WO2023050197A1 - 电池单体及其制造方法和制造系统、电池及用电装置 - Google Patents

电池单体及其制造方法和制造系统、电池及用电装置 Download PDF

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Publication number
WO2023050197A1
WO2023050197A1 PCT/CN2021/121845 CN2021121845W WO2023050197A1 WO 2023050197 A1 WO2023050197 A1 WO 2023050197A1 CN 2021121845 W CN2021121845 W CN 2021121845W WO 2023050197 A1 WO2023050197 A1 WO 2023050197A1
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WO
WIPO (PCT)
Prior art keywords
tab
welding
battery cell
electrode lead
layer
Prior art date
Application number
PCT/CN2021/121845
Other languages
English (en)
French (fr)
Inventor
杨振飞
温裕乾
朱文琪
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
Publication date
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 CN202180083628.0A priority Critical patent/CN116636077A/zh
Priority to EP21958785.4A priority patent/EP4358277A1/en
Priority to PCT/CN2021/121845 priority patent/WO2023050197A1/zh
Publication of WO2023050197A1 publication Critical patent/WO2023050197A1/zh
Priority to US18/520,465 priority patent/US20240097287A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/536—Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0422—Cells or battery with cylindrical casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0431—Cells with wound or folded electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/534—Electrode connections inside a battery casing characterised by the material of the leads or tabs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/552—Terminals characterised by their shape
    • H01M50/559—Terminals adapted for cells having curved cross-section, e.g. round, elliptic or button cells
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present application relates to the field of battery technology, and more specifically, to a battery cell, a manufacturing method and system thereof, a battery, and an electrical device.
  • Battery cells are widely used in electronic equipment, such as mobile phones, laptop computers, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.
  • the battery cells may include nickel-cadmium battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, secondary alkaline zinc-manganese battery cells, and the like.
  • the present application provides a battery cell, its manufacturing method and manufacturing system, a battery, and an electrical device, which can improve the overcurrent capability of the battery cell.
  • the embodiment of the present application provides a battery cell, including:
  • the shell including the electrode lead-out part
  • the electrode assembly is accommodated in the casing.
  • the electrode assembly is provided with a first tab at one end facing the electrode lead-out part.
  • the first tab is wound around the winding axis of the electrode assembly and includes a multi-turn tab layer.
  • the multi-turn tab welding at least part of the layers and forming a first weld;
  • a part of the multi-turn tab layer is welded to the electrode lead-out part to form a second welded part; in the tab layer connected to the first weld part, at least one circle of the tab layer is not welded to the electrode lead-out part.
  • the conductive path between the tab layers and the conductive path between the tab layer and the electrode lead-out part are shortened by welding the tab layer that is not welded to the electrode lead-out part, reducing the resistance and improving the current density. Uniformity, reduce the risk of pole piece polarization, and improve the overcurrent capability and charging efficiency of the battery cell.
  • At least one circle of the tab layer is connected to the first welding portion and the second welding portion.
  • the at least one circle of the tab layer can transmit the current collected by the first welding part to the second welding part, so as to shorten the conductive path between the first welding part and the second welding part, thereby reducing the resistance, Improve the uniformity of current density, reduce the risk of pole piece polarization, and improve the overcurrent capability and charging efficiency of the battery cell.
  • the first weld is directly connected to the second weld.
  • the current collected by the first welding part can directly flow into the second welding part, thereby further shortening the conductive path between the first welding part and the second welding part, reducing the resistance, and improving the overcurrent capacity and capacity of the battery cell. Charging efficiency.
  • the second welding portion includes a first portion formed on the electrode lead-out portion and a second portion formed on the first tab. In a direction parallel to the winding axis, the dimension of the second portion is greater than the dimension of the first weld.
  • the first welding part is made to have a smaller size, so as to reduce the energy required for welding the first tab and reduce the risk of burning the electrode assembly; the above solution makes the size of the second part larger than the size of the first welding part, In order to ensure the connection strength between the electrode lead-out part and the first tab, and reduce the risk of battery cell failure.
  • the size of the first welded portion is 0.2 mm-0.5 mm, and the size of the second portion is 0.5 mm-1.5 mm.
  • the total number of turns of the tab layer is N1
  • the tab layers of N2 turns are connected through the first welding part
  • the value of N2/N1 is 0.5-0.95.
  • the value of N2/N1 is set to 0.5-0.95 to reduce resistance, increase overcurrent, and reduce the risk of electrode assembly being burned.
  • the first welding portion includes a plurality of first sub-welding portions, and the plurality of first sub-welding portions are arranged at intervals along the circumference of the first tab.
  • the first welding portion can be formed by multiple times of welding, so as to reduce the heat generation of a single welding and reduce the risk of the electrode assembly being burned by high temperature.
  • the first sub-welding portion is straight, V-shaped, W-shaped or curved.
  • the first welding portion is a helical structure disposed around the winding axis.
  • the multiple second welding portions are arranged at intervals, and at least two second welding portions are connected to different tab layers.
  • multiple second welding parts can realize the current transmission between the first tab and the electrode lead-out part, so as to reduce the difference in the conductive path of different tab layers, improve the uniformity of the current density, and reduce the The risk of polarization can be improved, and the overcurrent capability and charging efficiency of the battery cell can be improved.
  • the end of the multi-turn tab layer facing the electrode lead-out part is bent and gathered to reduce the gap between the ends.
  • the ends are for welding to form a first weld and a second weld.
  • the ends of the multi-turn tab layers are bent and gathered to reduce the gap between the tab layers and reduce the risk of laser leakage during the welding process.
  • the electrode lead-out part includes a body part and a connection part, the connection part surrounds the outside of the body part, and the thickness of the connection part is smaller than that of the body part.
  • the connection part is used for welding to the first tab to form a second welding part. In a direction parallel to the winding axis, the first welding portion at least partially overlaps the body portion.
  • connection part by reducing the thickness of the connection part, the energy required for welding the connection part and the first tab is reduced, and the risk of the separator of the electrode assembly being burned is reduced.
  • first welding part is connected to the tab layer overlapping with the body part, so as to shorten the conductive path of the tab layer, reduce the resistance, and improve the overcurrent capability.
  • the electrode lead-out part further includes a reinforcement part protruding from the surface of the connection part away from the electrode assembly and connected to the main body part.
  • the portion of the connecting portion not covered by the reinforcing portion is used for welding to the first tab to form a second welding portion.
  • the reinforcement part is provided to increase the strength of the electrode lead-out part, reduce the deformation of the electrode lead-out part, and reduce the risk of cracking of the second welding part.
  • the reinforcing parts are arranged at intervals along the circumferential direction of the main body.
  • the plurality of reinforcing parts can further increase the strength of the electrode lead-out part and make the strength of the electrode lead-out part more uniform.
  • the housing includes a housing and an end cover, the housing has an opening, and the end cover covers the opening of the housing.
  • the end cap is the lead-out part of the electrode.
  • the end cap is used as the electrode lead-out part, so that the traditional electrode terminals can be omitted, thereby simplifying the structure of the battery cell.
  • the end cover is directly welded to the first tab, so that the traditional current collecting plate can be omitted, thereby reducing the cost and simplifying the assembly process.
  • the battery cells are cylindrical battery cells.
  • an embodiment of the present application provides a battery, including a plurality of battery cells in any embodiment of the first aspect.
  • an embodiment of the present application provides an electrical device, including the battery in the second aspect, and the battery is used to provide electrical energy.
  • the embodiment of the present application provides a method for manufacturing a battery cell, including:
  • An electrode assembly is provided, the electrode assembly is provided with a first tab at one end, the first tab is wound around the winding axis of the electrode assembly and includes a multi-turn tab layer;
  • the casing includes an electrode lead-out part, and the first tab is located at one end of the electrode assembly facing the electrode lead-out part;
  • At least one circle of the tab layer is not welded to the electrode lead-out part.
  • the embodiment of the present application provides a battery cell manufacturing system, including:
  • the first providing device provides an electrode assembly, the electrode assembly is provided with a first tab at one end, and the first tab is wound around the winding axis of the electrode assembly and includes a multi-turn tab layer;
  • the first welding device is used to weld at least part of the multi-turn tab layer to form a first welding part
  • the second providing device is used to provide a casing, and put the electrode assembly into the casing, the casing includes an electrode lead-out part, and the first tab is located at one end of the electrode assembly facing the electrode lead-out part;
  • the second welding device is used to weld a part of the multi-turn tab layer to the electrode lead-out part and form a second welding part;
  • At least one circle of the tab layer is not welded to the electrode lead-out part.
  • Fig. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Fig. 2 is a schematic explosion diagram of a battery provided by some embodiments of the present application.
  • FIG. 3 is a schematic structural diagram of the battery module shown in FIG. 2;
  • Fig. 4 is a schematic cross-sectional view of a battery cell provided by some embodiments of the present application.
  • FIG. 5 is an enlarged schematic view of the battery cell shown in FIG. 4 at the circle frame A;
  • FIG. 6 is a schematic structural view of an electrode assembly of a battery cell provided in some embodiments of the present application.
  • FIG. 7 is a schematic top view of a battery cell provided by some embodiments of the present application.
  • FIG. 8 is a schematic structural view of an electrode assembly of a battery cell provided in another embodiment of the present application.
  • FIG. 9 is a schematic flowchart of a method for manufacturing a battery cell provided in some embodiments of the present application.
  • Fig. 10 is a schematic block diagram of a battery cell manufacturing system provided by some embodiments of the present application.
  • connection In the description of this application, it should be noted that, unless otherwise clearly stipulated and limited, the terms “installation”, “connection”, “connection” and “attachment” should be understood in a broad sense, for example, it may be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediary, and it can be internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.
  • the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, detailed descriptions of the same components are omitted. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are for illustrative purposes only, and should not constitute any limitation to the application .
  • Multiple in this application refers to more than two (including two), and “multiple turns” refers to more than two turns (including two).
