强凸起2211b可以是对称布置，也可以是非对称布置。示例性的，在图7中，沿集流体的厚度方向X设置于本体部2211a的两侧的加强凸起2211b对称布置于本体部2211a的两侧。当然，在其他实施例中，参照图12所示，图12为本申请一些实施例提供的集流体2211在其他实施例中的剖视图，沿集流体的厚度方向X设置于本体部2211a的两侧的加强凸起2211b错位布置于本体部2211a的两侧，从而形成非对称布置的结构。
通过在本体部2211a的两个涂覆表面2211c均设置加强凸起2211b，也就是说，本体部2211a在集流体的厚度方向X上的两侧均凸设有加强凸起2211b，从而一方面有利于进一步增加集流体2211的整体结构强度，另一方面能够提升集流体2211的两侧与活性物质层2212的接触面积，且能够提升集流体2211的两侧的活性物质层2212的容纳量，进而有利于提升具有这种结构的集流体2211的极片221的整体使用性能。
根据本申请的一些实施例，本申请实施例还提供了一种极片221，包括活性物质层2212和以上任一方案的集流体2211，活性物质层2212涂覆于本体部2211a的涂覆表面2211c上。
需要说明的是，极片221可以是正极极片，也可以是负极极片，本申请实施例在此不做限定。
这种结构的极片221一方面能够有效增加集流体2211与活性物质层2212之间的接触面积，从而有利于提高集流体2211与活性物质层2212的粘接强度和连接稳定性，且有利于降低集流体2211与活性物质层2212之间的接触电阻，另一方面能够有效增加极片221的活性物质层2212的容纳量，且能够提高极片221对电解液的保存能力，从而有利于提升极片221的能量密度，以提升极片221的使用性能。
根据本申请的一些实施例，本体部2211a具有薄弱区，活性物质层2212覆盖薄弱区。
其中，在集流体2211上设置活性物质层2212后，通过对活性物质层2212进行冷压能够使得活性物质层2212的颗粒对本体部2211a进行挤压，以使活性物质层2212的颗粒能够对本体部2211a造成一定的破损或损坏，从而能够在本体部2211a上形成薄弱区，且薄弱区能够容纳活性物质层2212的部分，即活性物质层2212的部分颗粒。
示例性的，本体部2211a上形成的薄弱区可以为裂缝或凹槽，也就是说，当对活性物质层2212进行冷压时，活性物质层2212的部分颗粒能够对本体部2211a进行挤压并形成裂缝或凹槽，使得裂缝或凹槽能够容纳活性物质层2212的部分颗粒，即本体部2211a上形成的薄弱区。当然，在一些实施例中，也可以在集流体2211上涂覆活性物质层2212之前预先在集流体2211的本体部2211a上加工出凹槽或裂缝等作为薄弱区，之后再涂覆活性物质层2212。
通过在本体部2211a上设置薄弱区，且薄弱区覆盖有活性物质层2212，从而使得薄弱区能够对电解液起到一定的保存作用，进而有利于提升极片221对电解液的保存能力，以改善极片221的使用性能。
根据本申请的一些实施例，本申请实施例还提供了一种电极组件22，包括以上任一方案的极片221。
根据本申请的一些实施例，本申请实施例还提供了一种电池单体20，包括外壳21和以上任一方案的电极组件22，电极组件22容纳于外壳21内。
根据本申请的一些实施例，本申请实施例还提供了一种电池100，包括多个以上任一方案的电池单体20，多个电池单体20相互串联或并联。
根据本申请的一些实施例，本申请实施例还提供了一种用电装置，包括以上任一方案的电池100，并且电池100用于为用电装置提供电能。
用电装置可以是前述任一应用电池100的设备或***。
根据本申请的一些实施例，参见图5至图7所示，本申请提供了一种集流体2211，集流体2211包括本体部2211a和加强凸起2211b。沿集流体的厚度方向X，本体部2211a具有相对设置的两个涂覆表面2211c。两个涂覆表面2211c上均凸设有多个加强凸起2211b，加强凸起2211b为沿直线轨迹延伸的条状结构，加强凸起2211b的延伸方向垂直于集流体的厚度方向X。其中，本体部2211a的厚度为D4，满足，0.5μm≤D4≤10μm，且集流体2211的等效厚度为D3，满足，1μm≤D3≤20μm，D3＝m/(ρ×S1)，集流体2211的质量为m，集流体2211的密度为ρ，涂覆表面2211c的面积为S1。
本申请实施例还提供了一种极片221的制造方法，请参照图13，图13为本申请一些实施例提供的极片221的制造方法的流程示意图，该制造方法包括：
S100：提供集流体2211，集流体2211包括本体部2211a和加强凸起2211b，沿集流体的厚度方向X，本体部2211a具有相对设置的两个涂覆表面2211c，加强凸起2211b凸设于两个涂覆表面2211c中的至少一个涂覆表面2211c；
S200：将活性物质层2212涂覆于涂覆表面2211c上。
需要说明的是，通过上述各实施例提供的制造方法制造的极片221的相关结构，可参见前述各实施例提供的极片221，在此不再赘述。
根据本申请的一些实施例，请继续参见图13所示，在步骤S200：将活性物质层2212涂覆于涂覆表面2211c上之后，极片221的制造方法还包括：
S300：冷压活性物质层2212，以将活性物质层2212的部分压入本体部2211a内，本体部2211a在被活性物质层2212的部分压入的位置形成薄弱区。
其中，在对涂覆于本体部2211a的涂覆表面2211c上的活性物质层2212进行冷压后，能够实现活性物质层2212的颗粒对本体部2211a的涂覆表面2211c进行挤压，以使活性物质层2212的颗粒能够对本体部2211a造成一定的破损或损坏，从而能够在本体部2211a上形成薄弱区。本体部2211a在被活性物质层2212的部分压入的位置形成薄弱区，也就是说，本体部2211a被损坏的区域形成的薄弱区能够容纳活性物质层2212的部分，即活性物质层2212的部分颗粒。
示例性的，本体部2211a上形成的薄弱区可以为裂缝或凹槽，也就是说，当对活性物质层2212进行冷压时，活性物质层2212的部分颗粒能够对本体部2211a进行挤压并形成裂缝或凹槽，使得裂缝或凹槽能够容纳活性物质层2212的部分颗粒，即本体部2211a上形成的薄弱区。
通过对设置于涂覆表面2211c上的活性物质层2212进行冷压，从而能够将活性物质层2212的部分颗粒压入本体部2211a内，以在本体部2211a上形成薄弱区，进而使得薄弱区能够对电解液起到一定的保存作用，有利于提升极片221对电解液的保存能力。
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互结合。
以上仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (17)

