WO2024011379A1 - 电极组件、电化学装置及用电设备 - Google Patents

电极组件、电化学装置及用电设备 Download PDF

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Publication number
WO2024011379A1
WO2024011379A1 PCT/CN2022/104997 CN2022104997W WO2024011379A1 WO 2024011379 A1 WO2024011379 A1 WO 2024011379A1 CN 2022104997 W CN2022104997 W CN 2022104997W WO 2024011379 A1 WO2024011379 A1 WO 2024011379A1
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Prior art keywords
electrode tab
negative electrode
projection
pole piece
positive electrode
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PCT/CN2022/104997
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English (en)
French (fr)
Inventor
胡红伟
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宁德新能源科技有限公司
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Application filed by 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to CN202280007510.4A priority Critical patent/CN116848649A/zh
Priority to PCT/CN2022/104997 priority patent/WO2024011379A1/zh
Publication of WO2024011379A1 publication Critical patent/WO2024011379A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material

Definitions

  • the present application relates to the field of energy storage technology, specifically, to an electrode assembly, an electrochemical device and electrical equipment.
  • energy storage devices are increasingly used in mobile phones, laptops, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and Enter the power tools.
  • electrochemical devices As an energy storage device, electrochemical devices generally produce electrical energy through electrochemical reactions between electrode components and electrolytes. For electrochemical devices, charging efficiency and gravimetric energy density are both important performance indicators. However, in the existing technology, the charging efficiency and mass energy density of electrochemical devices cannot be balanced. While pursuing high charging efficiency, the mass energy density is designed to be low, and vice versa. Therefore, how to balance fast charging and high-quality energy density is an urgent problem that needs to be solved.
  • the purpose of this application is to provide an electrode assembly, an electrochemical device and electrical equipment.
  • This electrode assembly can not only meet the needs of fast charging, but also has high mass energy density.
  • inventions of the present application provide an electrode assembly.
  • the electrode assembly has a laminated structure.
  • the electrode assembly includes a first part and a second part that are stacked on each other. Both the first part and the second part include stacked positive electrode plates. , isolation film, negative electrode plate, the first part and the second part are configured to be independently chargeable and dischargeable, the mass energy density of the first part is greater than or equal to the mass energy density of the second part, and the charging rate of the first part is less than or equal to the charging of the second part magnification.
  • the electrode assembly includes a first part and a second part that are stacked on each other, and the first part and the second part include stacked positive electrode plates, isolation films, and negative electrode plates.
  • the first part and the second part can be charged independently of each other. Discharge, and the charging rate of the second part is greater than or equal to the charging rate of the first part.
  • the second part can be charged quickly to meet the user's temporary fast charging needs; at the same time, the mass energy density of the first part is greater than It is equal to the mass energy density of the second part, which can increase the overall capacity of the electrode assembly.
  • the first part can be charged to reserve energy in advance and reduce frequent fast charging of the second part. leading to a decrease in its cycle life.
  • This electrode assembly can not only meet the needs of fast charging, but also has high mass energy density.
  • the ratio of the mass energy density of the first part to the mass energy density of the second part is 1.1-2.2; the ratio of the charging rate of the first part to the charging rate of the second part is 0.2-0.8. If the difference between the mass energy density and the charging rate of the first part and the second part is too small, for example, the ratio of the mass energy density of the first part to the mass energy density of the second part is less than 1.1, the charging rate of the first part and the charging rate of the second part are The rate ratio is greater than 0.8.
  • the mass energy density and charging rate difference between the first part and the second part is too small, making the first part and the second part
  • the gap between energy density and charging capacity is too small, and the above technical effects are not obvious compared with the increase in material preparation costs caused by separately preparing pole pieces with different properties and the increase in production costs caused by assembling pole pieces with different properties into the first part and the second part.
  • the input-output is relatively low; if the difference in mass energy density and charging rate between the first part and the second part is too large, such as the ratio of the mass energy density of the first part to the mass energy density of the second part is greater than 2.2, the charging of the first part
  • the ratio of the charging rate to the charging rate of the second part is less than 0.2.
  • the ratio of the mass energy density of the first part to the mass energy density of the second part is 1.3 to 1.8; the ratio of the charging rate of the first part to the charging rate of the second part is 0.4 to 0.7, so that it is easy to pass through similar positive or negative electrode materials.
  • the pole piece can be prepared to meet the above-mentioned difference in energy density and charging rate between the first part and the second part, which can greatly reduce the cost of material preparation, and at the same time, it can take into account the power when charging the first part and the second part at the same time.
  • the local temperature difference inside the chemical device allows for better temperature management of the electrochemical device.
  • the coating weight of the active material of the first part of the positive electrode sheet is greater than or equal to the coating weight of the active material of the second part of the positive electrode sheet, and the compaction of the active material of the first part of the positive electrode sheet
  • the density is greater than or equal to the compacted density of the active material of the second part of the positive electrode plate
  • the coating weight of the active material of the first part of the negative electrode plate is greater than or equal to the coating weight of the active material of the second part of the negative electrode plate
  • the first part The compacted density of the active material of the negative electrode piece is greater than or equal to the compacted density of the active material of the second part of the negative electrode piece.
  • the coating weight (coating weight on one side) and compaction density of the active material of the first part of the positive electrode sheet are both greater than or equal to the coating weight and compaction density of the active material of the second part of the positive electrode sheet. density, so that the first part of the positive electrode piece has more active material capacity.
  • the coating weight and compaction density of the active material of the first part of the negative electrode piece are both greater than or equal to the active material of the second part of the negative electrode piece.
  • the coating weight and compaction density make the first part of the negative electrode sheet have more active material capacity, so that the mass energy density of the first part is greater than or equal to the mass energy density of the second part, thereby making the overall electrode assembly have a higher mass energy density to meet usage requirements.
  • an intermediate component is provided between the first part and the second part.
  • the first part and the second part are connected through the intermediate part to realize the assembly of the first part and the second part.
  • the intermediate component is a double-sided pole piece with active material disposed on both sides.
  • the middle part is a double-sided pole piece, and the middle part can be used in conjunction with the first part and the second part respectively.
  • the electrode assembly has more active material capacity to increase the overall capacity of the electrode assembly.
  • the coating weight of the active material on the side of the double-sided pole piece facing the first part is greater than or equal to the coating weight of the active material on the side facing the second part, and the double-sided pole piece faces the third part.
  • the compacted density of the active material on one side of the part is greater than or equal to the compacted density of the active material on the side facing the second part.
  • the coating weight and compaction density of the active material on the side of the double-sided pole piece facing the first part are both greater than or equal to the coating weight and compaction density of the active material on the side of the double-sided pole piece facing the second part, Make the coating weight and compaction density of the side of the double-sided pole piece facing the first part match the coating weight and compaction density of the first part of the pole piece, and the coating weight and compaction density of the side of the double-sided pole piece facing the second part.
  • the solid density can match the coating weight and compaction density of the second part of the pole piece, so that the double-sided pole piece forms a better fit with the first and second parts.
  • the intermediate component is an isolation membrane.
  • the isolation film is used as an intermediate component to ensure a compact structure of the electrode assembly. Compared with the double-sided pole piece as an intermediate component, the process of separately preparing the double-sided pole piece can be reduced, and the cost of material preparation and assembly can be reduced.
  • the pole piece closest to the intermediate component in the first part is the first pole piece
  • the pole piece closest to the intermediate component in the second part is the second pole piece
  • the pole piece closest to the intermediate component in the second part is the second pole piece.
  • the first pole piece and the second pole piece are provided with active materials on both sides of their respective current collectors, and the polarities of the first pole piece and the second pole piece are opposite.
  • the electrode assembly can be produced by sequentially stacking the most conventional positive electrode, separator, and negative electrode in a stacked battery, and when the first part and the second part are charged at the same time, the first pole piece and the second All active materials on the pole piece can participate in ion deintercalation, which can increase the mass energy density and achieve the same effect of increasing the overall capacity and mass energy density of the electrode assembly by using the double-sided pole piece as the middle component.
  • the intermediate component is an isolation film
  • the first pole piece and the second pole piece are double-sided pole pieces with opposite polarities
  • the first pole piece has a negative polarity and the second pole piece The piece is of positive polarity.
  • the first pole piece with a larger coating weight is the negative electrode, which can fully embed the lithium ions in the second pole piece without lithium precipitation.
  • the first pole piece is the positive electrode and the second pole piece is the negative electrode, since the coating weight of the first pole piece is larger, when the first and second parts are charged at the same time, lithium ions may escape from the first pole piece. If too much, the second pole piece cannot be fully embedded, leading to the risk of lithium precipitation. This situation can still solve the technical problem underlying this application, but it will cause a certain loss in cycle performance.
  • the first pole piece and/or the second pole piece can also be configured as a single-sided pole piece, that is, the first pole piece and The current collector on at least one side of the second pole piece close to the middle component is not coated with active material, and the polarity of the first pole piece and the second pole piece may be the same or different.
  • an insulating layer can be provided between the first pole piece and/or the second pole piece in the single-sided pole piece state and the isolation film.
  • the intermediate component can also be hot melt adhesive.
  • the insulating material is hot melt adhesive, which not only has an insulating effect, but also can enhance the connection stability between the first part and the second part. Reduces the risk of positional movement of the first part relative to the second part.
  • the first part of the positive electrode tab includes a first positive electrode tab
  • the first part of the negative electrode tab includes a first negative electrode tab
  • the second part of the positive electrode tab includes a second positive electrode tab
  • the second part of the positive electrode tab includes a first positive electrode tab.
  • Part of the negative electrode tab includes a second negative electrode tab; the electrode assembly satisfies the following requirements: along the stacking direction of the electrode tab, the projection of the first positive electrode tab does not overlap with the projection of the second positive electrode tab, and the projection of the first negative electrode tab does not overlap with the projection of the first negative electrode tab. The projections of the second negative electrode tab overlap.
  • the projection of the first positive electrode tab overlaps the projection of the second positive electrode tab, and the projection of the first negative electrode tab does not overlap with the projection of the second negative electrode tab.
  • the projection of the first positive electrode tab does not overlap with the projection of the second positive electrode tab, and the projection of the first negative electrode tab does not overlap with the projection of the second negative electrode tab.
  • the tabs of the electrode assembly can be set at different positions according to different needs.
  • the first part and the second part can share the tabs, so as to Reduce electrode output components and save manufacturing costs; the tabs of the first part and the second part may also not overlap to meet the situation where the first part and the second part are connected in series or parallel as needed inside the electrode assembly through circuit control to suit the user.
  • the first part and the second part can be connected in parallel (the first part and the second part can also be connected in parallel to output large current when they have a common pole).
  • the first part and the second part can be connected in series.
  • embodiments of the present application also provide an electrochemical device, including the electrode assembly provided in the embodiment of the first aspect, a receiving member, and an electrolyte.
  • the electrode assembly and the electrolyte are both accommodated in the receiving member.
  • the first part of the positive electrode tab includes a first positive electrode tab
  • the first part of the negative electrode tab includes a first negative electrode tab
  • the second part of the positive electrode tab includes a second positive electrode tab
  • the second part of the positive electrode tab includes a first positive electrode tab
  • Part of the negative electrode piece includes a second negative electrode tab.
  • the electrochemical device satisfies the following requirements: along the stacking direction of the electrode sheets, the projection of the first positive electrode tab does not overlap with the projection of the second positive electrode tab, the projection of the first negative electrode tab overlaps the projection of the second negative electrode tab, and the first positive electrode tab
  • the lug is welded to the first positive terminal
  • the second positive lug is welded to the second positive terminal
  • the first negative lug and the second negative lug are welded to the negative terminal
  • the first positive terminal, the second positive terminal, and the negative terminal extend out Containment items.
  • the projection of the first positive electrode tab overlaps the projection of the second positive electrode tab
  • the projection of the first negative electrode tab does not overlap the projection of the second negative electrode tab
  • the first negative electrode tab is welded to the first
  • the second negative electrode tab is welded to the second negative terminal
  • the first positive electrode tab and the second positive electrode tab are welded to the positive terminal
  • the first negative terminal, the second negative terminal and the positive terminal extend out of the receiving member.
  • the projection of the first positive electrode tab does not overlap with the projection of the second positive electrode tab
  • the projection of the first negative electrode tab does not overlap with the projection of the second negative electrode tab
  • the first positive electrode tab is welded
  • the second positive tab is welded to the fourth positive terminal
  • the first negative tab is welded to the third negative terminal
  • the second negative tab is welded to the fourth negative terminal
  • the third positive terminal and the fourth positive terminal are The terminal, the third negative terminal and the fourth negative terminal extend out of the receiving member.
  • embodiments of the present application further provide electrical equipment, including the electrochemical device provided in the embodiment of the second aspect.