  • the battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc.
  • the embodiment of the present application does not limit this.
  • the battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack, and the like.
  • Batteries generally include a case for enclosing one or more battery cells. The box can prevent liquid or other foreign objects from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte, and the electrode assembly includes a positive pole piece, a negative pole piece and a separator.
  • a battery cell works primarily by moving metal ions between the positive and negative pole pieces.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode current collector;
  • the positive electrode current collector includes a positive electrode current collector and a positive electrode lug connected to the positive electrode current collector, and the positive electrode current collector It is coated with a positive electrode active material layer, and the positive electrode tab is not coated with a positive electrode active material layer.
  • the material of the positive electrode current collector can be aluminum
  • the positive electrode active material layer includes the positive electrode active material
  • the positive electrode active material can be lithium cobaltate, 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, and the negative electrode active material layer is coated on the surface of the negative electrode current collector;
  • the negative electrode current collector includes a negative electrode current collector and a negative electrode tab connected to the negative electrode current collector, and the negative electrode current collector The negative electrode active material layer is coated, and the negative electrode tab is not coated with the negative electrode active material layer.
  • the material of the negative electrode current collector may be copper, the negative electrode active material layer includes the negative electrode active material, and the negative electrode active material may be carbon or silicon.
  • the material of the spacer can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene).
  • the battery cell also includes a casing for containing the electrode assembly and the electrolyte.
  • the casing includes a casing and an end cover connected to the casing.
  • the casing and the end cover form an accommodating cavity for accommodating the electrode assembly and the electrolyte.
  • the electrode assembly can be electrically connected to the end cap, and can also be electrically connected to the electrode terminal provided on the end cap.
  • the electrode assembly generally inputs and outputs current through tabs.
  • the inventors tried to arrange the tab in a winding structure.
  • the winding-type tab includes a multi-turn tab layer, and the multi-turn tab layer is connected end to end along the winding direction.
  • the wound tab has a larger flow area and a stronger ability to withstand large currents.
  • the inventors have found that when the tab is connected to the electrode lead-out part of the housing, the tab layer that can be directly welded to the electrode lead-out part is relatively limited due to constraints such as the shape and position of the electrode lead-out part, which leads to no contact with the electrode lead-out part.
  • the conductive path between the lug layer welded at the lead-out part and the lead-out part of the electrode is too long, which causes the resistance of the electrode assembly to be too high, the current density is uneven, and the risk of polarization of the pole piece is caused, which affects the overcurrent capability and charging of the battery cell efficiency.
  • the embodiment of the present application provides a technical solution to shorten the conductive path between the tab layers and the conductive path between the tab layer and the electrode lead-out part by welding the tab layer that is not welded to the electrode lead-out part , reduce the resistance of the electrode assembly, improve the uniformity of the current density, reduce the risk of pole piece polarization, and improve the overcurrent capability and charging efficiency of the battery cell.
  • Electric devices can be vehicles, mobile phones, portable devices, notebook computers, ships, spacecraft, electric toys and electric tools, and so on.
  • Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles;
  • spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.;
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric boat toys and electric airplane toys, etc.;
  • electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, electric planers, and more.
  • the embodiments of the present application do not impose special limitations on the above-mentioned electrical devices.
  • the electric device is taken as an example for description.
  • Fig. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • a battery 2 is arranged inside the vehicle 1 , and the battery 2 can be arranged at the bottom, head or tail of the vehicle 1 .
  • the battery 2 can be used for power supply of the vehicle 1 , for example, the battery 2 can be used as an operating power source of the vehicle 1 .
  • the vehicle 1 may also include a controller 3 and a motor 4 , the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, for the starting, navigation and working power requirements of the vehicle 1 during driving.
  • the battery 2 can not only be used as an operating power source for the vehicle 1 , but can also be used as a driving power source for the vehicle 1 to provide driving power for the vehicle 1 instead of or partially replacing fuel oil or natural gas.
  • Fig. 2 is a schematic explosion diagram of a battery provided by some embodiments of the present application.
  • the battery 2 includes a box body 5 and a battery cell (not shown in FIG. 2 ), and the battery cell is accommodated in the box body 5 .
  • the box body 5 is used to accommodate the battery cells, and the box body 5 may have various structures.
  • the box body 5 may include a first box body part 5a and a second box body part 5b, the first box body part 5a and the second box body part 5b cover each other, the first box body part 5a and the second box body part 5a
  • the two box parts 5b jointly define an accommodating space 5c for accommodating the battery cells.
  • the second box body part 5b can be a hollow structure with one end open, the first box body part 5a is a plate-shaped structure, and the first box body part 5a covers the opening side of the second box body part 5b to form an accommodating space 5c
  • the box body 5; the first box body portion 5a and the second box body portion 5b also can be a hollow structure with one side opening, and the opening side of the first box body portion 5a is covered on the opening side of the second box body portion 5b , to form a box body 5 with an accommodating space 5c.
  • the first box body part 5a and the second box body part 5b can be in various shapes, such as a cylinder, a cuboid, and the like.
  • a sealant such as sealant, sealing ring, etc., can also be provided between the first box body part 5a and the second box body part 5b. .
  • the first box part 5a covers the top of the second box part 5b
  • the first box part 5a can also be called an upper box cover
  • the second box part 5b can also be called a lower box.
  • the battery 2 there may be one or more battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel or in parallel.
  • the hybrid connection means that there are both series and parallel connections among the multiple battery cells.
  • a plurality of battery cells can be directly connected in series or in parallel or mixed together, and then the whole composed of a plurality of battery cells is accommodated in the box 5; of course, it is also possible to first connect a plurality of battery cells in series or parallel or
  • the battery modules 6 are formed by parallel connection, and multiple battery modules 6 are connected in series or in parallel or in series to form a whole, and are housed in the box body 5 .
  • FIG. 3 is a schematic structural diagram of the battery module shown in FIG. 2 .
  • FIG. 3 there are multiple battery cells 7 , and the multiple battery cells 7 are connected in series, in parallel, or in parallel to form a battery module 6 .
  • a plurality of battery modules 6 are connected in series, in parallel or in parallel to form a whole, and accommodated in the box.
  • the plurality of battery cells 7 in the battery module 6 can be electrically connected through a confluence component, so as to realize parallel connection, series connection or mixed connection of the plurality of battery cells 7 in the battery module 6 .
  • Fig. 4 is a schematic cross-sectional view of a battery cell provided in some embodiments of the present application
  • Fig. 5 is an enlarged schematic view of the battery cell shown in Fig. 4 at the circle frame A
  • Fig. 6 is a schematic view of a battery cell provided in some embodiments of the present application
  • 7 is a schematic top view of a battery cell provided by some embodiments of the present application.
  • the embodiment of the present application provides a battery cell 7, which includes: a casing 20, including an electrode lead-out part 21; an electrode assembly 10, accommodated in the casing 20, and the electrode assembly 10 faces the electrode
  • a first tab 11 the first tab 11 is wound around the winding axis X of the electrode assembly 10 and includes a multi-turn tab layer 111, at least part of the multi-turn tab layer 111 is welded And form the first welding portion W1.
  • a part of the multi-turn tab layer 111 is welded to the electrode lead-out part 21 to form the second welded part W2; in the tab layer 111 connected to the first weld part W1, at least one circle of the tab layer 111 is not connected to the electrode lead-out part. 21 welding.
  • the electrode assembly 10 includes a first pole piece, a second pole piece and a spacer, and the spacer is used to separate the first pole piece from the second pole piece.
  • the polarity of the first pole piece and the second pole piece is opposite, in other words, one of the first pole piece and the second pole piece is a positive pole piece, and the other of the first pole piece and the second pole piece is a negative pole piece pole piece.
  • the first pole piece, the second pole piece and the separator are all strip structures, and the first pole piece, the second pole piece and the separator are wound around the winding axis X to form a winding structure.
  • the winding structure can be a cylindrical structure, a flat structure or other shapes.
  • the electrode assembly 10 includes a main body 12 , a first tab 11 and a second tab 13 , and the first tab 11 and the second tab 13 protrude from the main body 12 .
  • the first tab 11 is the part of the first pole piece not coated with the active material layer
  • the second tab 13 is the part of the second pole piece not coated with the active material layer.
  • one of the first tab 11 and the second tab 13 is a tab of positive polarity
  • the other is a tab of negative polarity.
  • the first tab 11 and the second tab 13 are respectively provided on both sides of the main body 12 , in other words, the first tab 11 and the second tab 13 are respectively provided at both ends of the electrode assembly 10 .
  • the first tab 11 and the second tab 13 are respectively provided at both ends of the electrode assembly 10 .
  • the first tab 11 is wound around the winding axis X of the electrode assembly 10 , and the first tab 11 is generally cylindrical.
  • the first tab 11 includes a multi-turn tab layer 111 arranged around the winding axis X.
  • the first tab 11 includes N1 turns of the tab layer 111 , where N1 is a positive integer greater than 1.
  • the two ends of the first tab 11 along the winding direction Y are the inner end 11 a and the outer end 11 b respectively.
  • the tab layer 111 is divided based on the inner end 11 a of the first tab 11 .
  • the winding direction Y is perpendicular to the winding axis X.
  • the inner end 11a of the first tab 11 is the head end of the first tab layer 111
  • the tail end of the first tab layer 111 and the head end of the first tab layer 111 are in the first tab.
  • 11 is aligned in the radial direction
  • the first circle of tab layer 111 circles around the winding axis X for one circle.
  • the tail end of the first tab layer 111 is the head end of the second tab layer 111
  • N1 tab layers 111 are connected end to end along the winding direction Y.
  • the head end of each tab layer 111 is aligned with the inner end 11a of the first tab 11 along the radial direction of the first tab 11.
  • the radial direction of the first tab 11 is perpendicular to the winding axis X and passes through the winding axis X.
