WO2023236346A1 - 电极组件、电池单体、电池及用电装置 - Google Patents

电极组件、电池单体、电池及用电装置 Download PDF

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Publication number
WO2023236346A1
WO2023236346A1 PCT/CN2022/112849 CN2022112849W WO2023236346A1 WO 2023236346 A1 WO2023236346 A1 WO 2023236346A1 CN 2022112849 W CN2022112849 W CN 2022112849W WO 2023236346 A1 WO2023236346 A1 WO 2023236346A1
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WIPO (PCT)
Prior art keywords
length
tab
area
electrode assembly
coating area
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PCT/CN2022/112849
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English (en)
French (fr)
Inventor
吴宇堃
张小平
许文竹
Original Assignee
宁德时代新能源科技股份有限公司
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Publication of WO2023236346A1 publication Critical patent/WO2023236346A1/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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—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
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means
    • H01M50/597—Protection against reversal of polarity

Definitions

  • the present application relates to the field of battery technology, and in particular to an electrode assembly, a battery cell, a battery and an electrical device.
  • Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection.
  • battery technology is an important factor related to their development.
  • the present application provides an electrode assembly, a battery cell, a battery and an electrical device.
  • the electrode assembly can effectively increase energy density while ensuring stable performance.
  • the present application provides an electrode assembly.
  • the electrode assembly has a laminated structure.
  • the electrode assembly includes a plurality of first pole pieces stacked along a first direction, and each first pole piece includes a first coating area.
  • the second coating area and the first tab area, the second coating area and the first coating area are connected through the first tab area, along the first direction, the first tab areas of the plurality of first pole pieces Projection overlap; wherein, the electrode assembly satisfies one of the following conditions: a) the length of the first tab areas of the plurality of first pole pieces gradually decreases from one side to the other side in the first direction; b) multiple The length of the first tab area of each first pole piece gradually decreases from both sides in the first direction toward the middle.
  • the laminated tab set needs to be folded along its stacking direction before being connected to the adapter or electrode terminal to ensure the stability of the tab set connection. If the reserved length of the tab set is too short, the tab set will be retracted. Finally, some tabs are prone to have a too small connection area due to a long retracting path, which affects the stability of their connection and even poses a greater risk of breakage. If the reserved length of the tab group is too long, the number of electrode components will increase.
  • the length of the first tab area decreases from one side in the first direction (that is, the stacking direction of multiple first tab areas) to the other side, and all the first tab areas are along the first direction. It is gathered from the side of the first tab area with the longest length to the side of the first tab area with the shortest length, or the length of the first tab area is extended from the first direction (that is, multiple first tab areas).
  • the two sides of the tab area decrease toward the middle, and all the first tab areas converge toward the center on both sides in the first direction.
  • This structure makes the The connection area is sufficient, which reduces the risk of weld cracking and tab breakage due to excessive pre-tightening force after retracting and insufficient area to be connected on some tabs, effectively ensuring the stability of tab connection and thus effectively ensuring battery performance. Stability; on the other hand, it can effectively avoid excessive step redundancy after the first tab area is folded, which not only reduces material waste and battery weight, but also effectively reduces the space occupancy rate of the first tab area, thereby effectively improving the battery's performance. Energy Density.
  • each first pole piece of the electrode assembly of the present application includes a first coating area and a second coating area and a first tab area connecting the first coating area and the second coating area, then a plurality of third One pole piece is stacked along the first direction to form a conjoined bare battery core.
  • the conjoined bare battery core effectively reduces the number of connection points of the tabs, thereby further improving the stability of the tab connection. , thereby effectively improving the stability of battery performance.
  • the length of each first pole piece is the same; when the electrode assembly meets the above condition a), the electrode assembly simultaneously satisfies: the length of the first coating areas of the plurality of first pole pieces is determined by the first The length of the second coating areas of the plurality of first pole pieces gradually increases from one side of the first direction to the other side.
  • the length of each first pole piece is the same, and the length of the first coating area and the length of the second coating area of the plurality of first pole pieces are from one side to the other side in the first direction. Gradually increase, so that the length of the first tab areas of the plurality of first pole pieces gradually decreases from one side to the other side in the first direction.
  • the length is set to a length gradient type, which reduces redundant waste in the first tab area and effectively increases the coating area of part of the first pole piece's coating area, thereby effectively increasing the total area of the coating area of the electrode assembly, and by increasing the activity The total capacity of the material further effectively increases the energy density of the battery.
  • the length of each first pole piece is the same; when the electrode assembly meets the above condition b), the electrode assembly simultaneously satisfies: the length of the first coating areas of the plurality of first pole pieces is determined by the first The two sides in the direction gradually increase toward the middle, and the lengths of the second coating areas of the plurality of first pole pieces gradually increase from the two sides in the first direction toward the middle.
  • the length of each first pole piece is the same, and the length of the first coating area and the length of the second coating area of the plurality of first pole pieces gradually increase from both sides in the first direction to the middle. , so that the length of the first tab regions of the plurality of first pole pieces gradually decreases from both sides in the first direction to the middle.
  • the length gradient type reduces redundancy and waste in the first tab area while effectively increasing the coating area of part of the first pole piece, thereby effectively increasing the total area of the coating area of the electrode assembly and increasing the total capacity of the active material. And further effectively improve the energy density of the battery.
  • the ratio between the lengths of the shortest first coating area and the longest first coating area is greater than or equal to 0.9; and/or the length ratio of the shortest second coating area and the longest length is The length ratio of the two coating areas is greater than or equal to 0.9.
  • the length difference range of the first tab area is simultaneously limited, thereby limiting the length difference range of the first tab area.
  • the stacking thickness of one pole piece prevents some of the first pole pieces from having the first tab area that is too long and the coating area that is too short, thereby effectively ensuring the energy density of the overall electrode assembly while reducing tab redundancy.
  • the ratio of the length of the first coating area to the length of the first tab area of the same first pole piece is D 1 , satisfying 1.4 ⁇ D 1 ⁇ 1.8; and/or the same first pole piece is D 1 .
  • the ratio of the length of the second coating area of a pole piece to the length of the first tab area is D 2 , which satisfies 1.4 ⁇ D 2 ⁇ 1.8.
  • the first tab area accounts for the first pole area.
  • the difference in length between two adjacent first tab regions is D3, which satisfies 0.004mm ⁇ D 3 ⁇ 0.008mm.
  • the length difference between two adjacent first tab areas is greater than or equal to 0.004mm and less than or equal to 0.008mm, which further reduces the length of the first tab area while ensuring that the length of the first tab area changes in a step-like manner.
  • the electrode assembly further includes a plurality of second pole pieces.
  • a plurality of first pole pieces and a plurality of second pole pieces are alternately stacked along the first direction.
  • the first pole pieces and the second pole pieces are On the contrary, the second pole piece includes a third coating area, a fourth coating area and a second tab area, the third coating area and the fourth coating area are connected through the second tab area, along the first direction, The projections of the second tab areas of the plurality of second pole pieces overlap; wherein, the electrode assembly satisfies one of the following conditions: c)
  • the lengths of the second tab areas of the plurality of second pole pieces all extend from the first direction gradually decreases from one side to the other side; d) the lengths of the second tab regions of the plurality of second pole pieces gradually decrease from both sides in the first direction to the middle.
  • the electrode assembly includes a first pole piece and a second pole piece.
  • the first pole piece and the second pole piece can be respectively configured as the positive pole piece and the negative pole piece of the electrode assembly.
  • the second pole piece is connected to the first pole piece.
  • the structure of the second pole piece is the same, that is, the length of the second tab area of the second pole piece also decreases to one side along the first direction or decreases toward the middle along the first direction, thereby effectively preventing the second tab area from being closed.
  • the length of each second pole piece is the same; when the electrode assembly meets the above condition c), the electrode assembly simultaneously satisfies: the length of the third coating area of the plurality of second pole pieces is determined by the first The length of the fourth coating areas of the plurality of second pole pieces gradually increases from one side in the first direction to the other side.
  • the length of the second pole piece is the same, and the lengths of the third coating area and the fourth coating area gradually increase from one side to the other side in the first direction, so that the length of the second tab area It gradually decreases from one side to the other side in the first direction, thereby further reducing the redundant waste of the second tab area and effectively increasing the coating area of at least part of the second pole piece's coating area, thus effectively increasing the
  • the total area of the coating area of the electrode assembly further effectively increases the energy density of the battery by increasing the total capacity of the active material.
  • the length of each second pole piece is the same; when the electrode assembly meets the above condition d), the electrode assembly simultaneously satisfies: the length of the third coating area of the plurality of second pole pieces is determined by the first The lengths of the fourth coating areas of the plurality of second pole pieces gradually increase from both sides in the first direction to the middle.
  • the lengths of the second pole pieces are the same, and the lengths of the third coating area and the fourth coating area gradually increase from both sides in the first direction to the middle, so that the length of the second tab area increases from the first direction to the middle.
  • the two sides in one direction gradually decrease toward the middle, thereby further reducing the redundant waste of the second tab area and effectively increasing the coating area of at least part of the second pole piece's coating area, thereby effectively increasing the coating area of the electrode assembly.
  • the total area of the covered area further effectively increases the energy density of the battery by increasing the total capacity of the active material.
  • the present application provides a battery cell, including: the electrode assembly according to any one of the above solutions, the first tab area is bent so that the projection of the first coating area along its thickness direction is consistent with the first tab area.
  • the projections of the two coating areas overlap along their thickness directions; the housing component, the electrode assembly is contained in the housing component, and the housing component includes a first electrode lead-out part; a first adapter, the first adapter electrically connects a plurality of The first tab area and the first electrode lead-out part of the first pole piece.
  • the first tab area is bent so that the thickness directions of the first coating area and the second coating area are consistent, and the first tab area is on the same side of the first coating area and the second coating area.
  • the electrode assembly is accommodated in the case assembly, and the first adapter connects the first tab area and the first electrode lead-out part to form a battery cell. Due to the characteristics of the electrode assembly proposed in the first embodiment of the present application, the battery cell of the second embodiment of the present application also has better performance stability and higher energy density.
  • the first adapter includes a body, a first arm and a second arm.
  • the body is connected to the first electrode lead-out part.
  • the first arm and the second arm extend from one end of the body.
  • the first arm There is a gap between the first pole piece and the second arm, and the first tab areas of the plurality of first pole pieces are inserted into the gap and connected to the first arm and the second arm.
  • the first adapter includes a body and a first arm and a second arm extending from the same end of the body. There is a gap between the first arm and the second arm for the first tab area to be inserted, so that , after the first tab area is connected to the first electrode lead-out part through the first adapter with this structure, the first arm and the second arm of the first adapter tighten and limit the first tab area. function, reducing the risk of the first tab area collapsing toward the first coating area and the second coating area, thereby reducing the risk of short circuiting the battery cells due to deformation of the first tab area, and further effectively improving the performance of the battery cells. Performance stability.
  • the present application also provides a battery, including the battery cell as described in any of the above solutions.
  • the battery according to the third embodiment of the present application also has better performance stability and higher energy density.
  • the present application also provides an electrical device, including the battery described in the above solution, where the battery is used to provide electrical energy.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Figure 2 is an exploded view of a battery provided by some embodiments of the present application.
  • Figure 3 is an exploded view of a battery cell provided by some embodiments of the present application.
  • Figure 4 is a front view of an electrode assembly provided by some embodiments of the present application.
  • Figure 5 is a cross-sectional view of the first tab region in an uncontracted state of the first embodiment in the A-A direction shown in Figure 4;
  • Figure 6 is a cross-sectional view of the first tab area in a collapsed state of the first embodiment shown in Figure 5;
  • Figure 7 is a cross-sectional view of the first tab area in the uncontracted state of the second embodiment in the A-A direction shown in Figure 4;
  • Figure 8 is a cross-sectional view of the first tab area in a collapsed state of the second embodiment shown in Figure 7;
  • Figure 9 is a front view of an electrode assembly provided by some embodiments of the present application.
  • Figure 10 is a cross-sectional view of the first tab region in the uncontracted state of the first embodiment in the B-B direction shown in Figure 9;
  • Figure 11 is a cross-sectional view of the first tab area in a collapsed state of the first embodiment shown in Figure 10;
  • Figure 12 is a cross-sectional view of the first tab area in the uncontracted state of the second embodiment in the B-B direction shown in Figure 9;
  • Figure 13 is a cross-sectional view of the first tab area in a collapsed state of the second embodiment shown in Figure 12;
  • Figure 14 is a front cross-sectional view of a battery cell provided by some embodiments of the present application.
  • Figure 15 is an enlarged schematic diagram of the partial structure of part C shown in Figure 14;
  • Figure 16 is a front view of the first adapter provided by some embodiments of the present application.
