WO2024031427A1 - 极片、电极组件、电池单体、电池以及用电装置 - Google Patents

极片、电极组件、电池单体、电池以及用电装置 Download PDF

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Publication number
WO2024031427A1
WO2024031427A1 PCT/CN2022/111388 CN2022111388W WO2024031427A1 WO 2024031427 A1 WO2024031427 A1 WO 2024031427A1 CN 2022111388 W CN2022111388 W CN 2022111388W WO 2024031427 A1 WO2024031427 A1 WO 2024031427A1
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WIPO (PCT)
Prior art keywords
tab
edge
pole
pole piece
area
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Application number
PCT/CN2022/111388
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English (en)
French (fr)
Inventor
许虎
牛少军
金海族
赵丰刚
黄思应
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.)
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Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to PCT/CN2022/111388 priority Critical patent/WO2024031427A1/zh
Publication of WO2024031427A1 publication Critical patent/WO2024031427A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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

Definitions

  • the present application relates to the field of battery technology, and more specifically, to a pole piece, an electrode assembly, a battery cell, a battery and an electrical device.
  • Battery cells are widely used in electronic devices, such as mobile phones, laptops, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, electric tools, etc.
  • the present application provides a pole piece, electrode assembly, battery cell, battery and electrical device, which can improve the production yield of pole tabs.
  • embodiments of the present application provide a pole piece, including: a current collector and an active material layer; the current collector includes a coating area and a tab area arranged side by side along a first direction; The current collector includes a plurality of tab portions arranged side by side along the second direction, and the first direction intersects the second direction; the active material layer is coated on the coating area; wherein, the current collector
  • the buffer area includes a buffer portion extending in the second direction and connecting the plurality of tab portions, and the buffer portion is configured to absorb the bending stress of the plurality of tab portions.
  • a buffer zone is provided between the tab area and the coating area, so that the stress generated by the tab portion in the tab area during subsequent bending is transferred to the buffer area and is transferred by the buffer area. stress, reduce the possibility of damage to the root of the pole lug, reduce or even eliminate the impact of the stress generated on the pole lug on the coating area, reduce the risk of the active material layer falling in the coating area, and improve the yield of the pole piece .
  • the size of the tab portion in the first direction is H1
  • the size of the buffer portion in the first direction is H2
  • H1 and H2 satisfy: H1 ⁇ H2.
  • the larger the size of the tab portion in the first direction the more the tab plane area formed by the tab portion after bending has more tab coverage, which is conducive to ensuring that the current collector is consistent with the shaped pole. Connect the lug to other components and increase the flow area of the lug.
  • the size of the tab portion in the second direction is W1
  • the size of the tab portion in the first direction is H1.
  • H1 and W1 satisfy: 3W1 ⁇ H1 ⁇ 0.5W1.
  • the larger the size of the pole lug in the second direction the higher the difficulty of bending the pole lug. If the size of the pole lug in the second direction is too large, the bending of the pole lug will be difficult. Wrinkles are prone to appear later.
  • the smaller the size of the pole lug in the second direction the higher the difficulty of connecting the pole lug to other components after shaping, and the smaller the flow-passing area of the pole lug.
  • the size of the tab portion in the second direction is limited to 3W1 ⁇ H1 ⁇ 0.5W1 to balance the bending difficulty of the tab portion and the flow area.
  • the lug portion has opposite first edges and second edges in the second direction, and at least part of the first edge in the lug portion is inclined relative to the first direction.
  • the first edge in the lug portion is inclined, so that the lug portion can have a certain inclination tendency.
  • the lug portion can be aligned along the extension direction of the first edge. Folding is performed to simplify the plastic surgery of the extreme ears.
  • a first ray parallel to the first direction is formed in the direction from the tab area to the coating area.
  • the first ray has an end of the first edge away from the tab area as an endpoint, and the first edge is connected to the first ray.
  • the angle between a ray is ⁇ 1, ⁇ 1 satisfies, -75° ⁇ 1 ⁇ 75°.
  • the angle ⁇ 1 between the first edge and the first ray is a positive angle; assuming that the first edge If the edge is located within the 180° counterclockwise rotation range of the first ray, the angle ⁇ 1 between the first edge and the first ray is a negative angle.
  • the angle between the first edge and the first ray is the inclination angle of the first edge.
  • the angle between the first edge and the first ray is limited to -75° ⁇ 1 ⁇ 75° to balance the difficulty of shaping the tab part and the flow area.
  • At least part of the second edge in the lug portion is inclined relative to the first direction.
  • both edges of the tab part along the second direction are inclined, so that when multiple electrode assemblies are integrated into the tabs, the tab parts can be nested into each other, thereby improving the overcurrent capability.
  • a first ray parallel to the first direction is formed in a direction from the tab area to the coating area, and the first ray is away from an end of the coating area with a first edge. is the endpoint, the angle between the first edge and the first ray is ⁇ 1, forming a second ray parallel to the first direction in the direction from the tab area to the coating area, and the second ray moves away from the coating with the second edge.
  • the isosceles trapezoidal structure can provide sufficient structural strength between the tab portion and the buffer zone, increase the distance between adjacent tab portions, and facilitate bending of the tab portions.
  • a first ray parallel to the first direction is formed in a direction from the tab area to the coating area, and the first ray is away from an end of the coating area with a first edge. is the endpoint, the angle between the first edge and the first ray is ⁇ 1, a second ray parallel to the first direction is formed in the direction from the tab area to the coating area, and the second ray moves away from the coating with the second edge.
  • One end of the covered area is the endpoint, the angle between the second edge and the second ray is ⁇ 2, and at least part of ⁇ 1 and ⁇ 2 satisfy; ⁇ 1/ ⁇ 2>0.
  • the inclination direction of the first edge and the second edge is the same, so that the entire lug portion has a tendency to tilt in the same direction, so that multiple lug portions can be smoothed in the same direction during the smoothing process. Reduces the likelihood of wrinkles caused by multi-directional smoothing.
  • neither tab portion extends beyond the coating area in the second direction.
  • multiple tab portions in the tab area are arranged side by side along the second direction, and the tab portions are connected to the buffer area and the coating area.
  • the coating area occupies a larger area.
  • the tab area needs to adapt to the winding direction and number of winding turns of the coating area during the winding process, so that the winding process can be simplified.
  • the plurality of tab portions has a first tab portion at one end in the second direction
  • the coating area has a third edge in the second direction and on a side close to the first tab portion, and the third edge is connected to the first tab portion in the second direction.
  • the first tab portions are spaced apart in the second direction.
  • the tab portion is not provided on the side of at least one end of the current collector in the second direction in the first direction, thereby avoiding damage to the tab portion during the manufacturing process.
  • the plurality of tab portions has a first tab portion at one end in the second direction
  • the coating area has a third edge in the second direction and on a side close to the first tab portion
  • the first tab portion is In the lug portion
  • the second edge is located on a side of the first lug portion close to the third edge; wherein, in a direction away from the coating area, the second edge is inclined relative to the first direction.
  • the inclined edge can minimize damage to the first tab portion during the tab manufacturing process.
  • the first edge is parallel to the second edge in at least part of the lug.
  • the first edge of part of the pole lug part is parallel to the second edge, so that the cutting method of the first edge of this part of the pole lug part during the manufacturing process can be applied to the cutting of the second edge, thereby simplifying the pole lug part.
  • the tab portion has a fourth edge on a side away from the coating area; the second edge and the fourth edge are connected through an arc-shaped connecting section; or, the junction of the second edge and the fourth edge is provided with Missing corners.
  • a notch is provided between the second edge and the fourth edge through an arc-shaped connecting section or at the junction of the second edge and the fourth edge, so as to reduce the second edge of the pole lug after the current collector is bent.
  • the possibility of interference between the junction of the edge and the fourth edge and the adjacent tab Reduce the risk of corner cracking caused by excessive pressure on the corners when the pole lug is bent. Further reduce the weight of the pole piece.
  • adjacent tab portions are spaced apart in the second direction.
  • the weight of the pole piece is reduced by arranging pole tab parts at intervals.
  • the tab portion has opposite first edges and second edges in the second direction, the first edge is parallel to the second edge; the distance between adjacent tab portions in the second direction is the same as the distance between the tab portions.
  • the dimensions in the second direction are the same.
  • the die-cut area becomes The pole tab areas on the two current collectors can reduce the amount of current collectors, reduce the manufacturing cost of current collectors, and reduce the weight of the pole pieces.
  • the minimum distance between adjacent pole tabs is D1, and D1 satisfies: 0mm ⁇ D1 ⁇ 1000mm.
  • the minimum distance between adjacent pole tab parts may be zero. In other words, the edges of adjacent pole tab parts are in contact with each other. The larger the minimum distance between adjacent tabs, the fewer the number of tabs in the current collector, and the lower the current efficiency that can be transmitted after the tabs are shaped and electrically connected to other components. Limit the minimum distance D1 between adjacent pole tabs to 0mm ⁇ D1 ⁇ 1000mm. On the premise of ensuring the overcurrent efficiency of the pole tabs, increase the minimum distance between adjacent pole tabs as much as possible to reduce the risk of pole Tablet weight.
  • the structural strength of the buffer portion is no less than the structural strength of other locations within the tab area.
  • the structural strength of the buffer part no less than the structural strength of other positions in the tab area, the possibility of cracking between the buffer part and the tab part is reduced when the buffer part is subjected to bending stress, and the possibility of cracking between the buffer part and the tab part is reduced.
  • the possibility of bending wrinkles in the buffer part itself reduces the bending stress on the coating area.
  • the thickness of the buffer part is greater than the thickness of other parts in the tab area; and/or the hardness of the buffer part is greater than the hardness of other parts in the tab area.
  • the pole piece further includes a buffer layer, and the buffer layer is an inactive material layer coated on the buffer portion.
  • the structural strength of the buffer portion is further improved by providing a buffer layer.
  • some embodiments of the present application provide an electrode assembly, including a first pole piece and a second pole piece with opposite polarities.
  • the first pole piece is a pole piece as in any one of the multiple embodiments of the first aspect.
  • the electrode assembly is a cylindrical winding structure, and both the first pole piece and the second pole piece are pole pieces as in any one of the embodiments of the first aspect; the pole tab portion of the first pole piece and The tab portion of the second pole piece is located at the same end of the electrode assembly.
  • the tab portion of the first pole piece and the tab portion of the second pole piece are located at the same end of the electrode assembly, so that during the winding process or after the winding is completed, the first pole tab can be simultaneously
  • the pole ear part is smoothed with the pole ear part of the second pole piece.
  • the tab portion of the first pole piece and the tab portion of the second pole piece surround the winding axis of the electrode assembly and are spaced apart in the circumferential direction.
  • the pole tab surrounds the winding axis of the electrode assembly, so that the shaped pole tab has no sharp edges and corners, and reduces the possibility of the shaped pole tab being inserted into the interior of the electrode assembly.
  • the tab portion of the first pole piece and the tab portion of the second pole piece are symmetrically distributed on both sides of the winding axis of the electrode assembly.
  • the symmetrical distribution can make the spatial arrangement of the pole tab portion 121 in the first pole piece 300 and the pole tab portion 121 in the second pole piece 400 more reasonable.
  • the electrode assembly is a cylindrical wound structure, the distance between the tab portion in the first pole piece and the central axis of the electrode assembly is R, and the width of the tab portion is W1; at least part of the tab W1 and R in the part satisfy: W1 ⁇ R.
  • the width of the pole lug along the second direction is less than or equal to half of the maximum circumference of the winding structure, which facilitates the bending of the pole lug after shaping and reduces the pole lug curvature.
  • the electrode assembly has a central hole at the winding center, the radius of the central hole is r, and W1 and r in at least part of the pole tab satisfy: W1 ⁇ ⁇ r.
  • the width of the tab part in the second direction in the flattened state is less than or equal to half of the circumference of the central hole formed after winding, which is beneficial to the bending of the tab part and reduces the bending of the tab close to the center hole.
  • the possibility of the part being covered by the tab part far away from the central hole further improves the flow capacity between the tab part and other components.
  • some embodiments of the present application provide a battery cell, including a casing and an electrode assembly according to any embodiment of the second aspect, and the electrode assembly is disposed in the casing.
  • some embodiments of the present application provide a battery, including the battery cell according to any embodiment of the third aspect.
  • some embodiments of the present application provide an electrical device, including the battery cell according to any embodiment of the third aspect, and the battery cell is used to provide electric energy.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • FIG. 2 is an exploded schematic 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 Figure 2;
  • Figure 4 is a schematic diagram of the exploded structure of a battery cell provided by some embodiments of the present application.
  • Figure 5 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 6 is a schematic cross-sectional structural diagram along the A-A direction in Figure 5;
  • Figure 7 is an enlarged structural view of area Q shown in Figure 5;
  • Figure 8 is an enlarged structural view of the area S shown in Figure 5;
  • Figure 9 is a schematic structural diagram of the tab area of the pole piece provided by some embodiments of the present application.
  • Figure 10 is a schematic structural diagram of the tab area of the pole piece provided by some embodiments of the present application.
  • Figure 11 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 12 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 13 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 14 is a schematic cross-sectional structural diagram along the B-B direction in Figure 13;
  • Figure 15 is a schematic structural diagram of the tab area of the pole piece provided by some embodiments of the present application.
  • Figure 16 is a schematic structural diagram of an undie-cut pole piece provided by some embodiments of the present application.