  • the inner end 11 a and the outer end 11 b of the first tab 11 are aligned in the radial direction of the first tab 11 , so that each round of the tab layer 111 circles the winding axis X once.
  • this part circles the winding axis X for less than one turn.
  • this part can circle the winding axis for 1/3, 1/2, or 2/3. circle or 3/4 circle.
  • the first tab 11 is generally cylindrical, and there is a gap between two adjacent tab layers 111 .
  • the first tab 11 can be processed to reduce the gap between the tab layers 111 , so as to facilitate the connection between the first tab 11 and the electrode lead-out portion 21 .
  • the first tab 11 may be flattened so that the end area of the first tab 11 away from the main body 12 is gathered together.
  • the flattening treatment is to shape the end area of the first tab 11 away from the main body 12 by a flattening device, so as to compact the end area of the first tab 11 and form a dense end surface, reducing the thickness of the tab layer 111.
  • the gap between them is convenient for welding the first tab 11 and the electrode lead-out part 21 .
  • the second tab 13 is wound in multiple turns around the winding axis X of the electrode assembly 10 , and the second tab 13 includes multiple turns of tab layers.
  • the second tab 13 has also been smoothed to reduce the gap between the tab layers of the second tab 13 .
  • the housing 20 can be in various structural forms.
  • the casing 20 may include a housing 22 and an end cover 23, the housing 22 is a hollow structure with an opening, the end cover 23 covers the opening of the housing 22 and forms a sealed connection, so as to form a housing for accommodating the electrode assembly 10 and Electrolyte sealed space.
  • the housing 22 can be in various shapes, such as cylinder, cuboid and so on.
  • the shape of the casing 22 may be determined according to the specific shape of the electrode assembly 10 .
  • the end cap 23 can also be of various structures, for example, the end cap 23 is a plate-shaped structure, a hollow structure, and the like.
  • the shell 22 is a cylindrical structure
  • the end cap 23 is a plate structure
  • the end cap 23 covers the opening of the shell 22 .
  • the housing 20 includes a housing 22 and an end cover 23 , the housing 22 is a hollow structure with an opening on one side, and the end cover 23 covers the opening of the housing 22 .
  • the housing 20 includes a housing 22 and two end covers 23 , the housing 22 is a hollow structure with openings on opposite sides, and each end cover 23 covers a corresponding opening of the housing 22 .
  • the end cover 23 can be directly connected to the housing 22, or can be connected to the housing 22 through other components.
  • the housing 20 further includes a fixing piece 24 for fixing the end cover 23 to the casing 22 .
  • the fixing piece 24 surrounds the outside of the end cover 23 and clamps the edge of the end cover 23 to realize the connection between the fixing piece 24 and the end cover 23; the outer edge of the fixing piece 24 is welded to the housing 22 to realize the fixing piece 24 Connection to housing 22.
  • the casing 20 further includes a sealing member 25 for sealing the opening of the housing 22 to improve the sealing performance of the battery cell 7 .
  • the sealing member 25 may be clamped between the fixing piece 24 and the end cover 23 .
  • the material of the sealing member 25 can be PP (polypropylene, polypropylene), PE (polyethylene, polyethylene) or fluorine rubber.
  • the sealing member 25 is made of insulating material, which can insulate the end cover 23 from the housing 22 .
  • the end cap 23 is provided with an electrolyte injection hole, and the electrolyte injection hole penetrates the end cap 23 along the thickness direction of the end cap 23 .
  • the electrolyte injection hole penetrates the end cap 23 along the thickness direction of the end cap 23 .
  • the electrolyte enters the inside of the battery cell 7 through the electrolyte injection hole.
  • the battery cell 7 also includes a sealing plate 26 connected to the end cap 23 and covering the electrolyte injection hole for sealing the electrolyte injection hole after the electrolyte injection process is completed.
  • the casing 20 includes an electrode lead-out portion 21 , which is used to lead out the current in the electrode assembly 10 to output the electric energy generated by the electrode assembly 10 .
  • the electrode lead-out part 21 can be the end cap 23 , the shell 22 , or other parts of the housing 20 , which is not limited in this embodiment, as long as the current can be drawn out.
  • the end cap 23 serves as the electrode lead-out portion 21 and is electrically connected to the electrode assembly 10 .
  • the housing 20 further includes electrode terminals (not shown) disposed on the end cap 23 , and the electrode terminals serve as the electrode lead-out portion 21 and are electrically connected to the electrode assembly 10 .
  • the N2 turns of tab layers 111 are connected by welding to form a first welding portion W1 .
  • N2 is a positive integer, and 2 ⁇ N2 ⁇ N1.
  • a laser is irradiated on the end surface of the first tab 11 away from the main body 12 , and the laser welds N2 circles of the tab layer 111 to form a first welding portion W1 .
  • the N2 turns of the tab layers 111 are connected through the first welding portion W1 , so that the conductive path between the N2 turns of the tab layers 111 can be shortened to reduce the resistance.
  • N2 turns of the tab layer 111 can be continuously arranged along the winding direction Y.
  • a part of the tab layer 111 is continuously arranged along the winding direction Y
  • another part of the tab layer 111 is continuously arranged along the winding direction Y
  • the part of the tab layer 111 and the other part Other tab layers 111 not connected to the first welding portion W1 may be disposed between the tab layers 111 .
  • M is a positive integer, and 1 ⁇ M ⁇ N1.
  • the laser acts on the outer surface of the electrode lead-out part 21, and the laser welds the part of the electrode lead-out part 21 and the M circle tab layer 111 to form the second welding part W2 .
  • the current of each tab layer 111 can be transmitted to the electrode lead-out part 21 through the second welding part W2 without flowing through other tab layers 111, so that the M circles of tab layers can be shortened.
  • 111 conductive path, reducing resistance.
  • N3 is a positive integer, and 2 ⁇ N3 ⁇ N2.
  • the N3 circle tab layer 111 is not welded to the electrode lead-out part 21 , therefore, the current on the N3 circle tab layer 111 needs to be transmitted to the electrode lead-out part 21 through the tab layer 111 welded to the electrode lead-out part 21 . If the N3 turns of the tab layer 111 are not connected by the first welding part W1, then, in the N3 turns of the tab layer 111, the current on the tab layer 111 away from the second welding part W2 needs to flow through the second welding part close to the second welding part.
  • the tab layer 111 of the part W2 which results in a relatively long conductive path and a relatively large resistance.
  • the current can be directly transmitted through the first welding part W1, thereby shortening the conductive path between the N3 tab layers 111, so as to reduce the resistance.
  • the first welding portion W1 and the second welding portion W2 may be directly connected, or may be indirectly connected through the tab layer 111 .
  • the conductive path between the tab layers 111 and the distance between the tab layer 111 and the electrode lead-out portion 21 are shortened by welding the tab layer 111 that is not welded to the electrode lead-out portion 21.
  • the conductive path reduces the resistance, improves the uniformity of the current density, reduces the risk of pole piece polarization, and improves the overcurrent capability and charging efficiency of the battery cell 7 .
  • the housing 20 includes a housing 22 and an end cover 23 , the housing 22 has an opening, and the end cover 23 covers the opening of the housing 22 .
  • the end cap 23 is the electrode lead-out part 21 .
  • the end cap 23 is used as the electrode lead-out part 21 , so that the traditional electrode terminals can be omitted, thereby simplifying the structure of the battery cell 7 .
  • the end cover 23 is directly welded to the first lug 11 , so that the traditional current collecting plate can be omitted, thereby reducing the cost and simplifying the assembly process.
  • the laser acts on the outer surface of the end cap 23 , so that the casing 22 and the end cap 23 can protect the electrode assembly 10 from the outside, so as to reduce the risk of sputtering of metal particles generated by welding to the electrode assembly 10 .
  • the battery cells 7 are cylindrical battery cells.
  • the electrode assembly 10 is a cylindrical structure, and the casing 22 is a cylindrical hollow structure.
  • At least one circle of tab layer 111 is connected to the first welding portion W1 and the second welding portion W2.
  • the at least one circle of tab layer 111 can transmit the current collected by the first welding part W1 to the second welding part W2, so as to shorten the electrical conduction between the first welding part W1 and the second welding part W2. path, thereby reducing the resistance, improving the uniformity of the current density, reducing the risk of pole piece polarization, and improving the overcurrent capability and charging efficiency of the battery cell 7.
  • the first welding portion W1 is directly connected to the second welding portion W2.
  • the first tab 11 of the electrode assembly 10 is first welded to form the first welding part W1, and then the electrode lead-out part 21 and the first electrode lead-out part 21 are welded after the electrode assembly 10 is put into the casing 20. tab 11 to form the second welding portion W2.
  • the first welding part W1 is directly connected to the second welding part W2, so that the current collected by the first welding part W1 can directly flow into the second welding part W2, thereby further shortening the first welding part W1 and the second welding part.
  • the conductive path between W2 reduces the resistance and improves the overcurrent capability and charging efficiency of the battery cell 7 .
  • first welding portion W1 and the second welding portion W2 may also be arranged at intervals in the circumferential direction of the first tab 11 .
  • the part of the tab layer 111 connected to the first welding part W1 and the part of the tab layer 111 connected to the second welding part W2 The parts are arranged at intervals in the circumferential direction of the first tab 11 .
  • the second welding portion W2 includes a first portion W21 formed on the electrode lead-out portion 21 and a second portion W22 formed on the first tab 11 .
  • the dimension D1 of the second portion W22 is greater than the dimension D2 of the first weld W1 .
  • the thickness direction of the electrode lead-out portion 21 is parallel to the winding axis X.
  • the distance between the second welding portion W2 and the main body portion 12 is smaller than the distance between the first welding portion W1 and the main body portion 12 .
  • a part of the electrode lead-out part 21 forms the first part W21 after melting, solidification and other processes, and the aforementioned M-circle tab layer 111 forms the second part after melting and solidification.