  • Figure 1 is a structural diagram of a vehicle provided by some embodiments of the present application.
  • Figure 2 is a schematic structural diagram of an electrochemical device provided by some embodiments of the present application.
  • FIG. 3 is a schematic diagram of an electrode assembly provided by some embodiments of the present application.
  • Figure 4 is a schematic diagram of a pole piece provided by some embodiments of the present application.
  • Figure 5 is a schematic diagram of a pole piece provided by other embodiments of the present application.
  • Figure 6 is a schematic diagram of an intermediate component of an electrode assembly provided by some embodiments of the present application.
  • Figure 7 is a schematic diagram of an intermediate component of an electrode assembly provided by other embodiments of the present application.
  • Figure 8 is a schematic structural diagram of the first pole piece provided by some embodiments of the present application.
  • Figure 9 is a schematic structural diagram of the second pole piece provided by some embodiments of the present application.
  • Figure 10 is a schematic diagram of the first part of the strapping member provided by some embodiments of the present application.
  • Figure 11 is a schematic view of the second part of the strapping member provided by some embodiments of the present application.
  • Figure 12 is a schematic diagram of the first part of the strapping member provided by other embodiments of the present application.
  • Figure 13 is a schematic view of the second part of the strapping member provided by other embodiments of the present application.
  • Figure 14 is a schematic diagram of the overlap of the projection of the first negative electrode tab and the projection of the second negative electrode tab provided by some embodiments of the present application;
  • Figure 15 is a schematic diagram of the overlap of the projection of the first positive electrode tab and the projection of the second positive electrode tab provided by some embodiments of the present application;
  • Figure 16 is a schematic diagram in which the projection of the first positive electrode tab does not overlap with the projection of the second positive electrode tab, and the projection of the first negative electrode tab does not overlap with the projection of the second negative electrode tab provided by some embodiments of the present application;
  • Marking description 100-battery; 1-electrochemical device; 10-electrode assembly; 101-pole piece; 1011-current collector; 1012-active material layer; 1013-insulating layer; 102-isolation film; 11-first part; 111 -The first pole piece; 112-the first positive pole tab; 113-the first negative pole tab; 12-the second part; 121-the second pole piece; 122-the second positive pole tab; 123-the second negative pole tab ; 13-middle component; 14-bundling piece; 20-containing piece; 21-casing; 22-end cover; 23-electrode terminal; 200-controller; 300-motor; 1000-vehicle.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.
  • multiple refers to more than two (including two).
  • multiple groups refers to two or more groups (including two groups), and “multiple pieces” refers to means two or more pieces (including two pieces), unless otherwise clearly and specifically limited.
  • both gravimetric energy density and charge rate are key performance indicators of electrochemical devices.
  • the pole pieces of an electrochemical device are designed to meet specific charging capacity requirements.
  • the coating weight and compaction density of the active materials of each pole piece are at the same level, that is, all pole pieces in the electrochemical device
  • the charging capacity is the same.
  • An electrochemical device with high charging efficiency uses a thin pole piece, a low compaction density and coating weight of the active material of the pole piece, and a low mass energy density of the electrochemical device.
  • Electrochemical devices with high mass energy density use thicker pole pieces, which reduces the charging efficiency of the electrochemical device. In other words, it is impossible to meet the requirements of high-quality energy density and fast charging at the same time.
  • this application provides an electrode assembly.
  • the electrode assembly includes two parts, one part has a higher mass energy density and a lower charging rate, and the other part has a higher mass energy density and a lower charging rate. Some have higher charging rates and lower mass energy density.
  • the part with high charge rate can be charged separately; when the electrochemical device is not in urgent need of charging, the part with high mass energy density can be charged separately, or both parts can be charged at the same time. Therefore, this electrode assembly can take into account the requirements of high mass energy density and fast charging at the same time.
  • different parts of the electrode assembly can be flexibly used according to the user's actual use of electrical equipment to improve the cycle life of the electrode assembly.
  • the electrode assembly provided by the embodiment of the present application is suitable for electrochemical devices and electrical equipment using electrochemical devices.
  • Embodiments of the present application provide electrical equipment.
  • the electrical equipment includes an electrochemical device, and the electrochemical device is used to provide electric energy.
  • Electrical equipment may include but is not limited to: vehicles, mobile phones, laptops, headphones, video recorders, calculators, ships, spacecraft, electric toys, etc.
  • Vehicles can be fuel vehicles, gas vehicles, new energy vehicles, motorcycles, power-assisted bicycles, etc.
  • Spacecraft can be airplanes, rockets, space shuttles, spaceships, etc.; electric toys can be game consoles, electric car toys, electric ship toys, electric airplane toys, etc.; electric tools can be metal cutting power tools, grinding power tools, assembly power tools, etc. Tools, power tools for railways, etc.
  • the embodiments of this application impose no special restrictions on the above electrical equipment.
  • the following embodiments take the electrical equipment as a vehicle as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application.
  • a battery 100 is provided inside the vehicle 1000 .
  • the battery 100 can be used to power the vehicle 1000 .
  • the battery 100 can be installed at the bottom, head, or tail of the vehicle 1000 .
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to power the motor 300 .
  • Battery 100 may serve as an operating power source for vehicle 1000 . For example, it is used for the power requirements for starting, navigation and driving of the vehicle 1000 .
  • the battery 100 can also serve 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.
  • the battery 100 may include one or more electrochemical devices 1 .
  • the multiple electrochemical devices 1 can be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the multiple electrochemical devices 1 are connected in series and in parallel.
  • the battery 100 may also include a bus component, through which multiple electrochemical devices 1 can be electrically connected to achieve series, parallel or mixed connection of multiple electrochemical devices 1 .
  • the bus component can be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.
  • FIG 2 is a schematic structural diagram of an electrochemical device 1 provided by some embodiments of the present application.
  • the electrochemical device 1 includes an electrode assembly 10 and an electrolyte.
  • the electrochemical device 1 undergoes a chemical reaction through the electrode assembly 10 and the electrolyte. to output electrical energy.
  • the electrochemical device 1 may be a lithium-ion battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiments of the present application are not limited thereto.
  • the electrochemical device 1 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 thereto.
  • Electrochemical devices 1 are generally divided into three types according to packaging methods: cylindrical batteries, prismatic batteries and soft-pack batteries, and the embodiments of the present application are not limited to this.
  • the electrochemical device 1 may also include a receiving member 20 .
  • the receiving member 20 is used to receive the electrode assembly 10 and the electrolyte.
  • the receiving member 20 may be a receiving shell, such as an aluminum shell or a steel shell. Shell etc.
  • the holding member 20 may also be a holding bag, for example, a holding bag made of aluminum plastic film.
  • the receiving member 20 may include a housing 21 and an end cap 22 .
  • the housing 21 is a component for accommodating the electrode assembly 10.
  • the housing 21 may be a hollow structure with an opening formed at one end.
  • the housing 21 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.
  • the housing 21 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
  • the end cap 22 is a component that covers the opening of the housing 21 to isolate the internal environment of the electrochemical device 1 from the external environment.
  • the end cap 22 covers the opening of the casing 21 , and the end cap 22 and the casing 21 jointly define a sealed space for accommodating the electrode assembly 10 , electrolyte and other components.
  • the shape of the end cover 22 can be adapted to the shape of the casing 21.
  • the casing 21 has a rectangular parallelepiped structure, and the end cover 22 has a rectangular plate structure matching the casing 21.
  • the casing 21 has a cylindrical shape.
  • the end cover 22 is a circular plate-shaped structure that matches the housing 21 .
  • the end cap 22 can also be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
  • an electrode terminal 23 may be provided on the end cap 22, and the electrode terminal 23 is used to electrically connect with the electrode assembly 10 to output the electrical energy of the electrochemical device 1.
  • the electrode terminal 23 includes a positive terminal and a negative terminal. The positive terminal is electrically connected to the positive tab of the electrode assembly 10 , and the negative terminal is electrically connected to the negative tab of the electrode assembly 10 .
  • FIG. 3 shows a schematic diagram of the electrode assembly 10 provided by some embodiments of the present application.
  • the embodiment of the present application provides an electrode assembly 10.
  • the electrode assembly 10 has a laminated structure.
  • the electrode assembly 10 includes a first part 11 and a second part 12 stacked on each other.
  • the first part 11 and the second part 12 are configured to be independently chargeable and dischargeable.
  • the mass energy density of the first part 11 is greater than or equal to
  • the mass energy density of the second part 12 and the charging rate of the first part 11 are less than or equal to the charging rate of the second part 12 .
  • first part 11 and the second part 12 belong to the same electrode assembly 10 and are integrally packaged in a receiving member 20, and the receiving member 20 is injected with electrolyte.
  • the test method for mass energy density of first part 11 second part 12 electrode assembly 10 is as follows: in the process of preparing the electrochemical device, the weight W1 of the first part 11 and the weight W2 of the second part 12 can be measured first, and then After the electrode assembly 10 is assembled into an electrochemical device, the first part 11 and the second part 12 are charged and discharged respectively to obtain the energy C1 of the first part 11 and the energy C2 of the second part 12, which are calculated by C1/W1 and C2/W2 The mass energy density of the first part 11 and the second part 12.
  • the charging rate of the first part 11 and the second part 12 of the test electrode assembly 10 is as follows: first, charge the first part 11 and the second part 12 respectively to a certain voltage with a constant current of 100 to 1000 mA, and then charge with a constant voltage to The charging current is 20 ⁇ 200mA, in which the charging cut-off voltage can be set to a certain voltage gradient, such as between 3.5 ⁇ 4.6V, with a gradient set every 20mV ⁇ 50mV.
  • the above-mentioned electrochemical device that is fully charged according to different voltage gradients is carried out.
  • the highest voltage ladder U1 and U2 where the negative electrode interface of the first part 11 and the second part 12 is golden and there is no lithium precipitation is the full charging voltage of the two respectively, and the corresponding charging capacity of U1 and U2 is the first part 11 and
  • the second part 12 has rated capacities C1 and C2.
  • set a certain charging current gradient for example, charge the two parts according to 0.5C1 ⁇ 10C1 and 0.5C2 ⁇ 10C2, set a gradient every 0.5C ⁇ 1C, and charge the first part 11 and the second part 12 according to different current gradients respectively.
  • the electrode assembly 10 includes a first part 11 and a second part 12 stacked on each other, and the first part 11 and the second part 12 include stacked positive electrode plates, isolation films, and negative electrode plates,
  • the first part 11 and the second part 12 can charge and discharge independently of each other, and the charging rate of the second part 12 is greater than or equal to the charging rate of the first part 11.
  • the second part 12 can charge quickly, which can satisfy the user temporary fast charging needs; at the same time, the mass energy density of the first part 11 is greater than or equal to the mass energy density of the second part 12, which can increase the overall capacity of the electrode assembly 10.
  • the product is in standby, hibernation, etc.
  • the first part can be charged. 11 is charged to reserve energy in advance, and at the same time to reduce the frequency of fast charging of the second part 12 resulting in a decrease in its cycle life.
  • the electrode assembly 10 can not only meet the demand for fast charging, but also has a high mass energy density.
  • the ratio of the mass energy density of the first part 11 to the mass energy density of the second part 12 is 1.1 to 2.2; the ratio of the charging rate of the first part 11 to the charging rate of the second part 12 is 0.2 to 0.8. . If the difference in mass energy density and charging rate between the first part 11 and the second part 12 is too small, for example, the ratio of the mass energy density of the first part 11 to the mass energy density of the second part 12 is less than 1.1, the charging rate of the first part 11 is The charging rate ratio of the second part 12 is greater than 0.8.
  • the difference in mass energy density and charging rate between the first part 11 and the second part 12 is too small.
  • the gap between the energy density and charging capacity of the first part 11 and the second part 12 is too small.
  • the increase in production cost caused by the second part 12 is not obvious, that is, the input-output is relatively low; if the difference in mass energy density and charging rate between the first part 11 and the second part 12 is too large, for example, the mass energy density of the first part 11 and the second part 12
  • the ratio of the mass energy density of the second part 12 is greater than 2.2, and the ratio of the charging rate of the first part 11 to the charging rate of the second part 12 is less than 0.2.
  • the heat generated by the second part 12 will be much greater than the heat generated by the first part 11, which will easily cause obvious uneven temperature distribution inside the electrochemical device 1 and affect the electrolytic properties of different electrolytes inside the electrochemical device 1. performance, causing side reactions to occur and deteriorating the life of the electrochemical device.
  • the ratio of the mass energy density of the first part 11 to the mass energy density of the second part 12 may be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, etc.;
  • the ratio of the charging rate of one part 11 to the charging rate of the second part 12 may be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.