  • Figure 17 is a schematic structural diagram of the die-cut rear pole piece provided by some embodiments of the present application.
  • Figure 18 is a schematic structural diagram of an electrode assembly provided by some embodiments of the present application.
  • Figure 19 is a schematic structural diagram of an electrode assembly provided by some embodiments of the present application.
  • Figure 20 is another perspective view of the electrode assembly provided by some embodiments of the present application.
  • X first direction
  • Y second direction
  • 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).
  • 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., Some embodiments of the present application are not limited to this.
  • the battery cell may be in the shape of a cylinder, a flat body, a cuboid, or other shapes, and some embodiments of the present application are not limited to this.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly includes a positive electrode piece, a negative electrode piece and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector; the positive electrode current collector includes a positive electrode coating area and a positive electrode tab connected to the positive electrode coating area.
  • the positive electrode coating area The positive electrode active material layer is coated, and the positive electrode tab is not coated with the positive electrode active material layer.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material layer includes a positive electrode active material.
  • the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area.
  • the negative electrode coating area The negative electrode active material layer is coated, and the negative electrode tab is not coated with the negative electrode active material layer.
  • the negative electrode current collector may be made of copper, and the negative electrode active material layer may include a negative electrode active material.
  • the negative electrode active material may be carbon or silicon.
  • the separator may be made of polypropylene (PP) or polyethylene (PE).
  • the battery cell also includes a casing, an electrode terminal and an adapter member.
  • a receiving cavity for accommodating the electrode assembly is formed inside the casing, and the electrode terminal is installed on the casing.
  • the shell can protect the electrode assembly from the outside to prevent external foreign matter from affecting the charging or discharging of the electrode assembly.
  • the electrode terminal is used to electrically connect with the tab of the electrode assembly to draw out the electric energy generated by the electrode assembly.
  • the adapter member is used to connect the electrode terminal and the tab to electrically connect the electrode terminal and the tab.
  • the pole piece is rolled to form an electrode assembly.
  • the battery formed by the rolled electrode assembly has the advantages of low internal resistance and high energy density.
  • the manufacturing method of a rolled battery is usually to coat one end of the positive and negative electrode sheets with active material, and the other end is a blank part. During the winding process of the positive and negative electrode sheets or after the winding is completed, the blank part is smoothed to form Very ear.
  • the pole lug is connected to the electrode terminal through the adapter member after being shaped and bent.
  • the pole lug needs to withstand a certain amount of pressure, but the structural strength of the pole piece itself is the same, and the pole lug only occupies a small part of the pole piece, and the pole lug on the pole piece is usually
  • the structural strength between the pole tab and the pole piece coating area is much smaller than the coating area.
  • the pole tab is under pressure, the bending stress between the pole tab and the pole piece coating area is Maximum, resulting in a certain degree of damage to the connection between the pole lug and the pole piece.
  • the active material in the coating area can easily fall off, affecting the manufacturing yield of the battery cells.
  • a pole piece which includes: a current collector and an active material layer.
  • the current collector includes a coating area, a tab area, and a buffer area located between the coating area and the tab area, which are arranged side by side along the first direction.
  • the current collector includes a plurality of tab portions arranged side by side along the second direction in the tab area, and the first direction intersects with the second direction.
  • the active material layer is coated on the coating area.
  • the current collector includes a buffer portion in the buffer area, the buffer portion extends along the second direction and connects the plurality of tab portions, and the buffer portion is configured to absorb the bending stress of the plurality of tab portions.
  • a buffer zone is provided between the tab area and the coating area, so that after the stress generated by the tab portion in the tab area during subsequent bending is transferred to the buffer area, the buffer area will bear the transferred stress. Stress, reduce the possibility of damage to the root of the pole lug, reduce or even eliminate the impact of the stress generated on the pole lug on the coating area, reduce the risk of the active material layer falling in the coating area, and improve the yield of the pole piece.
  • Electrical devices can be vehicles, cell phones, portable devices, laptops, ships, spacecraft, electric toys and power tools, etc.
  • Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc.
  • spacecraft include aircraft, rockets, space shuttles, spaceships, etc.
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.
  • electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more.
  • the following embodiments take the electrical device as a vehicle as an example.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • a battery 2000 is disposed inside the vehicle 1000 .
  • the battery 2000 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 2000 may be used to power the vehicle 1000 , for example, the battery 2000 may serve as an operating power source for the vehicle 1000 .
  • the vehicle 1000 may also include a controller 3000 and a motor 4000.
  • the controller 3000 is used to control the battery 2000 to provide power to the motor 4000, for example, to meet the power requirements for starting, navigation and driving of the vehicle 1000.
  • the battery 2000 can not only be used as an operating power source for the vehicle 1000 , but can also be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • Figure 2 is an exploded schematic diagram of a battery provided by some embodiments of the present application.
  • a battery 2000 includes a case 2010 and a battery cell 1 (not shown in the figure).
  • the battery cell 1 is accommodated in the case 2010 .
  • the box 2010 is used to accommodate the battery cells 1, and the box 2010 can be of various structures.
  • the box body 2010 may include a first box body part 2011 and a second box body part 2012, the first box body part 2011 and the second box body part 2012 cover each other, the first box body part 2011 and the second box body part 2012
  • the two box parts 2012 jointly define an accommodating part 2013 for accommodating the battery cell 1 .
  • the second box part 2012 may be a hollow structure with one end open, and the first box part 2011 is a plate-like structure.
  • the first box part 2011 is covered with the open side of the second box part 2012 to form a receiving part 2013
  • the box 2010; the first box part 2011 and the second box part 2012 can also be hollow structures with one side open, and the open side of the first box part 2011 is covered with the open side of the second box part 2012 , to form a box 2010 having a receiving portion 2013.
  • the first box part 2011 and the second box part 2012 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.
  • a sealing member may also be provided between the first box part 2011 and the second box part 2012, such as sealant, sealing ring, etc. .
  • the first box part 2011 can also be called an upper box cover, and the second box part 2012 can also be called a lower box.
  • the battery 2000 there may be one battery cell 1 or a plurality of battery cells 1. If there are multiple battery cells 1 , the multiple battery cells 1 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 1 are both connected in series and in parallel. Multiple battery cells 1 can be directly connected in series, parallel, or mixed together, and then the whole composed of multiple battery cells 1 can be accommodated in the box 2010; of course, multiple battery cells 1 can also be connected in series first.
  • the battery modules 5000 are formed by parallel connection or mixed connection. Multiple battery modules are then connected in series, parallel or mixed connection to form a whole, and are accommodated in the box 2010 .
  • FIG. 3 is a schematic structural diagram of the battery module shown in FIG. 2 .
  • there are multiple battery cells 1 and the plurality of battery cells 1 are first connected in series, parallel, or mixed to form a battery module 5000.
  • Multiple battery modules 5000 are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 2010 .
  • Multiple battery cells 1 in the battery module are electrically connected through bus components to achieve parallel, series or mixed connection of the multiple battery cells 1 in the battery module.
  • FIG. 4 is a schematic exploded structural diagram of a battery cell 1 provided by some embodiments of the present application. As shown in FIG. 4 , the battery cell 1 includes a housing 11 and an electrode assembly 12 , and the electrode assembly 12 is accommodated in the housing 11 .
  • the electrode assembly 12 is the core component for realizing the charge and discharge function of the battery cell 1. It includes a positive electrode piece, a negative electrode piece and a separator. The positive electrode piece and the negative electrode piece have opposite polarities. The separator is used to connect the positive electrode piece and the negative electrode piece. The negative pole piece is insulated and isolated. The electrode assembly 12 mainly relies on metal ions to move between the positive electrode piece and the negative electrode piece.
  • the casing 11 has a hollow structure, and an accommodation cavity for accommodating the electrode assembly 12 and the electrolyte is formed inside.
  • the shell 11 can be in various shapes, such as cylinder, cuboid, etc.
  • the shape of the housing 11 can be determined according to the specific shape of the electrode assembly 12 . For example, if the electrode assembly 12 has a cylindrical structure, a cylindrical shell can be used; if the electrode assembly 12 has a rectangular parallelepiped structure, a rectangular parallelepiped shell can be used.
  • housing 11 includes a housing 111 and an end cap 112 .
  • the end cap 112 is sealingly connected to the housing 111 to form a sealed space for accommodating the electrode assembly 12 and the electrolyte.
  • one end of the housing 111 has an opening, and the end cap 112 is provided as one and covers the opening of the housing 111 .
  • two opposite ends of the housing 111 have openings, and two end caps 112 are provided, and the two end caps 112 cover the two openings of the housing 111 respectively.
  • the shape of the end cap 112 may be adapted to the shape of the housing 111 to fit the housing 111 .
  • the end cap 112 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 112 is less likely to deform when subjected to extrusion and collision, so that the battery cell 1 can have higher durability. Structural strength and safety performance can also be improved.
  • the housing 111 can be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the housing 111 can be determined according to the specific shape and size of the electrode assembly 12 .
  • the housing 111 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., which are not particularly limited in some embodiments of the present application.
  • functional components such as electrode terminals may be provided on the end cap 112 .
  • the electrode terminals may be used to electrically connect with the electrode assembly 12 for outputting or inputting electrical energy of the battery cell 1 .
  • the pole piece 10 may be a positive pole piece or a negative pole piece.
  • FIG. 5 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • FIG. 6 is a schematic cross-sectional structural diagram along the A-A direction in FIG. 5 .
  • FIG. 7 is an enlarged structural view of the region Q shown in FIG. 5 .
  • FIG. 8 is an enlarged structural view of the area S shown in FIG. 5 .
  • Figure 9 is a schematic structural diagram of the tab area of the pole piece provided by some embodiments of the present application.
  • FIG. 10 is a schematic structural diagram of the tab area 120 of the pole piece 10 provided by some embodiments of the present application.
  • the pole piece 10 includes a current collector 100 and an active material layer 200 .
  • the current collector 100 includes a coating area 110 arranged side by side along the first direction X, a tab area 120 and a buffer area 130 located between the coating area 110 and the tab area 120 .
  • the current collector 100 includes a plurality of tab portions 121 arranged side by side in the tab area 120 along the second direction Y, where the first direction X and the second direction Y intersect.
  • the active material layer 200 is coated on the coating area 110 .
  • the current collector 100 includes a buffer portion 131 in the buffer area 130 .
  • the buffer portion 131 extends along the second direction Y and connects the plurality of tab portions 121 .
  • the buffer portion 131 is configured to absorb the bending stress of the plurality of tab portions 121 .
  • the coating area 110 , the buffer area 130 and the tab area 120 in the current collector 100 are arranged side by side along the first direction
  • the buffer zone 130 and the buffer zone 130 may be disposed on opposite sides of the coating zone 110 .
  • the active material layer 200 is coated in the coating area 110 , and there is no active material layer 200 in the tab area 120 .
  • the plurality of tab portions 121 in the tab area 120 are arranged side by side along the second direction Y, and the plurality of tab portions 121 are independent structures in the second direction Y. In some examples, adjacent edges of two adjacent tab portions 121 abut each other. In other examples, there is a certain gap between adjacent edges of two adjacent tab portions 121 .
  • the general shapes of part or all of the tab portions 121 in the tab area 120 are similar.
  • the inclination directions of the tab portions 121 are similar or the shapes of the tab portions 121 are similar polygons.
  • the pole part 121 is shaped by spiral stacking, so that during rotation and shaping, the pole part 121 can be smoothed or flattened in the same direction, making it easier to achieve shaping.
  • the tab portion 121 forms a tab planar area after being bent.
  • the tab planar area needs to be electrically connected to other components in the battery cell 1.
  • the electrical connection area between the tab planar area and other components is larger than The larger the pole, the stronger the overcurrent capability of the pole.
  • the buffer area 130 is used to connect the tab area 120 and the coating area 110.
  • the length of the buffer area 130 along the second direction Y needs to be greater than or equal to the length of the tab area 120 in the second direction Y. And in order to reduce excessive influence on the current collector 100 during bending, the length of the buffer zone 130 along the second direction Y is less than or equal to the length of the coating zone 110 along the second direction Y.
  • the buffer portion 131 is integrally designed.
  • the number of buffer parts 131 is multiple, and the buffer parts 131 and the tab parts 121 are provided in one-to-one correspondence.
  • the buffer area 130 serves as an intermediate area connecting the tab area 120 and the coating area 110. Under the premise that the buffer area 130 can withstand a certain bending stress, the size of the buffer area 130 should be reduced as much as possible.
  • the active material layer 200 is provided on both sides of the coating area 110 .
  • a buffer zone 130 is provided between the tab area 120 and the coating area 110 , so that after the stress generated by the tab portion 121 in the tab area 120 during subsequent bending is transferred to the buffer area 130 , The buffer zone 130 withstands the transferred stress, reduces the possibility of damage to the root of the tab part 121, reduces or even eliminates the impact of the stress generated by the tab part 121 on the coating area 110, and reduces the active material layer 200 in the coating area 110. The risk of falling off improves the yield of the pole piece 10.
  • the size of the tab portion 121 in the first direction X is H1
  • the size of the buffer portion 131 in the first direction X is H2
  • H1 and H2 satisfy: H1 ⁇ H2.
  • the value of H1 is 3 mm to 9 mm, and the value of H2 is 1 mm to 2 mm.