  • Figure 17 is a bottom view of the first adapter provided by some embodiments of the present application.
  • Figure 18 is a bottom view of the first adapter provided by some embodiments of the present application.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.
  • the term “plurality” refers to two or more (including two).
  • the battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • multiple battery cells can be connected in series, parallel or mixed connection to directly form a battery.
  • Mixed connection means that multiple battery cells are connected in series and in parallel.
  • Multiple battery cells can also be connected in series, parallel or mixed to form a battery module, and then multiple battery modules can be connected in series, parallel or mixed to form a battery.
  • the battery may also include a case for enclosing one or more battery cells.
  • the box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • the battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium sulfur batteries, sodium lithium ion batteries, sodium ion batteries or magnesium ion batteries, etc., which are not limited in the embodiments of the present application.
  • the battery cell may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes, and the embodiments of the present application are not limited to this.
  • Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application are not limited to this.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly consists of a positive electrode plate, a negative electrode plate and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the positive electrode current collector that is not coated with the positive electrode active material layer protrudes from the positive electrode collector that is coated with the positive electrode active material layer. Fluid, the positive electrode current collector without the positive electrode active material layer is used as the positive electrode tab.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode collector that is coated with the negative electrode active material layer.
  • Fluid, the negative electrode current collector that is not coated with the negative electrode active material layer serves as the negative electrode tab.
  • the material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon.
  • the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together.
  • the material of the isolation film can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the electrode assembly may have a rolled structure or a laminated structure, and the embodiments of the present application are not limited thereto.
  • Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles and electric cars, as well as in many fields such as military equipment and aerospace. . As the application fields of power batteries continue to expand, their market demand is also constantly expanding.
  • the tab assembly when assembling an electrode assembly with a stacked tab assembly, the tab assembly needs to be folded along its stacking direction and then connected to an adapter or electrode terminal to ensure that each pole of the tab assembly is The tabs can be connected stably. Since the electrode assembly has a certain thickness, whether it is gathered to one side or toward the middle along the stacking direction of the tab group, the length of the retracting path of each tab of the tab group is different. In the early stage, In battery production technology, the length of each tab of the tab group is the same. If the reserved length of the tab group is too short, after the tab group is retracted, some tabs that are far away from the retracted position are likely to be damaged due to the long retracting path. The connection area is too small and the pre-tightening force is too high, which affects the stability of the connection. The tabs may even break abnormally, seriously affecting the stability of the battery.
  • the applicant initially lengthened the reserved length of the tab group to ensure that the tabs farthest from the retracting area can be retracted and connected stably.
  • Most of the tabs of the tab group will be redundant in the length direction. After the tab group is folded, a large step redundancy will be formed at the front end of the tab group.
  • the tab group with this structure occupies a large space.
  • the electrode assembly of the present application has a laminated structure.
  • the electrode assembly includes multiple electrodes stacked along a first direction.
  • first pole pieces each first pole piece includes a first coating area, a second coating area and a first tab area, the second coating area and the first coating area are connected through the first tab area,
  • the first tab regions of the plurality of first pole pieces are stacked along the first direction, and the length of the first tab regions of the plurality of first pole pieces gradually decreases from one side to the other side in the first direction; or , the lengths of the first tab regions of the plurality of first pole pieces gradually decrease from both sides in the first direction toward the middle.
  • the length of the plurality of first tab areas of the plurality of first pole pieces gradually decreases from one side to the other side in the first direction
  • the length of the plurality of first tab areas increases from one side in the first direction to the other.
  • One side of the first pole piece is gathered toward the other side; in a structure in which the length of the first tab areas of the plurality of first pole pieces gradually decreases from both sides in the first direction to the middle, the plurality of first tab areas are formed from the first The two sides in the direction are gathered toward the middle.
  • the length of all the first tab areas meets the folding requirements, and the area to be connected formed after all the first tab areas are folded is sufficient, and part of the first tabs can be reduced.
  • the risk of weld cracking and tab breakage due to excessive pre-tightening force and insufficient area to be connected after the area is closed effectively ensures the stability of the tab connection and at the same time avoids the redundant part of the first tab area from being inserted into the electrode.
  • the main body of the assembly will cause the problem of battery cell short circuit, thereby effectively improving the performance stability of the electrode assembly; and, because the structure of the present application effectively avoids excessive step redundancy after the first tab area is folded, it can effectively reduce the first
  • the space occupancy rate of the tab area is conducive to effectively improving the energy density of the battery.
  • the battery cells disclosed in the embodiments of the present application can be used in, but are not limited to, electrical devices such as vehicles, ships, or aircrafts.
  • a power supply system including the battery cells, batteries, etc. disclosed in this application can be used to form the electrical device.
  • Embodiments of the present application provide an electrical device that uses a battery as a power source.
  • the electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc.
  • electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc.
  • spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.
  • the battery described in the embodiments of the present application is not limited to the above-described electrical devices, but can also be applied to all electrical devices that use batteries. However, for the sake of simplicity of description, the following embodiment is based on an embodiment of the present application.
  • the electric device is a vehicle as an example for explanation.
  • FIG. 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application.
  • the vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • the battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 .
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • FIG. 2 is an exploded view of a battery 100 provided by some embodiments of the present application.
  • the battery 100 includes a box 20 and a battery cell 10 , and the battery cell 10 is accommodated in the box 20 .
  • the box 20 is used to provide an accommodation space for the battery cells 10 , and the box 20 can adopt a variety of structures.
  • the box 20 may include a first part 21 and a second part 22 , the first part 21 and the second part 22 covering each other, the first part 21 and the second part 22 jointly defining a space for accommodating the battery cell 10 of accommodation space.
  • the second part 22 may be a hollow structure with one end open, and the first part 21 may be a plate-like structure.
  • the first part 21 covers the open side of the second part 22 so that the first part 21 and the second part 22 jointly define a receiving space.
  • the first part 21 and the second part 22 may also be hollow structures with one side open, and the open side of the first part 21 covers the open side of the second part 22.
  • the box 20 formed by the first part 21 and the second part 22 can be in various shapes, such as rectangular parallelepiped, cube, etc.
  • the battery 100 there may be a plurality of battery cells 10 , and the plurality of battery cells 10 may be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the plurality of battery cells 10 are connected in series and in parallel.
  • Multiple battery cells 10 can be directly connected in series, parallel, or mixed together.
  • the battery 100 can also be in the form of a battery module in which multiple battery cells 10 are first connected in series, parallel, or mixed, and then multiple battery modules are connected in series. Either in parallel or mixed connection to form a whole.
  • Each battery cell 10 may be a secondary battery or a primary battery, or may be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto.
  • the battery cell 10 may include a case assembly 11, an electrode assembly 12 and an adapter.
  • the case assembly 11 may include a case 111 and an end cover 112.
  • the case 111 has an opening.
  • the end cover 112 covers the opening of the case 111 and forms a Sealing connections are made to form a sealed space for accommodating the electrode assembly 12 and the electrolyte.
  • the electrode assembly 12 When assembling the battery cell 10 , the electrode assembly 12 can be first placed into the casing 111 , the electrolyte is filled into the casing 111 , and then the end cap 112 is closed with the opening of the casing 111 .
  • the housing 111 can be of various shapes, and the shape of the housing 111 can be determined according to the specific shape of the electrode assembly 12 .
  • the electrode assembly 12 has a rectangular parallelepiped structure, a rectangular parallelepiped housing 111 may be used.
  • the end cap 112 can also have various structures.
  • the housing assembly 11 is not limited to the above structure.
  • the housing assembly 11 may include a shell 111 and two end caps 112.
  • the shell 111 is a hollow structure with openings on opposite sides, and one end cap 112 corresponds to
  • the cover is closed at an opening of the housing 111 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 12 and the electrolyte.
  • the housing assembly 11 also includes an electric energy lead-out part, which can be insulated and arranged on the end cover 112.
  • the electric energy lead-out part is used to output the current of the electrode assembly 12.
  • the electric energy lead-out part can be directly connected to the electrode assembly 12 or through a switch. Connector connection.
  • the adapter plays the role of overcurrent and convergence, and the electric energy extraction part is electrically connected to the tabs of the electrode assembly 12 through the connector.
  • the electrode assembly 12 is a component in the battery cell 10 where electrochemical reactions occur.
  • the electrode assembly 12 may include a positive electrode piece, a negative electrode piece, and a separator.
  • the electrode assembly 12 may be a roll structure formed by winding the positive electrode sheet, the isolation film and the negative electrode sheet, or it may be a stacked structure formed by a stacked arrangement of the positive electrode sheet, the isolation film and the negative electrode sheet.
  • Figure 4 is a front view of an electrode assembly provided by some embodiments of the present application
  • Figure 5 is a view of the first tab area in an unfolded state in the AA direction of the first embodiment shown in Figure 4.
  • Cross-sectional view
  • Figure 6 is a cross-sectional view of the first tab area of the first embodiment shown in Figure 5 in a folded state
  • Figure 7 is a cross-sectional view of the second embodiment in the AA direction shown in Figure 4 when the first tab area is not folded
  • FIG. 8 is a cross-sectional view of the second embodiment shown in FIG. 7 in the folded state of the first tab area.
  • Some embodiments of the present application provide an electrode assembly 12.
  • the electrode assembly 12 has a laminated structure.
  • the electrode assembly 12 includes a plurality of first pole pieces 121 stacked along a first direction. Each first pole piece 121 includes a third pole piece 121. A coating area 1211, a second coating area 1213 and a first tab area 1212. The second coating area 1213 and the first coating area 1211 are connected through the first tab area 1212.
  • a plurality of The projections of the first tab areas 1212 of a pole piece 121 overlap; wherein the electrode assembly 12 satisfies one of the following conditions: a) the length L 11 of the first tab areas of the plurality of first pole pieces 121 is determined by the first One side in the direction gradually decreases toward the other side; b) The length L 11 of the first tab areas of the plurality of first pole pieces 121 gradually decreases from both sides in the first direction toward the middle.
  • the first pole piece 121 includes a current collector and an active material layer coated on the current collector.
  • the area where the active material layer is coated on the current collector forms a first coating area 1211 and a second coating area 1213.
  • the area on the current collector that is not coated with the active material layer forms a first coating area 1211 and a second coating area 1213.
  • the blank area covered with the active material layer forms the first tab area 1212.
  • the first electrode piece 121 can be a positive electrode piece or a negative electrode piece. That is to say, the coating layers of the first coating area 1211 and the second coating area 1213 can be both positive electrode active material layers or both negative electrodes.
  • the active material layer of course, has the same polarity as the current collector and the active material.
  • Each first pole piece 121 includes a first coating area 1211, a second coating area 1213 and a first tab area 1212 connecting the first coating area 1211 and the second coating area 1213.
  • a plurality of first pole pieces After 121 are stacked along the first direction, a conjoined electrode assembly including two main body parts and one tab area can be formed.
  • the first direction may extend along the X direction in the figure.
  • the projections of the first tab regions 1212 of the plurality of first pole pieces 121 overlap.
  • the first coating area 1211, the first tab area 1212, and the second coating area 1213 are arranged along the second direction Y, and the second direction Y is perpendicular to the first direction X.
  • the length L 11 of a tab area is the size of the first tab area 1212 in the second direction Y
  • the length L 12 of the first coating area is the size of the first coating area 1211 in the second direction Y
  • the length L 13 of the second coating area is the length of the second coating area 1213 in the second direction Y.
  • the length L 11 of the first tab areas of the plurality of first pole pieces 121 may gradually decrease from one side in the first direction to the other side, or may gradually decrease from both sides in the first direction toward the middle.
  • the lengths L 12 of the first coating areas of the plurality of first pole pieces 121 may be equal or unequal.
  • the lengths L 13 of the plurality of second coating areas may be equal or unequal.
  • the length L 11 of the first tab area decreases from one side of the first direction X (that is, the stacking direction of the plurality of first tab areas 1212 ) to the other side.
  • the side of the first tab area 1212 with the longest length converges toward the side of the first tab area 1212 with the shortest length, or the length L 11 of the first tab area extends from both sides in the first direction X.
  • Decreasing in the middle all the first tab areas 1212 are gathered toward the middle along both sides of the first direction. This structure makes the area of all the first tab areas 1212 to be connected sufficient after the tab group is folded, reducing some of the poles.
  • the pre-tightening force after the ears are folded is too high and the area to be connected is insufficient, which may cause the risk of weld cracking and tab breakage.
  • This effectively ensures the stability of the tab connection thereby effectively ensuring the performance stability of the battery 100; on the other hand, it can effectively ensure the stability of the tab connection.
