WO2024108418A1 - 极片、电极组件、电池和用电装置 - Google Patents

极片、电极组件、电池和用电装置 Download PDF

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Publication number
WO2024108418A1
WO2024108418A1 PCT/CN2022/133693 CN2022133693W WO2024108418A1 WO 2024108418 A1 WO2024108418 A1 WO 2024108418A1 CN 2022133693 W CN2022133693 W CN 2022133693W WO 2024108418 A1 WO2024108418 A1 WO 2024108418A1
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Prior art keywords
compaction
anode
cathode
electrode sheet
active material
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PCT/CN2022/133693
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English (en)
French (fr)
Inventor
刘真威
吴译晨
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宁德时代新能源科技股份有限公司
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Priority to PCT/CN2022/133693 priority Critical patent/WO2024108418A1/zh
Publication of WO2024108418A1 publication Critical patent/WO2024108418A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the technical field of secondary batteries, and in particular to a pole piece, an electrode assembly, a battery and an electrical device.
  • secondary batteries are widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields.
  • energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields.
  • secondary batteries have made great progress, higher requirements are also put forward for the performance of secondary ion batteries.
  • the cathode electrode sheet and the anode electrode sheet need to be stacked and wound to form an electrode assembly with a cylindrical winding structure.
  • the electrode sheet expansion force inside the cylindrical winding structure electrode assembly is relatively large, which may cause the battery cell to easily have abnormal local electrolyte infiltration during the charge and discharge process, resulting in a low electrolyte infiltration rate of the battery cell.
  • the present application is made in view of the above-mentioned problems, and one of its purposes is to provide a pole piece, an electrode assembly, a battery and an electrical device, which can enable the battery including the pole piece and the electrode assembly to have a faster electrolyte infiltration rate.
  • the first aspect of the present application provides an anode pole piece, comprising an anode current collector and an anode active material layer disposed on the surface of the anode current collector, wherein the anode active material layer has a first compaction design area; in the first compaction design area, the compaction density of the anode active material layer gradually decreases and then gradually increases along the extension direction of the pole piece.
  • the expansion force of the anode active material layer on the anode pole piece during the battery charging and discharging process can be reduced, thereby effectively alleviating the problem of abnormal local electrolyte infiltration and improving the electrolyte infiltration rate of the battery.
  • the first compression design area covers the entire length of the anode electrode sheet.
  • the first compaction design area is from 6% to 80% of the total length of the anode pole piece. In this way, under the same compaction range (i.e., the difference between the maximum compaction density and the minimum compaction density in the first compaction design area), the expansion force of the anode active material layer on the anode pole piece can be better reduced, and the electrolyte infiltration rate can be better improved.
  • the first compaction design area is from 10% to 70% of the total length of the anode plate. In this way, under the same compaction range, the expansion force of the anode active material layer on the anode plate can be further reduced, and the electrolyte infiltration rate can be further increased.
  • the compaction density of the anode active material layer changes continuously along the extension direction of the anode pole piece.
  • This compaction design can effectively reduce the expansion force of the anode active material layer on the anode pole piece and improve the infiltration rate of the electrolyte.
  • the difference between the maximum and minimum compaction density of the anode active material layer along the extension direction of the anode pole piece is 0.01 g/cm 3 to 1.00 g/cm 3 . Setting the compaction density difference in the first compaction design area within the above range can better reduce the expansion force of the anode active material layer on the anode pole piece and increase the infiltration rate of the electrolyte.
  • the difference between the maximum and minimum compaction density of the anode active material layer along the extension direction of the anode electrode sheet is 0.01 g/cm 3 to 0.60 g/cm 3 . In this way, the expansion force of the anode active material layer can be better reduced, and the electrolyte infiltration rate can be further improved.
  • the compaction density of the anode active material layer at both ends of the first compaction design area and the compaction density of the anode active material layer outside the first compaction design area change continuously.
  • the compaction density of the anode active material layer changes gradually along the extension direction of the anode pole piece.
  • This compaction design can also reduce the expansion force of the anode active material layer on the anode pole piece and increase the infiltration rate of the electrolyte.