  • the larger the size of the tab portion 121 in the first direction The shaped tab connects it to other components and increases the flow area of the tab.
  • the size of the tab portion 121 in the second direction Y is W1
  • the size of the tab portion 121 in the first direction X is H1
  • W1 satisfy: 3W1 ⁇ H1 ⁇ 0.5W1.
  • the value of W1 is 3mm ⁇ 6mm
  • the lug portion 121 has opposite first edges 121 a and second edges 121 b in the second direction Y, and at least part of the first edge 121 a in the lug portion 121 is opposite to the first edge 121 a in the second direction Y.
  • X tilt setting is opposite to the first edge 121 a in the second direction Y.
  • the first edge 121a is inclined relative to the first direction X, that is, the extending direction of the first edge 121a intersects with the first direction X.
  • the first edge 121 a in the tab portion 121 is inclined, so that the tab portion 121 can have a certain tilt tendency.
  • the tab area 120 When the tab area 120 is bent, it can be bent along the first edge 121 a.
  • the extension direction of one edge 121a folds the pole lug portion 121, thereby simplifying the difficulty of shaping the pole lug portion 121.
  • the second edge 121b can be arranged parallel to the first direction X, or can be arranged inclined relative to the first direction X .
  • the end of the edge 121a away from the coating area 110 is the endpoint.
  • the angle between the first edge 121a and the first ray Z1 is ⁇ 1, and ⁇ 1 satisfies, -75° ⁇ 1 ⁇ 75°;
  • the angle ⁇ 1 between the first edge 121a and the first ray Z1 is a positive angle; assuming that the first edge 121a is located within the first ray Z1 Within the range of 180° of counterclockwise rotation of Z1, the angle ⁇ 1 between the first edge 121a and the first ray Z1 is a negative angle.
  • the first edge 121a is all located on the left side of the first ray Z1, and the first edge 121a is located within the range of 180° counterclockwise rotation of the first ray Z1 around its end point, so between the first edge 121a and the first ray Z1
  • the angle ⁇ 1 between the first edge 121a and the first ray Z1 cannot be 0. .
  • the angle of ⁇ 1 satisfies ⁇ 1 ⁇ [-30°, 30°].
  • the angle between the first edge 121a and the first direction The greater the number, the less difficult it is to reshape the ear part 121. If the inclination angle of the first edge 121a is too large, the length of the tab portion 121 along the first direction The flow area of the pole lug 121 is small. In the above technical solution, the angle between the first edge 121a and the first direction
  • At least part of the second edge 121b in the lug portion 121 is inclined relative to the first direction X.
  • first edge 121a and the second edge 121b are inclined in the same direction. In other examples, the first edge 121a and the second edge 121b are inclined in opposite directions.
  • a second ray Z2 parallel to the first direction The angle between the second edge 121b and the second ray Z2 is ⁇ 2.
  • the angle ⁇ 2 between the second edge 121b and the second ray Z2 is a positive angle; assuming the second The edge 121b is located within the 180° counterclockwise rotation range of the second ray Z2, so the angle ⁇ 2 between the second edge 121b and the second ray Z2 is a negative angle.
  • FIG. 9 the second edge 121b is all located on the right side of the second ray Z2, and the second edge 121b is located within the range of 180° clockwise rotation of the second ray Z2 around its end point. Therefore, the distance between the second edge 121b and the second ray Z2 is ⁇ 2 between is a positive angle.
  • both edges of the tab portion 121 along the second direction Y are inclined, and both edges of the tab portion 121 along the second direction Y are inclined, so that when multiple electrode assemblies 12 are integrated into the tabs, , the pole tabs 121 can be nested into each other, thereby improving the overcurrent capability.
  • the included angle ⁇ 1 is a positive angle
  • the included angle ⁇ 2 is a negative angle with the same angle value.
  • the value of ⁇ 1 is 30°
  • the value of ⁇ 2 is -30°
  • the value of ⁇ 1 is 45°
  • the value of ⁇ 2 is -45°
  • the value of ⁇ 1 is 50°
  • the value of ⁇ 2 is -50 °.
  • the isosceles trapezoid structure can provide sufficient structural strength between the pole lug portion 121 and the buffer zone 130, thereby increasing the relative strength.
  • the distance between adjacent pole tabs 121 facilitates bending of the pole tabs 121 .
  • ⁇ 2 is also a positive angle.
  • the value of ⁇ 1 is 30°
  • the value of ⁇ 2 is 30°
  • the value of ⁇ 1 is 45°
  • the value of ⁇ 2 is 40°
  • the value of ⁇ 1 is 50°
  • the value of ⁇ 2 is 60°.
  • the angle ⁇ 1 is a negative angle
  • ⁇ 2 is also a negative angle.
  • the value of ⁇ 1 is -30°
  • the value of ⁇ 2 is -30°
  • the value of ⁇ 1 is -45°
  • the value of ⁇ 2 is -40°
  • the value of ⁇ 1 is -50°
  • the value of ⁇ 2 is -60°.
  • the entire pole lug portion 121 has a tendency to tilt in the same direction, so that multiple pole tab portions 121 can be smoothed in the same direction during the smoothing process, thereby reducing the possibility of wrinkles caused by multi-directional smoothing.
  • the tilt direction of the tab portion 121 is the same as the winding direction of the current collector 100, so that the tab portion 121 can be smoothed along the winding direction during the winding process or after the winding is completed. This further reduces the stress generated on the buffer zone 130 when the pole lug portion 121 is smoothed.
  • Figure 11 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 12 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 13 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • any tab portion 121 does not exceed the coating area 110 in the second direction Y.
  • any lug portion 121 and the buffer area 130 does not exceed the coating area 110 in the second direction Y, and neither the first edge 121a nor the second edge 121b of any lug portion 121 extends in the second direction Y. Beyond the coating area 110 , and the side of either pole portion 121 away from the buffer area 130 does not exceed the coating area 110 in the second direction Y.
  • multiple tab portions 121 in the tab area 120 are arranged side by side along the second direction Y, and the tab portions 121 are all connected to the buffer area 130 and the coating area 110 .
  • the coating area 110 occupies a larger part of the volume.
  • the tab area 120 needs to adapt to the winding direction and number of winding turns of the coating area 110 to simplify the winding process.
  • the plurality of tab portions 121 have first tab portions 122 at one end in the second direction Y, and the coating area 110 is in the second direction Y and close to the first tab portion.
  • One side of the portion 122 has a third edge 110a, and the third edge 110a is spaced apart from the first tab portion 122 in the second direction Y.
  • the plurality of tabs 121 as a whole has two ends in the second direction Y, and both ends have first tabs 122.
  • the shape of the portion 122 can be exactly the same.
  • the shapes of the first tab portions 122 at the two ends may also be partly the same.
  • the first edge 121a or the second edge 121b of the first tab portions 122 at the two ends have the same inclination direction, or the first edges 121b at the two ends may have the same shape.
  • the first edge 121a or the second edge 121b of the tab portion 122 has the same inclination angle, or the first tab portions 122 at the two ends have the same size along the first direction The size of Y in both directions is the same.
  • the shapes of the first tab portions 122 at the two ends can also be completely different.
  • the entire coating area 110 has two ends in the second direction Y, and the shapes of the third edges 110a of the two ends may be exactly the same.
  • the shapes of the third edges 110a at the two ends may also be partly the same.
  • the dimensions of the third edges 110a at the two ends along the first direction X are the same, or the inclination directions between the third edges 110a at the two ends and the first direction
  • the angles between the first directions X are the same.
  • the shapes of the third edges 110a at the two ends can also be completely different.
  • At least one first tab portion 122 and the third edge 110 a are spaced apart in the second direction Y.
  • at least one end of the two ends of the current collector 100 in the second direction Y is in the first direction X.
  • the pole part 121 is not provided at the side position.
  • the distance between the third edge 110a corresponding to the end of the current collector 100 without the tab 121 and the first tab 122 along the second direction Y is L, and L satisfies 10 mm ⁇ L ⁇ 1500 mm.
  • L satisfies 300mm ⁇ L ⁇ 600mm.
  • connection area between the tab area 120 and the coating area 110 the two ends of the buffer area 130 do not exceed the third edge 110 a along the second direction Y, which simplifies the winding process of the current collector 100 .
  • the filling position E1 refers to one end of the current collector 100 along the second direction Y
  • the finishing position E2 refers to the end of the current collector 100 along the second direction Y.
  • the feeding position E1 at the other end of the second direction Y needs to let the coating area 110 enter first, so that the entire current collector 100 can be clamped.
  • the ending position E2 also needs the coating area 110 to leave last, so that the entire current collector 100 can be clamped.
  • the pole lug 121 is damaged.
  • at least one end of the current collector 100 in the second direction Y is not provided at a side position in the first direction X, so that the tab portion 121 can be avoided during the manufacturing process. damage occurs.
  • the plurality of tab portions 121 has a first tab portion 122 at one end in the second direction Y, and the coating area 110 is in the second direction Y and close to the first tab portion 122 has a third edge 110a on one side, and in the first tab portion 122, the second edge 121b is located on the side of the first tab portion 122 close to the third edge 110a; wherein, in the direction away from the coating area 110, The second edge 121b is inclined relative to the first direction X.
  • the second edge 121b of the first tab portion 122 is arranged obliquely with respect to the first direction X, because the first tab portion 122 does not exceed the coating area 110 in the second direction Y. , therefore, the inclination direction of the second edge 121 b can only be inclined toward the center of the tab region 120 .
  • the current collector 100 enters the feed position E1 or leaves the finishing position E2
  • the current collector 100 needs to move in the guide rail of the processing equipment. Inclining the edge of the first pole lug 122 can play a guiding role to a certain extent. Thereby, the damage of the guide rail to the first tab part 122 is reduced.
  • the first edge 121a is parallel to the second edge 121b.
  • the first edge 121a of a portion of the pole lug 121 is parallel to the second edge 121b.
  • the angle ⁇ 1 between the first edge 121a and the first direction The angle ⁇ 2 between the two edges 121b and the first direction X.
  • the first edges 121 a of all the tab portions 121 of the tab region 120 are parallel to the second edges 121 b.
  • the shape of the pole lug portion 121 is a parallelogram.
  • the first edge 121a of the first lug portion 122 is parallel to the second edge 121b. In other examples, referring to FIGS. 10 and 12 , the second edge 121 b of the first lug portion 122 is parallel to the third edge 110 a of the coating region 110 .
  • the first edge 121a of the part of the lug part 121 is parallel to the second edge 121b, so that the cutting method of the first edge 121a of this part of the lug part 121 during the manufacturing process can be applied to the second edge 121b. is being cut, thereby simplifying the manufacturing process of the tab portion 121 .
  • FIG. 14 is a schematic cross-sectional structural diagram along the B-B direction in FIG. 13 .
  • the structural strength of the buffer portion 131 is not less than the structural strength of other locations within the tab area 120 .
  • structural strength refers to the strength to withstand bending stress or the smoothing or smoothing force during shaping.
  • the structural strength of the buffer portion 131 not less than the structural strength at other locations of the tab area 120, cracks between the buffer portion 131 and the tab portion 121 are reduced when the buffer portion 131 is subjected to bending stress.
  • the possibility of bending wrinkles in the buffer portion 131 itself is reduced, and the bending stress on the coating area 110 is reduced.
  • the thickness of the buffer portion 131 is greater than the thickness of other parts in the tab area 120; and/or the hardness of the buffer portion 131 is greater than the hardness of other parts in the tab area 120.
  • the structural strength of the buffer portion 131 can be improved by increasing the thickness of the buffer portion 131 so that the thickness of the buffer portion 131 is greater than the thickness of other parts in the tab region 120 .
  • the overall thickness of buffer 131 is increased.
  • the thickness of localized areas in buffer portion 131 is increased.
  • the thickness of the buffer portion 131 near the tab portion 121 is increased.
  • the structural strength of the buffer portion 131 can be increased by adding a material with a larger hardness parameter to the buffer portion 131 .
  • a material with a larger hardness parameter is added to the entire area of the buffer portion 131 .
  • a material with a larger hardness parameter is added to a local area in the buffer portion 131 .
  • a material with a larger hardness parameter is added to the area of the buffer portion 131 close to the tab portion 121 .
  • materials with larger hardness parameters may be metals such as copper, silicon, magnesium, zinc, and manganese.
  • the hardness of the buffer portion 131 can be increased not only by changing the material of the buffer portion 131 , that is, by adding a material with a larger hardness parameter in the buffer portion 131 , but also by changing the hardness through process methods. Specifically, the surface properties of the buffer portion 131 can be changed through annealing, electroplating, oxidation, etc., so that the buffer portion 131 has stronger hardness.
  • improving the structural strength of the buffer portion 131 by increasing the thickness of the buffer portion 131 or adding materials with larger hardness parameters is very easy to achieve during the manufacturing process of the pole piece 10 without adding too many processes. link.
  • the pole piece 10 further includes a buffer layer 132 , and the buffer layer 132 is an inactive material layer 200 coated on the buffer portion 131 .
  • the buffer layer 132 has good bending stress absorption and high hardness properties, and is used to further improve the structural strength of the buffer portion 131 .
  • the material and thickness of the buffer portion 131 are the same as the thickness of the tab portion 121 , and the buffer layer 132 is coated on the buffer portion 131 . There is no need to perform special processing on the buffer portion 131 during the manufacturing process of the current collector 100 . After the die-cutting of the current collector 100 is completed, the buffer layer 132 can be coated on the buffer portion 131 , which simplifies the process difficulty of the current collector 100 .