  • each first pole piece 121 of the electrode assembly 12 of the present application includes a first coating area 1211 and a second coating area 1213 and a first tab connecting the first coating area 1211 and the second coating area 1213 area 1212, the plurality of first pole pieces 121 are stacked along the first direction , thereby further improving the stability of the tab connection, thereby effectively improving the stability of the performance of the battery 100 .
  • the length L 1 of each first pole piece is the same; when the electrode assembly 12 meets the above condition a), the electrode assembly 12 simultaneously satisfies: the first coating area of multiple first pole pieces 121 The length L 12 gradually increases from one side to the other side in the first direction, and the length L 13 of the second coating areas of the plurality of first pole pieces 121 gradually increases from one side to the other side in the first direction. .
  • each first pole piece is the same, which means that the length of each pole piece in the second direction Y is the same, that is, the first coating area 1211 and the first tab area 1212 of each first pole piece 121 It is the same as the total length of the second coating area 1213 in the second direction Y.
  • the two sides in the first direction are defined as the first side and the second side, and the length L 12 of the first coating areas of the plurality of first pole pieces 121 is from one side in the first direction to the other side.
  • the length L 13 of the second coating areas of the plurality of first pole pieces 121 gradually increases from one side to the other side in the first direction, which means that the length L 13 of the second coating areas of the plurality of first pole pieces 121 gradually increases.
  • the length L 12 gradually increases from the first side to the second side in the first direction.
  • the length L 13 of the second coating areas of the plurality of first pole pieces 121 increases from the first side to the second side in the first direction. Gradually increase on both sides.
  • each first pole piece 121 in the second direction Y is the same, and the length L 12 of the first coating area and the length L 13 of the second coating area of the plurality of first pole pieces 121 are both equal to Gradually increasing from the first side to the second side in the first direction, the length L11 of the first tab regions of the plurality of first pole pieces 121 will gradually decrease from the first side to the second side in the first direction. .
  • the first tab areas 1212 of the plurality of first pole pieces 121 are gathered along the first direction X from the first side to the second side, so as to gather the plurality of first tab areas 1212 into the shortest first tab area 1212 the side on which it is located.
  • two ends of the plurality of first pole pieces 121 along the second direction Y are substantially aligned in the first direction X, so as to maximize the overlapping area of the projection of the plurality of first tab regions 1212 in the first direction X. .
  • each first pole piece is the same.
  • the length L 12 of the first coating area and the length L 13 of the second coating area of the plurality of first pole pieces 121 are both from one side in the first direction to the other. One side gradually increases, so that the length L 11 of the first tab areas of the plurality of first pole pieces 121 gradually decreases from one side to the other side in the first direction.
  • Such a structure reduces the first coating area 1211 and the length L 13 of the second coating area is set to a length gradient type, which reduces the redundant waste of the first tab area 1212 and effectively increases the coating area of part of the coating area of the first pole piece 121, thereby effectively increasing the electrode assembly.
  • the total area of the coating area of 12 further effectively increases the energy density of the battery 100 by increasing the total capacity of the active material.
  • the length L 1 of each first pole piece is the same; when the electrode assembly 12 meets the above condition b), the electrode assembly 12 simultaneously satisfies: the first coating area of multiple first pole pieces 121
  • the length L 12 gradually increases from both sides in the first direction to the middle, and the length L 13 of the second coating areas of the plurality of first pole pieces 121 gradually increases from both sides in the first direction to the middle.
  • each first pole piece is the same, which means that the length of each pole piece in the second direction Y is the same, that is, the first coating area 1211 of each first pole piece 121, the first The total length of the tab area 1212 and the second coating area 1213 in the second direction Y is the same.
  • two ends of the plurality of first pole pieces 121 along the second direction Y are substantially aligned in the first direction X, so as to maximize the overlapping area of the projection of the plurality of first pole tabs in the first direction X, ensuring that When the plurality of first tab areas 1212 are gathered together, they can have a larger overlapping area, and an area to be connected is formed in the overlapping area to facilitate the connection between the first tab areas 1212 and the adapter or directly with the electric energy extraction part.
  • each first pole piece is the same.
  • the length L 12 of the first coating area and the length L 13 of the second coating area of the plurality of first pole pieces 121 are both from both sides in the first direction to the middle. gradually increases, so that the length L 11 of the first tab areas of the plurality of first pole pieces 121 gradually decreases from both sides in the first direction to the middle.
  • Such a structure separates the first coating area 1211 and the second coating area.
  • the length L 13 of the coating area is set to a length gradient type, which reduces the redundant waste of the first tab area 1212 and effectively increases the coating area of part of the coating area of the first pole piece 121 , thereby effectively increasing the coating of the electrode assembly 12
  • the total area of the battery 100 is further effectively increased by increasing the total capacity of the active material.
  • the ratio of the length L 12 of the shortest first coating area to the length L 12 of the longest first coating area is greater than or equal to 0.9; and/or the shortest second coating area 1213
  • the ratio of the length L 13 to the length L 13 of the longest second coating zone is greater than or equal to 0.9.
  • the first coating area 1211 with the shortest length refers to the first coating area 1211 with the shortest length in the second direction Y of all the first pole pieces 121
  • the first coating area 1211 with the longest length refers to all the first poles.
  • the second coating area 1213 with the shortest length refers to the shortest length of all the first pole pieces 121 in the second direction Y.
  • the second coating area 1213 and the second coating area 1213 with the longest length refer to the second coating area 1213 with the longest length in the second direction Y of all the first pole pieces 121 .
  • the ratio of the length L 12 of the shortest first coating zone to the length L 12 of the longest first coating zone may be 0.9, 0.91, 0.92, or any other value greater than or equal to 0.9 and less than 1.
  • the ratio of the length L 13 of the shortest second coating area to the length L 13 of the longest second coating area is greater than or equal to 0.9 and less than 1. That is to say, the length L 13 of the shortest second coating area
  • the ratio of the length L 13 to the length L 13 of the longest second coating zone may be 0.9, 0.91, 0.92, or any other value greater than or equal to 0.9 and less than 1.
  • the ratio of the length L 12 of the shortest first coating zone to the length L 12 of the longest first coating zone and the length L 13 of the shortest second coating zone to the longest second coating can effectively limit the length difference range of the coating area, thereby ensuring the overall capacity of the active material and effectively ensuring the energy density.
  • the length difference of the first tab area The range is synchronously limited, thereby limiting the stacking thickness of the first pole piece 121 and avoiding the situation where the first tab area 1212 is too long and the coating area is too short in some first pole pieces 121, thereby effectively reducing tab redundancy. The energy density of the overall electrode assembly 12 is ensured.
  • the ratio of the length L 12 of the first coating area and the length L 11 of the first tab area of the same first pole piece 121 is D 1 , satisfying 1.4 ⁇ D 1 ⁇ 1.8; and /Or the ratio of the length L 13 of the second coating area and the length L 11 of the first tab area of the same first pole piece 121 is D 2 , satisfying 1.4 ⁇ D 2 ⁇ 1.8.
  • the ratio of the length of the first coating area 1211 of the same first pole piece 121 in the second direction Y to the length of the first tab area 1212 in the second direction Y is D 1 .
  • the ratio of the length of the second coating area 1213 of a pole piece 121 in the second direction Y to the length of the first tab area 1212 in the second direction Y is D 2 .
  • the first tab area 1212 is defined by defining a ratio of the length L 11 of the first coating area 1211 to the first tab area and/or defining a ratio of the length L 11 of the second coating area 1213 to the first tab area.
  • the ratio of the total length of a pole piece 121 prevents the first tab area 1212 from being too long and affecting the energy density of the conjoined bare battery core, and also avoids the first tab area 1212 from being too short and causing difficulty in assembly and folding.
  • the problem of easy tearing is beneficial to effectively ensure its energy density while ensuring stable performance.
  • the length difference D 3 of two adjacent first tab areas is greater than or equal to 0.004 mm and less than or equal to 0.008 mm.
  • the lengths L 11 of the plurality of first tab areas can decrease in equal degrees, that is, the length difference between any two adjacent first tab areas is equal, and the length difference can be greater than or equal to 0.004 mm and less than Any value equal to 0.008mm; of course, the lengths L 11 of multiple first tab areas can also be non-aridally decreasing, that is, the length difference between any two adjacent first tab areas can be the same or different, and their lengths The difference is any value greater than or equal to 0.004mm and less than or equal to 0.008mm.
  • Figure 9 is a front view of an electrode assembly provided by some further embodiments of the present application;
  • Figure 10 is a first implementation in the BB direction shown in Figure 9
  • Figure 11 is a cross-sectional view of the first tab region in the folded state of the first embodiment shown in Figure 10;
  • Figure 12 is the second embodiment in the BB direction shown in Figure 9
  • FIG. 13 is a cross-sectional view of the second embodiment shown in FIG. 12 in a folded state of the first tab area.
  • the electrode assembly 12 also includes a plurality of second pole pieces 122. A plurality of first pole pieces 121 and a plurality of second pole pieces 122 are alternately stacked along the first direction.
  • the first pole pieces 121 and the second pole pieces 122 have opposite polarities.
  • the second pole piece 122 includes a third coating area 1221, a fourth coating area 1223 and a second tab area 1222, and the third coating area 1221 and the fourth coating area 1223 are connected through the second tab area 1222, Along the first direction, the projections of the second tab regions 1222 of the plurality of second pole pieces 122 overlap; wherein the electrode assembly 12 meets one of the following conditions: c) the second tabs of the plurality of second pole pieces 122 The lengths L 21 of the regions gradually decrease from one side to the other side in the first direction; d) The lengths L 21 of the second tab regions of the plurality of second pole pieces 122 all decrease from both sides in the first direction. gradually decreases towards the middle.
  • the first direction may extend along the X direction in the figure. Along the first direction X, the projections of the second tab regions 1222 of the plurality of second pole pieces 122 overlap.
  • the third coating area 1221, the second tab area 1222, and the fourth coating area 1223 are arranged along the second direction Y.
  • the second direction Y is perpendicular to the first direction X.
  • the length L 21 of the second tab area is the second The size of the tab area 1222 in the second direction Y
  • the length L 22 of the third coating area is the size of the third coating area 1221 in the second direction Y
  • the length L 23 of the fourth coating area is the fourth The length of the coating area 1223 in the second direction Y.
  • the electrode assembly 12 includes a first pole piece 121 and a second pole piece 122.
  • the first pole piece 121 and the second pole piece 122 can be respectively configured as the positive pole piece and the negative pole piece of the electrode assembly 12.
  • the second pole piece 122 is connected to the first pole piece 121 and the second pole piece 122.
  • the structure of one pole piece 121 is the same, that is, the length L 21 of the second tab area of the second pole piece 122 also decreases to one side along the first direction or decreases toward the middle along the first direction, thereby effectively avoiding the second pole tab.
  • part of the second tab area 1222 may have risks of weld cracking and tab breakage due to excessive pre-tightening force and insufficient area to be connected, and avoid excessive redundancy after the second tab area 1222 is closed. , while further ensuring the performance stability of the electrode assembly 12 and effectively improving the energy density of the battery 100 .
  • the length L 2 of each second pole piece is the same; when the electrode assembly 12 satisfies the above condition c), the electrode assembly 12 simultaneously satisfies: the third coating area of the plurality of second pole pieces 122
  • the length L 22 gradually increases from one side to the other side in the first direction
  • the length L 23 of the fourth coating areas of the plurality of second pole pieces 122 gradually increases from one side to the other side in the first direction.
  • each second pole piece is the same, which means that the length of each pole piece in the second direction Y is the same, that is, the third coating area 1221 and the second tab area 1222 of each second pole piece 122 It is the same as the total length of the fourth coating area 1223 in the second direction Y.
  • the two sides in the first direction are defined as the first side and the second side, and the length L 22 of the third coating areas of the plurality of second pole pieces 122 is from one side in the first direction to the other side.
  • the length L 23 of the fourth coating areas of the plurality of second pole pieces 122 gradually increases from one side to the other side in the first direction, which means that the length L 23 of the fourth coating areas of the plurality of second pole pieces 122 gradually increases.
  • the length L 22 gradually increases from the first side to the second side in the first direction.
  • the length L 23 of the fourth coating areas of the plurality of second pole pieces 122 increases from the first side to the second side in the first direction. Gradually increase on both sides.
  • each second pole piece 122 in the second direction Y is the same, and the length L 22 of the third coating area and the length L 23 of the fourth coating area of the plurality of second pole pieces 122 are both equal to Gradually increasing from the first side to the second side in the first direction side gradually decreases.
  • the second tab areas 1222 of the plurality of second pole pieces 122 are gathered along the first direction X from the first side to the second side, so as to gather the plurality of second tab areas 1222 into the second tab area 1222 with the shortest length. the side on which it is located.
  • two ends of the plurality of second pole pieces 122 along the second direction Y are substantially aligned in the first direction X, so as to maximize the overlapping area of the projection of the plurality of second pole tab regions 1222 in the first direction X. .