  • the ratio of the mass energy density of the first part 11 to the mass energy density of the second part 12 is 1.3-1.8; the ratio of the charging rate of the first part 11 to the charging rate of the second part 12 is 0.4-0.7, so that it is easy to pass the same kind of
  • the positive electrode or negative electrode material can be prepared to meet the difference in energy density and charging rate between the first part 11 and the second part 12 by just adjusting the degree of compaction, etc., which can greatly reduce the cost of material preparation, and at the same time, it can take into account the requirements of the first part 11
  • the difference in local temperature inside the electrochemical device 1 when charging the second part 12 allows for better temperature management of the electrochemical device 1 .
  • the first part 11 and the second part 12 each include at least one pole piece 101 .
  • the first part 11 and the second part 12 each include a plurality of pole pieces 101.
  • the plurality of pole pieces 101 include a positive pole piece and a negative pole piece.
  • the positive pole piece and the negative pole piece are stacked, and the metal ions are in the positive pole. between the positive electrode piece and the negative electrode piece, and an isolation film is provided between the positive electrode piece and the negative electrode piece.
  • Figure 4 is a schematic diagram of the pole piece 101 provided by some embodiments of the present application
  • Figure 5 is a schematic diagram of the pole piece 101 provided by other embodiments of the present application.
  • the pole piece 101 includes a current collector 1011 and an active material layer 1012 coated on the surface of the current collector 1011.
  • the active material layer 1012 is located on one side or two opposite sides of the current collector 1011 in the thickness direction.
  • the pole piece 101 when the active material layer 1012 is located on one side of the current collector 1011 in the thickness direction, the pole piece 101 is a single-sided pole piece; as shown in Figure 5, when the active material layer 1012 is located in the thickness direction of the current collector 1011 When there are two opposite sides, the pole piece 101 is a double-sided pole piece.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the current collector that is not coated with the positive electrode active material layer protrudes from the current collector that has been coated with the positive electrode active material layer.
  • Positive terminal ear Taking lithium-ion batteries as an example, 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 current collector that is not coated with the negative electrode active material layer protrudes from the current collector that has been coated with the negative electrode active material layer.
  • Negative terminal lug The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon. In order to ensure that large currents can pass through without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together.
  • the material of the isolation film can be PP or PE, etc.
  • the coating weight of the active material of the positive electrode sheet of the first part 11 is greater than or equal to the coating weight of the active material of the positive electrode sheet of the second part 12 , and the active material of the positive electrode sheet of the first part 11
  • the compacted density is greater than or equal to the compacted density of the active material of the positive electrode sheet of the second part 12
  • the coating weight of the active material of the negative electrode sheet of the first part 11 is greater than or equal to the active material of the negative electrode sheet of the second part 12
  • the coating weight and the compacted density of the active material of the negative electrode sheet in the first part 11 are greater than or equal to the compacted density of the active material of the negative electrode sheet in the second part 12 .
  • the material of the active material of the positive electrode piece of the first part 11 may be the same as the material of the active material of the positive electrode piece of the second part 12 .
  • the material of the active material of the negative electrode piece of the first part 11 may be the same as the material of the active material of the negative electrode piece of the second part 12 . That is, the first part 11 and the second part 12 can use the same type of positive and negative active materials, and achieve the mass energy density and charging rate of the first part 11 and the second part 12 by controlling the compaction density and coating weight of different parts of the pole pieces. different.
  • the coating weight of the active material mentioned above refers to the coating weight of the active material on one side of the current collector.
  • the coating weight and compaction density of the active material of the positive electrode sheet of the first part 11 are both greater than or equal to the coating weight and compaction density of the active material of the positive electrode sheet of the second part 12 , so that the first part 11 The positive electrode sheet has a larger active material capacity.
  • the coating weight and compaction density of the active material of the negative electrode sheet in the first part 11 are both greater than or equal to the active material coating of the negative electrode sheet in the second part 12
  • the weight and compaction density make the negative electrode piece of the first part 11 have more active material capacity, so that the mass energy density of the first part 11 is greater than or equal to the mass energy density of the second part 12, so that the overall electrode assembly 10 has a larger capacity. High mass energy density meets usage requirements.
  • Figure 6 is a schematic diagram of the middle component 13 of the electrode assembly 10 provided by some embodiments of the present application
  • Figure 7 is a schematic diagram of the middle component 13 of the electrode assembly 10 provided by other embodiments of the present application.
  • an intermediate component 13 is provided between the first part 11 and the second part 12 .
  • the intermediate component 13 is a component disposed between the first part 11 and the second part 12 .
  • the intermediate component 13 can connect the first part 11 and the second part 12 to realize the assembly of the first part 11 and the second part 12 .
  • the intermediate component 13 is a double-sided pole piece with active material disposed on both sides.
  • a double-sided pole piece means that active material layers are provided on both sides of the current collector in the thickness direction.
  • the double-sided pole piece can be a positive pole piece, or it can also be a negative pole piece.
  • the polarity of the pole pieces of the first part 11 and the second part 12 corresponding to the double-sided pole piece should be Opposite polarity to the double-sided pole piece.
  • the intermediate component 13 is a double-sided pole piece, and the intermediate component 13 can be used in conjunction with the first part 11 and the second part 12 respectively.
  • the electrode assembly 10 has more active material capacity to increase the overall capacity of the electrode assembly 10 .
  • the coating weight of the active material on the side of the double-sided pole piece facing the first part 11 is greater than or equal to the coating weight of the active material on the side facing the second part 12 , and the double-sided pole piece faces the first part 11
  • the compacted density of the active material on one side is greater than or equal to the compacted density of the active material on the side facing the second part 12 .
  • the coating weight and compaction density of the active material on the side of the double-sided pole piece facing the first part 11 are both greater than or equal to the coating weight and compaction density of the active material on the side of the double-sided pole piece facing the second part 12 Density, so that the coating weight and compaction density of the side of the double-sided pole piece facing the first part 11 can match the coating weight and compaction density of the pole piece of the first part 11, and the coating weight and compaction density of the side of the double-sided pole piece facing the second part 12
  • the coating weight and compaction density can match the coating weight and compaction density of the pole piece of the second part 12, so that the double-sided pole piece forms a better match with the first part 11 and the second part 12 to prevent lithium deposition or capacity waste.
  • the intermediate component 13 is an isolation film.
  • the isolation film is used as the intermediate component 13 instead of the double-sided pole piece, which can ensure the compact structure of the electrode assembly 10, can also reduce the process of separately preparing the double-sided pole piece, and reduce the cost of material preparation and assembly.
  • the pole piece closest to the intermediate component 13 in the first part 11 is the first pole piece 111
  • the pole piece closest to the intermediate component 13 in the second part 12 is the second pole piece 121.
  • the first pole piece 111 and the second pole piece 121 are both double-sided pole pieces with active materials disposed on both sides of the current collector.
  • the polarities of the first pole piece 111 and the second pole piece 121 are opposite.
  • the electrode assembly 10 can be produced by sequentially stacking the most conventional positive electrode, separator film, and negative electrode in a stacked battery, and when the first part 11 and the second part 12 are charged at the same time, the first pole piece 111 and the second pole piece 111 are charged.
  • All active materials on the diode piece 121 can participate in ion deintercalation, which can increase the mass energy density and achieve the same effect of improving the overall capacity and mass energy density of the electrode assembly 10 as the intermediate component 13 is the aforementioned double-sided pole piece.
  • the pole piece in the first part 11 that is closest to the middle part 13 refers to the pole piece that is closest to the middle part 13 relative to the other pole pieces among the plurality of pole pieces in the first part 11 .
  • This pole piece is called the first pole piece.
  • the pole piece in the second part 12 that is closest to the middle part 13 refers to the pole piece that is closest to the middle part 13 relative to the other pole pieces among the plurality of pole pieces in the second part 12. This pole piece is called the second pole piece.
  • Pole piece 121 Pole piece 121.
  • the intermediate component 13 is an isolation film
  • the first pole piece 111 and the second pole piece 121 are double-sided pole pieces with opposite polarities
  • the second pole piece 121 is of positive polarity. In this way, when the first part 11 and the second part 12 are charged at the same time, the first pole piece 111 with a larger coating weight is the negative electrode, and the lithium ions of the second pole piece 121 can be fully embedded without lithium precipitation.
  • first pole piece 111 is the positive electrode and the second pole piece 121 is the negative pole, due to the greater coating weight of the first pole piece 111, when charging the first part 11 and the second part 12 at the same time, the first pole may appear. Too many lithium ions are extracted from the piece 111, and the second pole piece 121 cannot be fully embedded, resulting in the risk of lithium precipitation. This situation can still solve the technical problem underlying this application, but it will cause a certain loss in cycle performance.
  • the first pole piece 111 and/or the second pole piece 121 can also be configured as a single-sided pole piece, that is, the first pole piece 111 and the second pole piece 121 can also be configured as single-sided pole pieces.
  • the current collector on the side of at least one of the diode pieces 121 close to the middle component 13 is not coated with active material.
  • the polarities of the first pole piece 111 and the second pole piece 121 may be the same or different.
  • the first pole piece 111 and/or the second pole piece 121 can also be configured as single-sided pole pieces, including the following situations: the first pole piece 111 is only provided with active material on the side away from the second part 12; or, the second pole The sheet 121 is only provided with active material on the side facing away from the first part 11; or, the first pole piece 111 is only provided with active material on the side facing away from the second part 12, and the second pole piece 121 is only provided on the side facing away from the first part 11. Active material is provided on one side.
  • the active material is provided only on the side of the first pole piece 111 away from the second part 12 means that the first pole piece 111 is a single-sided pole piece, and the current collector of the first pole piece 111 faces the second part 12
  • One side is not provided with an active material layer, that is, the side of the current collector of the first pole piece 111 facing the second part 12 is an empty foil area.
  • the side of the first pole piece 111 facing the middle part 13 is an empty foil area.
  • No active material is provided on the side.
  • the second pole piece 121 is provided with active material only on the side away from the first part 11 , which means that the second pole piece 121 is a single-sided pole piece and the current collector side of the second pole piece 121 facing the first part 11 is not provided.
  • an active material layer that is, the side of the current collector of the second pole piece 121 facing the first part 11 is an empty foil area.
  • the side of the second pole piece 121 facing the intermediate part 13 is not provided with an active material layer. substance. Due to the thin thickness of the current collector, the current collector is usually a foil, and the area of the current collector that is not coated with active material is called an empty foil area.
  • At least one of the first pole piece 111 and the second pole piece 121 is a single-sided pole piece, and the side of the single-sided pole piece facing the intermediate component 13 is not provided with active material, although the present invention can also be implemented.
  • the basic technical effect due to the existence of a single-sided empty foil area in the first pole piece 111 and/or the second pole piece 121 results in a reduction in the overall mass energy density of the electrode assembly 10 .
  • FIG. 8 is a schematic structural diagram of the first pole piece 111 provided by some embodiments of the present application.
  • the side of the first pole piece 111 that is not provided with active material may be provided with an insulating layer 1013 .
  • the intermediate component 13 between the first part 11 and the second part 12 is an isolation film
  • the first pole piece 111 is a single-sided pole piece
  • the side of the first pole piece 111 facing the second part 12 is not provided with an active material
  • the side of the current collector of the first pole piece 111 that is not coated with active material is an empty foil area.
  • the surface of the empty foil area has poor bonding effect with the isolation film, which easily causes the first part 11 and the second part 12 to interact with each other. The movement may lead to a short circuit between the positive electrode piece and the negative electrode piece in severe cases, affecting the safety and reliability of the electrode assembly 10 .
  • An insulating layer 1013 is provided on the side of the first pole piece 111 that is not provided with active material.
  • the insulating layer 1013 has a better bonding effect with the isolation film, which can increase the insulation effect between the first pole piece 111 and the second pole piece 121 , and can also reduce the risk of short circuit between the positive electrode piece and the negative electrode piece of the electrode assembly 10 .
  • FIG. 9 is a schematic structural diagram of the second pole piece 121 provided by some embodiments of the present application.
  • the side of the second pole piece 121 that is not provided with active material may be provided with an insulating layer 1013 .
  • the intermediate component 13 between the first part 11 and the second part 12 is an isolation film
  • the second pole piece 121 is a single-sided pole piece
  • the side of the second pole piece 121 facing the first part 11 is not provided with active material.
  • the side of the current collector of the second pole piece 121 that is not coated with active material is an empty foil area.
  • the surface of the empty foil area has poor bonding effect with the isolation film, which easily causes the first part 11 and the second part 12 to interfere with each other. In severe cases, the positive electrode piece and the negative electrode piece may be short-circuited, affecting the safety and reliability of the electrode assembly 10 .