  • the first part W21 and the second part W22 form an atomic-level integrated whole, so as to reduce the resistance between the first tab 11 and the electrode lead-out part 21 and improve the overcurrent capability.
  • the laser When welding the first lug 11, the laser directly acts on the first lug 11. Although the first lug 11 has been smoothed, if the energy of the laser is too high, the laser may still radiate from the lug layer 111. Passes through and burns the spacer, causing a safety risk. Therefore, in this embodiment, a low-energy laser is generally used to weld the tab layer 111 of the first tab 11 , and correspondingly, the dimension D2 of the first welding portion W1 is relatively small.
  • the multi-turn tab layer 111 of the first tab 11 is integrally connected to the ground, even if a crack occurs in the first welding part W1 due to low strength, the current can also be transmitted between the tab layers 111, that is to say, the crack has no effect on the current. The transmission has little effect. Therefore, this embodiment has lower requirements on the strength of the first welding portion W1, and the first welding portion W1 may have a relatively smaller size.
  • the second welding part W2 needs to connect the electrode lead part 21 and the first tab 11. If the size D1 of the second part W22 is equal to or smaller than the size D2 of the first welding part W1, then the strength of the second part W22 is low and easy to crack , which will affect the overcurrent capability of the battery cell 7, and even cause the battery cell 7 to fail.
  • the first welding part W1 has a smaller size, so as to reduce the energy required for welding the first tab 11 and reduce the risk of burning the electrode assembly 10; in this embodiment, the size D1 of the second part W22 is larger than the first The dimension D2 of the welding part W1 is to ensure the connection strength between the electrode lead part 21 and the first tab 11 and reduce the risk of failure of the battery cell 7 .
  • the dimension D2 of the first welding portion W1 is 0.2 mm-0.5 mm, and the dimension D1 of the second portion W22 is 0.5 mm-1.5 mm.
  • the inventors have tested and set the dimension D2 of the first welding part W1 to 0.2mm-0.5mm, which can make the energy required for welding the first tab 11 meet the requirements and ensure the strength of the first welding part W1 as much as possible.
  • the inventor set the dimension D1 of the second part W22 to 0.5mm-1.5mm to ensure the connection strength between the electrode lead-out part 21 and the first tab 11 and reduce the risk of the main part 12 being burned.
  • the total number of turns of the tab layer 111 is N1, N2 turns of the tab layer 111 are connected through the first welding part W1, and the value of N2/N1 is 0.5-0.95.
  • N2/N1 The larger the value of N2/N1 is, the larger the number of turns of the tab layer 111 connected to the first welding part W1 is, and the lower the resistance of the electrode assembly 10 is. However, if the value of N2/N1 is too large, the laser may be irradiated outside the first tab 11 due to errors during welding, causing the risk of burning the main body 12 of the electrode assembly 10 .
  • the inventor set the value of N2/N1 to 0.5-0.95 to reduce resistance, increase overcurrent, and reduce the risk of electrode assembly 10 being burned.
  • the value of N2/N1 is 0.7-0.9.
  • neither the outermost tab layer 111 nor the innermost tab layer 111 is welded to other tab layers 111 .
  • the first welding portion W1 includes a plurality of first sub-welding portions W11 , and the plurality of first sub-welding portions W11 are arranged at intervals along the circumferential direction of the first tab 11 .
  • the tab layer 111 connected to one first sub-welding portion W11 and the tab layer 111 connected to another first sub-welding portion W11 may be the same tab layer 111; in another example, The tab layer 111 connected by one first sub-welding part W11 and the tab layer 111 connected by another first sub-welding part W11 may be different tab layers 111; The tab layer 111 connected to the part W11 is partly the same as the tab layer 111 connected to the other first sub-welding part W11, that is, a part of the tab layer 111 is connected to the first sub-welding part W11 and the other at the same time. The first sub-welding part W11.
  • the first welding portion W1 can be formed by multiple weldings, so as to reduce the heat generation of a single welding and reduce the risk of the electrode assembly 10 being burned by high temperature.
  • the first sub-welding portion W11 is straight, V-shaped, W-shaped or curved.
  • multiple second welding portions W2 are provided, the multiple second welding portions W2 are arranged at intervals, and at least two second welding portions W2 are connected to different tab layers 111 .
  • the plurality of second welding parts W2 can realize the current transmission between the first tab 11 and the electrode lead-out part 21, so as to reduce the difference in the conductive paths of different tab layers 111 and improve the current density. Uniformity, reducing the risk of pole piece polarization, and improving the overcurrent capability and charging efficiency of the battery cell 7.
  • the end of the multi-turn tab layer 111 facing the electrode lead-out portion 21 is bent and gathered to reduce the gap between the ends.
  • the ends of the tab layer 111 are used for welding to form a first welding portion W1 and a second welding portion W2.
  • the ends of the multi-turn tab layers 111 are bent and gathered to reduce the gap between the tab layers 111 and reduce the risk of laser leakage during the welding process.
  • the electrode lead-out part 21 includes a body part 211 and a connection part 212 , the connection part 212 surrounds the outside of the body part 211 , and the thickness of the connection part 212 is smaller than that of the body part 211 .
  • the connecting portion 212 is used for welding to the first tab 11 to form a second welding portion W2. In a direction parallel to the winding axis X, the first welding portion W1 at least partially overlaps the body portion 211 .
  • the energy required for welding the connecting portion 212 and the first tab 11 is reduced, thereby reducing the risk of the separator of the electrode assembly 10 being burned.
  • the lug layer 111 In the direction parallel to the winding axis X, a part of the lug layer 111 overlaps the body part 211; and because the thickness of the body part 211 is relatively large, it is difficult to directly weld with the lug layer 111, which results in the tab overlapping the body part 211
  • the conductive path of layer 111 is long.
  • the first welding part W1 is connected to the tab layer 111 overlapping with the body part 211 , so as to shorten the conductive path of the tab layer 111 , reduce the resistance, and improve the overcurrent capability.
  • the electrolyte injection hole is disposed on the body portion 211 .
  • the connecting portion 212 is an annular flat plate.
  • the electrode lead-out part 21 further includes a reinforcement part 213 protruding from the surface of the connection part 212 away from the electrode assembly 10 and connected to the body part 211 .
  • the portion of the connecting portion 212 not covered by the reinforcing portion 213 is used for welding to the first tab 11 to form a second welding portion W2.
  • the reinforcing portion 213 is provided to increase the strength of the electrode lead-out portion 21 , reduce deformation of the electrode lead-out portion 21 , and reduce the risk of cracking of the second welding portion W2 .
  • the plurality of reinforcing parts 213 can further increase the strength of the electrode lead-out part 21 and make the strength of the electrode lead-out part 21 more uniform.
  • the reinforcement part 213 is provided with transition slopes 213 a at both ends along the circumferential direction of the main body part 211 , and the transition slopes 213 a are connected to the outer surface of the connection part 212 .
  • FIG. 8 is a schematic structural view of an electrode assembly of a battery cell provided by other embodiments of the present application.
  • the first welding portion W1 is a helical structure arranged around the winding axis.
  • FIG. 9 is a schematic flowchart of a method for manufacturing a battery cell provided by some embodiments of the present application.
  • the manufacturing method of the battery cell in the embodiment of the present application includes:
  • the electrode assembly is provided with a first tab at one end, the first tab is wound around the winding axis of the electrode assembly and includes a multi-turn tab layer;
  • the casing includes an electrode lead-out part, and the first tab is located at one end of the electrode assembly facing the electrode lead-out part;
  • At least one circle of the tab layer is not welded to the electrode lead-out part.
  • Fig. 10 is a schematic block diagram of a battery cell manufacturing system provided by some embodiments of the present application.
  • the battery cell manufacturing system 90 of the embodiment of the present application includes:
  • the first providing device 91 provides an electrode assembly, the electrode assembly is provided with a first tab at one end, and the first tab is wound around the winding axis of the electrode assembly and includes a multi-turn tab layer;
  • the first welding device 92 is used to weld at least part of the multi-turn tab layer to form a first welding part
  • the second providing device 93 is used to provide a casing, and put the electrode assembly into the casing, the casing includes an electrode lead-out part, and the first tab is located at one end of the electrode assembly facing the electrode lead-out part;
  • the second welding device 94 is used to weld a part of the multi-turn tab layer to the electrode lead-out part and form a second welding part;
  • At least one circle of the tab layer is not welded to the electrode lead-out part.