  • the length L 2 of the second pole piece is the same, and the length L 23 of the third coating area 1221 and the fourth coating area gradually increases from one side to the other side in the first direction, so that the length of the second tab area L 21 gradually decreases from one side to the other side in the first direction, thereby further reducing the redundant waste of the second tab area 1222 and effectively increasing the coating area of at least part of the coating area of the second pole piece 122 , thereby effectively increasing the total area of the coating area of the electrode assembly 12 and further effectively increasing the energy density of the battery 100 by increasing the total capacity of the active material.
  • the length L 2 of each second pole piece is the same; when the electrode assembly 12 meets the above condition d), the electrode assembly 12 simultaneously satisfies: the third coating area of the plurality of second pole pieces 122
  • the length L 22 gradually increases from both sides in the first direction to the middle, and the length L 23 of the fourth coating areas of the plurality of second pole pieces 122 gradually increases from both sides in the first direction to the middle.
  • each second pole piece is the same, which means that the length of each pole piece in the second direction Y is the same, that is, the third coating area 1221 of each second pole piece 122 and the second The total lengths of the tab area 1222 and the fourth coating area 1223 in the second direction Y are the same.
  • each second pole piece 122 in the second direction Y is the same, and the length L 22 of the third coating area and the length L 23 of the fourth coating area of the plurality of second pole pieces 122 are both equal to As the length L 21 of the second tab regions of the plurality of second pole pieces 122 gradually increases from both sides in the first direction toward the middle, the length L 21 of the second tab regions of the plurality of second pole pieces 122 gradually decreases from both sides in the first direction toward the middle.
  • the second tab areas 1222 of the plurality of second pole pieces 122 are gathered from both sides to the middle along the first direction The middle position in one direction X.
  • two ends of the plurality of second pole pieces 122 along the second direction Y are substantially aligned in the first direction X, so as to maximize the overlapping area of the projection of the plurality of second pole tabs in the first direction X, ensuring that When the plurality of second tab areas 1222 are gathered together, they can have a larger overlapping area, and an area to be connected is formed in the overlapping area to facilitate the connection between the first tab area 1212 and the adapter or directly with the electric energy extraction part.
  • the length L 2 of the second pole piece is the same, and the lengths of the third coating area 1221 and the fourth coating area gradually increase from both sides in the first direction to the middle, so that the length L 21 of the second tab area increases from The two sides in one direction gradually decrease toward the middle, thereby further reducing the redundant waste of the second tab area 1222 and effectively increasing the coating area of at least part of the coating area of the second pole piece 122 , thereby effectively increasing the electrode assembly.
  • the total area of the coating area of 12 further effectively increases the energy density of the battery 100 by increasing the total capacity of the active material.
  • the electrode assembly 12 has a laminated structure.
  • the electrode assembly 12 includes a plurality of first pole pieces 121 stacked along a first direction.
  • the first pole piece 121 includes a first coating area 1211, a second coating area 1213 and a first tab area 1212.
  • the second coating area 1213 and the first coating area 1211 are connected through the first tab area 1212, Along the first direction, the projections of the first tab areas 1212 of the plurality of first pole pieces 121 overlap; wherein the length L 1 of each first pole piece is the same, and the first coating areas of the plurality of first pole pieces 121
  • the length L 12 gradually increases from one side to the other side in the first direction
  • the length L 13 of the second coating areas of the plurality of first pole pieces 121 gradually increases from one side to the other side in the first direction.
  • the length L 11 of the first tab regions of the plurality of first pole pieces 121 gradually decreases from one side to the other side in the first direction.
  • the electrode assembly 12 has a laminated structure.
  • the electrode assembly 12 includes a plurality of first pole pieces 121 stacked along a first direction.
  • the first pole piece 121 includes a first coating area 1211, a second coating area 1213 and a first tab area 1212.
  • the second coating area 1213 and the first coating area 1211 are connected through the first tab area 1212, Along the first direction, the projections of the first tab areas 1212 of the plurality of first pole pieces 121 overlap; wherein the length L 1 of each first pole piece is the same, and the first coating areas of the plurality of first pole pieces 121
  • the length L 12 gradually increases from both sides in the first direction to the middle
  • the length L 13 of the second coating areas of the plurality of first pole pieces 121 gradually increases from both sides in the first direction to the middle.
  • the length L 11 of the first tab area of each first pole piece 121 gradually decreases from both sides in the first direction toward the middle.
  • Figure 14 is a front cross-sectional view of a battery unit provided by some embodiments of the present application;
  • Figure 15 is an enlarged partial structure of part C shown in Figure 14 Schematic diagram;
  • Figure 16 is a front view of the first adapter provided by some embodiments of the present application;
  • Figure 17 is a bottom view of the first adapter provided by some embodiments of the present application;
  • Figure 18 is provided by some further embodiments of the present application Bottom view of the first adapter.
  • Some embodiments of the present application also provide a battery cell 10, including an electrode assembly 12, a case assembly 11 and a first adapter 13.
  • the electrode assembly 12 can be the electrode assembly 12 described in any of the previous solutions.
  • the first tab area 1212 of the component 12 is bent so that the projection of the first coating area 1211 along its thickness direction overlaps the projection of the second coating area 1213 along its thickness direction.
  • the electrode assembly 12 is received in the housing assembly 11.