  • An insulating layer 1013 is provided on the side of the second pole piece 121 that is not provided with active material.
  • the insulating layer 1013 has a better bonding effect with the isolation film, which can increase the insulation effect between the second pole piece 121 and the first pole piece 111 , and can also reduce the risk of short circuit between the positive electrode piece and the negative electrode piece of the electrode assembly 10 .
  • the side of the first pole piece 111 not provided with active material and the side of the second pole piece 121 not provided with active material may both be provided with an insulating layer 1013 .
  • the intermediate component 13 between the first part 11 and the second part 12 is an isolation film
  • the first pole piece 111 and the second pole piece 121 are both single-sided pole pieces
  • the first pole piece 111 is not provided
  • Both the side with active material and the side of the second pole piece 121 without active material are provided with an insulating layer 1013, which can not only increase the insulation effect of the first part 11 and the second part 12, but also reduce the positive electrode of the electrode assembly 10. Risk of short circuit between pole piece and negative pole piece.
  • the insulating layer 1013 is provided on the side of the current collector of the pole piece that is not provided with active material.
  • the insulating layer 1013 is coated on the surface of the current collector.
  • the thickness of the insulating layer 1013 can be 5 to 70 ⁇ m, optionally, the thickness of the insulating layer 1013 is 7 to 10 ⁇ m.
  • the thickness of the insulating layer 1013 is selected within the above range, which can prevent coating leakage and has less impact on the mass energy density of the electrode assembly 10 . For example, when the thickness of the insulating layer 1013 is thick, the insulating layer 1013 will occupy space in the stacking direction, reducing the capacity of the active material, thereby reducing the mass energy density.
  • the intermediate component 13 is hot melt glue.
  • Hot melt adhesive (English name: Hot Glue) is a plastic adhesive. Within a certain temperature range, its physical state changes with temperature changes, but its chemical properties remain unchanged. It is non-toxic and odorless, and is an environmentally friendly chemical product. During the hot pressing process of the electrode assembly 10 , the hot melt adhesive can change into a molten state to increase the bonding effect between the first part 11 and the second part 12 .
  • the intermediate component 13 is made of hot melt glue, which not only has an insulating effect, but also can enhance the connection stability between the first part 11 and the second part 12 and reduce the risk of positional movement of the first part 11 relative to the second part 12 .
  • FIG. 10 is a schematic diagram of the binding member 14 provided by some embodiments of the present application on the first part 11 .
  • FIG. 11 is a schematic diagram of the binding member 14 provided by some embodiments of the present application on the second part 12 .
  • Figure 12 is a schematic view of the binding member 14 provided by other embodiments of the present application on the first part 11
  • Figure 13 is a schematic view of the binding member 14 provided by other embodiments of the present application on the second part 12.
  • the electrode assembly 10 may further include a binding member 14 connecting the first part 11 and the second part 12 to connect the first part 11 and the second part 12 . The risk of positional displacement of the first part 11 relative to the second part 12 is reduced.
  • the binding member 14 may be an adhesive tape to facilitate the connection of the first part 11 and the second part 12 .
  • the binding member 14 can be arranged in different positions.
  • the first part 11 and the second part 12 form a cuboid structure, and the tabs are located on one side of the cuboid structure.
  • the binding member 14 is located on the side of the cuboid structure where no tabs are provided. noodle.
  • the binding member 14 can be arranged in various ways. For example, as shown in FIGS. 10 and 11 , one end of the binding member 14 can be connected to a side of the first part 11 away from the second part 12 , and the other end of the binding member 14 can be connected to The side of the second part 12 away from the first part 11; or, both ends of the binding member 14 can be connected to the side of the first part 11 away from the second part 12; or, both ends of the binding member 14 can be connected to the second part 12. The side of the second part 12 away from the first part 11.
  • the wrapping method of the binding member 14 on the overall structure formed by the first part 11 and the second part 12 can be in various forms. As shown in FIG. 10 and FIG. 11 , the binding member 14 may not be wound in one turn; or, as shown in FIG. 12 As shown in FIG. 13 , the binding member 14 is wound around once; or, the binding member 14 is wound around more than one circle.
  • the strapping member 14 may be wound in a spiral.
  • the number of binding members 14 may be multiple, and the plurality of binding members 14 may be spaced apart to connect the first part 11 and the second part 12 at multiple locations. fixed.
  • the thickness of the binding member 14 can be 10-20 ⁇ m to reduce space occupation.
  • the width of the binding member 14 can be 5-40 mm, ensuring a large contact area with the first part 11 and the second part 12, ensuring connection strength, and at the same time lower cost.
  • FIG. 14 is a schematic diagram showing the overlap of the projection of the first negative electrode tab 113 and the projection of the second negative electrode tab 123 provided by some embodiments of the present application.
  • FIG. 15 is a schematic diagram of the third negative electrode tab 113 provided by some embodiments of the present application.
  • Figure 16 shows that the projection of the first positive electrode tab 112 and the projection of the second positive electrode tab 122 do not overlap according to some embodiments of the present application.
  • a schematic diagram showing that the projection of the first negative electrode tab 113 does not overlap with the projection of the second negative electrode tab 123 .
  • the positive electrode piece of the first part 11 includes a first positive electrode tab 112
  • the negative electrode piece of the first part 11 includes a first negative electrode tab 113
  • the second part 11 includes a first negative electrode tab 113 .
  • the positive electrode piece of 12 includes a second positive electrode tab 122, and the negative electrode piece of the second part 12 includes a second negative electrode tab 123; the electrode assembly 10 satisfies one of the following conditions: along the pole piece stacking direction, the first positive electrode tab
  • the projection of the lug 112 does not overlap with the projection of the second positive electrode lug 122, and the projection of the first negative electrode lug 113 overlaps with the projection of the second negative electrode lug 123; along the pole piece stacking direction, the projection of the first positive electrode lug 112 overlaps with the projection of the second positive electrode lug 123.
  • the projection of the second positive electrode tab 122 overlaps, and the projection of the first negative electrode tab 113 does not overlap with the projection of the second negative electrode tab 123; along the pole piece stacking direction, the projection of the first positive electrode tab 112 does not overlap with the projection of the second positive electrode tab 123.
  • the projection of 122 does not overlap, and the projection of the first negative electrode tab 113 does not overlap with the projection of the second negative electrode tab 123.
  • the pole piece 101 includes a current collector 1011 and an active material layer 1012 coated on the surface of the current collector 1011.
  • the portion of the current collector 1011 that is not coated with the active material layer 1012 is the tab.
  • the projection of the pole tab refers to the projection of the pole tab on a plane perpendicular to the pole piece stacking direction.
  • the projection of the first positive electrode tab 112 does not overlap with the projection of the second positive electrode tab 122, and the projection of the first negative electrode tab 113 overlaps with the projection of the second negative electrode tab 123" 14
  • the first positive electrode tab 112 and the second positive electrode tab 122 are arranged in a staggered manner
  • the first negative electrode tab 113 and the second negative electrode tab 123 are arranged correspondingly
  • the first negative electrode tab 113 and the second negative electrode tab 113 are arranged correspondingly.
  • the tabs 123 may be connected into one body, or the first negative tab 113 and the second negative tab 123 may be independent of each other.
  • the first part 11 and the second part 12 can share the negative electrode output part, that is, the electrode assembly 10 can only be provided with one negative electrode output part, saving components. Reduce assembly processes and reduce costs.
  • the projection of the first positive electrode tab 112 overlaps the projection of the second positive electrode tab 122, and the projection of the first negative electrode tab 113 does not overlap with the projection of the second negative electrode tab 123"
  • the first positive electrode tab 112 and the second positive electrode tab 122 are arranged correspondingly, the first negative electrode tab 113 and the second negative electrode tab 123 are arranged in an offset manner, and the first positive electrode tab 112 and the second positive electrode tab 112 are arranged in a staggered manner.
  • the tabs 122 may be connected into one body, or the first positive tab 112 and the second positive tab 122 may be independent of each other.
  • the first part 11 and the second part 12 can share the positive electrode output part, that is, the electrode assembly 10 can only be provided with one positive electrode output part, saving components. Reduce assembly processes and reduce costs.
  • the projection of the first positive electrode tab 112 does not overlap with the projection of the second positive electrode tab 122, and the projection of the first negative electrode tab 113 does not overlap with the projection of the second negative electrode tab 123"
  • the first positive electrode tab 112 and the second positive electrode tab 122 are arranged in a staggered manner
  • the first negative electrode tab 113 and the second negative electrode tab 123 are arranged in a staggered manner, so that the first part 11 has a first positive electrode output. and a second negative output part.
  • the second part 12 has a second positive output part and a second negative output part.
  • the first positive output part and the second positive output part are independent of each other.
  • the first negative output part and the second negative output part Independent of each other, the design of the electrode assembly 10 is flexible and facilitates independent charging and discharging of the first part 11 and the second part 12 .
  • the tabs of the electrode assembly 10 can be set at different positions according to different needs.
  • the first part 11 and the second part 12 can share the tabs to reduce electrode output components and save money. manufacturing cost.
  • the tabs of the first part 11 and the second part 12 may also not overlap (as shown in Figure 16) to meet the situation where the first part 11 and the second part 12 are connected in series or parallel as needed inside the electrode assembly 10 through circuit control.
  • the first part 11 and the second part 12 can be connected in parallel (the first part 11 and the second part 12 can also be connected in parallel to output a large current when they have a common lug); when the electrical equipment requires high voltage, the first part 11 and the second part 12 can be connected in series to provide high voltage and reduce the need for additional equipment.
  • the present application provides an electrochemical device 1.
  • the electrochemical device 1 includes an electrode assembly 10, a receiving member 20 and an electrolyte.
  • the electrode assembly 10 and the electrolyte are both accommodated in the receiving member 20.
  • the electrode assembly 10 of the present application and the electrolyte are directly accommodated in the same container 20, and different charging rates and mass energy density performances can be achieved in one container 20 of an electrochemical device 1.
  • the solution of this application can save processes and costs.
  • the positive electrode tab of the first part 11 includes a first positive electrode tab 112
  • the negative electrode tab of the first part 11 includes a first negative electrode tab 113
  • the positive electrode tab of the second part 12 includes a second positive electrode
  • the negative electrode tab 122 of the second part 12 includes a second negative electrode tab 123 .
  • the electrochemical device 1 satisfies the following requirements: along the stacking direction of the electrode sheets, the projection of the first positive electrode tab 112 does not overlap with the projection of the second positive electrode tab 122, and the projection of the first negative electrode tab 113 overlaps with the projection of the second negative electrode tab 123.
  • the first positive tab 112 is welded to the first positive terminal
  • the second positive tab 122 is welded to the second positive terminal
  • the first negative tab 113 and the second negative tab 123 are welded to the negative terminal
  • the first positive terminal
  • the second positive terminal and the negative terminal extend out of the receiving member 20 .
  • the projection of the first positive electrode tab 112 overlaps the projection of the second positive electrode tab 122, the projection of the first negative electrode tab 113 does not overlap with the projection of the second negative electrode tab 123, and the first negative electrode
  • the tab 113 is welded to the first negative terminal
  • the second negative tab 123 is welded to the second negative terminal
  • the first positive tab 112 and the second positive tab 122 are welded to the positive terminal
  • the first negative terminal and the second negative terminal are , the positive terminal extends out of the receiving member 20 .
  • the projection of the first positive electrode tab 112 does not overlap with the projection of the second positive electrode tab 122
  • the projection of the first negative electrode tab 113 does not overlap with the projection of the second negative electrode tab 123.
  • the first The positive tab 112 is welded to the third positive terminal
  • the second positive tab 122 is welded to the fourth positive terminal
  • the first negative tab 113 is welded to the third negative terminal
  • the second negative tab 123 is welded to the fourth negative terminal.
  • the third positive terminal, the fourth positive terminal, the third negative terminal and the fourth negative terminal extend out of the receiving member 20 .
  • the present application also provides an electrical equipment.
  • the electrical equipment includes the electrochemical device 1 of any of the above solutions.
  • the electrochemical device 1 is used to provide electric energy.
  • the electrical equipment is any of the above-mentioned equipment or systems applying the electrochemical device 1 .