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Abstract

本申请实施例提供一种电池单体及其制造方法和制造系统、电池以及用电装置。电池单体包括：外壳，包括电极引出部；电极组件，容纳于外壳内，电极组件在面向电极引出部的一端设有第一极耳，第一极耳绕电极组件的卷绕轴线卷绕设置且包括多圈极耳层，多圈极耳层中的至少部分焊接并形成第一焊接部。多圈极耳层中的一部分焊接于电极引出部并形成第二焊接部；在与第一焊接部相连的极耳层中，至少一圈极耳层未与电极引出部焊接。本申请能够提高电池单体的过流能力。

Description

电池单体及其制造方法和制造系统、电池及用电装置 技术领域
本申请涉及电池技术领域，并且更具体地，涉及一种电池单体及其制造方法和制造系统、电池以及用电装置。
背景技术
电池单体广泛用于电子设备，例如手机、笔记本电脑、电瓶车、电动汽车、电动飞机、电动轮船、电动玩具汽车、电动玩具轮船、电动玩具飞机和电动工具等等。电池单体可以包括镉镍电池单体、氢镍电池单体、锂离子电池单体和二次碱性锌锰电池单体等。
在电池技术的发展中，如何改善电池单体的过流能力，是电池技术中一个亟待解决的技术问题。
发明内容
本申请提供了一种电池单体及其制造方法和制造系统、电池以及用电装置，能够提高电池单体的过流能力。
第一方面，本申请实施例提供了一种电池单体，包括：
外壳，包括电极引出部；
电极组件，容纳于外壳内，电极组件在面向电极引出部的一端设有第一极耳，第一极耳绕电极组件的卷绕轴线卷绕设置且包括多圈极耳层，多圈极耳层中的至少部分焊接并形成第一焊接部；
其中，多圈极耳层中的一部分焊接于电极引出部并形成第二焊接部；在与第一焊接部相连的极耳层中，至少一圈极耳层未与电极引出部焊接。
上述方案中，通过将未与电极引出部焊接的极耳层焊接，以缩短极耳层之间的导电路径以及极耳层与电极引出部之间的导电路径，减小电阻，改善电流密度的均匀性，降低极片极化的风险，提高电池单体的过流能力和充电效率。
在一些实施例中，至少一圈极耳层连接于第一焊接部和第二焊接部。
上述方案中，该至少一圈极耳层能够将第一焊接部所汇集的电流传输到第二焊接部，以缩短第一焊接部和第二焊接部之间的导电路径，从而减小电阻，改善电流密度的均匀性，降低极片极化的风险，提高电池单体的过流能力和充电效率。
在一些实施例中，第一焊接部与第二焊接部直接相连。
上述方案中，第一焊接部汇集的电流能够直接流入第二焊接部，从而进一步缩 短第一焊接部和第二焊接部之间的导电路径，减小电阻，提高电池单体的过流能力和充电效率。
在一些实施例中，第二焊接部包括形成于电极引出部的第一部分和形成于第一极耳的第二部分。在平行于卷绕轴线的方向上，第二部分的尺寸大于第一焊接部的尺寸。
上述方案中，使第一焊接部具有较小的尺寸，以降低焊接第一极耳所需的能量，降低烧伤电极组件的风险；上述方案使第二部分的尺寸大于第一焊接部的尺寸，以保证电极引出部和第一极耳之间的连接强度，降低电池单体失效的风险。
在一些实施例中，在平行于卷绕轴线的方向上，第一焊接部的尺寸为0.2mm-0.5mm，第二部分的尺寸为0.5mm-1.5mm。
在一些实施例中，极耳层的总圈数为N1，N2圈的极耳层通过第一焊接部相连，N2/N1的值为0.5-0.95。
上述方案中，将N2/N1的值设置为0.5-0.95，以减小电阻、提高过流，并降低电极组件被烧伤的风险。
在一些实施例中，第一焊接部包括多个第一子焊接部，多个第一子焊接部沿第一极耳的周向间隔设置。
上述方案可以通过多次焊接来形成第一焊接部，以减小单次焊接的产热，降低电极组件被高温烧伤的风险。
在一些实施例中，第一子焊接部为直线形、V形、W形或曲线形。
在一些实施例中，第一焊接部为环绕卷绕轴线设置的螺旋状结构。
在一些实施例中，第二焊接部设置为多个，多个第二焊接部间隔设置，至少两个第二焊接部连接于不同的极耳层。
上述方案中，多个第二焊接部均可以实现第一极耳和电极引出部之间的电流传输，以减小不同极耳层的导电路径的差异，改善电流密度的均匀性，降低极片极化的风险，提高电池单体的过流能力和充电效率。
在一些实施例中，多圈极耳层的面向电极引出部的端部折弯并收拢，以减小端部之间的间隙。端部用于焊接，以形成第一焊接部和第二焊接部。
上述方案中，将多圈极耳层的端部折弯并收拢，以减小极耳层间的缝隙，降低在焊接过程中漏激光的风险。
在一些实施例中，电极引出部包括本体部和连接部，连接部环绕在本体部的外侧，且连接部的厚度小于本体部的厚度。连接部用于焊接于第一极耳以形成第二焊接部。在平行于卷绕轴线的方向上，第一焊接部与本体部至少部分地重叠。
上述方案中，通过减小连接部的厚度，以降低焊接连接部和第一极耳所需的能量，减小电极组件的隔离件被烧伤的风险。上述方案使第一焊接部连接到与本体部重叠的极耳层，以缩短极耳层的导电路径，减小电阻，提高过流能力。
在一些实施例中，电极引出部还包括加强部，加强部凸出于连接部的背离电极组件的表面并连接于本体部。连接部的未被加强部覆盖的部分用于焊接到第一极耳，以形成第二焊接部。
上述方案中，通过设置加强部，以增大电极引出部的强度，减小电极引出部的变形，降低第二焊接部开裂的风险。
在一些实施例中，加强部为多个，多个加强部沿着本体部的周向间隔设置。
上述方案中，多个加强部可以进一步增大电极引出部的强度，并使电极引出部的强度更为均匀。
在一些实施例中，外壳包括壳体和端盖，壳体具有开口，端盖盖合于壳体的开口。端盖为电极引出部。
上述方案中，将端盖作为电极引出部，这样可以省去传统的电极端子，从而简化电池单体的结构。上述方案将端盖直接与第一极耳焊接，这样可以省去传统的集流盘，从而降低成本，简化装配工艺。
在一些实施例中，电池单体为圆柱电池单体。
第二方面，本申请实施例提供了一种电池，包括多个第一方面任一实施例的电池单体。
第三方面，本申请实施例提供了一种用电装置，包括第二方面的电池，电池用于提供电能。
第四方面，本申请实施例提供了一种电池单体的制造方法，包括：
提供电极组件，电极组件在一端设有第一极耳，第一极耳绕电极组件的卷绕轴线卷绕设置且包括多圈极耳层；
将多圈极耳层中的至少部分焊接并形成第一焊接部；
提供外壳，并将电极组件放入外壳内，外壳包括电极引出部，第一极耳位于电极组件的面向电极引出部的一端；
将多圈极耳层中的一部分焊接于电极引出部并形成第二焊接部；
其中，在与第一焊接部相连的极耳层中，至少一圈极耳层未与电极引出部焊接。
第五方面，本申请实施例提供了一种电池单体的制造系统，包括：
第一提供装置，提供电极组件，电极组件在一端设有第一极耳，第一极耳绕电极组件的卷绕轴线卷绕设置且包括多圈极耳层；
第一焊接装置，用于将多圈极耳层中的至少部分焊接并形成第一焊接部；
第二提供装置，用于提供外壳，并将电极组件放入外壳内，外壳包括电极引出部，第一极耳位于电极组件的面向电极引出部的一端；
第二焊接装置，用于将多圈极耳层中的一部分焊接于电极引出部并形成第二焊接部；
其中，在与第一焊接部相连的极耳层中，至少一圈极耳层未与电极引出部焊接。
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爆炸示意图；
图3为图2所示的电池模块的结构示意图；
图4为本申请一些实施例提供的电池单体的剖视示意图；
图5为图4所示的电池单体在圆框A处的放大示意图；
图6为本申请一些实施例提供的电池单体的电极组件的结构示意图；
图7为本申请一些实施例提供的电池单体的俯视示意图；
图8为本申请另一些实施例提供的电池单体的电极组件的结构示意图；
图9为本申请一些实施例提供的电池单体的制造方法的流程示意图；
图10为本申请一些实施例提供的电池单体的制造系统的示意性框图。
在附图中，附图并未按照实际的比例绘制。
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)，“多圈”指的是两圈以上(包括两圈)。
本申请中，电池单体可以包括锂离子二次电池单体、锂离子一次电池单体、锂硫电池单体、钠锂离子电池单体、钠离子电池单体或镁离子电池单体等，本申请实施例对此并不限定。
本申请的实施例所提到的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。例如，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
电池单体包括电极组件和电解质，电极组件包括正极极片、负极极片和隔离件。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；正极集流体包括正极集流部和连接于正极集流部的正极极耳，正极集流部涂覆有正极活性物质层，正极极耳未涂覆正极活性物质层。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质层包括正极活性物质，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；负极集流体包括负极集流部和连接于负极集流部的负极极耳，负极集流部涂覆有负极活性物质层，负极极耳未涂覆负极活性物质层。负极集流体的材料可以为铜，负极活性物质层包括负极活性物质，负极活性物质可以为碳或硅等。隔离件的材质可以为PP(polypropylene，聚丙烯)或PE(polyethylene，聚乙烯)等。
电池单体还包括外壳，外壳用于容纳电极组件和电解质。外壳包括壳体和连接于壳体的端盖，壳体和端盖形成容纳腔，以容纳电极组件和电解质。电极组件可电连接于端盖，也可电连接于设置于端盖上的电极端子。
电极组件一般通过极耳来输入和输出电流。为了提高极耳的过流能力，发明人尝试将极耳设置为卷绕结构。卷绕式的极耳包括多圈极耳层，多圈极耳层沿卷绕方向首尾相连。与相关技术中的极耳相比，卷绕式的极耳具有更大的过流面积、更强的耐大电流能力。