  • the number of gradients of compaction density variation of the anode active material layer is 3 to 15, and the compaction density difference between adjacent gradients is 0.01 g/cm 3 to 0.30 g/cm 3 . In this way, the effect of electrolyte infiltration rate can be further improved.
  • the length of the region where the compaction density of the anode active material layer continuously decreases is equal to the length of the region where the compaction density continuously increases. In this way, the effect of the electrolyte infiltration rate can be better improved.
  • the second aspect of the present application provides a cathode electrode sheet, including a cathode current collector and a cathode active material layer disposed on the surface of the cathode current collector, wherein the cathode active material layer has a second compaction design area; in the second compaction design area, the compaction density of the cathode active material layer gradually increases and then gradually decreases along the extension direction of the cathode electrode sheet.
  • the second compaction design area of the cathode electrode sheet can provide a certain expansion space for the anode active material layer on the anode electrode sheet, thereby effectively alleviating the problem of abnormal local electrolyte infiltration and improving the electrolyte infiltration rate of the battery.
  • the second compaction design area covers the entire length of the cathode electrode piece.
  • the second compaction design area is from 6% to 80% of the total length of the cathode electrode. In this way, under the same compaction extreme difference, the problem of abnormal local electrolyte infiltration can be better alleviated, and the electrolyte infiltration rate of the battery can be improved.
  • the second compaction design area is from 10% to 70% of the total length of the cathode electrode sheet, so as to provide better expansion space for the anode active material layer and further improve the electrolyte infiltration rate.
  • the compaction density of the cathode active material layer changes continuously along the extension direction of the cathode electrode sheet.
  • the difference between the maximum and minimum compaction density of the cathode active material layer along the extension direction of the cathode pole piece is 0.01 g/cm 3 to 1.50 g/cm 3 . Setting the compaction density difference in the second compaction design area within the above range can better provide expansion space for the anode active material layer on the matching anode pole piece, thereby improving the electrolyte infiltration rate.
  • the difference between the maximum and minimum compaction density of the cathode active material layer along the extension direction of the cathode electrode sheet is 0.01 g/cm 3 to 0.80 g/cm 3 .
  • the anode active material layer can be better provided with expansion space, further improving the electrolyte infiltration rate.
  • the compaction density of the cathode active material layer at both ends of the second compaction design area and the compaction density of the cathode active material layer outside the second compaction design area change continuously.
  • the compaction density of the cathode active material layer changes in a gradient along the extension direction of the cathode electrode sheet.
  • the number of gradients of compaction density variation of the cathode active material layer is 3 to 20, and the compaction density difference between adjacent gradients is 0.01 g/cm 3 to 0.50 g/cm 3 .
  • This arrangement can further increase the electrolyte infiltration rate.
  • the length of the region where the compaction density of the cathode active material layer increases continuously is equal to the length of the region where the compaction density decreases continuously, which can further improve the infiltration rate of the electrolyte.
  • the third aspect of the present application provides an electrode assembly, comprising an anode electrode sheet and a cathode electrode sheet, wherein the anode electrode sheet is the anode electrode sheet of the first aspect of the present application and/or the cathode electrode sheet is the cathode electrode sheet of the second aspect of the present application, which can effectively improve the infiltration rate of the battery electrolyte.
  • the anode electrode piece is the anode electrode piece of the first aspect of the present application
  • the cathode electrode piece is the cathode electrode piece of the second aspect of the present application
  • the first compaction design area on the anode electrode piece corresponds to the second compaction design area on the cathode electrode piece.
  • the electrode assembly is a cylindrical electrode assembly formed by stacking and winding the anode electrode sheet and the cathode electrode sheet.
  • the fourth aspect of the present application provides a battery, comprising a housing, an electrode assembly and an electrolyte, wherein the electrode assembly comprises the electrode assembly of the third aspect of the present application, the electrode assembly is accommodated in the inner cavity of the housing, and the electrolyte is accommodated in the inner cavity of the housing and infiltrates the electrode assembly.
  • the battery cell well solves the problem of abnormal local electrolyte infiltration during charging and discharging, and has a high electrolyte infiltration rate.
  • the fifth aspect of the present application provides an electrical device, comprising the battery of the fourth aspect of the present application.