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Abstract

本申请涉及一种电极组件、电化学装置及用电设备，属于储能技术领域。本申请实施例提供了一种电极组件，所述电极组件为叠片式结构，所述电极组件包括相互堆叠的第一部分和第二部分，所述第一部分和所述第二部分被配置为可独立充放电，所述第一部分的质量能量密度大于等于所述第二部分的质量能量密度，所述第一部分的充电倍率小于等于所述第二部分的充电倍率。该电极组件，既能够满足快速充电需求，还具有较高的质量能量密度。

Description

电极组件、电化学装置及用电设备 技术领域
本申请涉及储能技术领域，具体而言，涉及一种电极组件、电化学装置及用电设备。
背景技术
随着新能源技术的发展，储能器件的应用越来越广泛，例如可应用在手机、笔记本电脑、电瓶车、电动汽车、电动飞机、电动轮船、电动玩具汽车、电动玩具轮船、电动玩具飞机和电动工具等上。
电化学装置作为储能器件一般通过电极组件和电解液发生电化学反应，从而输出电能。对于电化学装置而言，充电效率和质量能量密度都是重要的性能指标。但是，现有技术中，电化学装置的充电效率和质量能量密度却无法平衡。在追求高充电效率的同时，质量能量密度则设计地较低，反之亦然。因此，如何兼顾快速充电和高质量能量密度，是亟需解决的问题。
发明内容
本申请的目的在于提供一种电极组件、电化学装置及用电设备。该电极组件，既能够满足快速充电需求，还具有较高的质量能量密度。
本申请是通过下述技术方案实现的：
第一方面，本申请实施例提供了一种电极组件，电极组件为叠片式结构，电极组件包括相互堆叠的第一部分和第二部分，第一部分和第二部分均包含堆叠设置的正极极片、隔离膜、负极极片，第一部分和第二部分被配置为可独立充放电，第一部分的质量能量密度大于等于第二部分的质量能量密度，第一部分的充电倍率小于等于第二部分的充电倍率。在上述方案中，电极组件包括相互堆叠的第一部分和第二部分，且第一部分和第二部分包括堆叠设置的正极极片、隔离膜、负极极片，第一部分和第二部分能够相互独立充放电，并且第二部分的充电倍率大于等于第一部分的充电倍率，在用户需要快速充电时，第二部分能够进行快速充电，能够满足用户的临时快速充电需求；同时，第一部分的质量能量密度大于等于第二部分的质量能量密度，可以提高电极组件整体容量，在产品待机、休眠等不需要快充时，可对第一部分进行充电，以提前储备能量，同时减少对第二部分进行频繁快充导致其循环寿命下降。该电极组件，既能够满足快速充电需求，还具有较高的质量能量密度。
根据本申请的一些实施例，第一部分的质量能量密度与第二部分的质量能量密度的比值为1.1～2.2；第一部分的充电倍率与第二部分的充电倍率比值为0.2～0.8。如果第一部分和第二部分间的质量能量密度以及充电倍率差距过小，如第一部分的质量能 量密度与第二部分的质量能量密度的比值小于1.1，第一部分的充电倍率与第二部分的充电倍率比值为大于0.8，虽然从技术上能够实现上述灵活满足不同使用需求的技术效果，但是由于第一部分和第二部分间的质量能量密度以及充电倍率差距过小，使得第一部分和第二部分的能量密度和充电能力差距过小，上述技术效果与分别制备不同性能的极片带来的备料成本增加以及将不同性能的极片组装为第一部分和第二部分造成生产成本增加相比不明显，即投入产出比较低；如果第一部分和第二部分间的质量能量密度以及充电倍率差距过大，如第一部分的质量能量密度与第二部分的质量能量密度的比值大于2.2，第一部分的充电倍率与第二部分的充电倍率比值为小于0.2，虽然能够实现上述灵活满足不同使用需求的基础技术效果，但是在同时对第一部分和第二部分充电时，第二部分的发热将远大于第一部分的发热，容易在电化学装置内部造成明显的温度分布不均，影响电化学装置内部不同电解液的性能，导致副反应发生，恶化电化学装置寿命。
优选地，第一部分的质量能量密度与第二部分的质量能量密度的比值为1.3～1.8；第一部分的充电倍率与第二部分的充电倍率比值为0.4～0.7，如此容易通过同类正极或负极材料，仅通过压实程度等调整即制备处满足上述第一部分和第二部分能量密度和充电倍率差异地极片，能极大降低备料成本，同时能兼顾同时对第一部分和第二部分充电时电化学装置内部局部温度地差异，可以更好地进行电化学装置温度管理。
根据本申请的一些实施例，第一部分的正极极片的活性物质的涂布重量大于等于第二部分的正极极片的活性物质的涂布重量，第一部分的正极极片的活性物质的压实密度大于等于第二部分的正极极片的活性物质的压实密度；第一部分的负极极片的活性物质的涂布重量大于等于第二部分的负极极片的活性物质的涂布重量，第一部分的负极极片的活性物质的压实密度大于等于第二部分的负极极片的活性物质的压实密度。在上述方案中，第一部分的正极极片的活性物质的涂布重量(单面的涂布重量)以及压实密度均大于等于第二部分的正极极片的活性物质的涂布重量和压实密度，使得第一部分的正极极片具有较多的活性物质容量，同理，第一部分的负极极片的活性物质的涂布重量以及压实密度均大于等于第二部分的负极极片的活性物质的涂布重量和压实密度，使得第一部分的负极极片具有较多的活性物质容量，从而使得第一部分的质量能量密度大于等于第二部分的质量能量密度，进而使得电极组件整体具有较高的质量能量密度，满足使用需求。
根据本申请的一些实施例，第一部分和第二部分之间设置有中间部件。在上述方案中，第一部分和第二部分通过中间部件连接，以实现第一部分和第二部分的装配。
根据本申请的一些实施例，中间部件为两面均设置有活性物质的双面极片。在上述方案中，中间部件为双面极片，中间部件能够分别与第一部分和第二部分配合使用，电极组件具有较多的活性物质容量，以提高电极组件整体容量。
根据本申请的一些实施例，双面极片面向所述第一部分一侧的活性物质的涂布重量大于等于面向第二部分一侧的活性物质的涂布重量，双面极片面向所述第一部分 一侧的活性物质的压实密度大于等于面向所述第二部分一侧的活性物质的压实密度。在上述方案中，双面极片面向第一部分一侧的活性物质的涂布重量和压实密度均大于等于双面极片面向第二部分一侧的活性物质的涂布重量和压实密度，使得双面极片面向第一部分一侧的涂布重量和压实密度能够匹配第一部分的极片的涂布重量和压实密度，双面极片面向第二部分一侧的涂布重量和压实密度能够匹配第二部分的极片的涂布重量和压实密度，使得双面极片与第一部分和第二部分形成较佳的配合。
根据本申请的一些实施例，中间部件为隔离膜。在上述方案中，隔离膜作为中间部件，可以保证电极组件结构紧凑，相对于双面极片作为中间部件，可以减少单独制备双面极片的工序，减少备料和组装成本。
根据本申请的一些实施例，当中间部件为隔离膜时，第一部分中最靠近中间部件的极片为第一极片，第二部分中最靠近中间部件的极片为第二极片，第一极片和第二极片在各自的集流体两面都设置有活性物质，且第一极片和第二极片的极性相反。在上述方案中，可以通过叠片电池中最常规的正极、隔离膜、负极依次堆叠的方式生产所述电极组件，且当同时对第一部分和第二部分充电时，第一极片和第二极片上的所有活性物质均可参与离子脱嵌，可以提高质量能量密度，达到中间部件为前述双面极片一样的提升电极组件总体容量和质量能量密度的效果。
根据本申请的一些实施例，当中间部件为隔离膜时，且第一极片和第二极片为极性相反的双面极片时，优选第一极片为负极极性，第二极片为正极极性。如此，当同时对第一部分和第二部分充电时，涂布重量更大的第一极片为负极，可以充分嵌入第二极片的锂离子而不会发生析锂。而如果第一极片为正极，第二极片为负极，由于第一极片的涂布重量更大，同时对第一部分和第二部分充电时，有可能出现第一极片脱出的锂离子过多，第二极片无法充分嵌入，导致析锂风险的情况发生，此种情况仍然能解决本申请基础的技术问题，但是对循环性能有一定的损失。
值得注意的是，在本申请的其它的一些实施例中，当中间部件为隔离膜时，第一极片和/或第二极片也可设置为单面极片，即第一极片和第二极片中至少之一靠近中间部件的一侧的集流体上未涂覆活性物质，第一极片和第二极片的极性可以相同，也可以不同。同时由于作为中间部件的隔离膜与空白的集流体的粘结效果不佳，因此，可以在呈单面极片状态的第一极片和/或第二极片与隔离膜之间设置绝缘层或粘结材料以提高第一极片和/或第二极片与隔离膜的粘结效果，提高电极组件整体的粘结稳固性，同时能够增加第一极片与第二极片的绝缘效果，还能够降低电极组件的正极极片和负极极片接触短路的风险。
同时本申请的另一些实施例中，中间部件还可以为热熔胶，在上述方案中，绝缘材料为热熔胶，既具有绝缘效果，还能够增强第一部分与第二部分的连接稳定性，降低第一部分相对于第二部分产生位置移动的风险。
根据本申请的一些实施例，第一部分的正极极片包括第一正极极耳，第一部分的负极极片包括第一负极极耳，第二部分的正极极片包括第二正极极耳，第二部分的负极极片包括第二负极极耳；电极组件满足：沿所述极片层叠方向，第一正极极耳的投影与第二正极极耳的投影不重叠，第一负极极耳的投影与第二负极极耳的投影重 叠。或，沿极片层叠方向，第一正极极耳的投影与第二正极极耳的投影重叠，第一负极极耳的投影与第二负极极耳的投影不重叠。或，沿极片层叠方向，第一正极极耳的投影与第二正极极耳的投影不重叠，第一负极极耳的投影与第二负极极耳的投影不重叠。在上述方案中，电极组件的极耳可以根据不同的需求设置在不同的位置，同时，当第一部分和第二部分同极性极耳重叠时，第一部分和第二部分可以共用极耳，以减少电极输出部件，节省制造成本；第一部分和第二部分的极耳也可以均不重叠以满足通过电路控制在电极组件内部实现第一部分和第二部分按需串联或并联的情况，以适应用电设备复杂的用电需求，例如当用电设备需要大电流时，可以将第一部分和第二部分进行并联(第一部分和第二部分有共用极耳时也可以实现二者并联输出大电流)，当用电设备需要高电压时，可以将第一部分和第二部分串联。
第二方面，本申请实施例还提供了一种电化学装置，包括第一方面实施例提供的电极组件、收容件和电解液，电极组件和电解液均容置于收容件中。在上述方案中，直接将本申请的电极组件和电解液容置在同一个收容件中，可以在一个电化学装置的一个收容件中实现不同的充电倍率和质量能量密度的性能表达，相较于采用不同的电化学装置进行串并联后再进行包装以实现上述不同的充电倍率和质量能量密度的性能表达目的的传统方式，本申请的方案可以节约工序和成本。
根据本申请的一些实施例，第一部分的正极极片包括第一正极极耳，第一部分的负极极片包括第一负极极耳，第二部分的正极极片包括第二正极极耳，第二部分的负极极片包括第二负极极耳。
电化学装置满足：沿极片层叠方向，第一正极极耳的投影与第二正极极耳的投影不重叠，第一负极极耳的投影与第二负极极耳的投影重叠，第一正极极耳焊接于第一正极端子，第二正极极耳焊接于第二正极端子，第一负极极耳和第二负极极耳焊接于负极端子，第一正极端子、第二正极端子、负极端子伸出收容件。或，沿层叠方向，第一正极极耳的投影与第二正极极耳的投影重叠，第一负极极耳的投影与第二负极极耳的投影不重叠，第一负极极耳焊接于第一负极端子，第二负极极耳焊接于第二负极端子，第一正极极耳和第二正极极耳焊接于正极端子，第一负极端子、第二负极端子、正极端子伸出收容件。或，沿极片层叠方向，第一正极极耳的投影与第二正极极耳的投影不重叠，第一负极极耳的投影与第二负极极耳的投影不重叠，第一正极极耳焊接于第三正极端子，第二正极极耳焊接于第四正极端子，第一负极极耳焊接于第三负极端子，第二负极极耳焊接于第四负极端子，第三正极端子、第四正极端子、第三负极端子、第四负极端子伸出收容件。在上述方案中，可以实现在通过一个电化学装置中按需实现串联和/或并联，极大的扩展了电化学装置的适用场景。
第三方面，本申请实施例还提供了一种用电设备，包括第二方面实施例提供的电化学装置。
本申请的附加方面和优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本申请的实践了解到。
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意图；
图2为本申请一些实施例提供的电化学装置的结构示意图；
图3为本申请一些实施例提供的电极组件的示意图；
图4为本申请一些实施例提供的极片的示意图；
图5为本申请另一些实施例提供的极片的示意图；
图6为本申请一些实施例提供的电极组件的中间部件的示意图；
图7为本申请另一些实施例提供的电极组件的中间部件的示意图；
图8为本申请一些实施例提供的第一极片的结构示意图；
图9为本申请一些实施例提供的第二极片的结构示意图；
图10为本申请一些实施例提供的捆扎件在第一部分上的示意图；
图11为本申请一些实施例提供的捆扎件在第二部分上的示意图；
图12为本申请另一些实施例提供的捆扎件在第一部分上的示意图；
图13为本申请另一些实施例提供的捆扎件在第二部分上的示意图；
图14为本申请一些实施例提供的第一负极极耳的投影与第二负极极耳的投影重叠的示意图；
图15为本申请一些实施例提供的第一正极极耳的投影与第二正极极耳的投影重叠的示意图；
图16为本申请一些实施例提供的第一正极极耳的投影与第二正极极耳的投影不重叠、第一负极极耳的投影与第二负极极耳的投影不重叠的示意图；