  • the housing assembly 11 includes a first electrode lead-out part.
  • the first adapter 13 electrically connects the first tab areas 1212 of the plurality of first pole pieces 121 and the first electrode lead-out part. .
  • the thickness directions of the first coating region 1211 and the second coating region 1213 are uniform. Extending along the first direction X, after the first tab area 1212 is bent, the thickness directions of the first coating area 1211 and the second coating area 1213 both extend along the second direction Y. The first tab area 1212 is located on one side of the first coating area 1211 and the second coating area 1213 in the first direction X.
  • the structure of the housing assembly 11 may refer to the structure described above.
  • the first electrode lead-out part 113 may be an electrode terminal, a chip pole, or other components for outputting current from the electrode assembly 12.
  • the first electrode lead-out part 113 The polarity of is the same as the polarity of the first tab area 1212.
  • the first adapter 13 plays the role of overcurrent and sinking.
  • the first electrode lead-out part 113 is electrically connected to the first tab area 1212 through the first adapter 13 .
  • the battery cell 10 may further include a second electric energy extraction part and a second adapter.
  • the second adapter is electrically connected to the second tab area 1222 and the second electric energy extraction part.
  • the first tab area 1212 is bent so that the thickness directions of the first coating area 1211 and the second coating area 1213 are consistent, and the first tab area 1212 is located in the same direction as the first coating area 1211 and the second coating area 1213
  • the electrode assembly 12 is accommodated in the casing assembly 11 and the first adapter 13 connects the first tab area 1212 and the first electrode lead-out part to form the battery cell 10, which has good performance stability and has Higher energy density.
  • the first adapter 13 includes a body 131 , a first arm 132 and a second arm 133 .
  • the body 131 is connected to the first electrode lead-out part, and the first arm 132 and the second arm 133 extends from one end of the body 131.
  • the first tab areas 1212 of the plurality of first pole pieces 121 are inserted into the gap 134 and connected to the first arm 132 and second arm 133 .
  • the main body 131 can be implemented in a variety of structures, such as plate-shaped or block-shaped. As an example, the main body 131 is plate-shaped.
  • first arm 132 and the second arm 133 can be spaced apart along the first direction
  • the first adapter 13 can be a plate-like structure.
  • the plate-like structure has side walls along its thickness direction, and a groove is provided on the side wall.
  • the groove forms the above-mentioned gap 134.
  • the two walls of the groove The first arm 132 and the second arm 133 are formed.
  • the first adapter 13 includes a body 131 and a first arm 132 and a second arm 133 extending from the same end of the body 131 . There is a hole between the first arm 132 and the second arm 133 for the first tab area 1212 to be inserted. gap 134, so that after the first tab area 1212 is connected to the first electrode lead-out part through the first adapter 13 with this structure, the first arm 132 and the second arm 133 of the first adapter 13 pair the first
  • the tab area 1212 plays a fastening and limiting role, reducing the risk of the first tab area 1212 collapsing toward the first coating area 1211 and the second coating area 1213, thereby reducing the risk of deformation of the first tab area 1212.
  • the risk of short circuit of the battery cell 10 further effectively improves the performance stability of the battery cell 10 .
  • the present application also provides a battery 100, including the battery cell 10 described in any of the above solutions.
  • the present application also provides an electrical device, including the battery 100 described in the above solution, where the battery 100 is used to provide electrical energy.
  • the power-consuming device may be any of the aforementioned devices or systems using the battery 100 .

Abstract

本申请提供一种电极组件、电池单体、电池及用电装置，电极组件为叠片式结构，电极组件包括沿第一方向层叠设置的多个第一极片，每个第一极片包括第一涂覆区、第二涂覆区和第一极耳区，第二涂覆区和第一涂覆区通过第一极耳区连接，沿第一方向，多个第一极片的第一极耳区的投影重叠；其中，电极组件满足以下条件中的一者：a)多个第一极片的第一极耳区的长度由第一方向上的一侧向另一侧逐渐减小；b)多个第一极片的第一极耳区的长度由第一方向上的两侧向中间逐渐减小。本申请技术方案的电极组件能够在保证性能稳定的同时有效提高能量密度。

Description

电极组件、电池单体、电池及用电装置
相关申请的交叉引用
本申请要求享有2022年06月09日提交的名称为“电极组件、电池单体、电池及用电装置”的中国专利申请(202221426933.3)的优先权，该申请的全部内容通过引用并入本文中。
技术领域
本申请涉及电池技术领域，特别是涉及一种电极组件、电池单体、电池及用电装置。
背景技术
节能减排是汽车产业可持续发展的关键，电动车辆由于其节能环保的优势成为汽车产业可持续发展的重要组成部分。对于电动车辆而言，电池技术又是关乎其发展的一项重要因素。
在电池技术中，如何在保证电池性能稳定的同时提高电池的能量密度，是一个亟待解决的问题。
发明内容
本申请提供一种电极组件、电池单体、电池及用电装置，该电极组件能够在保证性能稳定的同时有效提高能量密度。
第一方面，本申请提供了一种电极组件，电极组件为叠片式结构，电极组件包括沿第一方向层叠设置的多个第一极片，每个第一极片包括第一涂覆区、第二涂覆区和第一极耳区，第二涂覆区和第一涂覆区通过第一极耳区连接，沿第一方向，多个第一极片的第一极耳区的投影重叠；其中，电极组件满足以下条件中的一者：a)多个第一极片的第一极耳区的长度由第一方向上的一侧向另一侧逐渐减小；b)多个第一极片的第一极耳区的长度由第一方向上的两侧向中间逐渐减小。
叠片式的极耳组需要沿其层叠方向收拢后再连接于转接件或电极端子，以保证极耳组连接的稳定性，如果极耳组的预留长度过短，则极耳组收拢后，部分极耳容易因收拢路径长而导致其连接区域过小，从而影响其连接的稳定性，甚至存在较大的断裂风险，如果极耳组的预留长度过长，则会增加电极组件的整体重量，且极耳组收拢后，极耳组的前端会形成较大的阶梯冗余，需要更大的安装空间，从而浪费电池的内部空间，不利于提高电池的能量密度，且存在较大的材料成本浪费。本申请技术方案中，第一极耳区的长度由第一方向(也就是多个第一极耳区的层叠方向)的一侧向另一侧递减，所有第一极耳区沿第一方向从长度最长的第一极耳区所在的一侧向长度最短的第一极耳区所在的一侧收拢，或者，第一极耳区的长度由第一方向(也就是多个第一极耳区的层叠方向)的两侧向中间递减，所有第一极耳区沿第一方向两侧向中间收拢，这样的结构一方面使得极耳组在收拢后，所有第一极耳区的待连接区域面积充足，降低部分极耳因收拢后预紧力过高、待连接区域面积不足而造成焊缝开裂、极耳断裂的风险，有效保证极耳连接的稳定性，从而有效保证电池的性能稳定性；另一方面可有效避免第一极耳区收拢后产生过多阶梯冗余，在降低材料浪费及电池重量的同时，有效降低第一极耳区的空间占用率，从而有效提高电池的能量密度。
另外，本申请的电极组件的每个第一极片包括第一涂覆区和第二涂覆区以及连接第一涂覆区和第二涂覆区的第一极耳区，则多个第一极片沿第一方向层叠后形成连体裸电芯，相较于电极组件分体设置的结构，连体裸电芯有效降低极耳的连接点数量，从而进一步提高极耳连接的稳定性，进而有效提高电池性能的稳定性。
根据本申请的一些实施例，每个第一极片的长度相同；当电极组件满足上述条件a)时，电极组件同时满足：多个第一极片的第一涂覆区的长度由第一方向上的一侧向另一侧逐渐增加，多个第一极片的第二涂覆区的长度由第一方向上的一侧向另一侧逐渐增加。
上述技术方案中，每个第一极片的长度相同，多个第一极片的第一涂覆区的长度和第二涂 覆区的长度均由第一方向上的一侧向另一侧逐渐增加，从而使得多个第一极片的第一极耳区的长度由第一方向上的一侧向另一侧逐渐减小，这样的结构将第一涂覆区和第二涂覆区的长度设置为长度渐变型，降低第一极耳区冗余浪费的同时有效增加部分第一极片的涂覆区的涂覆面积，从而有效增加电极组件的涂覆区总面积，通过增加活性物质的总容量而进一步有效提高电池的能量密度。
根据本申请的一些实施例，每个第一极片的长度相同；当电极组件满足上述条件b)时，电极组件同时满足：多个第一极片的第一涂覆区的长度由第一方向上的两侧向中间逐渐增大，多个第一极片的第二涂覆区的长度由第一方向上的两侧向中间逐渐增大。
上述技术方案中，每个第一极片的长度相同，多个第一极片的第一涂覆区的长度和第二涂覆区的长度均由第一方向上的两侧向中间逐渐增加，从而使得多个第一极片的第一极耳区的长度由第一方向上的两侧向中间逐渐减小，这样的结构将第一涂覆区和第二涂覆区的长度设置为长度渐变型，降低第一极耳区冗余浪费的同时有效增加部分第一极片的涂覆区的涂覆面积，从而有效增加电极组件的涂覆区总面积，通过增加活性物质的总容量而进一步有效提高电池的能量密度。
根据本申请的一些实施例，长度最短的第一涂覆区和长度最长的第一涂覆区的长度比值大于等于0.9；和/或长度最短的第二涂覆区和长度最长的第二涂覆区的长度比值大于等于0.9。
上述技术方案中，通过限制长度最短的第一涂覆区和长度最长的第一涂覆区的长度比值以及长度最短的第二涂覆区和长度最长的第二涂覆区的长度比值，以有效限定涂覆区的长度差范围，从而保证活性物质总体容量，有效保证能量密度，同时，限定涂覆区长度差范围后，第一极耳区的长度差范围同步限定，从而限制第一极片的堆叠厚度，避免部分第一极片出现第一极耳区过长、涂覆区过短的情况，以在降低极耳冗余的同时有效保证整体电极组件的能量密度。
根据本申请的一些实施例，同一个第一极片的第一涂覆区的长度和第一极耳区的长度的比值为D 1，满足1.4≤D 1≤1.8；和/或同一个第一极片的第二涂覆区的长度和第一极耳区的长度的比值为D 2，满足1.4≤D 2≤1.8。