  1. 一种集流体，包括：
    本体部，沿所述集流体的厚度方向，所述本体部具有相对设置的两个涂覆表面；以及
    加强凸起，凸设于两个所述涂覆表面中的至少一个所述涂覆表面。
  2. 根据权利要求1所述的集流体，其中，沿所述集流体的厚度方向，所述集流体的最大尺寸为D1，所述本体部的最小厚度为D2，满足，D1-D2≥0.5μm。
  3. 根据权利要求1或2所述的集流体，其中，所述集流体的等效厚度为D3，满足，1μm≤D3≤20μm；
    其中，D3＝m/(ρ×S1)，所述集流体的质量为m，所述集流体的密度为ρ，所述涂覆表面的面积为S1。
  4. 根据权利要求1-3任一项所述的集流体，其中，所述本体部的厚度为D4，满足，0.5μm≤D4≤10μm。
  5. 根据权利要求1-4任一项所述的集流体，其中，沿所述集流体的厚度方向，所述加强凸起背离所述本体部的一端的端面的面积为S2，所述涂覆表面的面积为S1，满足，0.1≤(S2×n)/S1≤0.9；
    其中，n为所述涂覆表面上的所述加强凸起的数量。
  6. 根据权利要求1-5任一项所述的集流体，其中，所述加强凸起为沿直线轨迹延伸的条状结构，所述加强凸起的延伸方向垂直于所述集流体的厚度方向。
  7. 根据权利要求1-6任一项所述的集流体，其中，所述集流体的断裂伸长率为e，满足，1.1％≤e≤8％。
  8. 根据权利要求1-7任一项所述的集流体，其中，所述涂覆表面凸设有多个所述加强凸起。
  9. 根据权利要求1-8任一项所述的集流体，其中，两个所述涂覆表面均凸设有所述加强凸起。
  10. 一种极片，包括：
    根据权利要求1-9任一项所述的集流体；以及
    活性物质层，涂覆于所述涂覆表面上。
  11. 根据权利要求10所述的极片，其中，所述本体部具有薄弱区，所述活性物质层覆盖所述薄弱区。
  12. 一种电极组件，包括根据权利要求10或11所述的极片。
  13. 一种电池单体，包括：
    外壳；以及
    根据权利要求12所述的电极组件，所述电极组件容纳于所述外壳内。
  14. 一种电池，包括多个根据权利要求13所述的电池单体。
  15. 一种用电装置，包括根据权利要求14所述的电池。
  16. 一种极片的制造方法，包括：
    提供集流体，所述集流体包括本体部和加强凸起，沿所述集流体的厚度方向，所述本体部具有相对设置的两个涂覆表面，所述加强凸起凸设于两个所述涂覆表面中的至少一个所述涂覆表面；
    将活性物质层涂覆于所述涂覆表面上。
  17. 根据权利要求16所述的极片的制造方法，其中，在所述将活性物质层涂覆于 所述涂覆表面上之后，所述极片的制造方法还包括：
    冷压所述活性物质层，以将所述活性物质层的部分压入所述本体部内，所述本体部在被所述活性物质层的部分压入的位置形成薄弱区。
PCT/CN2023/080133 2022-05-20 2023-03-07 集流体、极片、电极组件、电池单体、电池及用电装置 WO2023221606A1 (zh)

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Publication number Priority date Publication date Assignee Title
JP2012018785A (ja) * 2010-07-07 2012-01-26 Dainippon Screen Mfg Co Ltd 電池用電極の製造方法、電池の製造方法、電池、車両および電子機器
CN207303231U (zh) * 2017-08-16 2018-05-01 青岛科技大学 一种石墨烯锂离子负极极片
CN207732007U (zh) * 2017-10-23 2018-08-14 宁德新能源科技有限公司 负极极片以及锂离子电池
CN212485372U (zh) * 2020-06-30 2021-02-05 上海卡耐新能源有限公司 集流体、电极片及锂离子电池

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Publication number Priority date Publication date Assignee Title
JP2012018785A (ja) * 2010-07-07 2012-01-26 Dainippon Screen Mfg Co Ltd 電池用電極の製造方法、電池の製造方法、電池、車両および電子機器
CN207303231U (zh) * 2017-08-16 2018-05-01 青岛科技大学 一种石墨烯锂离子负极极片
CN207732007U (zh) * 2017-10-23 2018-08-14 宁德新能源科技有限公司 负极极片以及锂离子电池
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