  • the anode pole piece of the present application designs the compaction density of the first compaction design area of the anode active material layer so that the compaction density of the anode active material layer in the first compaction design area first gradually decreases and then gradually increases along the extension direction of the pole piece. This can reduce the expansion force of the anode active material layer on the anode pole piece during the charge and discharge process of the battery, thereby alleviating the problem of abnormal local electrolyte infiltration and improving the electrolyte infiltration rate of the battery.
  • the cathode electrode sheet of the present application designs the compaction density of the second compaction design area of the cathode active material layer so that the compaction density of the cathode active material layer in the second compaction design area first gradually increases and then gradually decreases along the extension direction of the electrode sheet; when the cathode electrode sheet is combined with the anode electrode sheet (especially the second compaction design area is combined with the first compaction design area of the cathode electrode sheet of the present application) to form an electrode assembly, the second compaction design area of the cathode electrode sheet can provide a certain expansion space for the anode active material layer on the anode electrode sheet, thereby effectively alleviating the problem of abnormal local electrolyte infiltration and improving the electrolyte infiltration rate of the battery.
  • FIG. 1 is a partial schematic diagram of the pairing of an anode electrode piece and a cathode electrode piece in Example 1 of the present application.
  • FIG. 2 is a partial schematic diagram of the pairing of the anode electrode piece and the cathode electrode piece in Example 2 of the present application.
  • FIG3 is a partial schematic diagram of the pairing of the anode electrode piece and the cathode electrode piece in Example 13 of the present application.
  • FIG. 4 is a partial schematic diagram of the pairing of the anode electrode piece and the cathode electrode piece in Example 14 of the present application.
  • FIG. 5 is a schematic diagram of an electrical device using a battery as a power source according to an embodiment of the present application.
  • range disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range.
  • the range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected.
  • the numerical range "a-b" represents an abbreviation of any real number combination between a and b, wherein a and b are both real numbers.
  • the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • the method may further include step (c), which means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
  • the “include” and “comprising” mentioned in this application represent open-ended or closed-ended expressions.
  • the “include” and “comprising” may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • the term "or” is inclusive.
  • the phrase “A or B” means “A, B, or both A and B”. More specifically, any of the following conditions satisfies the condition "A or B”: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
  • the cathode electrode sheet and the anode electrode sheet need to be stacked and wound to form an electrode assembly with a cylindrical winding structure.
  • the electrode sheet expansion force inside the electrode assembly is relatively large, and it is easy to have the problem of abnormal local electrolyte infiltration during the charging and discharging process, which makes the electrolyte infiltration rate of the battery low. Therefore, seeking an electrode sheet and battery structure that can effectively reduce the expansion force of the battery cell electrode sheet and increase the electrolyte infiltration rate has become one of the research directions that technicians in this field focus on.
  • the inventors have discovered a pole piece that can effectively reduce pole piece expansion force and solve the problem of abnormal local electrolyte infiltration during charging and discharging by compacting the active material layer on the current collector in a specific manner, thereby increasing the electrolyte infiltration rate of the battery.
  • a first aspect of the present application provides an anode pole piece, comprising an anode current collector and an anode active material layer disposed on the surface of the anode current collector, the anode active material layer having a first compaction design area; within the first compaction design area, the compaction density of the anode active material layer first gradually decreases and then gradually increases along the extension direction of the pole piece.
  • the anode pole piece of the present application is provided with a first compaction design area on the anode active material layer, so that the compaction density of the anode active material layer in the first compaction design area gradually decreases and then gradually increases along the extension direction of the pole piece. That is, in the first compaction design area, the compaction density of the anode active material layer at both ends in the extension direction of the pole piece is greater than the compaction density in the middle.
  • the anode active material layer on the anode pole piece has a larger expansion force in the area near the middle of the pole piece along the length direction during the charge and discharge process, and the expansion force at both ends is relatively small; accordingly, the expansion rate of the anode active material layer near the middle is also relatively large.
  • the compaction density first gradually decreases and then gradually increases along the extension direction of the pole piece can mean first continuously decreasing and then continuously increasing, or first decreasing according to a certain gradient and then increasing according to a certain gradient.
  • the compaction design can be formed by uniformly coating the anode active material on the upper and lower surfaces of the anode current collector and drying them, and then rolling the anode active material on the upper and lower surfaces by a rolling device. By adjusting the gap between the upper and lower rollers of the rolling device, the compaction density of each part can be adjusted.