然而，发明人发现，当极耳与外壳的电极引出部相连时，受到电极引出部的形状、位置等因素的限制，能够直接与电极引出部焊接的极耳层比较有限，这导致未与电极引出部焊接的极耳层与电极引出部之间的导电路径偏长，造成电极组件的电阻偏大、电流密度不均，引发极片极化的风险，影响电池单体的过流能力和充电效率。
鉴于此，本申请实施例提供一种技术方案，通过将未与电极引出部焊接的极耳层焊接，以缩短极耳层之间的导电路径以及极耳层与电极引出部之间的导电路径，减小电极组件的电阻，改善电流密度的均匀性，降低极片极化的风险，提高电池单体的过流能力和充电效率。
本申请实施例描述的技术方案适用于电池以及使用电池的用电装置。
用电装置可以是车辆、手机、便携式设备、笔记本电脑、轮船、航天器、电动玩具和电动工具等等。车辆可以是燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等；航天器包括飞机、火箭、航天飞机和宇宙飞船等等；电动玩具包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等；电动工具包括金属切削电动工具、研磨电动工具、装配电动工具和铁道用电动工具，例如，电钻、电动砂轮机、电动扳手、电动螺丝刀、电锤、冲击电钻、混凝土振动器和电刨等等。本申请实施例对上述用电装置不做特殊限制。
以下实施例为了方便说明，以用电装置为车辆为例进行说明。
图1为本申请一些实施例提供的车辆的结构示意图。
如图1所示，车辆1的内部设置有电池2，电池2可以设置在车辆1的底部或头部或尾部。电池2可以用于车辆1的供电，例如，电池2可以作为车辆1的操作电源。
车辆1还可以包括控制器3和马达4，控制器3用来控制电池2为马达4供电，例如，用于车辆1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2不仅仅可以作为车辆1的操作电源，还可以作为车辆1的驱动电源，代替或部分地代替燃油或天然气为车辆1提供驱动动力。
图2为本申请一些实施例提供的电池的爆炸示意图。
如图2所示，电池2包括箱体5和电池单体(图2未示出)，电池单体容纳于箱体5内。
箱体5用于容纳电池单体，箱体5可以是多种结构。在一些实施例中，箱体5可以包括第一箱体部5a和第二箱体部5b，第一箱体部5a与第二箱体部5b相互盖合，第一箱体部5a和第二箱体部5b共同限定出用于容纳电池单体的容纳空间5c。第二箱体部5b可以是一端开口的空心结构，第一箱体部5a为板状结构，第一箱体部5a盖合于第二箱体部5b的开口侧，以形成具有容纳空间5c的箱体5；第一箱体部5a和第二箱体部5b也均可以是一侧开口的空心结构，第一箱体部5a的开口侧盖合于第二箱体部5b的开口侧，以形成具有容纳空间5c的箱体5。当然，第一箱体部5a和第二箱体部5b可以是多种形状，比如，圆柱体、长方体等。
为提高第一箱体部5a与第二箱体部5b连接后的密封性，第一箱体部5a与第二箱体部5b之间也可以设置密封件，比如，密封胶、密封圈等。
假设第一箱体部5a盖合于第二箱体部5b的顶部，第一箱体部5a亦可称之为上箱盖，第二箱体部5b亦可称之为下箱体。
在电池2中，电池单体可以是一个，也可以是多个。若电池单体为多个，多个电池单体之间可串联或并联或混联，混联是指多个电池单体中既有串联又有并联。多个电池单体之间可直接串联或并联或混联在一起，再将多个电池单体构成的整体容纳于箱体5内；当然，也可以是多个电池单体先串联或并联或混联组成电池模块6，多个电池模块6再串联或并联或混联形成一个整体，并容纳于箱体5内。
图3为图2所示的电池模块的结构示意图。
在一些实施例中，如图3所示，电池单体7为多个，多个电池单体7先串联或并联或混联组成电池模块6。多个电池模块6再串联或并联或混联形成一个整体，并容纳于箱体内。
电池模块6中的多个电池单体7之间可通过汇流部件实现电连接，以实现电池模块6中的多个电池单体7的并联或串联或混联。汇流部件可为一个或多个，各汇流部件用于将至少两个电池单体电连接。
图4为本申请一些实施例提供的电池单体的剖视示意图；图5为图4所示的电池单体在圆框A处的放大示意图；图6为本申请一些实施例提供的电池单体的电极组件的结构示意图；图7为本申请一些实施例提供的电池单体的俯视示意图。
如图4至图7所示，本申请实施例提供了一种电池单体7，其包括：外壳20，包括电极引出部21；电极组件10，容纳于外壳20内，电极组件10在面向电极引出部21的一端设有第一极耳11，第一极耳11绕电极组件10的卷绕轴线X卷绕设置且包括多圈极耳层111，多圈极耳层111中的至少部分焊接并形成第一焊接部W1。多圈极耳层111中的一部分焊接于电极引出部21并形成第二焊接部W2；在与第一焊接部W1相连的极耳层111中，至少一圈极耳层111未与电极引出部21焊接。
电极组件10包括第一极片、第二极片和隔离件，隔离件用于将第一极片和第二极片隔开。第一极片和第二极片的极性相反，换言之，第一极片和第二极片中的一者为正极极片，第一极片和第二极片中的另一者为负极极片。
第一极片、第二极片和隔离件均为带状结构，第一极片、第二极片和隔离件绕卷绕轴线X卷绕为一体并形成卷绕结构。卷绕结构可以为圆柱状结构、扁平状结构或其它形状的结构。
从电极组件10的外形看，电极组件10包括主体部12、第一极耳11和第二极耳13，第一极耳11和第二极耳13凸出于主体部12。第一极耳11为第一极片的未涂覆活性物质层的部分，第二极耳13为第二极片的未涂覆活性物质层的部分。对应地，第一极耳11和第二极耳13中的一者为正极性的极耳，另一者为负极性的极耳。
第一极耳11和第二极耳13分别设于主体部12的两侧，换言之，第一极耳11和第二极耳13分别设于电极组件10的两端。可选地，沿平行于卷绕轴线X的方向，第一极耳11和第二极耳13分别设于电极组件10的两端。
第一极耳11环绕电极组件10的卷绕轴线X卷绕，且第一极耳11大体为柱体状。第一极耳11包括环绕卷绕轴线X设置的多圈极耳层111。示例性地，第一极耳11包括N1圈极耳层111，N1为大于1的正整数。
第一极耳11沿卷绕方向Y的两端分别为内端11a和外端11b，本实施例以第一极耳11的内端11a为基准划分极耳层111。卷绕方向Y垂直于卷绕轴线X。
具体地，第一极耳11的内端11a为第一圈极耳层111的首端，第一圈极耳层111的尾端与第一圈极耳层111的首端在第一极耳11的径向上对齐，第一圈极耳层111环绕卷绕轴线X一圈。对应地，第一圈极耳层111的尾端即为第二圈极耳层111的首端，以此类推，N1圈极耳层111沿卷绕方向Y首尾相连。在划分极耳层111时，每圈 极耳层111的首端与第一极耳11的内端11a沿第一极耳11的径向上对齐。第一极耳11的径向垂直于卷绕轴线X并通过卷绕轴线X。
示例性地，第一极耳11的内端11a和外端11b在第一极耳11的径向上对齐，这样，每一圈极耳层111环绕卷绕轴线X一圈。
当然，可替代地，第一极耳11的尾部存着一部分，该部分环绕卷绕轴线X不足一圈，例如，该部分可以环绕卷绕轴线1/3圈、1/2圈、2/3圈或3/4圈。
在卷绕完成后，第一极耳11大体为柱体状，相邻的两圈极耳层111之间留有缝隙。本申请实施例可以对第一极耳11进行处理，以减小极耳层111间的缝隙，便于第一极耳11与电极引出部21连接。例如，本申请实施例可对第一极耳11进行揉平处理，以使第一极耳11的远离主体部12的端部区域收拢、集合在一起。揉平处理是通过揉平装置对第一极耳11远离主体部12的端部区域进行整形，以把第一极耳11的端部区域压实并形成致密的端面，减小极耳层111间的缝隙，便于第一极耳11与电极引出部21焊接。
可选地，第二极耳13环绕电极组件10的卷绕轴线X卷绕为多圈，第二极耳13包括多圈极耳层。示例性地，且第二极耳13也经过了揉平处理，以减小第二极耳13的极耳层间的缝隙。
外壳20可以是多种结构形式。例如，外壳20可以包括壳体22和端盖23，壳体22为具有开口的空心结构，端盖23盖合于壳体22的开口处并形成密封连接，以形成用于容纳电极组件10和电解质的密封空间。
壳体22可以是多种形状，比如，圆柱体、长方体等。壳体22的形状可根据电极组件10的具体形状来确定。比如，若电极组件10为圆柱体结构，则可选用为圆柱体壳体；若电极组件10为长方体结构，则可选用长方体壳体。当然，端盖23也可以是多种结构，比如，端盖23为板状结构、空心结构等。示例性的，壳体22为圆柱体结构，端盖23为板状结构，端盖23盖合于壳体22的开口。
在一些示例中，外壳20包括壳体22和一个端盖23，壳体22为在一侧开口的空心结构，端盖23盖合于壳体22的开口处。在另一些示例中，外壳20包括壳体22和两个端盖23，壳体22为相对的两侧开口的空心结构，每个端盖23对应盖合于壳体22的对应一个开口处。
端盖23可直接连接于壳体22，也可以通过其它构件连接于壳体22。示例性地，外壳20还包括固定件24，固定件24用于将端盖23固定于壳体22。例如，固定件24环绕在端盖23的外侧并夹持端盖23的边缘，以实现固定件24与端盖23的连接；固定件24的外缘焊接于壳体22，以实现固定件24与壳体22的连接。
外壳20还包括密封构件25，密封构件25用于密封壳体22的开口，提高电池单体7的密封性能。示例性地，密封构件25可夹持于固定件24与端盖23之间。
密封构件25的材质可为PP(polypropylene，聚丙烯)、PE(polyethylene，聚乙烯)或者氟橡胶。可选地，密封构件25由绝缘材料制成，其能够将端盖23和壳体22绝缘隔开。