在附图中，附图并未按照实际的比例绘制。
标记说明：100-电池；1-电化学装置；10-电极组件；101-极片；1011-集流体；1012-活性物质层；1013-绝缘层；102-隔离膜；11-第一部分；111-第一极片；112-第一正极极耳；113-第一负极极耳；12-第二部分；121-第二极片；122-第二正极极耳；123-第二负极极耳；13-中间部件；14-捆扎件；20-收容件；21-壳体；22-端盖；23-电极端子；200-控制器；300-马达；1000-车辆。
具体实施方式
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)，同理，“多组”指的是两组以上(包括两组)，“多片”指的是两片以上(包括两片)，除非另有明确具体的限定。
在本申请实施例的描述中，除非另有明确的规定和限定，技术术语“安装”“相连”“连接”“固定”等术语应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或成一体；也可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通或两个元件的相互作用关系。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请实施例中的具体含义。
质量能量密度和充电倍率均为电化学装置的关键性能指标。现有技术中，电化学装置的极片是按照满足特定的充电能力要求进行设计的，各极片的活性物质的涂布重量和压实密度是同一水平，即，电化学装置中所有极片的充电能力是一样的。充电效率高的电化学装置，其采用的极片的厚度较薄，极片的活性物质的压实密度和涂布重量较低，电化学装置的质量能量密度较低。质量能量密度高的电化学装置，其采用的极片的厚度较厚，电化学装置的充电效率降低。也即，无法同时兼顾高质量能量密度和快速充电的需求。
鉴于此，为了同时兼顾电化学装置的高质量能量密度和快速充电的需求，本申请提供了一种电极组件，该电极组件包括两部分，一部分的质量能量密度较高、充电倍率较低，另一部分充电倍率较高、质量能量密度较底。当电化学装置急需充电时，可以单独给充电倍率高的部分充电；当电化学装置不急需充电时，可以单独给质量能量密度高的部分充电，或者同时给两部分充电。因此，该电极组件能够同时兼顾较高的质量能量密度和快速充电的需求，同时可以根据用户实际使用用电设备情况灵活调用不同部分的电极组件，提高电极组件的循环寿命。
本申请实施例提供的电极组件适用于电化学装置以及使用电化学装置的用电设备。
本申请实施例提供一种用电设备，用电设备包括电化学装置，电化学装置用于提供电能。
用电设备可以包括但不限于：车辆、手机、笔记本电脑、耳机、录像机、计算器、轮船、航天器、电动玩具等。车辆可以是燃油汽车、燃气汽车、新能源汽车、摩 托车、助力自行车等。航天器可以是飞机、火箭、航天飞机、宇宙飞船等；电动玩具可以是游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等；电动工具可以是金属切削电动工具、研磨电动工具、装配电动工具、铁道用电动工具等。本申请实施例对上述用电设备不做特殊限制。
以下实施例为了方便说明，以用电设备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的内部设置有电池100，电池100可以用于车辆1000的供电，电池100可以设置在车辆1000的底部或头部或尾部。
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。电池100可以作为车辆1000的操作电源。例如，用于车辆1000的启动、导航和行驶时的工作用电需求。电池100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。
在本申请实施例中，电池100可以包括一个或多个电化学装置1。在电池100中，若电化学装置1为多个，多个电化学装置1之间可串联或并联或混联，混联是指多个电化学装置1中既有串联又有并联。
电池100还可以包括汇流部件，多个电化学装置1之间可通过汇流部件实现电连接，以实现多个电化学装置1的串联或并联或混联。汇流部件可以是金属导体，比如，铜、铁、铝、不锈钢、铝合金等。
请参照图2，图2为本申请一些实施例提供的电化学装置1的结构示意图，电化学装置1包括电极组件10和电解液，电化学装置1通过电极组件10和电解液发生化学反应，以输出电能。
电化学装置1可以是锂离子电池、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。电化学装置1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。电化学装置1一般按封装的方式分成三种：柱形电池、方形电池和软包电池，本申请实施例对此也不限定。
在一些实施例中，请继续参照图2，电化学装置1还可以包括收容件20，收容件20用于收容电极组件10和电解液，收容件20可以是收容外壳，例如，铝壳、钢壳等。收容件20也可以是收容袋，例如，由铝塑膜制成的收容袋。
在一些实施例中，收容件20可以包括壳体21和端盖22。壳体21是用于收容电极组件10的部件，壳体21可以是一端形成开口的空心结构。壳体21可以是多种形状，比如，圆柱体、长方体等。壳体21的材质可以是多种，比如，铜、铁、铝、钢、铝合金等。端盖22是盖合于壳体21的开口以将电化学装置1的内部环境与外部环境隔绝的部件。端盖22盖合于壳体21的开口，端盖22与壳体21共同限定出用于容纳电极组件10、电解液以及其他部件的密封空间。端盖22的形状可以与壳体21的形状相适配，比如，壳体21为长方体结构，端盖22为与壳体21相适配的矩形板状结构，再如，壳体21为圆柱体结构，端盖22为与壳体21相适配的圆形板状结构。端盖22的材质也可以是多种，比如，铜、铁、铝、钢、铝合金等。
此外，端盖22上可以设置电极端子23，电极端子23用于与电极组件10电连 接，以输出电化学装置1的电能。电极端子23包括正极端子和负极端子，正极端子与电极组件10的正极极耳电连接，负极端子与电极组件10的负极极耳电连接。
请参见图3，图3示出了本申请一些实施例提供的电极组件10的示意图。本申请实施例提供了一种电极组件10。电极组件10为叠片式结构，电极组件10包括相互堆叠的第一部分11和第二部分12，第一部分11和第二部分12被配置为可独立充放电，第一部分11的质量能量密度大于等于第二部分12的质量能量密度，第一部分11的充电倍率小于等于第二部分12的充电倍率。值得注意的是，图3中的包围第一部分和第二部分的虚线框仅仅是为了在附图上更好的区分两部分以方便标识，并不表明第一部分11和第二部分12被分别封装，实际生产中，第一部分11和第二部分12属于同一个电极组件10，被整体封装在一个收容件20中，且收容件20中注入电解液，图6、图7同理。
第一部分11第二部分12电极组件10电极组件10质量能量密度的测试方法为：在制备电化学装置的过程中，可以先测出第一部分11的重量W1和第二部分12的重量W2，将电极组件10组装为电化学装置后，分别对第一部分11和第二部分12进行充放电，得到第一部分11的能量C1和第二部分12的能量C2，通过C1/W1和C2/W2计算出第一部分11和第二部分12的质量能量密度。
充电倍率是充电快慢的一种量度，是指电化学装置在规定的时间内充电至其额定容量时所需要的电流值，它在数值上等于电化学装置额定容量的倍数，即“充电电流/额定容量＝充电倍率”。测试电极组件10第一部分11和第二部分12的充电倍率采用如下方式：首先，以100～1000mA的恒定电流分别对第一部分11和第二部分12充电至一定的电压，然后再恒压充电至电流充电为20～200mA，其中，充电截止电压可以设置一定的电压梯度，如3.5～4.6V之间，每20mV～50mV设置1个梯度，对上述按照不同电压梯度充完电的电化学装置进行拆解，第一部分11和第二部分12的负极界面金黄且无析锂现象的最高的电压梯U1和U2分别为二者的满充电压，U1和U2对应的充电的容量作为第一部分11和第二部分12的额定容量C1和C2。然后设置一定的充电电流梯度，如按照0.5C1～10C1和0.5C2～10C2分别对两部分充电，每0.5C～1C设置1个梯度，对第一部分11和第二部分12分别按照不同电流梯度恒流充电至满充电压U1和U2，然后再恒压充电至电流降低至0.01C1～0.1C1/0.01C2～0.1C2(常用的截止电流值，有0.02、0.025或0.05倍的额定容量)，充电完成后对电化学装置进行拆解，第一部分11和第二部分12的负极界面金黄且无析锂现象的最高的电流梯度，或额定容量的倍数X1和X2分别作为第一部分11和第二部分12的充电倍率。
根据本申请实施例的电极组件10，电极组件10包括相互堆叠的第一部分11和第二部分12，且第一部分11和第二部分12包括堆叠设置的正极极片、隔离膜、负极极片，第一部分11和第二部分12能够相互独立充放电，并且第二部分12的充电倍率大于等于第一部分11的充电倍率，在用户需要快速充电时，第二部分12能够进行快速充电，能够满足用户的临时快速充电需求；同时，第一部分11的质量能量密度大于等于第二部分12的质量能量密度，可以提高电极组件10整体容量，在产品待机、休眠等不需要快充时，可对第一部分11进行充电，以提前储备能量，同时减少对第二部 分12进行频繁快充导致其循环寿命下降。该电极组件10，既能够满足快速充电需求，还具有较高的质量能量密度。
根据本申请的一些实施例，第一部分11的质量能量密度与第二部分12的质量能量密度的比值为1.1～2.2；第一部分11的充电倍率与第二部分12的充电倍率比值为0.2～0.8。如果第一部分11和第二部分12间的质量能量密度以及充电倍率差距过小，如第一部分11的质量能量密度与第二部分12的质量能量密度的比值小于1.1，第一部分11的充电倍率与第二部分12的充电倍率比值为大于0.8，虽然从技术上能够实现上述灵活满足不同使用需求的技术效果，但是由于第一部分11和第二部分12间的质量能量密度以及充电倍率差距过小，使得第一部分11和第二部分12的能量密度和充电能力差距过小，上述技术效果与分别制备不同性能的极片带来的备料成本增加以及将不同性能的极片组装为第一部分11和第二部分12造成生产成本增加相比不明显，即投入产出比较低；如果第一部分11和第二部分12间的质量能量密度以及充电倍率差距过大，如第一部分11的质量能量密度与第二部分12的质量能量密度的比值大于2.2，第一部分11的充电倍率与第二部分12的充电倍率比值为小于0.2，虽然能够实现上述灵活满足不同使用需求的基础技术效果，但是在同时对第一部分11和第二部分12充电时，第二部分12的发热将远大于第一部分11的发热，容易在电化学装置1内部造成明显的温度分布不均，影响电化学装置1内部不同电解液的性能，导致副反应发生，恶化电化学装置1寿命。
可选地，第一部分11的质量能量密度与第二部分12的质量能量密度的比值可以为1.1、1.2、1.3、1.4、1.5、1.6、1.7、1.8、1.9、2、2.1、2.2等；第一部分11的充电倍率与第二部分12的充电倍率比值可以为0.2、0.3、0.4、0.5、0.6、0.7、0.8等。
优选地，第一部分11的质量能量密度与第二部分12的质量能量密度的比值为1.3～1.8；第一部分11的充电倍率与第二部分12的充电倍率比值为0.4～0.7，如此容易通过同类正极或负极材料，仅通过压实程度等调整即制备处满足上述第一部分11和第二部分12能量密度和充电倍率差异地极片，能极大降低备料成本，同时能兼顾同时对第一部分11和第二部分12充电时电化学装置1内部局部温度地差异，可以更好地进行电化学装置1温度管理。
第一部分11和第二部分12各包括至少一个极片101。可选地，第一部分11和第二部分12各包括多个极片101，该多个极片101包括正极极片和负极极片，正极极片和负极极片层叠设置，金属离子在正极极片和负极极片之间移动，正极极片和负极极片之间设有隔离膜。
请参见图4和图5，图4为本申请一些实施例提供的极片101的示意图，图5为本申请另一些实施例提供的极片101的示意图。极片101包括集流体1011和涂布于集流体1011的表面的活性物质层1012，活性物质层1012位于集流体1011的厚度方向的一面或者相对的两面。如图4所示，当活性物质层1012位于集流体1011的厚度方向的一面时，该极片101为单面极片；如图5所示，当活性物质层1012位于集流体1011的厚度方向的相对的两面时，该极片101为双面极片。
正极极片包括正极集流体和正极活性物质层，正极活性物质层涂布于正极集流 体的表面，未涂布正极活性物质层的集流体凸出于已涂布正极活性物质层的集流体作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片包括负极集流体和负极活性物质层，负极活性物质层涂布于负极集流体的表面，未涂布负极活性物质层的集流体凸出于已涂布负极活性物质层的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或PE等。