  • the first compaction design area covers the entire length of the anode pole piece. That is, the first compaction design area runs through the entire anode pole piece from the starting point to the end point in the extension direction. In other words, the anode active material layer on the anode pole piece is compacted and designed according to the above rules.
  • the first compaction design area is from 6% to 80% of the total length of the anode pole piece. That is, the first compaction design area only includes a portion of the total length of the anode pole piece; that is, only the area from 6% to 80% of the length of the starting point of the length direction of the anode pole piece is compacted and designed.
  • the starting point of the anode pole piece in the extension direction is defined as the 0% length position, and the end point is defined as the 100% length position.
  • the expansion force of the anode active material layer on the anode pole piece is not consistent in the charging and discharging process, but the expansion of the anode active material layer is relatively large in the region from 6% to 80% of the total length of the anode pole piece.
  • the expansion force of the anode active material layer on the anode pole piece can be better reduced under the same compaction range (i.e., the difference between the maximum compaction density and the minimum compaction density in the first compaction design region), and the electrolyte infiltration rate can be better improved.
  • the first compaction design area is from 10% to 70% of the total length of the anode pole piece. Further research has found that setting the first compaction design area from 10% to 70% of the total length of the anode pole piece can further reduce the expansion force of the anode active material layer and further increase the electrolyte infiltration rate.
  • the first compaction design area occupies the full width of the anode pole piece, that is, the first compaction design area covers the entire width of the anode pole piece.
  • the compaction density of the anode active material layer changes continuously along the extension direction of the anode pole piece. That is, within the first compaction design area, the compaction density of the anode active material layer along the extension direction of the anode pole piece is continuous, and there is no sudden change in compaction density.
  • the compaction density within the first compaction design area can change in the manner of a certain mathematical function, such as a linear change, a quadratic function change, and the like.
  • the difference in compaction density of the anode active material layer along the extension direction of the anode pole piece (the difference between the maximum value and the minimum value, i.e., the compaction range) is 0.01 g/cm 3 to 1.00 g/cm 3 .
  • the difference in compaction density between the maximum and minimum compaction densities of the anode active material layer is 0.01 g/cm 3 to 1.00 g/cm 3 .
  • the difference between the maximum and minimum compaction density of the anode active material layer along the extension direction of the anode electrode sheet may be, but is not limited to, 0.01 g/cm 3 , 0.05 g/cm 3 , 0.10 g/cm 3 , 0.20 g/cm 3 , 0.30 g/cm 3 , 0.40 g/cm 3 , 0.50 g/cm 3 , 0.60 g/cm 3 , 0.70 g/cm 3 , 0.80 g/cm 3 , 0.90 g/cm 3 , or 1.00 g/cm 3 .
  • the difference between the maximum and minimum compaction density of the anode active material layer along the extension direction of the anode electrode sheet is 0.01 g/cm 3 to 0.60 g/cm 3 . Further research has found that setting the compaction density difference in the first compaction design area within the above range can better reduce the expansion force of the anode active material layer and further improve the electrolyte infiltration rate.
  • the compaction density of the anode active material layer at both ends of the first compaction design area and the compaction density of the anode active material layer outside the first compaction design area continuously change.
  • the compaction density of the anode active material layer at both ends of the first compaction design area and the compaction density of the anode active material layer outside the first compaction design area continuously transition, and there is no sudden change in compaction density.
  • the compaction density of the anode active material layer changes in a gradient along the extension direction of the anode pole piece. That is, within the first compaction design area, the compaction density of the anode active material layer along the extension direction of the anode pole piece is discontinuous, but changes according to multiple gradients, and the compaction density of each gradient may be different.
  • This compaction design can also reduce the expansion force of the anode active material layer on the anode pole piece and increase the infiltration rate of the electrolyte.
  • the number of gradients of compaction density variation of the anode active material layer is 3 to 15, and the compaction density difference between adjacent gradients is 0.01 g/cm 3 to 0.30 g/cm 3 .
  • the number of gradients of compaction density variation of the anode active material layer in the first compaction design area may be, but is not limited to, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15.