在一些示例中，端盖23设有电解质注入孔，电解质注入孔沿端盖23的厚度方 向贯通端盖23。在电池单体7的电解质注入工序中，电解质经由电解质注入孔进入电池单体7内部。电池单体7还包括密封板26，连接于端盖23并覆盖电解质注入孔，用于在电解质注入工序完成后，密封电解质注入孔。
外壳20包括电极引出部21，电极引出部21用于将电极组件10中的电流引出，以输出电极组件10所产生的电能。电极引出部21可以为端盖23，可以为壳体22，也可以为外壳20的其它部分，本实施例对此不作限制，只要能够将电流引出即可。例如，在一些示例中，端盖23作为电极引出部21并电连接于电极组件10。可替代地，外壳20还包括设置于端盖23的电极端子(未示出)，电极端子作为电极引出部21并电连接于电极组件10。
在第一极耳11中，N2圈极耳层111通过焊接相连并形成第一焊接部W1。N2为正整数，且2≤N2≤N1。示例性地，第一极耳11经过揉平处理后，在第一极耳11的背离主体部12的端面照射激光，激光将N2圈极耳层111焊接并形成第一焊接部W1。
N2圈极耳层111通过第一焊接部W1相连接，这样可以缩短这N2圈极耳层111之间的导电路径，以达到减小电阻的目的。
N2圈极耳层111可沿卷绕方向Y连续设置。可替代地，在N2圈极耳层111中，一部分极耳层111沿卷绕方向Y连续设置，另一部分极耳层111沿卷绕方向Y连续设置，该一部分极耳层111与该另一部分极耳层111之间可设置有不与第一焊接部W1相连的其它极耳层111。
在第一极耳11中，M圈极耳层111焊接于电极引出部21并形成第二焊接部W2。M为正整数，且1≤M＜N1。示例性地，在电极组件10放入外壳20之内后，激光作用在电极引出部21的外表面，激光将电极引出部21的部分和M圈极耳层111焊接并形成第二焊接部W2。
在该M圈极耳层111中，各极耳层111的电流可以通过第二焊接部W2传输到电极引出部21，而无需流经其它极耳层111，这样可以缩短这M圈极耳层111的导电路径、减小电阻。
N2圈极耳层111和M圈极耳层111之间可以存着交集；换言之，一部分的极耳层111既用于形成第一焊接部W1，也用于形成第二焊接部W2。当然，可替代地，N2圈极耳层111和M圈极耳层111之间不存在交集；换言之，用于形成第一焊接部W1的极耳层111不同于用于形成第二焊接部W2的极耳层111。
在N2圈极耳层111中，N3圈极耳层111未与电极引出部21焊接。N3为正整数，且2≤N3≤N2。
该N3圈极耳层111未与电极引出部21焊接，因此，该N3圈极耳层111上的电流需要通过与电极引出部21焊接相连的极耳层111传输到电极引出部21。如果该N3圈极耳层111未通过第一焊接部W1相连，那么，在该N3圈极耳层111中，远离第二焊接部W2的极耳层111上的电流需要流过靠近第二焊接部W2的极耳层111，这造成导电路径偏长、电阻偏大。而本实施例通过将该N3圈极耳层111焊接，使电流可以直接通过第一焊接部W1传输，从而缩短该N3圈极耳层111之间的导电路径，以达到减小电阻的目的。
第一焊接部W1和第二焊接部W2可以直接连接，也可以通过极耳层111间接地连接。
在本申请的电池单体7中，通过将未与电极引出部21焊接的极耳层111焊接，以缩短极耳层111之间的导电路径以及极耳层111与电极引出部21之间的导电路径，减小电阻，改善电流密度的均匀性，降低极片极化的风险，提高电池单体7的过流能力和充电效率。
在一些实施例中，外壳20包括壳体22和端盖23，壳体22具有开口，端盖23盖合于壳体22的开口。端盖23为电极引出部21。
本实施例将端盖23作为电极引出部21，这样可以省去传统的电极端子，从而简化电池单体7的结构。
本实施例将端盖23直接与第一极耳11焊接，这样可以省去传统的集流盘，从而降低成本，简化装配工艺。焊接时，激光作用在端盖23的外表面，这样，壳体22和端盖23可以从外侧保护电极组件10，以降低焊接产生的金属颗粒溅射到电极组件10的风险。
在一些实施例中，电池单体7为圆柱电池单体。对应地，电极组件10为圆柱结构，壳体22为圆柱状的中空结构。
在一些实施例中，至少一圈极耳层111连接于第一焊接部W1和第二焊接部W2。
在本实施例中，该至少一圈极耳层111能够将第一焊接部W1所汇集的电流传输到第二焊接部W2，以缩短第一焊接部W1和第二焊接部W2之间的导电路径，从而减小电阻，改善电流密度的均匀性，降低极片极化的风险，提高电池单体7的过流能力和充电效率。
在一些实施例中，第一焊接部W1与第二焊接部W2直接相连。
在电池单体7的装配过程中，先焊接电极组件10的第一极耳11以形成第一焊接部W1，然后在将电极组件10放入外壳20内之后再焊接电极引出部21和第一极耳11，以形成第二焊接部W2。
在焊接电极引出部21和第一极耳11时，第一焊接部W1的部分熔化并与电极引出部21连接，从而使形成的第二焊接部W2与第一焊接部W1交叉并直接相连。
本实施例使第一焊接部W1与第二焊接部W2直接相连，以使第一焊接部W1汇集的电流能够直接流入第二焊接部W2，从而进一步缩短第一焊接部W1和第二焊接部W2之间的导电路径，减小电阻，提高电池单体7的过流能力和充电效率。
在另一些实施例中，第一焊接部W1与第二焊接部W2也可以在第一极耳11的周向上间隔设置。例如，对于同时连接于第一焊接部W1和第二焊接部W2的极耳层111，极耳层111的连接于第一焊接部W1的部分与极耳层111的连接于第二焊接部W2的部分在第一极耳11的周向上间隔设置。
在一些实施例中，第二焊接部W2包括形成于电极引出部21的第一部分W21和形成于第一极耳11的第二部分W22。在平行于卷绕轴线X的方向上，第二部分W22的尺寸D1大于第一焊接部W1的尺寸D2。
示例性地，电极引出部21的厚度方向平行于卷绕轴线X。
在平行于卷绕轴线X的方向上，第二焊接部W2与主体部12之间的距离小于第一焊接部W1与主体部12之间的距离。
在焊接电极引出部21和第一极耳11的工艺中，电极引出部21的一部分经过熔化、凝固等过程之后形成第一部分W21，前述M圈极耳层111经过熔化、凝固等过程之后形成第二部分W22。第一部分W21和第二部分W22形成原子层级结合的整体，以减小第一极耳11和电极引出部21之间的电阻，提高过流能力。
在焊接第一极耳11时，激光直接作用在第一极耳11上，虽然第一极耳11经过了揉平处理，但如果激光的能量过高，激光仍然可能会从极耳层111之间穿过并烧伤隔离件，引发安全风险。因此，本实施例一般采用低能量激光来焊接第一极耳11的极耳层111，对应地，第一焊接部W1的尺寸D2也相对较小。
第一极耳11的多圈极耳层111是一体连接地，即使第一焊接部W1因强度较低而出现裂纹，电流也可以在极耳层111之间传输，也就是说，裂纹对电流的传输的影响较小。因此，本实施例对第一焊接部W1的强度要求较低，第一焊接部W1可以具有相对较小的尺寸。
第二焊接部W2需要连接电极引出部21和第一极耳11，如果第二部分W22的尺寸D1等于或小于第一焊接部W1的尺寸D2，那么第二部分W22的强度偏低、容易开裂，这会影响电池单体7的过流能力，甚至导致电池单体7失效。
本实施例使第一焊接部W1具有较小的尺寸，以降低焊接第一极耳11所需的能量，降低烧伤电极组件10的风险；本实施例使第二部分W22的尺寸D1大于第一焊接部W1的尺寸D2，以保证电极引出部21和第一极耳11之间的连接强度，降低电池单体7失效的风险。
在一些实施例中，在平行于卷绕轴线X的方向上，第一焊接部W1的尺寸D2为0.2mm-0.5mm，第二部分W22的尺寸D1为0.5mm-1.5mm。
第一焊接部W1的尺寸D2越小，第一焊接部W1的强度越低，第一焊接部W1开裂和失效的风险也越高；第一焊接部W1的尺寸D2越大，焊接所需的能量也越大，激光烧伤电极组件10的主体部12的风险也越高。发明人经过试验，将第一焊接部W1的尺寸D2设置为0.2mm-0.5mm，可以使焊接第一极耳11所需的能量符合要求，并尽可能的保证第一焊接部W1的强度。
第二部分W22的尺寸D1越小，电极引出部21和第一极耳11之间的连接强度越低；第二部分W22的尺寸D1越大，第二部分W22与主体部12的间距越小，焊接产生的热量烧伤主体部12的风险也越高。发明人经过试验，将第二部分W22的尺寸D1设置为0.5mm-1.5mm，以保证电极引出部21和第一极耳11之间的连接强度，并降低主体部12被烧伤的风险。
在一些实施例中，极耳层111的总圈数为N1，N2圈的极耳层111通过第一焊接部W1相连，N2/N1的值为0.5-0.95。
N2/N1的值越大，第一焊接部W1所连接的极耳层111的圈数越多，电极组件10的电阻越小。但是，如果N2/N1的值过大，在焊接时，激光可能会因为误差而照射到第一极耳11外，引发电极组件10的主体部12被烧伤的风险。
发明人经过试验，将N2/N1的值设置为0.5-0.95，以减小电阻、提高过流，并降低电极组件10被烧伤的风险。
在一些实施例中，N2/N1的值为0.7-0.9。
在一些实施例中，最外圈的极耳层111和最内圈的极耳层111均未与其它极耳层111焊接。
在一些实施例中，第一焊接部W1包括多个第一子焊接部W11，多个第一子焊接部W11沿第一极耳11的周向间隔设置。
在一些示例中，一个第一子焊接部W11所连接的极耳层111与另一个第一子焊接部W11所连接的极耳层111可以为相同的极耳层111；在另一个示例中，一个第一子焊接部W11所连接的极耳层111与另一个第一子焊接部W11所连接的极耳层111可以为不同的极耳层111；在又一示例中，一个第一子焊接部W11所连接的极耳层111与另一个第一子焊接部W11所连接的极耳层111部分地相同，即一部分极耳层111同时连接于该一个第一子焊接部W11和该另一个第一子焊接部W11。
本实施例可以通过多次焊接来形成第一焊接部W1，以减小单次焊接的产热，降低电极组件10被高温烧伤的风险。