  • the structural strength of the buffer portion 131 is further improved by providing the buffer layer 132 .
  • Figure 15 is a schematic structural diagram of the tab area of the pole piece provided by some embodiments of the present application.
  • the tab portion 121 has a fourth edge 121c on a side away from the coating area 110; the second edge 121b and the fourth edge 121c are connected by an arc-shaped connecting section 121d.
  • a notch is provided at the interface between the second edge 121b and the fourth edge 121c.
  • connection method between the first edge 121a and the fourth edge 121c may be the same as the connection method between the second edge 121b and the fourth edge 121c.
  • the interface between the first edge 121a and the buffer portion 131 may be connected through an arc-shaped connecting section 121d.
  • the interface between the second edge 121b and the buffer portion 131 may be connected through an arc-shaped connecting section. This further reduces the risk of cracking on the side of the tab portion 121 close to the buffer zone 130 during the bending process of the tab portion 121 .
  • a notch is provided between the second edge 121b and the fourth edge 121c through an arc-shaped connecting section 121d or at the junction of the second edge 121b and the fourth edge 121c, which reduces the current collector 100 after being bent.
  • the junction of the second edge 121b and the fourth edge 121c of the pole portion 121 interferes with the adjacent pole portion 121. This reduces the risk of corner cracking caused by excessive pressure on the corners of the pole lug portion 121 when it is bent. The weight of the pole piece 10 is further reduced.
  • Figure 16 is a schematic structural diagram of an undie-cut pole piece provided by some embodiments of the present application.
  • Figure 17 is a schematic structural diagram of the die-cut rear pole piece provided by some embodiments of the present application.
  • adjacent tab portions 121 are spaced apart in the second direction Y.
  • some of the tab portions 121 in the tab area 120 are spaced at the same distance along the second direction Y. In other examples, the spacing distances along the second direction Y of some of the tab portions 121 in the tab area 120 are different. In some further examples, the spacing distance of some of the tab portions 121 in the tab area 120 along the second direction Y is correlated with the number of the tab portions 121 .
  • the pole tabs 121 are arranged at intervals to reduce the weight of the pole piece 10 .
  • the pole lug portion 121 has opposite first edges 121 a and second edges 121 b in the second direction Y, and the first edge 121 a is parallel to the second edge 121 b.
  • the distance between adjacent tab portions 121 in the second direction Y is the same as the size of the tab portions 121 in the second direction Y.
  • the angle between the first edge 121a and the first direction X is an acute angle. In other examples, the angle between the first edge 121a and the first direction X is a right angle.
  • the current collector 100 During the manufacturing process of the current collector 100, multiple current collectors 100 are usually die-cut from a large blank current collector 100, and the area formed after die-cutting is often the tab area 120.
  • the distance between adjacent tab portions 121 in the second direction Y is the same as the size of the tab portions 121 in the second direction Y. Therefore, for a complete blank current collector 100, die-cutting The latter area will become the tab area 120 on the two current collectors 100, thereby reducing the amount of current collector 100, reducing the manufacturing cost of the current collector 100, and reducing the weight of the pole piece 10.
  • the minimum distance between adjacent tab parts 121 is D1, and D1 satisfies: 0mm ⁇ D1 ⁇ 1000mm.
  • the minimum distance between adjacent tab portions 121 may be zero. In other words, the edges of adjacent tab portions 121 are in contact with each other. The larger the minimum distance between adjacent tab portions 121 is, the fewer the number of tab portions 121 in the current collector 100 is, and the lower the current efficiency that the tab portions 121 can transmit after being shaped and electrically connected to other components.
  • the minimum distance D1 between adjacent pole tabs 121 is limited to 0mm ⁇ D1 ⁇ 1000mm. On the premise of ensuring the overcurrent efficiency of the pole tabs 121, the minimum distance between adjacent pole tabs 121 should be increased as much as possible. To reduce the weight of the pole piece 10.
  • Figure 18 is a schematic structural diagram of an electrode assembly provided by some embodiments of the present application.
  • Figure 19 is a schematic structural diagram of an electrode assembly provided by some embodiments of the present application.
  • Figure 20 is another perspective view of an electrode assembly provided by some embodiments of the present application.
  • the present application also provides an electrode assembly 12, including a first pole piece 300 and a second pole piece 400 with opposite polarities.
  • the first pole piece 300 is a pole as in any of the above embodiments.
  • the electrode assembly 12 is a cylindrical wound structure, and the first pole piece 300 and the second pole piece 400 are pole pieces as in any of the above embodiments. 10.
  • the tab portion 121 of the first pole piece 300 and the tab portion 121 of the second pole piece 400 are located at the same end of the electrode assembly 12 .
  • the first pole piece 300 and the second pole piece 400 have different polarities.
  • the first pole piece 300 has a positive polarity and the second pole piece 400 has a negative polarity.
  • the tab portion 121 of the first pole piece 300 and the tab portion 121 of the second pole piece 400 are located at the same end of the electrode assembly 12, so that they can be aligned simultaneously during the winding process or after the winding is completed.
  • the tab portion 121 of the first pole piece 400 is smoothed with the tab portion 121 of the second pole piece 400 .
  • the tab portion 121 of the first pole piece 300 and the tab portion 121 of the second pole piece 400 surround the winding axis 500 of the electrode assembly 12 and are spaced apart in the circumferential direction.
  • the shape of the tab portion 121 includes a fan shape and a rectangular shape.
  • the sectors and rectangles mentioned in this embodiment are rough outlines rather than precise patterns.
  • the tab portion 121 surrounds the winding axis 500 of the electrode assembly 12 so that the shaped tab has no sharp edges and reduces the possibility of the shaped tab being inserted into the inside of the electrode assembly 12 .
  • the tab portion 121 of the first pole piece 300 and the tab portion 121 of the second pole piece 400 are symmetrically distributed on both sides of the winding axis 500 of the electrode assembly 12 .
  • the symmetrical distribution can make the spatial arrangement of the pole tabs 121 in the first pole piece 300 and the pole tabs 121 in the second pole piece 400 more reasonable.
  • the electrode assembly 12 is a cylindrical wound structure, the distance between the tab portion 121 in the first pole piece 300 and the central axis of the electrode assembly 12 is R, and the width of the tab portion 121 is W1 ; W1 and R in at least part of the pole portion 121 satisfy: W1 ⁇ ⁇ R.
  • the distance between the pole lug 121 in the first pole piece 300 and the central axis of the cylindrical structure is R and satisfies 9 mm ⁇ R ⁇ 34 mm.
  • the distance R between the tab portion 121 and the central axis of the electrode assembly 12 refers to the distance between any tab portion 121 and the central axis of the electrode assembly 12 .
  • the width of the pole tab 121 along the second direction Y is less than or equal to half of the circumference of the corresponding position of the winding structure where the pole tab 121 is located, which facilitates the bending of the pole tab 121 after shaping and lowers the pole tab.
  • the electrode assembly 12 has a central hole 600 at the winding center, the radius of the central hole 600 is r, and W1 and r in at least part of the pole lug 121 satisfy: W1 ⁇ r.
  • r satisfies, 1 mm ⁇ r ⁇ 6 mm.
  • W1 and r satisfy, W1 ⁇ 1/4*2 ⁇ *r.
  • the width of the tab portion 121 along the second direction Y in the flattened state is less than or equal to half the circumference of the central hole 600 formed after winding, which is beneficial to the bending of the tab portion 121 and reduces the risk of getting closer to the center.
  • the possibility that the tab portion 121 of the hole 600 is covered by the tab portion 121 away from the central hole 600 further improves the flow capacity between the tab portion 121 and other components.
  • the present application also provides a battery cell 1 , including a casing 11 and a plurality of electrode assemblies 12 of any of the above embodiments.
  • the electrode assemblies 12 are disposed in the casing 11 .
  • the present application also provides a battery 2000 including a plurality of battery cells 1 of any of the above embodiments.
  • the present application also provides an electrical device, including the battery cell 1 of any of the above embodiments, and the battery cell 1 is used to provide electric energy.
  • the pole piece 10 includes: a current collector 100 and an active material layer 200.
  • the current collector 100 includes a coating area 110 arranged side by side along the first direction X, a tab area 120, and a buffer located between the coating area 110 and the tab area 120.
  • Area 130 the current collector 100 includes a plurality of tab portions 121 arranged side by side along the second direction Y in the tab area 120, and the first direction X intersects the second direction Y; the active material layer 200 is coated on the coating area 110 ;
  • the current collector 100 includes a buffer portion 131 in the buffer area 130.
  • the buffer portion 131 extends along the second direction Y and connects the plurality of tab portions 121.
  • the buffer portion 131 is configured to absorb the bending stress of the plurality of tab portions 121. .
  • the size of the tab portion 121 in the first direction X is H1, and the size of the buffer portion 131 in the first direction X is H2.
  • H1 and H2 satisfy: H1 ⁇ H2.
  • the size of the tab portion 121 in the second direction Y is W1, and the size of the tab portion 121 in the first direction X is H1.
  • H1 and W1 satisfy: 3W1 ⁇ H1 ⁇ 0.5W1.
  • Neither pole portion 121 exceeds the coating area 110 in the second direction Y. At least part of the first edge 121a and the second edge 121b of the pole portion 121 are inclined relative to the first direction X.
  • the electrode assembly 12 has a cylindrical winding structure.
  • the distance between the tab portion 121 in the first pole piece 300 and the central axis of the electrode assembly 12 is R, and the width of the tab portion 121 is W1; W1 and R in at least part of the pole part 121 satisfy: W1 ⁇ R.
  • the radius of the central hole 600 is r, and W1 and r in at least part of the pole lug 121 satisfy: W1 ⁇ ⁇ r.