  • the compaction density difference between adjacent gradients may be, but is not limited to, 0.01 g/cm 3 , 0.02 g/cm 3 , 0.05 g/cm 3 , 0.08 g/cm 3 , 0.10 g/cm 3 , 0.12 g/cm 3 , 0.15 g/cm 3 , 0.18 g/ cm 3 , 0.20 g/cm 3 , 0.22 g/cm 3 , 0.25 g/cm 3 , 0.28 g / cm 3 , 0.30 g/cm 3 .
  • the length of the area where the compaction density of the anode active material layer decreases continuously is equal to the length of the area where the compaction density increases continuously.
  • the compaction density of the anode active material layer is symmetrically distributed along the cross section in the first compaction design area perpendicular to the extension direction of the anode electrode sheet. That is, the compaction densities of the anode active material layers on both sides of the cross section in the first compaction design area correspond to each other, and the compaction densities at the same distance on both sides of the middle cross section are equal.
  • the second aspect of the present application provides a cathode electrode sheet, comprising a cathode current collector and a cathode active material layer disposed on the surface of the cathode current collector, the cathode active material layer having a second compaction design area; within the second compaction design area, the compaction density of the cathode active material layer first gradually increases and then gradually decreases along the extension direction of the cathode electrode sheet.
  • the cathode pole piece of the present application is provided with a second compaction design area on the cathode active material layer, so that the compaction density of the cathode active material layer in the second compaction design area gradually increases and then gradually decreases along the extension direction of the pole piece. That is, in the second compaction design area, the compaction density of the cathode active material layer at both ends in the extension direction of the pole piece is less than the compaction density in the middle.
  • the thickness of the cathode active material layer at both ends of the second compaction design area is greater than the thickness in the middle.
  • the second compaction design area of the cathode pole piece can provide a certain expansion space for the anode active material layer on the anode pole piece, thereby effectively alleviating the problem of abnormal local electrolyte infiltration and improving the electrolyte infiltration rate of the battery.
  • the cathode electrode piece can be used in conjunction with the anode electrode piece of the first aspect of the present application to form an electrode assembly, or it can be used in conjunction with an ordinary anode electrode piece to form an electrode assembly.
  • the cathode electrode piece is used in conjunction with the anode electrode piece of the first aspect of the present application, so that on the one hand, the compaction design in the first compaction design area can reduce the expansion of the anode active material layer, and at the same time, the compaction design in the second compaction design area can provide a certain expansion space for the anode active material layer.
  • the two aspects work together to more effectively improve the infiltration rate of the battery electrolyte.
  • the cathode electrode piece is used in conjunction with the anode electrode piece of the first aspect of the present application, it is preferred that the positions of the first compaction design area and the second compaction design area correspond to each other.
  • the above compaction design can be formed by uniformly coating the cathode active material on the upper and lower surfaces of the cathode current collector and drying them, and then rolling the cathode active material on the upper and lower surfaces by a rolling device. By adjusting the gap between the upper and lower rollers of the rolling device, the compaction density of each part can be adjusted.
  • the second compaction design area is the entire length of the cathode plate. That is, the second compaction design area runs through the entire length direction of the cathode plate from the starting point to the end point. In other words, the cathode active material layer on the cathode plate is compacted and designed according to the above rules.
  • the second compaction design area is from 6% to 80% of the total length of the cathode plate. That is, the second compaction design area only includes a portion of the total length of the cathode plate; that is, only the area from 6% to 80% of the length of the starting point of the length direction of the cathode plate is compacted and designed.
  • the starting position of the cathode electrode in the length direction is defined as the 0% length position, and the end position is defined as the 100% length position.
  • the expansion force of the anode active material layer on the anode pole piece is not uniform at all locations, but the expansion of the anode active material layer is relatively large in the region from 6% to 80% of the total length of the anode pole piece.
  • the second compaction design region is set to the 6% to 80% length of the total length of the cathode pole piece, under the same compaction range (i.e., the difference between the maximum compaction density and the minimum compaction density in the second compaction design region)
  • the anode pole piece matched with the cathode pole piece can be better provided with expansion space, thereby better improving the electrolyte infiltration rate.
  • the second compaction design area is from 10% to 70% of the total length of the cathode electrode piece. Setting the second compaction design area from 10% to 70% of the total length of the cathode electrode piece can better provide expansion space for the anode active material layer and further improve the electrolyte infiltration rate.