上述技术方案中，通过限定第一涂覆区与第一极耳区的长度比值和/或限定第二涂覆区与第一极耳区的长度比值而限定第一极耳区占第一极片的总长度的比值，避免第一极耳区长度过长而影响连体裸电芯的能量密度，同时避免因第一极耳区长度过短而造成装配困难、折叠后容易撕裂的问题，从而有利于在保证性能稳定的同时有效保证其能量密度。
根据本申请的一些实施例，沿第一方向，相邻两个第一极耳区的长度的差值为D3，满足0.004mm≤D 3≤0.008mm。
上述技术方案中，相邻两个第一极耳区的长度差值大于等于0.004mm且小于等于0.008mm，在保证第一极耳区的长度呈阶梯状变化的同时进一步降低第一极耳区合拢后的冗余量。
根据本申请的一些实施例，电极组件还包括多个第二极片，多个第一极片和多个第二极片沿第一方向交替层叠设置，第一极片和第二极片极性相反，第二极片包括第三涂覆区、第四涂覆区和第二极耳区，第三涂覆区和第四涂覆区通过第二极耳区连接，沿第一方向，多个第二极片的第二极耳区的投影重叠；其中，电极组件满足以下条件中的一者：c)多个第二极片的第二极耳区的长度均由第一方向上的一侧向另一侧逐渐减小；d)多个第二极片的第二极耳区的长度均由第一方向上的两侧向中间逐渐减小。
上述技术方案中，电极组件包括第一极片和第二极片，第一极片和第二极片可以分别设置为电极组件的正极极片和负极极片，第二极片与第一极片的结构同理，即第二极片的第二极耳区的长度也沿第一方向向一侧递减或沿第一方向向中间递减，从而有效避免第二极耳区合拢后部分第二极耳区因预紧力过高、待连接区域面积不足而造成焊缝开裂、极耳断裂的风险，且避免第二极耳区收拢后产生过多冗余，在进一步保证电极组件性能稳定性的同时有效提高电池的能量密度。
根据本申请的一些实施例，每个第二极片的长度相同；当电极组件满足上述条件c)时，电极组件同时满足：多个第二极片的第三涂覆区的长度由第一方向上的一侧向另一侧逐渐增加，多个第二极片的第四涂覆区的长度由第一方向上的一侧向另一侧逐渐增加。
上述技术方案中，第二极片的长度相同，第三涂覆区和第四涂覆区的长度均由第一方向上的一侧向另一侧逐渐增加，使得第二极耳区的长度由第一方向上的一侧向另一侧逐渐减小，从而在进一步降低第二极耳区冗余浪费的同时有效增加至少部分第二极片的涂覆区的涂覆面积，从而有效增加电极组件的涂覆区总面积，通过增加活性物质的总容量而进一步有效提高电池的能量密度。
根据本申请的一些实施例，每个第二极片的长度相同；当电极组件满足上述条件d)时， 电极组件同时满足：多个第二极片的第三涂覆区的长度由第一方向上的两侧向中间逐渐增大，多个第二极片的第四涂覆区的长度由第一方向上的两侧向中间逐渐增大。
上述技术方案中，第二极片的长度相同，第三涂覆区和第四涂覆区的长度均由第一方向上的两侧向中间逐渐增加，使得第二极耳区的长度由第一方向上的两侧向中间逐渐减小，从而在进一步降低第二极耳区冗余浪费的同时有效增加至少部分第二极片的涂覆区的涂覆面积，从而有效增加电极组件的涂覆区总面积，通过增加活性物质的总容量而进一步有效提高电池的能量密度。
第二方面，本申请提供一种电池单体，包括：如上述任一项方案所述的电极组件，第一极耳区弯折，以使第一涂覆区沿其厚度方向的投影与第二涂覆区沿其厚度方向的投影重叠；壳体组件，电极组件收容于壳体组件内，壳体组件包括第一电极引出部；第一转接件，第一转接件电连接多个第一极片的第一极耳区和第一电极引出部。
上述技术方案中，第一极耳区弯折，使得第一涂覆区和第二涂覆区的厚度方向一致，第一极耳区处于第一涂覆区和第二涂覆区的同一侧，电极组件容纳于壳体组件内且第一转接件连接第一极耳区和第一电极引出部，形成电池单体。由于本申请第一方面实施例提出的电极组件的特性，本申请第二方面实施例的电池单体也具备较好的性能稳定性，且具有较高的能量密度。
根据本申请的一些实施例，第一转接件包括本体、第一臂和第二臂，本体连接于第一电极引出部，第一臂和第二臂从本体的一端延伸出，第一臂和第二臂之间具有间隙，多个第一极片的第一极耳区插入间隙且连接于第一臂和第二臂。
上述技术方案中，第一转接件包括本体和从本体的同一端延伸出的第一臂和第二臂，第一臂和第二臂之间具有供第一极耳区插入的间隙，这样，第一极耳区通过这种结构的第一转接件与第一电极引出部连接后，第一转接件的第一臂和第二臂对第一极耳区起到紧固及限位作用，降低第一极耳区向第一涂覆区和第二涂覆区塌陷的风险，从而降低因第一极耳区变形而造成电池单体短路的风险，进一步有效提高电池单体的性能稳定性。
第三方面，本申请还提供了一种电池，包括如上述任一方案所述的电池单体。
由于本申请第二方面实施例提出的电池单体的特性，本申请第三方面实施例的电池也具备较好的性能稳定性及较高的能量密度。
第四方面，本申请还提供了一种用电装置，包括上述方案所述的电池，所述电池用于提供电能。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本申请的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的爆炸图；
图3为本申请一些实施例提供的电池单体的爆炸图；
图4为本申请一些实施例提供的电极组件的主视图；
图5为图4所示的A-A方向的第一种实施方式的第一极耳区未收拢状态的剖视图；
图6为图5所示的第一种实施方式的第一极耳区收拢状态的剖视图；
图7为图4所示的A-A方向的第二种实施方式的第一极耳区未收拢状态的剖视图；
图8为图7所示的第二种实施方式的第一极耳区收拢状态的剖视图；
图9为本申请又一些实施例提供的电极组件的主视图；
图10为图9所示的B-B方向的第一种实施方式的第一极耳区未收拢状态的剖视图；
图11为图10所示的第一种实施方式的第一极耳区收拢状态的剖视图；
图12为图9所示的B-B方向的第二种实施方式的第一极耳区未收拢状态的剖视图；
图13为图12所示的第二种实施方式的第一极耳区收拢状态的剖视图；
图14为本申请一些实施例提供的电池单体的主视剖面图；
图15为图14所示的C部分的局部结构放大示意图；
图16为本申请一些实施例提供的第一转接件的主视图；
图17为本申请一些实施例提供的第一转接件的仰视图；
图18为本申请又一些实施例提供的第一转接件的仰视图。
在附图中，附图并未按照实际的比例绘制。
标记说明：1000-车辆；100-电池；10-电池单体；11-壳体组件；111-外壳；112-端盖；113-第一电极引出部；12-电极组件；121-第一极片；1211-第一涂覆区；1212-第一极耳区；1213-第二涂覆区；122-第二极片；1221-第三涂覆区；1222-第二极耳区；1223-第四涂覆区；13-第一转接件；131-本体；132-第一臂；133-第二臂；134-间隙；20-箱体；21-第一部分；22-第二部分；L 1-第一极片的长度；L 11-第一极耳区的长度；L 12-第一涂覆区的长度；L 13-第二涂覆区的长度；L 2-第二极片的长度；L 21-第二极耳区的长度；L 22-第三涂覆区的长度；L 23-第四涂覆区的长度；200-控制器；300-马达。
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、完整地描述，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。通常在此处附图中描述和示出的本申请实施例的组件可以以各种不同的配置来布置和设计。
因此，以下对在附图中提供的本申请的实施例的详细描述并非旨在限制要求保护的本申请的范围，而是仅仅表示本申请的选定实施例。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。
下面将结合附图对本申请技术方案的实施例进行详细的描述。以下实施例仅用于更加清楚地说明本申请的技术方案，因此只作为示例，而不能以此来限制本申请的保护范围。
除非另有定义，本文所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本文中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。
在本申请实施例的描述中，技术术语“第一”“第二”等仅用于区别不同对象，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量、特定顺序或主次关系。在本申请实施例的描述中，“多个”的含义是两个以上，除非另有明确具体的限定。
在本文中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本文所描述的实施例可以与其它实施例相结合。
在本申请实施例的描述中，术语“多个”指的是两个以上(包括两个)。
在本申请实施例的描述中，技术术语“中心”“纵向”“横向”“长度”“宽度”“厚度”“上”“下”“前”“后”“左”“右”“竖直”“水平”“顶”“底”“内”“外”“顺时针”“逆时针”“轴向”“径向”“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请实施例和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请实施例的限制。
在本申请实施例的描述中，除非另有明确的规定和限定，技术术语“设置”“安装”“相连”“连接”“固定”等术语应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或成一体；可以是机械连接，也可以是电连接、信号连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通或两个元件的相互作用关系。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请实施例中的具体含义。
在本申请的实施例中，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。其中，多个电池单体之间可以串联、并联或者混联直接组成电池，混联指的是，多 个电池单体中既有串联又有并联。多个电池单体也可以先串联、并联或者混联组成电池模块，多个电池模块再串联、并联或者混联组成电池。电池还可以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。
电池单体可以包括锂离子二次电池、锂离子一次电池、锂硫电池、钠锂离子电池、钠离子电池或镁离子电池等，本申请实施例对此并不限定。电池单体可呈圆柱体、扁平体、长方体或其它形状等，本申请实施例对此也不限定。电池单体一般按封装的方式分成三种：柱形电池单体、方形电池单体和软包电池单体，本申请实施例对此也不限定。
电池单体包括电极组件和电解液，电极组件由正极极片、负极极片和隔离膜组成。电池单体主要依靠金属离子在正极极片和负极极片之间移动来工作。正极极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂敷正极活性物质层的正极集流体凸出于已涂覆正极活性物质层的正极集流体，未涂敷正极活性物质层的正极集流体作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂敷负极活性物质层的负极集流体凸出于已涂覆负极活性物质层的负极集流体，未涂敷负极活性物质层的负极集流体作为负极极耳。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。为了保证通过大电流而不发生熔断，正极极耳的数量为多个且层叠在一起，负极极耳的数量为多个且层叠在一起。隔离膜的材质可以为PP(polypropylene，聚丙烯)或PE(polyethylene，聚乙烯)等。此外，电极组件可以是卷绕式结构，也可以是叠片式结构，本申请实施例并不限于此。
目前，从市场形势的发展来看，动力电池的应用越加广泛。动力电池不仅被应用于水力、火力、风力和太阳能电站等储能电源系统，而且还被广泛应用于电动自行车、电动摩托车、电动汽车等电动交通工具，以及军事装备和航空航天等多个领域。随着动力电池应用领域的不断扩大，其市场的需求量也在不断地扩增。
在电池技术中，如何在保证电池性能稳定的同时提高电池的能量密度，是一个亟待解决的问题。
申请人分析注意到，具有叠片式的极耳组的电极组件在组装时，极耳组需要沿其层叠方向收拢后再连接于转接件或电极端子，以保证极耳组的每个极耳能够连接稳定，由于电极组件具有一定厚度，所以不管是沿极耳组的层叠方向向一侧收拢还是向中间收拢，极耳组的每个极耳的收拢路径的长度均不相同，在前期电池生产技术中，极耳组的每个极耳的长度相同，如果极耳组的预留长度过短，则极耳组收拢后，部分远离收拢位置的极耳容易因收拢路径长而导致其连接区域过小、预紧力过高，从而影响其连接的稳定性，甚至会发生极耳断裂异常，严重影响电池的稳定性。
为了保证极耳组的各个极耳的连接稳定性，申请人前期加长极耳组的预留长度，以保证离收拢区最远的极耳能够稳定的收拢和连接，但采用这种方式后，极耳组的大部分极耳会在其长度方向上产生冗余，极耳组收拢后，极耳组的前端会形成较大的阶梯冗余，此种结构的极耳组空间占用率大，需要预留更大的安装空间，从而浪费电池的内部空间，不利于提高电池的能量密度；且电池成组后，极耳的冗余部容易插入电极组件的主体部而造成电池短路，从而进一步影响电池的性能稳定性。
为了在提高电池单体性能稳定性的同时有效提高能量密度，申请人经过研究，设计了一种电极组件，本申请的电极组件为叠片式结构，电极组件包括沿第一方向层叠设置的多个第一极片，每个第一极片包括第一涂覆区、第二涂覆区和第一极耳区，第二涂覆区和第一涂覆区通过第一极耳区连接，多个第一极片的第一极耳区沿第一方向层叠设置，多个第一极片的第一极耳区的长度由第一方向上的一侧向另一侧逐渐减小；或，多个第一极片的第一极耳区的长度由第一方向上的两侧向中间逐渐减小。
可以理解的是，多个第一极片的第一极耳区的长度由第一方向上的一侧向另一侧逐渐减小的结构中，多个第一极耳区由第一方向上的一侧向另一侧收拢；多个第一极片的第一极耳区的长度由第一方向上的两侧向中间逐渐减小的结构中，多个第一极耳区由第一方向上的两侧向中间收拢。
采用这种结构的电极组件，使得极耳组在收拢后，所有第一极耳区的长度满足收拢需求，所有第一极耳区收拢后形成的待连接区域面积充足，降低部分第一极耳区因收拢后预紧力过高、待连接区域面积不足而造成焊缝开裂、极耳断裂的风险，有效保证极耳连接的稳定性，同时，避免第一极耳区的冗余部插入电极组件的主体而造成电池单体短路的问题，从而有效提高电极组件的性能稳定性；并且，因为本申请结构有效避免第一极耳区收拢后产生过多阶梯冗余，所以能够有效降低 第一极耳区的空间占用率，从而有利于有效提高电池的能量密度。
本申请实施例公开的电池单体可以但不限用于车辆、船舶或飞行器等用电装置中。可以使用具备本申请公开的电池单体、电池等组成该用电装置的电源系统。
本申请实施例提供一种使用电池作为电源的用电装置，用电装置可以为但不限于手机、平板、笔记本电脑、电动玩具、电动工具、电瓶车、电动汽车、轮船、航天器等等。其中，电动玩具可以包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等，航天器可以包括飞机、火箭、航天飞机和宇宙飞船等等。
本申请的实施例描述的电池不仅仅局限适用于上述所描述的用电装置，还可以适用于所有使用电池的用电装置，但为描述简洁，以下实施例以本申请一实施例的一种用电装置为车辆为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000可以为燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源。车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在其他一些实施例中，电池100不仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2，图2为本申请一些实施例提供的电池100的爆炸图，电池100包括箱体20和电池单体10，电池单体10容纳于箱体20内。其中，箱体20用于为电池单体10提供容纳空间，箱体20可以采用多种结构。在一些实施例中，箱体20可以包括第一部分21和第二部分22，第一部分21与第二部分22相互盖合，第一部分21和第二部分22共同限定出用于容纳电池单体10的容纳空间。第二部分22可以为一端开口的空心结构，第一部分21可以为板状结构，第一部分21盖合于第二部分22的开口侧，以使第一部分21与第二部分22共同限定出容纳空间；第一部分21和第二部分22也可以是均为一侧开口的空心结构，第一部分21的开口侧盖合于第二部分22的开口侧。当然，第一部分21和第二部分22形成的箱体20可以是多种形状，比如，长方体、正方体等。