Abstract

本申请实施例提供一种极片、电极组件、电池单体、电池以及用电装置。极片包括：集流体和活性物质层，集流体包括沿第一方向并排设置的涂覆区、极耳区以及位于涂覆区和极耳区之间的缓冲区，集流体在极耳区包括多个沿第二方向并排上设置的极耳部，第一方向与第二方向相交；活性物质层涂覆于涂覆区；其中，集流体在缓冲区包括缓冲部，缓冲部沿第二方向延伸并连接多个极耳部，缓冲部被配置为吸收多个极耳部的弯折应力。本申请实施例通过在极耳区和涂覆区之间设置缓冲区，降低极耳部根部损伤的可能性，减小甚至消除极耳部产生的应力对涂覆区产生影响，减小涂覆区中活性物质层掉落的风险，提高极片的良率。

Description

极片、电极组件、电池单体、电池以及用电装置 技术领域
本申请涉及电池技术领域，并且更具体地，涉及一种极片、电极组件、电池单体、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。
在现有的电池技术中，电池单体中的极耳在制作过程中容易发生形变，如何保证电流的过流能力的同时，降低极耳在制造过程中的不良率，是电池技术中亟待解决的技术问题。
发明内容
本申请提供了一种极片、电极组件、电池单体、电池以及用电装置，其能够提高极耳的制作良率。
第一方面，本申请实施例提供了一种极片，包括：集流体和活性物质层，集流体包括沿第一方向并排设置的涂覆区、极耳区以及位于涂覆区和极耳区之间的缓冲区，集流体在极耳区包括多个沿第二方向并排上设置的极耳部，第一方向与第二方向相交；活性物质层涂覆于涂覆区；其中，集流体在缓冲区包括缓冲部，缓冲部沿第二方向延伸并连接多个极耳部，缓冲部被配置为吸收多个极耳部的弯折应力。
在上述技术方案中，通过在极耳区和涂覆区之间设置缓冲区，使得极耳区中的极耳部在后续弯折时产生的应力传递至缓冲区后，由缓冲区承受传递过来的应力，降低极耳部根部损伤的可能性，减小甚至消除极耳部产生的应力对涂覆区产生影响，减小涂覆区中活性物质层掉落的风险，提 高极片的良率。
在一些实施方式中，极耳部在第一方向上的尺寸为H1，缓冲部在第一方向上的尺寸为H2，H1和H2满足：H1≥H2。
在上述技术方案中，极耳部在第一方向上的尺寸越大，极耳部在弯折后形成的极耳平面区具有越多的极耳覆盖，有利于保证集流体同整形后的极耳与其他部件的连接以及提高极耳的过流面积。
在一些实施方式中，极耳部在第二方向上的尺寸为W1，极耳部在第一方向上的尺寸为H1，H1和W1满足：3W1≥H1≥0.5W1。
在上述技术方案中，极耳部在第二方向上的尺寸越大，极耳部的弯折难度会越高，如果极耳部在第二方向上的尺寸过大，极耳部在弯折后容易出现褶皱。极耳部在第二方向上的尺寸越小，极耳部在整形后的与其他部件的连接难度越高，极耳部的过流面积越小。在上述技术方案中，将极耳部在第二方向上的尺寸限定为3W1≥H1≥0.5W1，以平衡极耳部的弯折难度和过流面积。
在一些实施方式中，极耳部在第二方向上具有相对的第一边缘和第二边缘，至少部分极耳部中的第一边缘相对第一方向倾斜设置。
在上述技术方案中，极耳部中的第一边缘倾斜设置，使得极耳部能够具有一定的倾斜趋势，在极耳区进行弯折时，可以顺着第一边缘的延伸方向对极耳部进行翻折，简化极耳部的整形难度。
在一些实施方式中，在由极耳区到涂覆区的方向上形成平行于第一方向的第一射线，第一射线以第一边缘远离极耳区的一端为端点，第一边缘与第一射线之间的夹角为α1，α1满足，-75°≤α1≤75°。其中，假定所述第一边缘位于所述第一射线顺时针转动180°范围内，则所述第一边缘与所述第一射线之间的夹角α1为正夹角；假定所述第一边缘位于所述第一射线逆时针转动180°范围内，则所述第一边缘与所述第一射线之间的夹角α1为负夹角。
在上述技术方案中，第一边缘与第一射线之间的夹角为第一边缘的倾斜角度，第一边缘的倾斜角度越大，极耳部的倾斜角度也随之增加，那么极耳部的整形难度越低。如果第一边缘的倾斜角度过大，那么极耳部沿 第一方向上的长度会随之减小，进而导致极耳部在弯折后与其他部件的连接难度增加，且减小极耳部的过流面积。在上述技术方案中，将第一边缘与第一射线的夹角限定为-75°≤α1≤75°，以平衡极耳部的整形难度和过流面积。
在一些实施方式中，至少部分极耳部中的第二边缘相对第一方向倾斜设置。
在上述技术方案中，极耳部中沿第二方向两个边缘均倾斜设置，以便多个电极组件集成极耳时，极耳部之间能够进行互相嵌套，从而提高过流能力。
在一些实施方式中，在至少部分极耳部中，在由极耳区到涂覆区的方向上形成平行于第一方向的第一射线，第一射线以第一边缘远离涂覆区的一端为端点，第一边缘与第一射线之间的夹角为α1在由极耳区到涂覆区的方向上形成平行于第一方向的第二射线，第二射线以第二边缘远离涂覆区的一端为端点，第二边缘与第二射线之间的夹角为α2，α1和α2满足；α1+α2＝0°。
在上述技术方案中，等腰梯形的结构能够使极耳部与缓冲区之间具有足够的结构强度，增加相邻极耳部之间的间距，便于极耳部弯折。
在一些实施方式中，在至少部分极耳部中，在由极耳区到涂覆区的方向上形成平行于第一方向的第一射线，第一射线以第一边缘远离涂覆区的一端为端点，第一边缘与第一射线之间的夹角为α1，在由极耳区到涂覆区的方向上形成平行于第一方向的第二射线，第二射线以第二边缘远离涂覆区的一端为端点，第二边缘与第二射线之间的夹角为α2，至少部分α1和α2满足；α1/α2＞0。
在上述技术方案中，第一边缘和第二边缘的倾斜方向相同，使得极耳部整体具有向同一方向倾斜的趋势，使得在抚平过程中多个极耳部能够按照同一方向进行抚平，降低多方向抚平造成的褶皱的可能性。
在一些实施方式中，任一极耳部在第二方向上均不超出涂覆区。
在上述技术方案中，极耳区中的多个极耳部沿第二方向并排设置，且极耳部均与缓冲区以及涂覆区进行连接，而在集流体中，涂覆区占据较 大一部分的体积，在卷绕过程中需要极耳区适应涂覆区的卷绕方向、卷绕圈数，才能够简化卷绕工艺。
在一些实施方式中，多个极耳部在第二方向的一端具有第一极耳部，涂覆区在第二方向且靠近第一极耳部的一侧具有第三边缘，第三边缘与第一极耳部在第二方向上间隔设置。
在上述技术方案中，通过在集流体在第二方向上的两端至少有一端在第一方向上的侧部位置并没有设置极耳部，从而避免极耳部在制作过程中出现损伤。
在一些实施方式中，多个极耳部在第二方向的一端具有第一极耳部，涂覆区在第二方向且靠近第一极耳部的一侧具有第三边缘，在第一极耳部中，第二边缘位于第一极耳部靠近第三边缘的一侧；其中，在远离涂覆区的方向上，第二边缘相对于第一方向倾斜设置。
在上述技术方案中，倾斜的边缘能够尽可能的减小极耳制作过程对第一极耳部的损伤。
在一些实施方式中，在至少部分极耳部中，第一边缘平行于第二边缘。
在上述技术方案中，将部分极耳部的第一边缘平行于第二边缘，使得此部分极耳部在制造过程中第一边缘的切割方式能够应用在第二边缘的切割中，从而简化极耳部的制造流程。。
在一些实施方式中，极耳部在远离涂覆区的一侧具有第四边缘；第二边缘与第四边缘通过弧形连接段连接；或者，第二边缘与第四边缘的交界处设置有缺角。
在上述技术方案中，第二边缘和第四边缘之间通过弧形连接段或者第二边缘和第四边缘的交界处设置缺角，减小集流体在弯折后，极耳部的第二边缘和第四边缘的交界处与相邻极耳部干涉的可能性。降低极耳部在弯折时，边角承受压力过大导致的边角开裂的风险。进一步减轻极片的重量。
在一些实施方式中，相邻极耳部在第二方向上间隔设置。
在上述技术方案中，通过间隔设置极耳部，来减轻极片的重量。
在一些实施方式中，极耳部在第二方向上具有相对的第一边缘和第二边缘，第一边缘平行于第二边缘；相邻极耳部在第二方向上的间距与极耳部在第二方向上的尺寸相同。
在上述技术方案中，集流体在制造过程中通常采用在一整块大的空白集流体上模切出多个集流体，而模切后形成的区域往往是极耳区。在本实施例中，相邻极耳部在第二方向上的间距与极耳部在第二方向上的尺寸相同，那么对于一整块的空白集流体来说，模切后的区域会成为两个集流体上的极耳区，从而减少集流体的用量，降低集流体的制造成本，减轻极片的重量。
在一些实施方式中，相邻极耳部之间的最小距离为D1，D1满足于：0mm≤D1≤1000mm。
在上述技术方案中，相邻极耳部之间的最小距离可以为零，换言之，相邻极耳部的边缘的互相抵接的。相邻极耳部之间的最小距离越大，那么集流体中的极耳部的数量越少，极耳部整形后与其他部件电连接后所能传递的电流效率越低。将相邻极耳部之间的最小距离D1限定为0mm≤D1≤1000mm，在保证极耳部过流效率的前提下，尽可能的增加相邻极耳部之间的最小距离，以减轻极片的重量。
在一些实施方式中，缓冲部的结构强度不小于极耳区内其他位置处的结构强度。
在上述技术方案中，通过使缓冲部的结构强度不小于极耳区其他位置处的结构强度，以降低缓冲部在承受弯折应力时缓冲部与极耳部之间出现开裂的可能性，降低缓冲部自身出现弯曲褶皱现象的可能性，减小涂覆区受到的弯折应力。
在一些实施方式中，缓冲部的厚度大于极耳区内其他部分的厚度；和/或，缓冲部的硬度大于极耳区内其他部分的硬度。
在上述技术方案中，通过增加缓冲部厚度或添加硬度参数较大的材料来提高缓冲部的结构强度，在极片的制造过程中是极容易实现的，且无需增加过多的工艺环节。
在一些实施方式中，极片还包括缓冲层，缓冲层为涂覆于缓冲部的 非活性物质层。
在上述技术方案中，通过设置缓冲层来进一步提高缓冲部的结构强度
第二方面，本申请一些实施例提供了一种电极组件，包括极性相反的第一极片和第二极片，第一极片为如多个第一方面任一实施方式的极片。
在一些实施方式中，电极组件为圆柱形的卷绕结构，第一极片和第二极片均为如多个第一方面任一实施方式的极片；第一极片的极耳部与第二极片的极耳部位于电极组件的同一端。
在上述技术方案中，第一极片的极耳部与第二极片的极耳部位于电极组件的同一端，使得在卷绕过程中或卷绕完成后，能够同时对第一极耳的极耳部与第二极片的极耳部进行抚平。
在一些实施方式中，第一极片的极耳部与第二极片的极耳部环绕电极组件的卷绕轴，且在周向方向上间隔布置。
在上述技术方案中，极耳部环绕电极组件的卷绕轴，使得整形后的极耳无尖锐棱角，降低整形后的极耳下插至电极组件内部的可能性。
在一些实施方式中，第一极片的极耳部与第二极片的极耳部对称分布在电极组件卷绕轴的两侧。
在上述技术方案中，对称分布能够使得对称分布能够使得第一极片300中的极耳部121与第二极片400中的极耳部121空间布置更合理。
在一些实施方式中，电极组件为圆柱形的卷绕结构，第一极片中的极耳部与电极组件的中心轴之间的距离为R，极耳部的宽度为W1；至少部分极耳部中的W1和R满足：W1≤πR。
在上述技术方案中，极耳部沿第二方向的宽度小于等于卷绕结构最大周长的一半，便于极耳部在整形后弯折，便于极耳部在整形后弯折，降低极耳弧度过大导致的弯折后出现褶皱的可能性。
在一些实施方式中，电极组件在卷绕中心处具有中心孔，中心孔的半径为r，至少部分极耳部中的W1和r满足：W1≤πr。
在上述技术方案中，极耳部在展平状态下沿第二方向的宽度小于等于卷绕后形成的中心孔周长的一半，有利于极耳部的弯折，降低靠近中心 孔的极耳部被远离中心孔的极耳部覆盖的可能性，进一步提高极耳部与其他部件之间的过流能力。
第三方面，本申请一些实施例提供了一种电池单体，包括外壳以及第二方面任一实施方式的电极组件，电极组件设置于外壳内。
第四方面，本申请一些实施例提供了一种电池，包括第三方面任一实施方式的电池单体。
第五方面，本申请一些实施例提供了一种用电装置，包括第三方面任一实施方式的电池单体，电池单体用于提供电能。
附图说明
为了更清楚地说明本申请一些实施例的技术方案，下面将对本申请一些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爆炸结构示意图；
图5为本申请一些实施例提供的极片的结构示意图；
图6为图5中沿A-A方向的剖视结构示意图；
图7为图5中所示区域Q的结构放大图；
图8为图5中所示区域S的结构放大图；
图9为本申请一些实施例提供的极片的极耳区的结构示意图；
图10为本申请又一些实施例提供的极片的极耳区的结构示意图；
图11为本申请又一些实施例提供的极片的结构示意图；
图12为本申请又一些实施例提供的极片的结构示意图；
图13为本申请又一些实施例提供的极片的结构示意图；
图14为图13中沿B-B方向的剖视结构示意图；
图15为本申请又一些实施例提供的极片的极耳区的结构示意图；
图16为本申请一些实施例提供的未模切的极片的结构示意图；
图17为本申请一些实施例提供的模切后极片的结构示意图；
图18为本申请一些实施例提供的电极组件的结构示意图；
图19为本申请又一些实施例提供的电极组件的结构示意图；
图20为本申请一些实施例提供的电极组件又一视角示意图；
在附图中，附图并未按照实际的比例绘制。
标记说明：
1000、车辆；2000、电池；2010、箱体；2011、第一箱体部；2012、第二箱体部；2013、容纳部；3000、控制器；4000、马达；5000、电池模块；
1、电池单体；11、外壳；111、壳体；112、端盖；12、电极组件；
10、极片；
100、集流体；110、涂覆区；110a、第三边缘；120、极耳区；121、极耳部；121a、第一边缘；121b、第二边缘；121c、第四边缘；121d弧形连接段和缺角；122、第一极耳部；130、缓冲区；131、缓冲部；132、缓冲层；
200、活性物质层；
300、第一极片；
400、第二极片；
500、卷绕轴；
600、中心孔；
X、第一方向；Y、第二方向。
具体实施方式
为使本申请一些实施例的目的、技术方案和优点更加清楚，下面将结合本申请一些实施例中的附图，对本申请一些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，附图示出的本申请一些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，本申请一些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，本申请一些实施例对此也不限定。