  • the second compaction design area occupies the full width of the cathode electrode sheet, that is, the second compaction design area covers the entire width of the cathode electrode sheet.
  • the compaction density of the cathode active material layer changes continuously along the extension direction of the cathode pole piece. That is, within the second compaction design area, the compaction density of the cathode active material layer along the extension direction of the cathode pole piece is continuous, and there is no sudden change in compaction density.
  • the compaction density within the second compaction design area can change in the manner of a certain mathematical function, such as a linear change, a quadratic function change, and the like.
  • the difference between the maximum and minimum values of the compaction density of the cathode active material layer along the extension direction of the cathode pole piece is 0.01 g/cm 3 to 1.50 g/cm 3.
  • the difference between the compaction density of the cathode active material layer at the maximum and minimum points is 0.01 g/cm 3 to 1.50 g/cm 3. Setting the compaction density difference in the second compaction design area within the above range can better provide expansion space for the anode active material layer on the anode pole piece used in conjunction, thereby increasing the infiltration rate of the electrolyte.
  • the difference between the maximum and minimum compaction density of the cathode active material layer along the extension direction of the cathode electrode sheet may be, but is not limited to, 0.01 g/cm 3 , 0.05 g/cm 3 , 0.10 g/cm 3 , 0.20 g/cm 3 , 0.30 g/cm 3 , 0.40 g/cm 3 , 0.50 g/cm 3 , 0.60 g/cm 3 , 0.70 g/cm 3 , 0.80 g/cm 3 , 0.90 g/cm 3 , 1.00 g/cm 3 , 1.10 g/cm 3 , 1.20 g/cm 3 , 1.30 g/cm 3 , 1.40 g /cm 3 , 1.50 g/cm 3 .
  • the difference between the maximum and minimum compaction density of the cathode active material layer along the extension direction of the cathode electrode sheet is 0.01 g/cm 3 to 0.80 g/cm 3. Further research has found that setting the compaction density difference in the second compaction design area within the above range can better provide expansion space for the anode active material layer and further improve the electrolyte infiltration rate.
  • the compaction density of the cathode active material layer at both ends of the second compaction design area and the compaction density of the cathode active material layer outside the second compaction design area continuously change.
  • the compaction density of the cathode active material layer at both ends of the second compaction design area and the compaction density of the cathode active material layer outside the second compaction design area continuously transition, and there is no sudden change in compaction density.
  • the compaction density of the cathode active material layer changes in a gradient along the extension direction of the cathode pole piece. That is, within the second compaction design area, the compaction density of the cathode active material layer along the extension direction of the cathode pole piece is discontinuous, but changes according to multiple gradients, and the compaction density of each gradient may be different.
  • This compaction design can also provide expansion space for the anode active material layer on the anode pole piece and improve the infiltration rate of the electrolyte.
  • the number of gradients of compaction density variation of the cathode active material layer is 3 to 20, and the compaction density difference between adjacent gradients is 0.01 g/cm 3 to 0.50 g/cm 3 .
  • the number of gradients of the compaction density change of the cathode active material layer in the second compaction design area can be but not limited to 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20.
  • the compacted density difference between adjacent gradients may be, but is not limited to, 0.01 g/cm 3 , 0.02 g/cm 3 , 0.05 g/cm 3 , 0.08 g/cm 3 , 0.10 g/cm 3 , 0.12 g/cm 3 , 0.15 g/cm 3 , 0.18 g/cm 3 , 0.20 g/cm 3 , 0.22 g/cm 3 , 0.25 g/cm 3 , 0.28 g/cm 3 , 0.30 g/cm 3 , 0.32 g/cm 3 , 0.34 g/cm 3 , 0.36 g/cm 3 , 0.38 g/cm 3 , 0.40 g/cm 3
  • the length of the area where the compaction density of the cathode active material layer increases continuously is equal to the length of the area where the compaction density decreases continuously.
  • the compaction density of the cathode active material layer is symmetrically distributed along the cross section in the second compaction design area perpendicular to the extension direction of the cathode electrode sheet. That is, the compaction densities of the cathode active material layers on both sides of the cross section in the second compaction design area correspond to each other, and the compaction densities at the same distance on both sides of the middle cross section are equal.