根据本申请的一些实施例，第一部分11的正极极片的活性物质的涂布重量大于等于第二部分12的正极极片的活性物质的涂布重量，第一部分11的正极极片的活性物质的压实密度大于等于第二部分12的正极极片的活性物质的压实密度；第一部分11的负极极片的活性物质的涂布重量大于等于第二部分12的负极极片的活性物质的涂布重量，第一部分11的负极极片的活性物质的压实密度大于等于第二部分12的负极极片的活性物质的压实密度。如此，可以实现第一部分11和第二部分12的质量能量密度和充电倍率的差异化。第一部分11的正极极片的活性物质的材料可以与第二部分12的正极极片的活性物质的材料相同。第一部分11的负极极片的活性物质的材料可以与第二部分12的负极极片的活性物质的材料。即第一部分11和第二部分12可以采用相同种类的正负极活性物质，通过控制不同部分极片的压实密度和涂布重量实现第一部分11和第二部分12的质量能量密度和充电倍率不同。当然本领域技术人员也可以通过调整活性材料的种类结合极片制备工艺等方式结合的方式实现第一部分11和第二部分12的质量能量密度和充电倍率的差异化。需要指出的是，上述的活性物质的涂布重量是指集流体的一面的活性物质的涂布重量。
在上述方案中，第一部分11的正极极片的活性物质的涂布重量以及压实密度均大于等于第二部分12的正极极片的活性物质的涂布重量和压实密度，使得第一部分11的正极极片具有较多的活性物质容量，同理，第一部分11的负极极片的活性物质的涂布重量以及压实密度均大于等于第二部分12的负极极片的活性物质的涂布重量和压实密度，使得第一部分11的负极极片具有较多的活性物质容量，从而使得第一部分11的质量能量密度大于等于第二部分12的质量能量密度，进而使得电极组件10整体具有较高的质量能量密度，满足使用需求。
请参见图6和图7，图6为本申请一些实施例提供的电极组件10的中间部件13的示意图，图7为本申请另一些实施例提供的电极组件10的中间部件13的示意图。根据本申请的一些实施例，第一部分11和第二部分12之间设置有中间部件13。
中间部件13为设置于第一部分11和第二部分12之间的部件，中间部件13可以连接第一部分11和第二部分12，以实现第一部分11和第二部分12的装配。
根据本申请的一些实施例，如图6所示，中间部件13为两面均设置有活性物质的双面极片。双面极片是指集流体的厚度方向的两面均设置有活性物质层。双面极片可以为正极极片，或者，也可以为负极极片，相应的，本领域公知，与该双面极片相对应的第一部分11和第二部分12的极片的极性应该与双面极片的极性相反。
在上述方案中，中间部件13为双面极片，中间部件13能够分别与第一部分11和第二部分12配合使用，电极组件10具有较多的活性物质容量，以提高电极组件10整体容量。
根据本申请的一些实施例，双面极片面向第一部分11一侧的活性物质的涂布重量大于等于面向第二部分12一侧的活性物质的涂布重量，双面极片面向第一部分11一侧的活性物质的压实密度大于等于面向第二部分12一侧的活性物质的压实密度。
在上述方案中，双面极片面向第一部分11一侧的活性物质的涂布重量和压实密度均大于等于双面极片面向第二部分12一侧的活性物质的涂布重量和压实密度，使得双面极片面向第一部分11一侧的涂布重量和压实密度能够匹配第一部分11的极片的涂布重量和压实密度，双面极片面向第二部分12一侧的涂布重量和压实密度能够匹配第二部分12的极片的涂布重量和压实密度，使得双面极片与第一部分11和第二部分12形成较佳的配合，防止析锂或者容量浪费。
根据本申请的一些实施例，如图7所示，中间部件13为隔离膜。在上述方案中，采用隔离膜替代双面极片作为中间部件13，可以保证电极组件10结构紧凑，还可以减少单独制备双面极片的工序，减少备料和组装成本。
同时，当中间部件13为隔离膜时，第一部分11中最靠近中间部件13的极片为第一极片111，第二部分12中最靠近中间部件13的极片为第二极片121，第一极片111和第二极片121均为在集流体两面都设置有活性物质的双面极片，第一极片111和第二极片121的极性相反。上述方案中，可以通过叠片电池中最常规的正极、隔离膜、负极依次堆叠的方式生产电极组件10，且当同时对第一部分11和第二部分12充电时，第一极片111和第二极片121上的所有活性物质均可参与离子脱嵌，可以提高质量能量密度，达到中间部件13为前述双面极片一样的提升电极组件10总体容量和质量能量密度的效果。
第一部分11中最靠近中间部件13的极片是指，在第一部分11的多个极片中，相对于其他极片最靠近中间部件13的一个极片，该极片称为第一极片111。第二部分12中最靠近中间部件13的极片是指，在第二部分12的多个极片中，相对于其他极片最靠近中间部件13的一个极片，该极片称为第二极片121。
根据本申请的一些实施例，当中间部件13为隔离膜时，且第一极片111和第二极片121为极性相反的双面极片时，优选第一极片111为负极极性，第二极片121为正极极性。如此，当同时对第一部分11和第二部分12充电时，涂布重量更大的第一极片111为负极，可以充分嵌入第二极片121的锂离子而不会发生析锂。而如果第一极片111为正极，第二极片121为负极，由于第一极片111的涂布重量更大，同时对第一部分11和第二部分12充电时，有可能出现第一极片111脱出的锂离子过多，第二极片121无法充分嵌入，导致析锂风险的情况发生，此种情况仍然能解决本申请基础的技术问题，但是对循环性能有一定的损失。
在本申请的其它的一些实施例中，当中间部件13为隔离膜时，第一极片111和/或第二极片121也可设置为单面极片，即第一极片111和第二极片121中至少之一靠近中间部件13的一侧的集流体上未涂覆活性物质，第一极片111和第二极片121的 极性可以相同，也可以不同。第一极片111和/或第二极片121也可设置为单面极片包括以下情况：第一极片111仅在背离第二部分12的一侧设置有活性物质；或者，第二极片121仅在背离第一部分11的一侧设置有活性物质；又或者，第一极片111仅在背离第二部分12的一侧设置有活性物质和第二极片121仅在背离第一部分11的一侧设置有活性物质。
其中，第一极片111仅在背离第二部分12的一侧设置有活性物质是指，第一极片111为单面极片，第一极片111的集流体的面向第二部分12的一侧未设置有活性物质层，也即，第一极片111的集流体的面向第二部分12的一侧为空箔区，换句话说，第一极片111的面向中间部件13的一侧未设置有活性物质。第二极片121仅在背离第一部分11的一侧设置有活性物质是指，第二极片121为单面极片，第二极片121的集流体的面向第一部分11的一侧未设置有活性物质层，也即，第二极片121的集流体的面向第一部分11的一侧为空箔区，换句话说，第二极片121的面向中间部件13的一侧未设置有活性物质。由于集流体的厚度较薄，集流体通常为箔材，集流体的未涂布活性物质的区域称为空箔区。
在上述方案中，第一极片111和第二极片121中至少一者为单面极片，单面极片的面向中间部件13的一侧未设置有活性物质，虽然也能实现本发明的基础技术效果，但是由于第一极片111和/或第二极片121存在单面空箔区导致电极组件10整体质量能量密度降低。
请参见图8，图8为本申请一些实施例提供的第一极片111的结构示意图。根据本申请的一些实施例，第一极片111未设置有活性物质的一侧可以设置有绝缘层1013。
当第一部分11和第二部分12之间的中间部件13为隔离膜时，由于第一极片111为单面极片、第一极片111的面向第二部分12的一侧未设置有活性物质，第一极片111的集流体的未涂布活性物质的一侧为空箔区，空箔区的表面与隔离膜的粘接效果较差，容易导致第一部分11和第二部分12相互窜动，严重时导致正极极片和负极极片接触短路，影响电极组件10的安全可靠性。
在第一极片111的未设置有活性物质的一侧的设置绝缘层1013，绝缘层1013与隔离膜粘接效果较好，既能够增加第一极片111与第二极片121的绝缘效果，还能够降低电极组件10的正极极片和负极极片接触短路的风险。
请参见图9，图9为本申请一些实施例提供的第二极片121的结构示意图。根据本申请的一些实施例，第二极片121未设置有活性物质的一侧可以设置有绝缘层1013。
当第一部分11和第二部分12之间的中间部件13为隔离膜时，由于第二极片121为单面极片、第二极片121的面向第一部分11的一侧未设置有活性物质，第二极片121的集流体的未涂布活性物质的一侧为空箔区，空箔区的表面与隔离膜的粘接效果较差，容易导致第一部分11和第二部分12相互窜动，严重时导致正极极片和负极极片接触短路，影响电极组件10的安全可靠性。
在第二极片121的未设置有活性物质的一侧的设置绝缘层1013，绝缘层1013 与隔离膜粘接效果较好，既能够增加第二极片121与第一极片111的绝缘效果，还能够降低电极组件10的正极极片和负极极片接触短路的风险。
根据本申请的一些实施例，第一极片111未设置有活性物质的一侧和第二极片121未设置有活性物质的一侧可以均设置有绝缘层1013。
在第一部分11和第二部分12之间的中间部件13为隔离膜的实施例中，在第一极片111和第二极片121均为单面极片时，第一极片111未设置有活性物质的一侧和第二极片121未设置有活性物质的一侧均设置有绝缘层1013，既能够增加第一部分11与第二部分12的绝缘效果，还能够降低电极组件10的正极极片和负极极片接触短路的风险。
在上述设置绝缘层1013的实施例中，极片的集流体的未设置有活性物质的一侧设置绝缘层1013，绝缘层1013涂布于集流体的表面，绝缘层1013的厚度可以为5～70μm，可选地，绝缘层1013的厚度为7～10μm。绝缘层1013的厚度选取上述范围，既可以防止漏涂，还对电极组件10的质量能量密度影响较小。例如，当绝缘层1013的厚度较厚时，绝缘层1013会占用层叠方向上的空间，使得活性物质容量减少，从而降低质量能量密度。
根据本申请的一些实施例，中间部件13为热熔胶。热熔胶(英文名：Hot Glue)是一种可塑性的粘合剂，在一定温度范围内其物理状态随温度改变而改变，而化学特性不变，其无毒无味，属环保型化学产品。在电极组件10的热压过程中，热熔胶能够变为熔融状态而增加第一部分11和第二部分12的粘接效果。
在上述方案中，中间部件13为热熔胶，既具有绝缘效果，还能够增强第一部分11与第二部分12的连接稳定性，降低第一部分11相对于第二部分12产生位置移动的风险。
请参见图10至图13，图10为本申请一些实施例提供的捆扎件14在第一部分11上的示意图，图11为本申请一些实施例提供的捆扎件14在第二部分12上的示意图，图12为本申请另一些实施例提供的捆扎件14在第一部分11上的示意图，图13为本申请另一些实施例提供的捆扎件14在第二部分12上的示意图。在第一极片111和第二极片121中至少一者为单面极片的实施例中，电极组件10还可以包括捆扎件14，捆扎件14连接第一部分11和第二部分12，以降低第一部分11相对于第二部分12产生位置移动的风险。
捆扎件14可以为胶带，便于实现对第一部分11和第二部分12的连接。根据设计需求不同，捆扎件14可以设置于不同的位置，例如，第一部分11和第二部分12构成长方体结构，极耳位于该长方体结构的一面，捆扎件14位于长方体结构的未设置极耳的面。
捆扎件14的设置方式可以多种，例如，如图10和图11所示，捆扎件14的一端可以连接于第一部分11的远离第二部分12的一面，捆扎件14的另一端可以连接于第二部分12的远离第一部分11的一面；或者，捆扎件14的两端均可以连接于第一部分11的远离第二部分12的一面；又或者，捆扎件14的两端均可以连接于第二部分12的远离第一部分11的一面。
同时，捆扎件14在第一部分11和第二部分12构成的整体结构上的缠绕方式可以多种形式，如图10和图11所示，捆扎件14可以未缠绕一圈；或者，如图12和图13所示，捆扎件14缠绕一圈；又或者，捆扎件14缠绕大于一圈。
在一些实施例中，捆扎件14可以呈螺旋线缠绕。为了保证第一部分11和第二部分12的连接稳定性，捆扎件14的数量可以为多个，多个捆扎件14间隔分布，以在多个位置实现对第一部分11和第二部分12的连接固定。
需要指出的是，捆扎件14的厚度可以为10～20μm，减少空间占用。捆扎件14的宽度可以为5～40mm，保证与第一部分11和第二部分12具有较大的接触面积，保证连接强度，同时成本较低。
请参见图14至图16，图14为本申请一些实施例提供的第一负极极耳113的投影与第二负极极耳123的投影重叠的示意图，图15为本申请一些实施例提供的第一正极极耳112的投影与第二正极极耳122的投影重叠的示意图，图16为本申请一些实施例提供的第一正极极耳112的投影与第二正极极耳122的投影不重叠、第一负极极耳113的投影与第二负极极耳123的投影不重叠的示意图。