电池单体包括电极组件和电解液，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涂覆区和连接于正极涂覆区的正极极耳，正极涂覆区涂覆有正极活性物质层，正极极耳未涂覆正极活性物质层。以锂离子电池单体为例，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涂覆区和连接于负极涂覆区的负极极耳，负极涂覆区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聚丙烯(polypropylene，PP)或聚乙烯(polyethylene，PE)等。
电池单体还包括外壳、电极端子和转接构件，外壳内部形成用于容纳电极组件的容纳腔，电极端子安装在外壳上。外壳可以从外侧保护电极组件，以避免外部的异物影响电极组件的充电或放电。电极端子用于与电极组件的极耳电连接，以将电极组件产生的电能引出。转接构件用于连接电极端子和极耳，以将电极端子与极耳电连接。
在相关技术中，极片通过卷绕的方式形成一个电极组件，由卷绕式电极组件形成的电池具有内阻低、能量密度高的优点。卷绕式电池的制作方式通常是分布将正负极片的一端涂覆活性材料，其另一端为空白部分，在正负极片卷绕过程中或卷绕完成后，将空白部分抚平形成极耳。极耳经过整形弯折后通过转接构件与电极端子连接。
发明人发现，极耳在整形过程中，极耳需要承受一定的压力，而极片自身的结构强度是相同的，而极耳仅占据极片的一小部分，且极片上的极耳通常是分隔的多个极耳，极耳与极片涂覆区之间的结构强度是远小于涂覆区的，极耳在承受压力时，极耳与极片涂覆区之间承受的弯折应力最大，导致极耳与极片之间的连接出现一定程度的损伤。同时，在涂覆区 靠近极耳的区域在压力的影响下，容易导致涂覆区中的活性材料脱落，影响电池单体的制造良率。
鉴于此，本申请一些实施例提供了一种极片，极片包括：集流体和活性物质层。集流体包括沿第一方向并排设置的涂覆区、极耳区以及位于涂覆区和极耳区之间的缓冲区。集流体在极耳区包括多个沿第二方向并排上设置的极耳部，第一方向与第二方向相交。活性物质层涂覆于涂覆区。其中，集流体在缓冲区包括缓冲部，缓冲部沿第二方向延伸并连接多个极耳部，缓冲部被构造成吸收多个极耳部的弯折应力。
本申请一些实施例通过在极耳区和涂覆区之间设置缓冲区，使得极耳区中的极耳部在后续弯折时产生的应力传递至缓冲区后，由缓冲区承受传递过来的应力，降低极耳部根部损伤的可能性，减小甚至消除极耳部产生的应力对涂覆区产生影响，减小涂覆区中活性物质层掉落的风险，提高极片的良率。
本申请一些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。本申请一些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1000的内部设置有电池2000，电池2000可以设置在车辆1000的底部或头部或尾部。电池2000可以用于车辆1000的供电，例如，电池2000可以作为车辆1000的操作电源。
车辆1000还可以包括控制器3000和马达4000，控制器3000用来控制电池2000为马达4000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2000不仅仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
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2000包括箱体2010和电池单体1(图中未示出)，电池单体1容纳于箱体2010内。
箱体2010用于容纳电池单体1，箱体2010可以是多种结构。在一些实施例中，箱体2010可以包括第一箱体部2011和第二箱体部2012，第一箱体部2011与第二箱体部2012相互盖合，第一箱体部2011和第二箱体部2012共同限定出用于容纳电池单体1的容纳部2013。第二箱体部2012可以是一端开口的空心结构，第一箱体部2011为板状结构，第一箱体部2011盖合于第二箱体部2012的开口侧，以形成具有容纳部2013的箱体2010；第一箱体部2011和第二箱体部2012也均可以是一侧开口的空心结构，第一箱体部2011的开口侧盖合于第二箱体部2012的开口侧，以形成具有容纳部2013的箱体2010。当然，第一箱体部2011和第二箱体部2012可以是多种形状，比如，圆柱体、长方体等。
为提高第一箱体部2011与第二箱体部2012连接后的密封性，第一箱体部2011与第二箱体部2012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2011盖合于第二箱体部2012的顶部，第一箱体部2011亦可称之为上箱盖，第二箱体部2012亦可称之为下箱体。
在电池2000中，电池单体1可以是一个，也可以是多个。若电池单体1为多个，多个电池单体1之间可串联或并联或混联，混联是指多个电池单体1中既有串联又有并联。多个电池单体1之间可直接串联或并联或混联在一起，再将多个电池单体1构成的整体容纳于箱体2010内；当然，也可以是多个电池单体1先串联或并联或混联组成电池模块5000，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2010内。
图3为图2所示的电池模块的结构示意图。如图3所示，在一些实施例中，电池单体1为多个，多个电池单体1先串联或并联或混联组成电池模块5000。多个电池模块5000再串联或并联或混联形成一个整体，并容纳于箱体2010内。
电池模块中的多个电池单体1通过汇流部件实现电连接，以实现电池模块中的多个电池单体1的并联或串联或混联。
图4为本申请一些实施例提供的电池单体1的爆炸结构示意图，如图4所示，电池单体1包括外壳11和电极组件12，电极组件12容纳于外壳11内。
电极组件12为电池单体1实现充放电功能的核心部件，其包括正极极片、负极极片和隔离件，正极极片和负极极片的极性相反，隔离件用于将正极极片和负极极片绝缘隔离。电极组件12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。
外壳11为空心结构，其内部形成用于容纳电极组件12和电解液的容纳腔。外壳11可以是多种形状，比如，圆柱体、长方体等。外壳11的形状可根据电极组件12的具体形状来确定。比如，若电极组件12为圆柱体结构，则可选用为圆柱体外壳；若电极组件12为长方体结构，则可选用长方体外壳。
在一些实施例中，外壳11包括壳体111和端盖112。
端盖112与壳体111密封连接，以形成用于容纳电极组件12和电解液的密封空间。在一些示例中，壳体111的一端具有开口，端盖112设置为一个并盖合于壳体111的开口。在另一些示例中，壳体111相对的两端均具有开口，端盖112设置为两个，两个端盖112分别盖合于壳体111的两个开口。
不限地，端盖112的形状可以与壳体111的形状相适应以配合壳体111。可选地，端盖112可以由具有一定硬度和强度的材质(如铝合金)制成，这样，端盖112在受挤压碰撞时就不易发生形变，使电池单体1能够具备更高的结构强度，安全性能也可以有所提高。
壳体111可以是多种形状和多种尺寸的，例如长方体形、圆柱体形、六棱柱形等。具体地，壳体111的形状可以根据电极组件12的具体形状和尺寸大小来确定。壳体111的材质可以是多种，比如，铜、铁、铝、不锈钢、铝合金等，本申请一些实施例对此不作特殊限制。
在一些实施例中，端盖112上可以设置有如电极端子等的功能性部件。电极端子可以用于与电极组件12电连接，以用于输出或输入电池单体1的电能。
以下结合附图对极片的具体结构进行详细阐述。极片10可以是正极极片，也可以是负极极片。
图5为本申请一些实施例提供的极片的结构示意图。图6为图5中沿A-A方向的剖视结构示意图。图7为图5中所示区域Q的结构放大图。图8为图5中所示区域S的结构放大图。图9为本申请一些实施例提供的极片的极耳区的结构示意图。图10为本申请又一些实施例提供的极片10的极耳区120的结构示意图。
如图5至图10所示，本申请一些实施例提供一种极片10。极片10包括集流体100和活性物质层200。集流体100包括沿第一方向X并排设置的涂覆区110、极耳区120以及位于涂覆区110和极耳区120之间的缓冲区130。集流体100在极耳区120包括多个沿第二方向Y并排上设置的极耳部121，第一方向X与第二方向Y相交。活性物质层200涂覆于涂覆区110。其中，集流体100在缓冲区130包括缓冲部131，缓冲部131沿第二方向Y延伸并连接多个极耳部121，缓冲部131被构造成吸收多个极耳部121的弯折应力。
集流体100中的涂覆区110、缓冲区130以及极耳区120沿第一方向X并排设置，极耳区120和缓冲区130可设置于涂覆区110的一侧，或者极耳区120和缓冲区130均可设置在涂覆区110相对的两侧。活性物质层200涂覆于涂覆区110内，极耳区120内不存在有活性物质层200。
极耳区120中的多个极耳部121沿第二方向Y并排设置，多个极耳部121为在第二方向Y上互相独立的结构。在一些示例中，两个相邻极耳部121相邻的边缘互相抵接。在另一些示例中，两个相邻极耳部121相邻的边缘之间具有一定的间隙。
在一些示例中，极耳区120中的一部分或全部极耳部121的大体形状相仿，示例性地，极耳部121的倾斜方向相仿或极耳部121的形状为相似的多边形，在极耳部121的整形过程中，极耳部121通过螺旋层叠整形，使得旋转整形时，极耳部121可以顺着相同的方向进行抚平或者揉平，更容易实现整形。需要说明的是，极耳部121在弯折后形成极耳平面区，极耳平面区需要与电池单体1中的其他部件电连接，极耳平面区与其他部件之间电连接的面积越大，极耳的过流能力越强。
缓冲区130用于连接极耳区120和涂覆区110，缓冲区130沿第二方向Y的长度需要大于或等于极耳区120在第二方向Y上的长度。并且为了减少集流体100在弯折时受到过多的影响，缓冲区130沿第二方向Y上的长度小于或等于涂覆区110沿第二方向Y上的长度。在一些示例中，缓冲部131为一体设计。在又一些示例中，缓冲部131的数量为多个，缓冲部131与极耳部121一一对应设置。
可以理解的是，缓冲区130作为连接极耳区120和涂覆区110的中间区域，缓冲区130能够承受一定弯折应力的前提下，缓冲区130的尺寸尽可能的要减小。
可选的，活性物质层200设置在涂覆区110的两侧表面。
本申请一些实施例通过在极耳区120和涂覆区110之间设置缓冲区130，使得极耳区120中的极耳部121在后续弯折时产生的应力传递至缓冲区130后，由缓冲区130承受传递过来的应力，降低极耳部121根部损伤的可能性，减小甚至消除极耳部121产生的应力对涂覆区110产生影响，减小涂覆区110中活性物质层200掉落的风险，提高极片10的良率。
在一些实施例中，请参照图7，极耳部121在第一方向X上的尺寸为H1，缓冲部131在第一方向X上的尺寸为H2，H1和H2满足：H1≥H2。
在一些实施方式的示例中，H1的值为3mm～9mm，H2的值为1mm～2mm。
在本实施例中，极耳部121在第一方向X上的尺寸越大，极耳部121在弯折后形成的极耳平面区具有越多的极耳覆盖，有利于保证集流体 100同整形后的极耳与其他部件的连接以及提高极耳的过流面积。
在一些实施例中，请继续参照图6，极耳部121在第二方向Y上的尺寸为W1，极耳部121在第一方向X上的尺寸为H1，H1和W1满足：3W1≥H1≥0.5W1。
在一些实施方式的示例中，W1的值为3mm～6mm，
在本实施例中，极耳部121在第二方向Y上的尺寸越大，极耳部121的弯折难度会越高，如果极耳部121在第二方向Y上的尺寸过大，极耳部121在弯折后容易出现褶皱。极耳部121在第二方向Y上的尺寸越小，极耳部121在整形后的与其他部件的连接难度越高，极耳部121的过流面积越小。将极耳部121在第二方向Y上的尺寸限定为3W1≥H1≥0.5W1，以平衡极耳部121的弯折难度和过流面积。
在一些实施例中，请参照图8，极耳部121在第二方向Y上具有相对的第一边缘121a和第二边缘121b，至少部分极耳部121中的第一边缘121a相对第一方向X倾斜设置。
第一边缘121a相对第一方向X倾斜设置，即第一边缘121a的延伸方向与第一方向X相交。在本实施例中，请参照图8，极耳部121中的第一边缘121a倾斜设置，使得极耳部121能够具有一定的倾斜趋势，在极耳区120进行弯折时，可以顺着第一边缘121a的延伸方向对极耳部121进行翻折，简化极耳部121的整形难度。
需要说明的是，对于第二边缘121b与第一方向X之间的关系，本申请一些实施例不作限制，第二边缘121b可以平行于第一方向X设置，也可以相对第一方向X倾斜设置。
在一些实施例中，请一并参阅图5和图9，在由极耳区120到涂覆区110的方向上形成平行于第一方向X的第一射线Z1，第一射线Z1以第一边缘121a远离涂覆区110的一端为端点，第一边缘121a与第一射线Z1之间的夹角为α1，α1满足，-75°≤α1≤75°；
其中，假定第一边缘121a位于第一射线Z1顺时针转动180°范围内，则第一边缘121a与第一射线Z1之间的夹角α1为正夹角；假定第一边缘121a位于第一射线Z1逆时针转动180°范围内，则第一边缘121a 与第一射线Z1之间的夹角α1为负夹角。
在本实施例中，以图9为例进行具体说明。在图9中第一边缘121a全部位于第一射线Z1的左侧，第一边缘121a位于第一射线Z1绕其端点逆时针转动180°范围内，因此第一边缘121a与第一射线Z1之间的夹角α1为负夹角，示例性地，在图9中，α1＝-30°