  • the third aspect of the present application provides an electrode assembly, comprising an anode electrode sheet and a cathode electrode sheet, wherein the anode electrode sheet is the anode electrode sheet of the first aspect of the present application and/or the cathode electrode sheet is the cathode electrode sheet of the second aspect of the present application.
  • the anode electrode sheet of the electrode assembly is the anode electrode sheet of the first aspect of the present application, and the cathode electrode sheet adopts a common cathode electrode sheet, that is, the compaction density of the cathode active material layer on the cathode electrode sheet is consistent everywhere.
  • the anode electrode of the electrode assembly is a common anode electrode, that is, the compaction density of the anode active material layer on the anode electrode is consistent everywhere, and the cathode electrode is the cathode electrode of the second aspect of the present application.
  • the anode electrode sheet of the electrode assembly adopts the anode electrode sheet of the first aspect of the present application
  • the cathode electrode sheet adopts the cathode electrode sheet of the second aspect of the present application.
  • the infiltration rate of the battery electrolyte can be effectively improved by the compaction density design in the first compaction design area and the second compaction design area.
  • the anode pole piece of the first aspect of the present application and the cathode pole piece of the second aspect of the present application are matched and combined to form an electrode assembly, and the infiltration rate of the electrolyte can be better improved by matching the compaction density design of the first compaction design area and the second compaction design area.
  • the electrode assembly is a cylindrical electrode assembly formed by stacking and winding the anode electrode sheet and the cathode electrode sheet.
  • the expansion of the electrode active material during the charge and discharge process is more likely to cause the problem of abnormal local electrolyte infiltration.
  • the use of the structural design of the present application in a cylindrical electrode assembly can well alleviate the abnormal local electrolyte infiltration.
  • the fourth aspect of the present application provides a battery, comprising a housing, an electrode assembly and an electrolyte, wherein the housing has an inner cavity, the electrode assembly comprises the electrode assembly of the third aspect of the present application, the electrode assembly is accommodated in the inner cavity of the housing, and the electrolyte is accommodated in the inner cavity of the housing and infiltrates the electrode assembly.
  • the battery cell of the present application solves the problem of abnormal local electrolyte infiltration during charging and discharging, and has a high electrolyte infiltration rate.
  • the fifth aspect of the present application provides an electrical device, comprising the battery of the fourth aspect of the present application, wherein the battery serves as a power source for the electrical device to provide electrical energy for the electrical device.
  • a battery includes a cathode plate 2, an anode plate 1, an electrolyte and a separator.
  • active ions are embedded and removed back and forth between the cathode plate 2 and the anode plate 1.
  • the electrolyte plays a role in conducting ions between the cathode plate 2 and the anode plate 1.
  • the separator is arranged between the cathode plate 2 and the anode plate 1, mainly to prevent the cathode and anode from short-circuiting, while allowing ions to pass through.
  • the cathode electrode sheet 2 includes a cathode current collector 21 and a cathode film layer (ie, a cathode active material layer 22 ) disposed on at least one surface of the cathode current collector 21 , wherein the cathode film layer includes a cathode active material.
  • a cathode film layer ie, a cathode active material layer 22
  • the cathode current collector 21 has two surfaces opposite to each other in its thickness direction, and the cathode film layer is disposed on any one or both of the two opposite surfaces of the cathode current collector 21 .
  • the cathode current collector 21 may be a metal foil or a composite current collector.
  • aluminum foil may be used as the metal foil.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector may be formed by forming a metal material on a polymer material substrate.
  • the metal material includes but is not limited to aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • Polymer material substrate such as substrates of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • the cathode active material may include a cathode active material for a battery known in the art.
  • the cathode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds.
  • the present application is not limited to these materials, and other conventional materials that can be used as battery cathode active materials may also be used. These cathode active materials may be used alone or in combination of two or more.
  • lithium transition metal oxides may include, but are not limited to , lithium cobalt oxide (such as LiCoO2 ), lithium nickel oxide (such as LiNiO2 ), lithium manganese oxide (such as LiMnO2 , LiMn2O4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333 ), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523 ) , LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211 ) , LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622 ), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05
  • lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate and carbon
  • the weight ratio of the cathode active material in the cathode film layer is 80 wt % to 100 wt %, based on the total weight of the cathode film layer.