根据本申请的一些实施例，如图14至图16所示，第一部分11的正极极片包括第一正极极耳112，第一部分11的负极极片包括第一负极极耳113，第二部分12的正极极片包括第二正极极耳122，第二部分12的负极极片包括第二负极极耳123；电极组件10满足以下条件中的一者：沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影不重叠，第一负极极耳113的投影与第二负极极耳123的投影重叠；沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影重叠，第一负极极耳113的投影与第二负极极耳123的投影不重叠；沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影不重叠，第一负极极耳113的投影与第二负极极耳123的投影不重叠。
极片101包括集流体1011和涂布于集流体1011的表面的活性物质层1012，集流体1011的未涂布活性物质层1012的部分为极耳。
沿极片层叠方向，极耳的投影是指，极耳在垂直于极片层叠方向的平面上的投影。
在“沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影不重叠，第一负极极耳113的投影与第二负极极耳123的投影重叠”的实施例中，如图14所示，第一正极极耳112与第二正极极耳122错位设置，第一负极极耳113和第二负极极耳123对应设置，第一负极极耳113和第二负极极耳123可以连接于一体，或者，第一负极极耳113和第二负极极耳123可以相互独立。当第一负极极耳113和第二负极极耳123连接于一体时，第一部分11和第二部分12可以共用负极输出部，也即，电极组件10可以仅设置一个负极输出部，节省部件，减少装配工艺，降低成本。
在“沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影重叠，第一负极极耳113的投影与第二负极极耳123的投影不重叠”的实施例中，如图15所示，第一正极极耳112和第二正极极耳122对应设置，第一负极极耳113和 第二负极极耳123错位设置，第一正极极耳112和第二正极极耳122可以连接于一体，或者，第一正极极耳112和第二正极极耳122可以相互独立。当第一正极极耳112和第二正极极耳122连接于一体时，第一部分11和第二部分12可以共用正极输出部，也即，电极组件10可以仅设置一个正极输出部，节省部件，减少装配工艺，降低成本。
在“沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影不重叠，第一负极极耳113的投影与第二负极极耳123的投影不重叠”的实施例中，如图16所示，第一正极极耳112与第二正极极耳122错位设置，第一负极极耳113和第二负极极耳123错位设置，使得第一部分11具有第一正极输出部和第二负极输出部，第二部分12具有第二正极输出部和第二负极输出部，第一正极输出部和第二正极输出部相互独立，第一负极输出部和第二负极输出部相互独立，从而使得电极组件10设计灵活，便于实现第一部分11和第二部分12的独立充放电。
在上述方案中，电极组件10的极耳可以根据不同的需求设置在不同的位置，同时，当极耳重叠时，第一部分11和第二部分12可以共用极耳，以减少电极输出部件，节省制造成本。第一部分11和第二部分12的极耳也可以均不重叠(如图16所示)以满足通过电路控制在电极组件10内部实现第一部分11和第二部分12按需串联或并联的情况，以适应用电设备复杂的用电需求，例如当用电设备需要大电流时，例如电动汽车或者电动自行车启动阶段，可以将第一部分11和第二部分12进行并联(第一部分11和第二部分12有共用极耳时也可以实现二者并联输出大电流)；当用电设备需要高电压时，可以将第一部分11和第二部分12串联，以提供高电压，减少用电设备中增设相关升压电子元器件的使用，减少成本。
需要指出的是，在上述各方案中，在与极片层叠方向垂直的方向上，不重叠的不同极耳可以位于电极组件10的同一侧，也可以位于电极组件10的不同侧。可选地，为了便于实现与其他部件的连接，电极组件10的所有极耳可以设置于电极组件10的同一侧。
根据本申请的一些实施例，本申请提供了一种电化学装置1，电化学装置1包括电极组件10、收容件20和电解液，电极组件10和电解液均容置于收容件20中。在上述方案中，直接将本申请的电极组件10和电解液容置在同一个收容件20中，可以在一个电化学装置1的一个收容件20中实现不同的充电倍率和质量能量密度的性能表达，相较于采用不同的电化学装置1进行串并联后再进行包装以实现上述不同的充电倍率和质量能量密度的性能表达目的的传统方式，本申请的方案可以节约工序和成本。
根据本申请的一些实施例，第一部分11的正极极片包括第一正极极耳112，第一部分11的负极极片包括第一负极极耳113，第二部分12的正极极片包括第二正极极耳122，第二部分12的负极极片包括第二负极极耳123。
电化学装置1满足：沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影不重叠，第一负极极耳113的投影与第二负极极耳123的投影重叠，第一正极极耳112焊接于第一正极端子，第二正极极耳122焊接于第二正极端 子，第一负极极耳113和第二负极极耳123焊接于负极端子，第一正极端子、第二正极端子、负极端子伸出收容件20。或，沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影重叠，第一负极极耳113的投影与第二负极极耳123的投影不重叠，第一负极极耳113焊接于第一负极端子，第二负极极耳123焊接于第二负极端子，第一正极极耳112和第二正极极耳122焊接于正极端子，第一负极端子、第二负极端子、正极端子伸出收容件20。或，沿极片层叠方向，第一正极极耳112的投影与第二正极极耳122的投影不重叠，第一负极极耳113的投影与第二负极极耳123的投影不重叠，第一正极极耳112焊接于第三正极端子，第二正极极耳122焊接于第四正极端子，第一负极极耳113焊接于第三负极端子，第二负极极耳123焊接于第四负极端子，第三正极端子、第四正极端子、第三负极端子、第四负极端子伸出收容件20。在上述方案中，可以实现在通过一个电化学装置1中按需实现串联和/或并联，极大的扩展了电化学装置1的适用场景。
根据本申请的一些实施例，本申请还提供了一种用电设备，用电设备包括上述任一方案的电化学装置1，电化学装置1用于提供电能。用电设备为上述任一应用电化学装置1的设备或系统。
虽然已经参考优选实施例对本申请进行了描述，但在不脱离本申请的范围的情况下，可以对其进行各种改进并且可以用等效物替换其中的部件。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (14)

  1. 一种电极组件，所述电极组件为叠片式结构，所述电极组件包括相互堆叠的第一部分和第二部分，所述第一部分和所述第二部分均包含堆叠设置的正极极片、隔离膜和负极极片，所述第一部分和所述第二部分被配置为可独立充放电，所述第一部分的质量能量密度大于等于所述第二部分的质量能量密度，所述第一部分的充电倍率小于等于所述第二部分的充电倍率。
  2. 根据权利要求1所述的电极组件，其中，所述第一部分的质量能量密度与所述第二部分的质量能量密度的比值为1.1～2.2；所述第一部分的充电倍率与所述第二部分的充电倍率比值为0.2～0.8。
  3. 根据权利要求2所述的电极组件，其中，所述第一部分的质量能量密度与所述第二部分的质量能量密度的比值为1.3～1.8；所述第一部分的充电倍率与所述第二部分的充电倍率比值为0.4～0.7。
  4. 根据权利要求1所述的电极组件，其中，所述第一部分的正极极片的活性物质的涂布重量大于等于所述第二部分的正极极片的活性物质的涂布重量，所述第一部分的正极极片的活性物质的压实密度大于等于所述第二部分的正极极片的活性物质的压实密度；
    所述第一部分的负极极片的活性物质的涂布重量大于等于所述第二部分的负极极片的活性物质的涂布重量，所述第一部分的负极极片的活性物质的压实密度大于等于所述第二部分的负极极片的活性物质的压实密度。
  5. 根据权利要求1所述的电极组件，其中，所述第一部分和所述第二部分之间设置有中间部件。
  6. 根据权利要求5所述的电极组件，其中，所述中间部件为在集流体两面均设置有活性物质的双面极片。
  7. 根据权利要求6所述的电极组件，其中，所述双面极片面向所述第一部分一侧的活性物质的涂布重量大于等于面向所述第二部分一侧的活性物质的涂布重量，所述双面极片面向所述第一部分一侧的活性物质的压实密度大于等于面向所述第二部分一侧的活性物质的压实密度。
  8. 根据权利要求5所述的电极组件，其中，所述中间部件为隔离膜。
  9. 根据权利要求8所述的电极组件，其中，所述第一部分中最靠近所述中间部件的极片为第一极片，所述第二部分中最靠近所述中间部件的极片为第二极片，所述第一极片在集流体两面均设置有活性物质，所述第二极片在集流体两面均设置有活性物质，所述第一极片和第二极片的极性相反。
  10. 根据权利要求9所述的电极组件，其中，所述第一极片的极性为负极，所述第二极片的极性为正极。
  11. 根据权利要求1所述的电极组件，其中，所述第一部分的正极极片包括第一正极极耳，所述第一部分的负极极片包括第一负极极耳，所述第二部分的正极极片包括第二正极极耳，所述第二部分的负极极片包括第二负极极耳；
    所述电极组件满足：
    沿所述极片层叠方向，所述第一正极极耳的投影与所述第二正极极耳的投影不重叠，所述第一负极极耳的投影与所述第二负极极耳的投影重叠；或，
    沿所述极片层叠方向，所述第一正极极耳的投影与所述第二正极极耳的投影重叠，所述第一负极极耳的投影与所述第二负极极耳的投影不重叠；或，
    沿所述极片层叠方向，所述第一正极极耳的投影与所述第二正极极耳的投影不重叠，所述第一负极极耳的投影与所述第二负极极耳的投影不重叠。
  12. 一种电化学装置，其中，包括如权利要求1-11中任一项所述的电极组件、收容件和电解液，所述电极组件和所述电解液均容置于所述收容件中。
  13. 一种如权利要求12所述的电化学装置，其中，所述第一部分的正极极片包括第一正极极耳，所述第一部分的负极极片包括第一负极极耳，所述第二部分的正极极片包括第二正极极耳，所述第二部分的负极极片包括第二负极极耳；
    所述电极电化学装置满足：
    沿所述极片层叠方向，所述第一正极极耳的投影与所述第二正极极耳的投影不重叠，所述第一负极极耳的投影与所述第二负极极耳的投影重叠，所述第一正极极耳焊接于第一正极端子，所述第二正极极耳焊接于第二正极端子，所述第一负极极耳和所述第二负极极耳焊接于负极端子；所述第一正极端子、所述第二正极端子、所述负极端子伸出所述收容件；或，
    沿所述极片层叠方向，所述第一正极极耳的投影与所述第二正极极耳的投影重叠，所述第一负极极耳的投影与所述第二负极极耳的投影不重叠，所述第一负极极耳焊接于第一负极端子，所述第二负极极耳焊接于第二负极端子，所述第一正极极耳和所述第二正极极耳焊接于正极端子；所述第一负极端子、所述二负极端子、所述正极端子伸出所述收容件；或，
    沿所述极片层叠方向，所述第一正极极耳的投影与所述第二正极极耳的投影不重叠，所述第一负极极耳的投影与所述第二负极极耳的投影不重叠，所述第一正极极耳焊接于第三正极端子，所述第二正极极耳焊接于第四正极端子，所述第一负极极耳焊接于第三负极端子，所述第二负极极耳焊接于第四负极端子；所述第三正极端子、所述第四正极端子、所述第三负极端子、所述第四负极端子伸出所述收容件。
  14. 一种用电设备，包括如权利要求12或13所述的电化学装置。
PCT/CN2022/104997 2022-07-11 2022-07-11 电极组件、电化学装置及用电设备 WO2024011379A1 (zh)

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JPH11332023A (ja) * 1998-05-14 1999-11-30 Nissan Motor Co Ltd 電気自動車用バッテリー
JP2004031269A (ja) * 2002-06-28 2004-01-29 Nissan Motor Co Ltd 二次電池
JP2005293977A (ja) * 2004-03-31 2005-10-20 Enerstruct Kk 複合電池
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* Cited by examiner, † Cited by third party
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JPH11332023A (ja) * 1998-05-14 1999-11-30 Nissan Motor Co Ltd 電気自動車用バッテリー
JP2004031269A (ja) * 2002-06-28 2004-01-29 Nissan Motor Co Ltd 二次電池
JP2005293977A (ja) * 2004-03-31 2005-10-20 Enerstruct Kk 複合電池
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