需要说明的是，由于第一边缘121a相对第一方向X倾斜设置，而第一射线Z1平行于第一方向X，因此第一边缘121a与第一射线Z1之间的夹角α1不可能为0。
在一些实施方式的示例中，α1的角度满足α1∈[-30°，30°]。
在一些实施方式的示例中，第一边缘121a与第一方向X之间的夹角为第一边缘121a的倾斜角度，第一边缘121a的倾斜角度越大，极耳部121的倾斜角度也随之增加，那么极耳部121的整形难度越低。如果第一边缘121a的倾斜角度过大，那么极耳部121沿第一方向X上的长度会随之减小，进而导致极耳部121在弯折后与其他部件的连接难度增加，且减小极耳部121的过流面积。在上述技术方案中，将第一边缘121a与第一方向X的夹角限定为-75°＜α1≤75°，以平衡极耳部121的整形难度和过流面积。
在一些实施例中，如图9所述，至少部分极耳部121中的第二边缘121b相对第一方向X倾斜设置。
在一些示例中，第一边缘121a与第二边缘121b的倾斜方向相同。在另一些示例中，第一边缘121a与第二边缘121b的倾斜方向相反。
示例性地，在由极耳区120到涂覆区110的方向上形成平行于第一方向X的第二射线Z2，第二射线Z2以第二边缘121b远离涂覆区110的一端为端点，第二边缘121b与第二射线Z2之间的夹角为α2。
与夹角α1相似的是，假定第二边缘121b位于第二射线Z2顺时针转动180°范围内，则第二边缘121b与第二射线Z2之间的夹角α2为正夹角；假定第二边缘121b位于第二射线Z2逆时针转动180°范围内，则第二边缘121b与第二射线Z2之间的夹角α2为负夹角。
在本实施例中，以图9为例进行具体说明。在图9中，第二边缘 121b全部位于第二射线Z2的右侧，第二边缘121b位于第二射线Z2绕自身端点顺时针转动180°范围内，因此第二边缘121b与第二射线Z2之间的α2为正夹角。
需要说明的是，由于第二边缘121b相对第一方向X倾斜设置，而第二射线Z2平行于第一方向X，因此第二边缘121b与第二射线Z2之间的夹角α2不可能为0。
在本实施例中，极耳部121中沿第二方向Y两个边缘均倾斜设置，极耳部121沿第二方向Y的两个边缘均倾斜设置，以便多个电极组件12集成极耳时，极耳部121之间能够进行互相嵌套，从而提高过流能力。
在一些实施例中，如图9所示，α1和α2满足，α1+α2＝0°。即第一边缘121a和第二边缘121b的倾斜方向不同。
具体地说，夹角α1为正角度时，夹角α2为相同角度值的负角度。示例性地，α1的值为30°时，α2的值为-30°；α1的值为45°时，α2的值为-45°；α1的值为50°时，α2的值为-50°。
从而保证极耳部121沿厚度方向上的投影的形状为等腰梯形，在本实施例中，等腰梯形的结构能够使极耳部121与缓冲区130之间具有足够的结构强度，增加相邻极耳部121之间的间距，便于极耳部121弯折。
在一些实施例中，请一并参阅图5和图10，至少部分α1和α2满足；α1/α2＞0。即第一边缘121a和第二边缘121b的倾斜方向相同。
具体地说，当夹角α1为正角度时，α2也为正角度。示例性地，α1的值为30°时，α2的值为30°；α1的值为45°时，α2的值为40°；α1的值为50°时，α2的值为60°。，当夹角α1为负角度时，α2也为负角度。示例性地，α1的值为-30°时，α2的值为-30°；α1的值为-45°时，α2的值为-40°；α1的值为-50°时，α2的值为-60°。
使得极耳部121整体具有向同一方向倾斜的趋势，使得在抚平过程中多个极耳部121能够按照同一方向进行抚平，降低多方向抚平造成的褶皱的可能性。在一些实施方式的示例中，极耳部121的倾斜方向与集流体100的卷绕方向相同，使得极耳部121在卷绕过程中或卷绕完成后能够顺着卷绕方向进行抚平，进一步降低极耳部121抚平时对缓冲区130产生 的应力。
图11为本申请又一些实施例提供的极片的结构示意图。图12为本申请又一些实施例提供的极片的结构示意图。图13为本申请又一些实施例提供的极片的结构示意图。
在一些实施例中，如图11至图13所示，任一极耳部121在第二方向Y上均不超出涂覆区110。
任一极耳部121与缓冲区130连接处在第二方向Y上均不超出涂覆区110，任一极耳部121的第一边缘121a或第二边缘121b在第二方向Y上均不超出涂覆区110，以及任一极耳部121背离缓冲区130的一侧在第二方向Y上均不超出涂覆区110。
在本实施例中，极耳区120中的多个极耳部121沿第二方向Y并排设置，且极耳部121均与缓冲区130以及涂覆区110进行连接，而在集流体100中，涂覆区110占据较大一部分的体积，在卷绕过程中需要极耳区120适应涂覆区110的卷绕方向、卷绕圈数，才能够简化卷绕工艺。
在一些实施例中，请参照图11至图13，多个极耳部121在第二方向Y的一端具有第一极耳部122，涂覆区110在第二方向Y且靠近第一极耳部122的一侧具有第三边缘110a，第三边缘110a与第一极耳部122在第二方向Y上间隔设置。
在极耳区120中，多个极耳部121形成的整体在第二方向Y上具有两端，这两端均具有第一极耳部122，需要说明的是，这两端的第一极耳部122的形状可完全相同。这两端的第一极耳部122的形状也可部分相同，示例性地，这两端的第一极耳部122的第一边缘121a或第二边缘121b的倾斜方向相同，或这两端的第一极耳部122的第一边缘121a或第二边缘121b的倾斜角度相同，或这两端的第一极耳部122沿第一方向X的尺寸相同，或这两端的第一极耳部122沿第二方向Y的尺寸相同。这两端的第一极耳部122的形状也可完全不同。
相应的，涂覆区110形成的整体在第二方向Y上具有两端，这两端具有的第三边缘110a的形状可完全相同。这两端具有的第三边缘110a的形状也可部分相同。示例性地，这两端的第三边缘110a沿第一方向X上 的尺寸相同，或这两端的第三边缘110a与第一方向X之间的倾斜方向相同，或这两端的第三边缘110a与第一方向X之间的夹角相同。这两端具有的第三边缘110a的形状也可完全不同。
如图11所示，至少一个第一极耳部122与第三边缘110a在第二方向Y上间隔设置，换言之，集流体100在第二方向Y上的两端至少有一端在第一方向X上的侧部位置并没有设置极耳部121。可选的，集流体100中没有设置极耳部121的一端对应的第三边缘110a沿第二方向Y与第一极耳部122的距离为L，L满足10mm≤L≤1500mm。优选的，L满足300mm≤L≤600mm。
作为极耳区120和涂覆区110的连接区域，缓冲区130的两端沿第二方向Y上不超过第三边缘110a，简化集流体100的卷绕工艺。
在极耳部121制作过程中具有入料位E1和收尾位E2，如图12所示，入料位E1是指集流体100沿第二方向Y的一端，收尾位E2是指集流体100沿第二方向Y的另一端入料位E1需要让涂覆区110先进入，才能够对集流体100的整体进行夹持，同样的，收尾位E2也需要涂覆区110最后离开，才能够不损伤极耳部121。在本实施例中，通过在集流体100在第二方向Y上的两端至少有一端在第一方向X上的侧部位置并没有设置极耳部121，从而避免极耳部121在制作过程中出现损伤。
在一些实施例中，如图12所示，多个极耳部121在第二方向Y的一端具有第一极耳部122，涂覆区110在第二方向Y且靠近第一极耳部122的一侧具有第三边缘110a，在第一极耳部122中，第二边缘121b位于第一极耳部122靠近第三边缘110a的一侧；其中，在远离涂覆区110的方向上，第二边缘121b相对于所述第一方向X倾斜。
在本实施例中，参考图12，第一极耳部122的第二边缘121b相对于第一方向X倾斜设置，由于第一极耳部122在第二方向Y上是不超过涂覆区110的，因此，第二边缘121b的倾斜方向只能是向极耳区120的中心的方向倾斜靠近。集流体100在进入入料位E1或离开收尾位E2时，集流体100是需要在加工器材的导轨中移动的，将第一极耳部122的边缘倾斜设置，能够起到一定程度的导向作用，从而减小导轨对第一极耳部122 的损伤。
在一些实施例中，如图13所示，在至少部分极耳部121中，第一边缘121a平行于第二边缘121b。
在一些示例中，参考图10和图13，一部分极耳部121的第一边缘121a平行于第二边缘121b，示例性地，第一边缘121a与第一方向X之间的夹角α1等于第二边缘121b与第一方向X之间的夹角α2。在另一些示例中，参考图10和图11，极耳区120的所有极耳部121的第一边缘121a平行于第二边缘121b。
可选的，极耳部121的形状为平行四边形。
在一些示例中，参考图10和图11，第一极耳部122的第一边缘121a平行于第二边缘121b。在另一些示例中，参考图10和图12，第一极耳部122的第二边缘121b与涂覆区110的第三边缘110a平行。
在本实施例中，将部分极耳部121的第一边缘121a平行于第二边缘121b，使得此部分极耳部121在制造过程中第一边缘121a的切割方式能够应用在第二边缘121b的切割中，从而简化极耳部121的制造流程。
图14为图13中沿B-B方向的剖视结构示意图。
在一些实施例中,缓冲部131的结构强度不小于极耳区120内其他位置处的结构强度。
在本申请中，结构强度指的是承受弯折应力或承受整形过程中抚平或揉平力的强度。
在本实施例中，通过使缓冲部131的结构强度不小于极耳区120其他位置处的结构强度，以降低缓冲部131在承受弯折应力时缓冲部131与极耳部121之间出现开裂的可能性，降低缓冲部131自身出现弯曲褶皱现象的可能性，减小涂覆区110受到的弯折应力。
在一些实施例中，缓冲部131的厚度大于极耳区120内其他部分的厚度；和/或，缓冲部131的硬度大于极耳区120内其他部分的硬度。
可选的，通过增加缓冲部131的厚度，使缓冲部131的厚度大于极耳区120内其他部分的厚度，来提高缓冲部131的结构强度。在一些示例中，增加缓冲部131的整体厚度。在另一些示例中，增加缓冲部131中 局部区域的厚度。示例性地，增加缓冲部131靠近极耳部121区域的厚度。或增加缓冲部131靠近涂覆区110区域的厚度。
可选的，通过在缓冲部131添加硬度参数较大的材料来增加缓冲部131的结构强度。在一些示例中，在缓冲部131的整体区域添加硬度参数较大的材料。在另一些示例中，在缓冲部131中局部区域添加硬度参数较大的材料。示例性地，在缓冲部131靠近极耳部121的区域添加硬度参数较大的材料。或在缓冲部131靠近涂覆区110的区域添加硬度参数较大的材料。示例性的，硬度参数较大的材料可以为铜、硅、镁、锌、锰等金属。需要说明的是，缓冲部131硬度的增大除了可以通过改变缓冲部131的材料，即在缓冲部131内添加硬度参数较大的材料外，还可以通过工艺方法实现硬度的改变。具体地说，可以通过退火、电镀、氧化等手段改变缓冲部131的表面性质，使得缓冲部131具有更强的硬度。
在本实施例中，通过增加缓冲部131厚度或添加硬度参数较大的材料来提高缓冲部131的结构强度，在极片10的制造过程中是极容易实现的，且无需增加过多的工艺环节。
在一些实施例中，如图14所示，极片10还包括缓冲层132，缓冲层132为涂覆于缓冲部131的非活性物质层200。
缓冲层132具有较好的吸收弯折应力和硬度高的特性，用来进一步提高缓冲部131的结构强度。
在一些示例中，缓冲部131的材料和厚度与极耳部121的厚度相同，在缓冲部131上涂覆缓冲层132，在集流体100的制造过程中无需对缓冲部131进行特殊处理，仅在集流体100模切完成后，针对缓冲部131涂覆缓冲层132即可，简化集流体100的工艺难度。
在本实施例中，通过设置缓冲层132来进一步提高缓冲部131的结构强度。
图15为本申请又一些实施例提供的极片的极耳区的结构示意图。
在一些实施例中，极耳部121在远离涂覆区110的一侧具有第四边缘121c；第二边缘121b与第四边缘121c通过弧形连接段121d连接。或者，第二边缘121b与第四边缘121c的交界处设置有缺角。
在一些实施方式的示例中，如图15所示，第一边缘121a与第四边缘121c之间的连接方式可以与第二边缘121b和第四边缘121c的连接方式相同。
在一些示例中，如图15所示，第一边缘121a与缓冲部131的交界处可通过弧形连接段121d连接。第二边缘121b与缓冲部131的交界处可通过弧形连接段连接。进一步降低极耳部121在弯折过程中，极耳部121靠近缓冲区130的一侧出现开裂的风险。
在本实施例中，第二边缘121b和第四边缘121c之间通过弧形连接段121d或者第二边缘121b和第四边缘121c的交界处设置缺角，减小集流体100在弯折后，极耳部121的第二边缘121b和第四边缘121c的交界处与相邻极耳部121干涉的可能性。降低极耳部121在弯折时，边角承受压力过大导致的边角开裂的风险。进一步减轻极片10的重量。
图16为本申请一些实施例提供的未模切的极片的结构示意图。图17为本申请一些实施例提供的模切后极片的结构示意图。
在一些实施例中，如图16和图17所示，相邻极耳部121在第二方向Y上间隔设置。
在一些示例中，极耳区120中部分极耳部121沿第二方向Y的间隔距离相同。在另一些示例中，极耳区120中部分极耳部121沿第二方向Y的间隔距离不同。在又一些示例中，极耳区120中部分极耳部121沿第二方向Y的间隔距离与极耳部121数量呈相关性。
在本实施例中，通过间隔设置极耳部121，来减轻极片10的重量。
在一些实施例中，如图15至图17所示，极耳部121在第二方向Y上具有相对的第一边缘121a和第二边缘121b，第一边缘121a平行于第二边缘121b。相邻极耳部121在第二方向Y上的间距与极耳部121在第二方向Y上的尺寸相同。
在一些示例中，第一边缘121a与第一方向X之间的夹角为锐角。在另一些示例中，第一边缘121a与第一方向X之间的夹角为直角。