在电池100中，电池单体10可以是多个，多个电池单体10之间可串联或并联或混联，混联是指多个电池单体10中既有串联又有并联。多个电池单体10之间可直接串联或并联或混联在一起，当然，电池100也可以是多个电池单体10先串联或并联或混联组成电池模块形式，多个电池模块再串联或并联或混联形成一个整体。
每个电池单体10可以为二次电池或一次电池，也可以是锂硫电池、钠离子电池或镁离子电池，但不局限于此。
请参照图3，图3为本申请一些实施例提供的电池单体的爆炸图。电池单体10可以包括壳体组件11、电极组件12和转接件，壳体组件11可以包括外壳111和端盖112，外壳111具有开口，端盖112盖合于外壳111的开口处并形成密封连接，以形成用于容纳电极组件12和电解质的密封空间。
在组装电池单体10时，可先将电极组件12放入外壳111内，并向外壳111内填充电解质，再将端盖112盖合于外壳111的开口。
外壳111可以是多种形状，外壳111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为长方体结构，则可选用长方体外壳111。当然，端盖112也可以是多种结构。
可理解的，壳体组件11并不仅仅局限于上述结构，比如，壳体组件11可以包括外壳111和两个端盖112，外壳111为相对的两侧开口的空心结构，一个端盖112对应盖合于外壳111的一个开口处并形成密封连接，以形成用于容纳电极组件12和电解质的密封空间。
其中，壳体组件11还包括电能引出部，电能引出部可以绝缘设置在端盖112上，电能引出部用于输出电极组件12的电流，电能引出部可以与电极组件12直接连接也可以通过转接件连接。
转接件起到过流和汇流的作用，电能引出部通过连接件与电极组件12的极耳电连接。
电极组件12是电池单体10中发生电化学反应的部件。电极组件12可以包括正极极片、负极极片和隔离膜。电极组件12可以是由正极极片、隔离膜和负极极片通过卷绕形成的卷绕式结构，也可以是由正极极片、隔离膜和负极极片通过层叠布置形成的层叠式结构。
请参照图4至图8，图4为本申请一些实施例提供的电极组件的主视图；图5为图4所示的A-A方向的第一种实施方式的第一极耳区未收拢状态的剖视图；图6为图5所示的第一种实施方式的第一极耳区收拢状态的剖视图；图7为图4所示的A-A方向的第二种实施方式的第一极耳区未收拢状态的剖视图；图8为图7所示的第二种实施方式的第一极耳区收拢状态的剖视图。本申请一些实施例提供了一种电极组件12，电极组件12为叠片式结构，电极组件12包括沿第一方向层叠设置的多个第一极片121，每个第一极片121包括第一涂覆区1211、第二涂覆区1213和第一极耳区1212，第二涂覆区1213和第一涂覆区1211通过第一极耳区1212连接，沿第一方向，多个第一极片121的第一极耳区1212的投影重叠；其中，电极组件12满足以下条件中的一者：a)多个第一极片121的第一极耳区的长度L 11由第一方向上的一侧向另一侧逐渐减小；b)多个第一极片121的第一极耳区的长度L 11由第一方向上的两侧向中间逐渐减小。
第一极片121包括集流体和涂覆在集流体上的活性物质层，集流体上涂覆活性物质层的区域形成第一涂覆区1211和第二涂覆区1213，集流体上未涂覆活性物质层的空白区域形成第一极耳区1212。第一极片121可以为正极极片也可以为负极极片，也就是说，第一涂覆区1211和第二涂覆区1213的涂覆层可以同是正极活性物质层也可以同是负极活性物质层，当然，集流体与活性物质的极性相同。
每个第一极片121包括第一涂覆区1211、第二涂覆区1213和连接第一涂覆区1211、第二涂覆区1213的第一极耳区1212，多个第一极片121沿第一方向层叠设置后，可以形成包括两个主体部分、一个极耳区的连体式电极组件。
如图5所示，第一方向可以沿图中的X方向延伸，沿第一方向X，多个第一极片121的第一极耳区1212的投影重叠。
其中，如图4和图5所示，第一涂覆区1211、第一极耳区1212、第二涂覆区1213沿第二方向Y排列，第二方向Y与第一方向X垂直，第一极耳区的长度L 11为第一极耳区1212在第二方向Y上的尺寸，第一涂覆区的长度L 12为第一涂覆区1211在第二方向Y上的尺寸，第二涂覆区的长度L 13为第二涂覆区1213在第二方向Y上的长度。
多个第一极片121的第一极耳区的长度L 11可以由第一方向上的一侧向另一侧逐渐减小，也可以由第一方向上的两侧向中间逐渐减小，其中，多个第一极片121的第一涂覆区的长度L 12可以相等也可以不等，同理，多个第二涂覆区的长度L 13可以相等也可以不等。
第一极耳区的长度L 11由第一方向X(也就是多个第一极耳区1212的层叠方向)的一侧向另一侧递减，所有第一极耳区1212沿第一方向从长度最长的第一极耳区1212所在的一侧向长度最短的第一极耳区1212所在的一侧收拢，或者，第一极耳区的长度L 11由第一方向X的两侧向中间递减，所有第一极耳区1212沿第一方向两侧向中间收拢，这样的结构一方面使得极耳组在收拢后，所有第一极耳区1212的待连接区域面积充足，降低部分极耳因收拢后预紧力过高、待连接区域面积不足而造成焊缝开裂、极耳断裂的风险，有效保证极耳连接的稳定性，从而有效保证电池100的性能稳定性；另一方面可有效避免第一极耳区1212收拢后产生过多阶梯冗余，在降低材料浪费及电池100重量的同时，有效降低第一极耳区1212的空间占用率，从而有效提高电池100的能量密度。
另外，本申请的电极组件12的每个第一极片121包括第一涂覆区1211和第二涂覆区1213以及连接第一涂覆区1211和第二涂覆区1213的第一极耳区1212，则多个第一极片121沿第一方向X层叠后形成连体裸电芯，相较于电极组件12分体设置的结构，连体裸电芯有效降低极耳的连接点数量，从而进一步提高极耳连接的稳定性，进而有效提高电池100性能的稳定性。
根据本申请的一些实施例，每个第一极片的长度L 1相同；当电极组件12满足上述条件a)时，电极组件12同时满足：多个第一极片121的第一涂覆区的长度L 12由第一方向上的一侧向另一侧逐渐增加，多个第一极片121的第二涂覆区的长度L 13由第一方向上的一侧向另一侧逐渐增加。
每个第一极片的长度L 1相同，是指每个极片在第二方向Y上的长度相同，即每个第一极片121的第一涂覆区1211、第一极耳区1212和第二涂覆区1213在第二方向Y上的总长相同。
为了方便理解，定义第一方向上的两侧为第一侧和第二侧，多个第一极片121的第一涂覆 区的长度L 12由第一方向上的一侧向另一侧逐渐增加，多个第一极片121的第二涂覆区的长度L 13由第一方向上的一侧向另一侧逐渐增加是指，多个第一极片121的第一涂覆区的长度L 12由第一方向上的第一侧向第二侧逐渐增加，同时，多个第一极片121的第二涂覆区的长度L 13由第一方向上的第一侧向第二侧逐渐增加。
可以理解的是，每个第一极片121在第二方向Y上的长度相同，多个第一极片121的第一涂覆区的长度L 12和第二涂覆区的长度L 13均由第一方向上的第一侧向第二侧逐渐增加，则多个第一极片121的第一极耳区的长度L11会由第一方向上的第一侧向第二侧逐渐减小。多个第一极片121的第一极耳区1212沿第一方向X由第一侧向第二侧收拢，以将多个第一极耳区1212收拢在长度最短的第一极耳区1212所在的一侧。
其中，多个第一极片121的沿第二方向Y的两端在第一方向X上大致对齐，以使多个第一极耳区1212在第一方向X上的投影的重叠面积最大化。
每个第一极片的长度L 1相同，多个第一极片121的第一涂覆区的长度L 12和第二涂覆区的长度L 13均由第一方向上的一侧向另一侧逐渐增加，从而使得多个第一极片121的第一极耳区的长度L 11由第一方向上的一侧向另一侧逐渐减小，这样的结构将第一涂覆区1211和第二涂覆区的长度L 13设置为长度渐变型，降低第一极耳区1212冗余浪费的同时有效增加部分第一极片121的涂覆区的涂覆面积，从而有效增加电极组件12的涂覆区总面积，通过增加活性物质的总容量而进一步有效提高电池100的能量密度。
根据本申请的一些实施例，每个第一极片的长度L 1相同；当电极组件12满足上述条件b)时，电极组件12同时满足：多个第一极片121的第一涂覆区的长度L 12由第一方向上的两侧向中间逐渐增大，多个第一极片121的第二涂覆区的长度L 13由第一方向上的两侧向中间逐渐增大。
如上所述，每个第一极片的长度L 1相同，是指每个极片在第二方向Y上的长度相同，即每个第一极片121的第一涂覆区1211、第一极耳区1212和第二涂覆区1213在第二方向Y上的总长相同。
可以理解的是，每个第一极片121在第二方向Y上的长度相同，多个第一极片121的第一涂覆区的长度L 12和第二涂覆区的长度L 13均由第一方向上的两侧向中间逐渐增加，则多个第一极片121的第一极耳区的长度L 11会由第一方向上的两侧向中间逐渐减小。多个第一极片121的第一极耳区1212沿第一方向X由两侧向中间收拢，以将多个第一极耳区1212收拢在长度最短的第一极耳区1212所在的第一方向X上的中间位置。
其中，多个第一极片121的沿第二方向Y的两端在第一方向X上大致对齐，以使多个第一极耳在第一方向X上的投影的重叠面积最大化，确保多个第一极耳区1212收拢后能够具有较大的重合区域，该重合区域内形成待连接区域，便于第一极耳区1212与转接件或直接与电能引出部连接。
每个第一极片的长度L 1相同，多个第一极片121的第一涂覆区的长度L 12和第二涂覆区的长度L 13均由第一方向上的两侧向中间逐渐增加，从而使得多个第一极片121的第一极耳区的长度L 11由第一方向上的两侧向中间逐渐减小，这样的结构将第一涂覆区1211和第二涂覆区的长度L 13设置为长度渐变型，降低第一极耳区1212冗余浪费的同时有效增加部分第一极片121的涂覆区的涂覆面积，从而有效增加电极组件12的涂覆区总面积，通过增加活性物质的总容量而进一步有效提高电池100的能量密度。
根据本申请的一些实施例，长度最短的第一涂覆区的长度L 12和最长的第一涂覆区的长度L 12比值大于等于0.9；和/或长度最短的第二涂覆区1213的长度L 13和最长的第二涂覆区的长度L 13比值大于等于0.9。
长度最短的第一涂覆区1211是指所有第一极片121的在第二方向Y上长度最短的第一涂覆区1211，长度最长的第一涂覆区1211是指所有第一极片121的在第二方向Y上长度最长的第一涂覆区1211，同理，长度最短的第二涂覆区1213是指所有第一极片121的在第二方向Y上长度最短的第二涂覆区1213，长度最长的第二涂覆区1213是指所有第一极片121的在第二方向Y上长度最长的第二涂覆区1213。
长度最短的第一涂覆区的长度L 12和最长的第一涂覆区的长度L 12的比值可以为0.9,0.91,0.92等任意大于等于0.9且小于1的数值。同理，长度最短的第二涂覆区的长度L 13和最长的第二涂覆区的长度L 13的比值大于等于0.9且小于1，也就是说，长度最短的第二涂覆区的长度L 13和最长的第二涂覆区的长度L 13的比值可以为0.9,0.91,0.92等任意大于等于0.9且小于1的数 值。
通过限制长度最短的第一涂覆区的长度L 12和最长的第一涂覆区的长度L 12的比值以及长度最短的第二涂覆区的长度L 13和最长的第二涂覆区的长度L 13的比值，以有效限定涂覆区的长度差范围，从而保证活性物质总体容量，有效保证能量密度，同时，限定涂覆区长度差范围后，第一极耳区的长度差范围同步限定，从而限制第一极片121的堆叠厚度，避免部分第一极片121出现第一极耳区1212过长、涂覆区过短的情况，以在降低极耳冗余的同时有效保证整体电极组件12的能量密度。
根据本申请的一些实施例，同一个第一极片121的第一涂覆区的长度L 12和第一极耳区的长度L 11的比值为D 1，满足1.4≤D 1≤1.8；和/或同一个第一极片121的第二涂覆区的长度L 13和第一极耳区的长度L 11的比值为D 2，满足1.4≤D 2≤1.8。
具体而言，同一个第一极片121的第一涂覆区1211在第二方向Y上的长度和第一极耳区1212在第二方向Y上的长度的比值为D 1，同一个第一极片121的第二涂覆区1213在第二方向Y上的长度和第一极耳区1212在第二方向Y上的长度的比值为D 2。
其中，同一个第一极片121的第一涂覆区1211在第二方向Y上的长度和第一极耳区1212在第二方向Y上的长度的比值可以为1.4、1.5、1.8等任意的大于等于1.4且小于等于1.8的数值。同样的，同一个第一极片121的第二涂覆区1213在第二方向Y上的长度和第一极耳区1212在第二方向Y上的长度的比值可以为1.4、1.5、1.8等任意的大于等于1.4且小于等于1.8的数值。
通过限定第一涂覆区1211与第一极耳区的长度L 11比值和/或限定第二涂覆区1213与第一极耳区的长度L 11比值而限定第一极耳区1212占第一极片121的总长度的比值，避免第一极耳区1212长度过长而影响连体裸电芯的能量密度，同时避免因第一极耳区1212长度过短而造成装配困难、折叠后容易撕裂的问题，从而有利于在保证性能稳定的同时有效保证其能量密度。
根据本申请的一些实施例，沿第一方向X，相邻两个第一极耳区1212的沿第二方向Y的长度的差值为D 3，满足0.004mm≤D 3≤0.008mm。
具体而言，沿第一方向X，相邻两个第一极耳区的长度差值D 3大于等于0.004mm且小于等于0.008mm。可以理解的是，多个第一极耳区的长度L 11可以等差递减，即任意相邻两个第一极耳区的长度差值相等，且长度差值可以为大于等于0.004mm并小于等于0.008mm的任意数值；当然，多个第一极耳区的长度L 11也可以非等差递减，即任意相邻两个第一极耳区的长度差值可以相同也可以不同，其长度差值为大于等于0.004mm并小于等于0.008mm的任意数值。
相邻两个第一极耳区的长度差值大于等于0.004mm且小于等于0.008mm，在保证第一极耳区的长度L 11呈阶梯状变化的同时进一步降低第一极耳区1212合拢后的冗余量。
根据本申请的又一些实施例，请参照图9至图13，图9为本申请又一些实施例提供的电极组件的主视图；图10为图9所示的B-B方向的第一种实施方式的第一极耳区未收拢状态的剖视图；图11为图10所示的第一种实施方式的第一极耳区收拢状态的剖视图；图12为图9所示的B-B方向的第二种实施方式的第一极耳区未收拢状态的剖视图；图13为图12所示的第二种实施方式的第一极耳区收拢状态的剖视图。电极组件12还包括多个第二极片122，多个第一极片121和多个第二极片122沿第一方向交替层叠设置，第一极片121和第二极片122极性相反，第二极片122包括第三涂覆区1221、第四涂覆区1223和第二极耳区1222，第三涂覆区1221和第四涂覆区1223通过第二极耳区1222连接，沿第一方向，多个第二极片122的第二极耳区1222的投影重叠；其中，电极组件12满足以下条件中的一者：c)多个第二极片122的第二极耳区的长度L 21均由第一方向上的一侧向另一侧逐渐减小；d)多个第二极片122的第二极耳区的长度L 21均由第一方向上的两侧向中间逐渐减小。
如前所述，第一极片121可以为正极极片也可以为负极极片，当第一极片121为正极极片时，第二极片122可以为负极极片，当第一极片121为负极极片时，第二极片122就可以为正极极片，第一极片121和第二极片122沿第一方向交替层叠设置，以形成叠片式电极组件12。