在一些实施例中，第一子焊接部W11为直线形、V形、W形或曲线形。
在一些实施例中，第二焊接部W2设置为多个，多个第二焊接部W2间隔设置，至少两个第二焊接部W2连接于不同的极耳层111。
在本实施例中，多个第二焊接部W2均可以实现第一极耳11和电极引出部21之间的电流传输，以减小不同极耳层111的导电路径的差异，改善电流密度的均匀性，降低极片极化的风险，提高电池单体7的过流能力和充电效率。
在一些实施例中，多圈极耳层111的面向电极引出部21的端部折弯并收拢，以减小端部之间的间隙。极耳层111的端部用于焊接，以形成第一焊接部W1和第二焊接部W2。
本实施例将多圈极耳层111的端部折弯并收拢，以减小极耳层111间的缝隙，降低在焊接过程中漏激光的风险。
在一些实施例中，电极引出部21包括本体部211和连接部212，连接部212环绕在本体部211的外侧，且连接部212的厚度小于本体部211的厚度。连接部212用于焊接于第一极耳11以形成第二焊接部W2。在平行于卷绕轴线X的方向上，第一焊接部W1与本体部211至少部分地重叠。
本实施例通过减小连接部212的厚度，以降低焊接连接部212和第一极耳11所需的能量，减小电极组件10的隔离件被烧伤的风险。
在平行于卷绕轴线X的方向上，一部分极耳层111与本体部211重叠；而由于本体部211厚度较大，难以直接与极耳层111焊接，这导致与本体部211重叠的极耳层111的导电路径偏长。本实施例使第一焊接部W1连接到与本体部211重叠的极耳层111，以缩短极耳层111的导电路径，减小电阻，提高过流能力。
在一些实施例中，电解质注入孔设置于本体部211。
在一些实施例中，连接部212为环形的平板。
在一些实施例中，电极引出部21还包括加强部213，加强部213凸出于连接部212的背离电极组件10的表面并连接于本体部211。连接部212的未被加强部213覆盖的部分用于焊接到第一极耳11，以形成第二焊接部W2。
本实施例通过设置加强部213，以增大电极引出部21的强度，减小电极引出部21的变形，降低第二焊接部W2开裂的风险。
在一实施例中，加强部213为多个，多个加强部213沿着本体部211的周向间隔设置。
在本实施例中，多个加强部213可以进一步增大电极引出部21的强度，并使电极引出部21的强度更为均匀。
在一些实施例中，加强部213沿本体部211的周向的两端设置有过渡斜面213a，过渡斜面213a与连接部212的外表面相连。
图8为本申请另一些实施例提供的电池单体的电极组件的结构示意图。
如图8所示，在一些实施例中，第一焊接部W1为环绕卷绕轴线设置的螺旋状结构。
图9为本申请一些实施例提供的电池单体的制造方法的流程示意图。
如图9所示，本申请实施例的电池单体的制造方法包括：
S100、提供电极组件，电极组件在一端设有第一极耳，第一极耳绕电极组件的卷绕轴线卷绕设置且包括多圈极耳层；
S200、将多圈极耳层中的至少部分焊接并形成第一焊接部；
S300、提供外壳，并将电极组件放入外壳内，外壳包括电极引出部，第一极耳位于电极组件的面向电极引出部的一端；
S400、将多圈极耳层中的一部分焊接于电极引出部并形成第二焊接部；
其中，在与第一焊接部相连的极耳层中，至少一圈极耳层未与电极引出部焊接。
需要说明的是，通过上述电池单体的制造方法制造出的电池单体的相关结构，可参见上述各实施例提供的电池单体。
图10为本申请一些实施例提供的电池单体的制造系统的示意性框图。
如图10所示，本申请实施例的电池单体的制造系统90包括：
第一提供装置91，提供电极组件，电极组件在一端设有第一极耳，第一极耳绕电极组件的卷绕轴线卷绕设置且包括多圈极耳层；
第一焊接装置92，用于将多圈极耳层中的至少部分焊接并形成第一焊接部；
第二提供装置93，用于提供外壳，并将电极组件放入外壳内，外壳包括电极引出部，第一极耳位于电极组件的面向电极引出部的一端；
第二焊接装置94，用于将多圈极耳层中的一部分焊接于电极引出部并形成第二焊接部；
其中，在与第一焊接部相连的极耳层中，至少一圈极耳层未与电极引出部焊接。
通过上述制造系统制造出的电池单体的相关结构，可参见上述各实施例提供的电池单体。
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 相互组合。
最后应说明的是：以上实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换，但这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的精神和范围。

Claims (20)

  1. 一种电池单体，包括：
    外壳，包括电极引出部；
    电极组件，容纳于所述外壳内，所述电极组件在面向所述电极引出部的一端设有第一极耳，所述第一极耳绕所述电极组件的卷绕轴线卷绕设置且包括多圈极耳层，所述多圈极耳层中的至少部分焊接并形成第一焊接部；
    其中，所述多圈极耳层中的一部分焊接于所述电极引出部并形成第二焊接部；在与所述第一焊接部相连的所述极耳层中，至少一圈所述极耳层未与所述电极引出部焊接。
  2. 根据权利要求1所述的电池单体，其中，至少一圈所述极耳层连接于所述第一焊接部和所述第二焊接部。
  3. 根据权利要求2所述的电池单体，其中，所述第一焊接部与所述第二焊接部直接相连。
  4. 根据权利要求1-3中任一项所述的电池单体，其中，所述第二焊接部包括形成于所述电极引出部的第一部分和形成于所述第一极耳的第二部分；
    在平行于所述卷绕轴线的方向上，所述第二部分的尺寸大于所述第一焊接部的尺寸。
  5. 根据权利要求4所述的电池单体，其中，在平行于所述卷绕轴线的方向上，所述第一焊接部的尺寸为0.2mm-0.5mm，所述第二部分的尺寸为0.5mm-1.5mm。
  6. 根据权利要求1-5中任一项所述的电池单体，其中，所述极耳层的总圈数为N1，N2圈的所述极耳层通过所述第一焊接部相连，N2/N1的值为0.5-0.95。
  7. 根据权利要求1-6中任一项所述的电池单体，其中，所述第一焊接部包括多个第一子焊接部，多个所述第一子焊接部沿所述第一极耳的周向间隔设置。
  8. 根据权利要求7所述的电池单体，其中，所述第一子焊接部为直线形、V形、W形或曲线形。
  9. 根据权利要求1-6中任一项所述的电池单体，其中，所述第一焊接部为环绕所述卷绕轴线设置的螺旋状结构。
  10. 根据权利要求1-6中任一项所述的电池单体，其中，所述第二焊接部设置为多个，多个所述第二焊接部间隔设置，至少两个所述第二焊接部连接于不同的所述极耳层。
  11. 根据权利要求1-10中任一项所述的电池单体，其中，所述多圈极耳层的面向所述电极引出部的端部折弯并收拢，以减小所述端部之间的间隙；
    所述端部用于焊接，以形成所述第一焊接部和所述第二焊接部。
  12. 根据权利要求1-11中任一项所述的电池单体，其中，所述电极引出部包括本体部和连接部，所述连接部环绕在所述本体部的外侧，且所述连接部的厚度小于所述本体部的厚度；
    所述连接部用于焊接于所述第一极耳以形成所述第二焊接部；在平行于所述卷绕 轴线的方向上，所述第一焊接部与所述本体部至少部分地重叠。
  13. 根据权利要求12所述的电池单体，其中，所述电极引出部还包括加强部，所述加强部凸出于所述连接部的背离所述电极组件的表面并连接于所述本体部；
    所述连接部的未被所述加强部覆盖的部分用于焊接到所述第一极耳，以形成所述第二焊接部。
  14. 根据权利要求13所述的电池单体，其中，所述加强部为多个，多个所述加强部沿着所述本体部的周向间隔设置。
  15. 根据权利要求1-14中任一项所述的电池单体，其中，所述外壳包括壳体和端盖，所述壳体具有开口，所述端盖盖合于所述壳体的开口；
    所述端盖为所述电极引出部。
  16. 根据权利要求1-15中任一项所述的电池单体，其中，所述电池单体为圆柱电池单体。
  17. 一种电池，包括多个根据权利要求1-16中任一项所述的电池单体。
  18. 一种用电装置，包括根据权利要求17所述的电池，所述电池用于提供电能。
  19. 一种电池单体的制造方法，包括：
    提供电极组件，所述电极组件在一端设有第一极耳，所述第一极耳绕所述电极组件的卷绕轴线卷绕设置且包括多圈极耳层；
    将所述多圈极耳层中的至少部分焊接并形成第一焊接部；
    提供外壳，并将所述电极组件放入所述外壳内，所述外壳包括电极引出部，所述第一极耳位于所述电极组件的面向所述电极引出部的一端；
    将所述多圈极耳层中的一部分焊接于所述电极引出部并形成第二焊接部；
    其中，在与所述第一焊接部相连的所述极耳层中，至少一圈所述极耳层未与所述电极引出部焊接。
  20. 一种电池单体的制造系统，包括：
    第一提供装置，提供电极组件，所述电极组件在一端设有第一极耳，所述第一极耳绕所述电极组件的卷绕轴线卷绕设置且包括多圈极耳层；
    第一焊接装置，用于将所述多圈极耳层中的至少部分焊接并形成第一焊接部；
    第二提供装置，用于提供外壳，并将所述电极组件放入所述外壳内，所述外壳包括电极引出部，所述第一极耳位于所述电极组件的面向所述电极引出部的一端；
    第二焊接装置，用于将所述多圈极耳层中的一部分焊接于所述电极引出部并形成第二焊接部；
    其中，在与所述第一焊接部相连的所述极耳层中，至少一圈所述极耳层未与所述电极引出部焊接。
PCT/CN2021/121845 2021-09-29 2021-09-29 电池单体及其制造方法和制造系统、电池及用电装置 WO2023050197A1 (zh)

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