集流体100在制造过程中通常采用在一整块大的空白集流体100上模切出多个集流体100，而模切后形成的区域往往是极耳区120。在本实 施例中，相邻极耳部121在第二方向Y上的间距与极耳部121在第二方向Y上的尺寸相同，那么对于一整块的空白集流体100来说，模切后的区域会成为两个集流体100上的极耳区120，从而减少集流体100的用量，降低集流体100的制造成本，减轻极片10的重量。
在一些实施例中，请参照图17，相邻极耳部121之间的最小距离为D1，D1满足于：0mm≤D1≤1000mm。
在本实施例中，相邻极耳部121之间的最小距离可以为零，换言之，相邻极耳部121的边缘的互相抵接的。相邻极耳部121之间的最小距离越大，那么集流体100中的极耳部121的数量越少，极耳部121整形后与其他部件电连接后所能传递的电流效率越低。将相邻极耳部121之间的最小距离D1限定为0mm≤D1≤1000mm，在保证极耳部121过流效率的前提下，尽可能的增加相邻极耳部121之间的最小距离，以减轻极片10的重量。
图18为本申请一些实施例提供的电极组件的结构示意图。图19为本申请又一些实施例提供的电极组件的结构示意图。图20为本申请一些实施例提供的电极组件又一视角示意图。
在一些实施例中，本申请还提供了一种电极组件12，包括极性相反的第一极片300和第二极片400，第一极片300为如多个以上任一实施例的极片10。
在一些实施例中，如图18和图19所示，电极组件12为圆柱形的卷绕结构，第一极片300和第二极片400均为如多个以上任一实施例的极片10。第一极片300的极耳部121与第二极片400的极耳部121位于电极组件12的同一端。
第一极片300和第二极片400具有的极性不同，示例性地，第一极片300具有正极极性，第二极片400具有负极极性。
在本实施例中，第一极片300的极耳部121与第二极片400的极耳部121位于电极组件12的同一端，使得在卷绕过程中或卷绕完成后，能够同时对第一极耳的极耳部121与第二极片400的极耳部121进行抚平。
在一些实施例中，第一极片300的极耳部121与第二极片400的 极耳部121环绕电极组件12的卷绕轴500，且在周向方向上间隔布置。
沿轴向方向上的正投影，极耳部121的形状包括扇形和矩形。在本实施例中提到的扇形和矩形为大致轮廓，而非精确图案。
在本实施例中，极耳部121环绕电极组件12的卷绕轴500，使得整形后的极耳无尖锐棱角，降低整形后的极耳下插至电极组件12内部的可能性。
在一些实施例中，第一极片300的极耳部121与第二极片400的极耳部121对称分布在电极组件12卷绕轴500的两侧。
在本实施例中，对称分布能够使得第一极片300中的极耳部121与第二极片400中的极耳部121空间布置更合理。
在一些实施例中，电极组件12为圆柱形的卷绕结构，第一极片300中的极耳部121与电极组件12的中心轴之间的距离为R，极耳部121的宽度为W1；至少部分极耳部121中的W1和R满足：W1≤πR。
在一些实施方式的示例中中，第一极片300中极耳部121与圆柱形结构中心轴之间的距离为R满足，9mm≤R≤34mm。
需要说明的是，极耳部121与电极组件12的中心轴之间的距离为R指的是任意极耳部121与电极组件12的中心轴之间的距离。
在本实施例中，极耳部121沿第二方向Y的宽度小于等于该极耳部121所在卷绕结构对应位置的周长的一半，便于极耳部121在整形后弯折，降低极耳弧度过大导致的弯折后出现褶皱的可能性。
在一些实施例中，如图17至图19所示，电极组件12在卷绕中心处具有中心孔600，中心孔600的半径为r，至少部分极耳部121中的W1和r满足：W1≤πr。
在一些实施方式的示例中中，r满足，1mm≤r≤6mm。
在一些实施方式的示例中中，W1和r满足，W1≤1/4*2π*r。
在本实施例中，极耳部121在展平状态下沿第二方向Y的宽度小于等于卷绕后形成的中心孔600周长的一半，有利于极耳部121的弯折，降低靠近中心孔600的极耳部121被远离中心孔600的极耳部121覆盖的可能性，进一步提高极耳部121与其他部件之间的过流能力。
在一些实施例中，本申请还提供了一种电池单体1，包括外壳11以及多个以上任一实施例的电极组件12，电极组件12设置于外壳11内。
在一些实施例中，本申请还提供了一种电池2000，包括多个以上任一实施例的电池单体1。
在一些实施例中，本申请还提供了一种用电装置，包括以上任一实施例的电池单体1，电池单体1用于提供电能。
在一些实施例中，请一并参照图5至图10，本申请提供了一种极片10。极片10包括：集流体100和活性物质层200，集流体100包括沿第一方向X并排设置的涂覆区110、极耳区120以及位于涂覆区110和极耳区120之间的缓冲区130，集流体100在极耳区120包括多个沿第二方向Y并排上设置的极耳部121，第一方向X与第二方向Y相交；活性物质层200涂覆于涂覆区110；其中，集流体100在缓冲区130包括缓冲部131，缓冲部131沿第二方向Y延伸并连接多个极耳部121，缓冲部131被配置为吸收多个极耳部121的弯折应力。
参照图5至图8，极耳部121在第一方向X上的尺寸为H1，缓冲部131在第一方向X上的尺寸为H2，H1和H2满足：H1≥H2。极耳部121在第二方向Y上的尺寸为W1，极耳部121在第一方向X上的尺寸为H1，H1和W1满足：3W1≥H1≥0.5W1。任一极耳部121在第二方向Y上均不超出涂覆区110。至少部分极耳部121中的第一边缘121a和第二边缘121b相对第一方向X均倾斜设置。参照图18至图20，电极组件12为圆柱形的卷绕结构,第一极片300中的极耳部121与电极组件12的中心轴之间的距离为R，极耳部121的宽度为W1；至少部分极耳部121中的W1和R满足：W1≤πR。中心孔600的半径为r，至少部分极耳部121中的W1和r满足：W1≤πr。
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 (27)

  1. 一种极片，包括：
    集流体，包括沿第一方向并排设置的涂覆区、极耳区以及位于所述涂覆区和所述极耳区之间的缓冲区，所述集流体在所述极耳区包括多个沿第二方向并排上设置的极耳部，所述第一方向与所述第二方向相交；
    活性物质层，所述活性物质层涂覆于所述涂覆区；
    其中，所述集流体在所述缓冲区包括缓冲部，所述缓冲部沿所述第二方向延伸并连接多个所述极耳部，所述缓冲部被构造成吸收多个所述极耳部的弯折应力。
  2. 根据权利要求1所述的极片，其中，所述极耳部在所述第一方向上的尺寸为H1，所述缓冲部在所述第一方向上的尺寸为H2，H1和H2满足：H1≥H2。
  3. 根据权利要求1或2所述的极片，其中，所述极耳部在所述第二方向上的尺寸为W1，所述极耳部在所述第一方向上的尺寸为H1，H1和W1满足：3W1≥H1≥0.5W1。
  4. 根据权利要求1-3任一项所述的极片，其中，所述极耳部在所述第二方向上具有相对的第一边缘和第二边缘，至少部分所述极耳部中的所述第一边缘相对所述第一方向倾斜设置。
  5. 根据权利要求4所述的极片，其中，在由所述极耳区到所述涂覆区的方向上形成平行于所述第一方向的第一射线，所述第一射线以所述第一边缘远离所述极耳区的一端为端点，所述第一边缘与所述第一射线之间的夹角为α1，α1满足，-75°≤α1≤75°；
    其中，假定所述第一边缘位于所述第一射线顺时针转动180°范围内， 则所述第一边缘与所述第一射线之间的夹角α1为正夹角；假定所述第一边缘位于所述第一射线逆时针转动180°范围内，则所述第一边缘与所述第一射线之间的夹角α1为负夹角。
  6. 根据权利要求4所述的极片，其中，至少部分所述极耳部中的所述第二边缘相对所述第一方向倾斜设置。
  7. 根据权利要求6所述的极片，其中，在由所述极耳区到所述涂覆区的方向上形成平行于所述第一方向的第一射线，所述第一射线以所述第一边缘远离所述涂覆区的一端为端点，所述第一边缘与所述第一射线之间的夹角为α1；
    在由所述极耳区到所述涂覆区的方向上形成平行于所述第一方向的第二射线，所述第二射线以所述第二边缘远离所述涂覆区的一端为端点，所述第二边缘与所述第二射线之间的夹角为α2，α1和α2满足；α1+α2＝0°。
  8. 根据权利要求6所述的极片，其中，在由所述极耳区到所述涂覆区的方向上形成平行于所述第一方向的第一射线，所述第一射线以所述第一边缘远离所述涂覆区的一端为端点，所述第一边缘与所述第一射线之间的夹角为α1；
    在由所述极耳区到所述涂覆区的方向上形成平行于所述第一方向的第二射线，所述第二射线以所述第二边缘远离所述涂覆区的一端为端点，所述第二边缘与所述第二射线之间的夹角为α2，至少部分α1和α2满足；α1/α2＞0。
  9. 根据权利要求8所述的极片，其中，任一所述极耳部在所述第二方向上均不超出所述涂覆区。
  10. 根据权利要求9所述的极片，其中，多个所述极耳部形成的整体在所述第二方向的一端具有第一极耳部，所述涂覆区在所述第二方向且靠 近所述第一极耳部的一侧具有第三边缘，所述第三边缘与所述第一极耳部在所述第二方向上间隔设置。
  11. 根据权利要求9所述的极片，其中，多个所述极耳部形成的整体在所述第二方向的一端具有第一极耳部，所述涂覆区在所述第二方向且靠近所述第一极耳部的一侧具有第三边缘，在所述第一极耳部中，所述第二边缘位于所述第一极耳部靠近所述第三边缘的一侧；
    其中，在远离所述涂覆区的方向上，所述第二边缘相对于所述第一方向倾斜设置。
  12. 根据权利要求8所述的极片，其中，在至少部分所述极耳部中，所述第一边缘平行于所述第二边缘。
  13. 根据权利要求4所述的极片，其中，所述极耳部在远离涂覆区的一侧具有第四边缘；
    所述第二边缘与所述第四边缘通过弧形连接段连接；或者，
    所述第二边缘与所述第四边缘的交界处设置有缺角。
  14. 根据权利要求1-13任一项所述的极片，其中，相邻所述极耳部在所述第二方向上间隔设置。
  15. 根据权利要求14所述的极片，其中，所述极耳部在所述第二方向上具有相对的第一边缘和第二边缘，所述第一边缘平行于所述第二边缘；
    相邻所述极耳部在所述第二方向上的间距与所述极耳部在所述第二方向上的尺寸相同。
  16. 根据权利要求1-15任一项所述的极片，其中，相邻所述极耳部之间的最小距离为D1，D1满足于：0mm≤D1≤1000mm。
  17. 根据权利要求1-16任一项所述的极片，其中，
    所述缓冲部的结构强度不小于所述极耳区内其他位置处的结构强度；和/或，
    所述缓冲部的厚度大于所述极耳区内其他部分的厚度；和/或，
    所述缓冲部的硬度大于所述极耳区内其他部分的硬度。
  18. 根据权利要求17所述的极片，其中，所述极片还包括缓冲层，所述缓冲层为涂覆于所述缓冲部的非活性物质层。
  19. 一种电极组件，包括极性相反的第一极片和第二极片，所述第一极片为如权利要求1至18任一项所述的极片。
  20. 根据权利要求19所述的电极组件，其中，所述电极组件为圆柱形的卷绕结构，所述第一极片和所述第二极片均为如权利要求1至19任一项所述的极片；
    所述第一极片的所述极耳部与所述第二极片的所述极耳部位于所述电极组件的同一端。
  21. 根据权利要求20所述的电极组件，其中，所述第一极片的所述极耳部与所述第二极片的所述极耳部环绕所述电极组件的卷绕轴，且在周向方向上间隔布置。
  22. 根据权利要求21所述的电极组件，其中，所述第一极片的所述极耳部与所述第二极片的所述极耳部对称分布在所述电极组件卷绕轴的两侧。
  23. 根据权利要求19-22任一项所述的电极组件，其中，所述电极组件为圆柱形的卷绕结构，所述第一极片中的所述极耳部与所述电极组件的中心轴之间的距离为R，所述极耳部的宽度为W1；
    至少部分所述极耳部中的W1和R满足：W1≤πR。
  24. 根据权利要求23所述的电极组件，其中，所述电极组件在卷绕中心处具有中心孔，所述中心孔的半径为r，至少部分所述极耳部中的W1和r满足：W1≤πr。
  25. 一种电池单体，包括外壳以及如权利要求19至24所述的电极组件，所述电极组件设置于所述外壳内。
  26. 一种电池，包括多个如权利要求25所述的电池单体。
  27. 一种用电装置，包括如权利要求25所述的电池单体，所述电池单体用于提供电能。
PCT/CN2022/111388 2022-08-10 2022-08-10 极片、电极组件、电池单体、电池以及用电装置 WO2024031427A1 (zh)

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CN112397684A (zh) * 2020-11-18 2021-02-23 珠海冠宇电池股份有限公司 一种多极耳电池极片及其制作方法
CN113193165A (zh) * 2021-05-28 2021-07-30 微宏动力系统（湖州）有限公司 极耳极片及卷绕电池
CN216488415U (zh) * 2021-12-02 2022-05-10 云山新能源材料技术(深圳)有限公司 一种卷绕电池
CN216529013U (zh) * 2021-11-12 2022-05-13 云山新能源材料技术(深圳)有限公司 一种卷焊一体的卷绕电池

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CN112397684A (zh) * 2020-11-18 2021-02-23 珠海冠宇电池股份有限公司 一种多极耳电池极片及其制作方法
CN113193165A (zh) * 2021-05-28 2021-07-30 微宏动力系统（湖州）有限公司 极耳极片及卷绕电池
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