第一方向可以沿图中的X方向延伸，沿第一方向X，多个第二极片122的第二极耳区1222的投影重叠。
第三涂覆区1221、第二极耳区1222、第四涂覆区1223沿第二方向Y排列，第二方向Y与第一方向X垂直，第二极耳区的长度L 21为第二极耳区1222在第二方向Y上的尺寸，第三涂覆区的长度L 22为第三涂覆区1221在第二方向Y上的尺寸，第四涂覆区的长度L 23为第四涂覆区1223在第二方向Y上的长度。
多个第二极片122的第二极耳区的长度L 21可以由第一方向上的一侧向另一侧逐渐减小，也可以由第一方向上的两侧向中间逐渐减小，其中，多个第二极片122的第三涂覆区的长度L 22可以相等也可以不等，同理，多个第四涂覆区的长度L 23可以相等也可以不等。
可以理解的是，多个第一极片121的第一极耳区1212和多个第二极片122的第二极耳区1222应间隔设置，以避免极性不同的第一极耳区1212与第二极耳区1222接触而造成短路。如图9所示，第一极耳区1212和第二极耳区1222沿第三方向Z间隔设置，其中，第三方向Z垂直于第一方向X和第二方向Y。
电极组件12包括第一极片121和第二极片122，第一极片121和第二极片122可以分别设置为电极组件12的正极极片和负极极片，第二极片122与第一极片121的结构同理，即第二极片122的第二极耳区的长度L 21也沿第一方向向一侧递减或沿第一方向向中间递减，从而有效避免第二极耳区1222合拢后部分第二极耳区1222因预紧力过高、待连接区域面积不足而造成焊缝开裂、极耳断裂的风险，且避免第二极耳区1222收拢后产生过多冗余，在进一步保证电极组件12性能稳定性的同时有效提高电池100的能量密度。
根据本申请的一些实施例，每个第二极片的长度L 2相同；当电极组件12满足上述条件c)时，电极组件12同时满足：多个第二极片122的第三涂覆区的长度L 22由第一方向上的一侧向另一侧逐渐增加，多个第二极片122的第四涂覆区的长度 L23由第一方向上的一侧向另一侧逐渐增加。
每个第二极片的长度L 2相同，是指每个极片在第二方向Y上的长度相同，即每个第二极片122的第三涂覆区1221、第二极耳区1222和第四涂覆区1223在第二方向Y上的总长相同。
为了方便理解，定义第一方向上的两侧为第一侧和第二侧，多个第二极片122的第三涂覆区的长度L 22由第一方向上的一侧向另一侧逐渐增加，多个第二极片122的第四涂覆区的长度L 23由第一方向上的一侧向另一侧逐渐增加是指，多个第二极片122的第三涂覆区的长度L 22由第一方向上的第一侧向第二侧逐渐增加，同时，多个第二极片122的第四涂覆区的长度L 23由第一方向上的第一侧向第二侧逐渐增加。
可以理解的是，每个第二极片122在第二方向Y上的长度相同，多个第二极片122的第三涂覆区的长度L 22和第四涂覆区的长度L 23均由第一方向X上的第一侧向第二侧逐渐增加，则相对应的，多个第二极片122的第四极耳区的长度会由第一方向上的第一侧向第二侧逐渐减小。多个第二极片122的第二极耳区1222沿第一方向X由第一侧向第二侧收拢，以将多个第二极耳区1222收拢在长度最短的第二极耳区1222所在的一侧。
其中，多个第二极片122的沿第二方向Y的两端在第一方向X上大致对齐，以使多个第二极耳区1222在第一方向X上的投影的重叠面积最大化。
第二极片的长度L 2相同，第三涂覆区1221和第四涂覆区的长度L 23均由第一方向上的一侧向另一侧逐渐增加，使得第二极耳区的长度L 21由第一方向上的一侧向另一侧逐渐减小，从而在进一步降低第二极耳区1222冗余浪费的同时有效增加至少部分第二极片122的涂覆区的涂覆面积，从而有效增加电极组件12的涂覆区总面积，通过增加活性物质的总容量而进一步有效提高电池100的能量密度。
根据本申请的一些实施例，每个第二极片的长度L 2相同；当电极组件12满足上述条件d)时，电极组件12同时满足：多个第二极片122的第三涂覆区的长度L 22由第一方向上的两侧向中间逐渐增大，多个第二极片122的第四涂覆区的长度L 23由第一方向上的两侧向中间逐渐增大。
如上所述，每个第二极片的长度L 2相同，是指每个极片在第二方向Y上的长度相同，即每个第二极片122的第三涂覆区1221、第二极耳区1222和第四涂覆区1223在第二方向Y上的总长相同。
可以理解的是，每个第二极片122在第二方向Y上的长度相同，多个第二极片122的第三涂覆区的长度L 22和第四涂覆区的长度L 23均由第一方向上的两侧向中间逐渐增加，则多个第二极片122的第二极耳区的长度L 21会由第一方向上的两侧向中间逐渐减小。多个第二极片122的第二极耳区1222沿第一方向X由两侧向中间收拢，以将多个第二极耳区1222收拢在长度最短的第二极耳区1222所在的第一方向X上的中间位置。
其中，多个第二极片122的沿第二方向Y的两端在第一方向X上大致对齐，以使多个第二极耳在第一方向X上的投影的重叠面积最大化，确保多个第二极耳区1222收拢后能够具有较大的 重合区域，该重合区域内形成待连接区域，便于第一极耳区1212与转接件或直接与电能引出部连接。
第二极片的长度L 2相同，第三涂覆区1221和第四涂覆区的长度均由第一方向上的两侧向中间逐渐增加，使得第二极耳区的长度L 21由第一方向上的两侧向中间逐渐减小，从而在进一步降低第二极耳区1222冗余浪费的同时有效增加至少部分第二极片122的涂覆区的涂覆面积，从而有效增加电极组件12的涂覆区总面积，通过增加活性物质的总容量而进一步有效提高电池100的能量密度。
请参照图4至图8，本申请一些实施例提供了一种电极组件12，电极组件12为叠片式结构，电极组件12包括沿第一方向层叠设置的多个第一极片121，每个第一极片121包括第一涂覆区1211、第二涂覆区1213和第一极耳区1212，第二涂覆区1213和第一涂覆区1211通过第一极耳区1212连接，沿第一方向，多个第一极片121的第一极耳区1212的投影重叠；其中，每个第一极片的长度L 1相同，多个第一极片121的第一涂覆区的长度L 12由第一方向上的一侧向另一侧逐渐增加，多个第一极片121的第二涂覆区的长度L 13由第一方向上的一侧向另一侧逐渐增加，多个第一极片121的第一极耳区的长度L 11由第一方向上的一侧向另一侧逐渐减小。
请参照图4至图8，本申请一些实施例提供了一种电极组件12，电极组件12为叠片式结构，电极组件12包括沿第一方向层叠设置的多个第一极片121，每个第一极片121包括第一涂覆区1211、第二涂覆区1213和第一极耳区1212，第二涂覆区1213和第一涂覆区1211通过第一极耳区1212连接，沿第一方向，多个第一极片121的第一极耳区1212的投影重叠；其中，每个第一极片的长度L 1相同，多个第一极片121的第一涂覆区的长度L 12由第一方向上的两侧向中间逐渐增大，多个第一极片121的第二涂覆区的长度L 13由第一方向上的两侧向中间逐渐增大，多个第一极片121的第一极耳区的长度L 11由第一方向上的两侧向中间逐渐减小。
请参照图3至图13，并进一步参照图14至图18，图14为本申请一些实施例提供的电池单体的主视剖面图；图15为图14所示的C部分的局部结构放大示意图；图16为本申请一些实施例提供的第一转接件的主视图；图17为本申请一些实施例提供的第一转接件的仰视图；图18为本申请又一些实施例提供的第一转接件的仰视图。本申请一些实施例还提供一种电池单体10，包括电极组件12、壳体组件11和第一转接件13，其中，电极组件12可以是前述任一方案所述的电极组件12，电极组件12的第一极耳区1212弯折，以使第一涂覆区1211沿其厚度方向的投影与第二涂覆区1213沿其厚度方向的投影重叠。电极组件12收容于壳体组件11内，壳体组件11包括第一电极引出部，第一转接件13电连接多个第一极片121的第一极耳区1212和第一电极引出部。
在第一极耳区1212弯折前，因电极组件12的多个第一极片121均沿第一方向X层叠设置，所以第一涂覆区1211和第二涂覆区1213的厚度方向均沿第一方向X延伸，第一极耳区1212弯折后，第一涂覆区1211和第二涂覆区1213的厚度方向均沿第二方向Y延伸。第一极耳区1212位于第一涂覆区1211和第二涂覆区1213的第一方向X的一侧。
壳体组件11的结构参照前文所述结构即可，其中，第一电极引出部113可以是电极端子、片式极柱或其他用于输出电极组件12的电流的部件，第一电极引出部113的极性与第一极耳区1212的极性相同。
第一转接件13起到过流和汇流的作用，第一电极引出部113通过第一转接件13与第一极耳区1212电连接。
可以理解的是，电池单体10还可以包括第二电能引出部和第二转接件，相应的，第二转接件电连接第二极耳区1222和第二电能引出部。
第一极耳区1212弯折，使得第一涂覆区1211和第二涂覆区1213的厚度方向一致，第一极耳区1212处于第一涂覆区1211和第二涂覆区1213的同一侧，电极组件12容纳于壳体组件11内且第一转接件13连接第一极耳区1212和第一电极引出部，形成电池单体10，其具备较好的性能稳定性，且具有较高的能量密度。
根据本申请的一些实施例，请参照图14至图18，第一转接件13包括本体131、第一臂132和第二臂133，本体131连接于第一电极引出部，第一臂132和第二臂133从本体131的一端延伸出，第一臂132和第二臂133之间具有间隙134，多个第一极片121的第一极耳区1212插入间隙134且连接于第一臂132和第二臂133。
本体131的实施结构可以有多种，比如板状、块状，示例性的，本体131为板状。
可以理解的是，第一臂132和第二臂133可以沿第一方向X间隔设置，第一臂132和第二 臂133可以与本体131一体成型，也可以与本体131分体设置。
如图18所示，第一转接件13可以为板状结构，板状结构具有沿其厚度方向的侧壁，在侧壁设置凹槽，凹槽形成上述间隙134，凹槽的两个壁部形成第一臂132和第二臂133。
第一转接件13包括本体131和从本体131的同一端延伸出的第一臂132和第二臂133，第一臂132和第二臂133之间具有供第一极耳区1212插入的间隙134，这样，第一极耳区1212通过这种结构的第一转接件13与第一电极引出部连接后，第一转接件13的第一臂132和第二臂133对第一极耳区1212起到紧固及限位作用，降低第一极耳区1212向第一涂覆区1211和第二涂覆区1213塌陷的风险，从而降低因第一极耳区1212变形而造成电池单体10短路的风险，进一步有效提高电池单体10的性能稳定性。
根据本申请的一些实施例，本申请还提供了一种电池100，包括以上任一方案所述的电池单体10。
根据本申请的一些实施例，本申请还提供了一种用电装置，包括上述方案所述的电池100，所述电池100用于提供电能。
其中，用电装置可以是前述任一应用电池100的设备或系统。
需要说明的是，在不冲突的情况下，本申请中的实施例的特征可以相互结合。
虽然已经参考优选实施例对本申请进行了描述，但在不脱离本申请的范围的情况下，可以对其进行各种改进并可以用等效物替换其中的部件。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (13)

  1. 一种电极组件，其特征在于，所述电极组件为叠片式结构，所述电极组件包括沿第一方向层叠设置的多个第一极片，每个所述第一极片包括第一涂覆区、第二涂覆区和第一极耳区，所述第二涂覆区和所述第一涂覆区通过所述第一极耳区连接，沿所述第一方向，所述多个第一极片的所述第一极耳区的投影重叠；
    其中，所述电极组件满足以下条件中的一者：
    a)所述多个第一极片的所述第一极耳区的长度由所述第一方向上的一侧向另一侧逐渐减小；
    b)所述多个第一极片的所述第一极耳区的长度由所述第一方向上的两侧向中间逐渐减小。
  2. 根据权利要求1所述的电极组件，其特征在于，每个所述第一极片的长度相同；
    当所述电极组件满足上述条件a)时，所述电极组件同时满足：
    所述多个第一极片的所述第一涂覆区的长度由所述第一方向上的一侧向另一侧逐渐增加，所述多个第一极片的所述第二涂覆区的长度由所述第一方向上的一侧向另一侧逐渐增加。
  3. 根据权利要求1所述的电极组件，其特征在于，每个所述第一极片的长度相同；
    当所述电极组件满足上述条件b)时，所述电极组件同时满足：
    所述多个第一极片的所述第一涂覆区的长度由所述第一方向上的两侧向中间逐渐增大，所述多个第一极片的所述第二涂覆区的长度由所述第一方向上的两侧向中间逐渐增大。
  4. 根据权利要求2或3所述的电极组件，其特征在于，长度最短的所述第一涂覆区和长度最长的所述第一涂覆区的长度比值大于等于0.9；和/或
    长度最短的所述第二涂覆区和长度最长的所述第二涂覆区的长度比值大于等于0.9。
  5. 根据权利要求2-4中任一项所述的电极组件，其特征在于，同一个所述第一极片的所述第一涂覆区的长度和所述第一极耳区的长度的比值为D 1，满足1.4≤D 1≤1.8；和/或
    同一个所述第一极片的所述第二涂覆区的长度和所述第一极耳区的长度的比值为D 2，满足1.4≤D 2≤1.8。
  6. 根据权利要求1-5中任一项所述的电极组件，其特征在于，沿所述第一方向，相邻两个所述第一极耳区的长度的差值为D 3，满足0.004mm≤D 3≤0.008mm。
  7. 根据权利要求1-6中任一项所述的电极组件，其特征在于，所述电极组件还包括多个第二极片，所述多个第一极片和所述多个第二极片沿所述第一方向交替层叠设置，所述第一极片和所述第二极片极性相反，所述第二极片包括第三涂覆区、第四涂覆区和第二极耳区，所述第三涂覆区和所述第四涂覆区通过所述第二极耳区连接，沿所述第一方向，所述多个第二极片的所述第二极耳区的投影重叠；
    其中，所述电极组件满足以下条件中的一者：
    c)所述多个第二极片的所述第二极耳区的长度均由所述第一方向上的一侧向另一侧逐渐减小；
    d)所述多个第二极片的所述第二极耳区的长度均由所述第一方向上的两侧向中间逐渐减小。
  8. 根据权利要求7所述的电极组件，其特征在于，每个所述第二极片的长度相同；
    当所述电极组件满足上述条件c)时，所述电极组件同时满足：
    所述多个第二极片的所述第三涂覆区的长度由所述第一方向上的一侧向另一侧逐渐增加，所述多个第二极片的所述第四涂覆区的长度由所述第一方向上的一侧向另一侧逐渐增加。
  9. 根据权利要求7所述的电极组件，其特征在于，每个所述第二极片的长度相同；
    当所述电极组件满足上述条件d)时，所述电极组件同时满足：
    所述多个第二极片的所述第三涂覆区的长度由所述第一方向上的两侧向中间逐渐增大，所述多个第二极片的所述第四涂覆区的长度由所述第一方向上的两侧向中间逐渐增大。
  10. 一种电池单体，其特征在于，包括：
    如权利要求1-9中任一项所述的电极组件，所述第一极耳区弯折，以使所述第一涂覆区沿其厚度方向的投影与所述第二涂覆区沿其厚度方向的投影重叠；
    壳体组件，所述电极组件收容于所述壳体组件内，所述壳体组件包括第一电极引出部；
    第一转接件，所述第一转接件电连接所述多个第一极片的所述第一极耳区和所述第一电极引出部。
  11. 根据权利要求10所述的电池单体，其特征在于，所述第一转接件包括本体、第一臂和第二臂，所述本体连接于所述第一电极引出部，所述第一臂和所述第二臂从所述本体的一端延伸出，所述第一臂和所述第二臂之间具有间隙，所述多个所述第一极片的所述第一极耳区插入所述间隙且连接于所述第一臂和所述第二臂。
  12. 一种电池，其特征在于，包括如权利要求10或11所述的电池单体。
  13. 一种用电装置，其特征在于，包括如权利要求12所述的电池，所述电池用于提供电能。
PCT/CN2022/112849 2022-06-09 2022-08-16 电极组件、电池单体、电池及用电装置 WO2023236346A1 (zh)

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