  • the cathode film layer may further include a binder.
  • the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer
  • the cathode film layer may further include a conductive agent.
  • the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the weight ratio of the conductive agent in the cathode film layer is 0 wt % to 20 wt %, based on the total weight of the cathode film layer.
  • the cathode electrode sheet 2 can be prepared in the following manner: the above-mentioned components for preparing the cathode electrode sheet 2, such as cathode active materials, conductive agents, binders and any other components, are dispersed in a solvent (such as N-methylpyrrolidone) to form a cathode slurry, wherein the cathode slurry has a solid content of 40wt% to 80wt%, and the viscosity at room temperature is adjusted to 5000mPa ⁇ s to 25000mPa ⁇ s, the cathode slurry is coated on the surface of the cathode current collector 21, and after drying, the cathode electrode sheet 2 is formed by cold pressing through a cold rolling mill.
  • a solvent such as N-methylpyrrolidone
  • a second compaction design area 23 is further provided on the cathode active material layer 22 of the cathode plate 2.
  • the compaction density is designed in the second compaction design area 23 in accordance with a specific method of the present application. Some examples of the cathode plate 2 are shown in FIGS. 1 to 4 .
  • the anode electrode sheet 1 includes an anode current collector 11 and an anode film layer (ie, an anode active material layer 12 ) disposed on at least one surface of the anode current collector 11 , wherein the anode film layer includes an anode active material.
  • anode film layer ie, an anode active material layer 12
  • the anode current collector 11 has two surfaces opposite to each other in its thickness direction, and the anode film layer is disposed on any one or both of the two opposite surfaces of the anode current collector 11 .
  • the anode current collector 11 may be a metal foil or a composite current collector.
  • copper foil may be used as the metal foil.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate.
  • the composite current collector may be formed by forming a metal material on a polymer material substrate.
  • the metal material includes but is not limited to copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • the polymer material substrate includes but is not limited to polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE) and other substrates.
  • the anode active material may be an anode active material for a battery known in the art.
  • the anode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • the present application is not limited to these materials, and other traditional materials that can be used as battery anode active materials may also be used. These anode active materials may be used alone or in combination of two or more.
  • the anode film layer may further include a binder.
  • the binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • SBR styrene-butadiene rubber
  • PAA polyacrylic acid
  • PAAS sodium polyacrylate
  • PAM polyacrylamide
  • PVA polyvinyl alcohol
  • SA sodium alginate
  • PMAA polymethacrylic acid
  • CMCS carboxymethyl chitosan
  • the anode film layer may further include a conductive agent.
  • the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the weight ratio of the conductive agent in the anode film layer is 0 wt % to 20 wt %, based on the total weight of the anode film layer.
  • the anode film layer may further include other additives, such as a thickener (such as sodium carboxymethyl cellulose (CMC-Na)), etc.
  • a thickener such as sodium carboxymethyl cellulose (CMC-Na)
  • the weight ratio of the other additives in the anode film layer is 0 wt % to 15 wt %, based on the total weight of the anode film layer.
  • the anode electrode sheet can be prepared in the following manner: the above-mentioned components for preparing the anode electrode sheet, such as the anode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form an anode slurry, wherein the anode slurry has a solid content of 30wt% to 70wt%, and the viscosity at room temperature is adjusted to 2000mPa ⁇ s to 10000mPa ⁇ s; the obtained anode slurry is coated on the anode current collector 11, and after a drying process, cold pressing such as rolling is performed to obtain the anode electrode sheet 1.
  • a solvent such as deionized water
  • a first compaction design area 13 is further provided on the anode active material layer 12 of the anode pole piece 1.
  • the compaction density is designed in the first compaction design area 13 according to a specific method of the present application. Some examples of the anode pole piece 1 are shown in FIGS. 1 to 4 .
  • the electrolyte plays a role in conducting ions between the cathode electrode 2 and the anode electrode 1.
  • the present application has no specific restrictions on the type of electrolyte, which can be selected according to needs.
  • the electrolyte can be liquid, gel or all-solid.
  • the electrolyte is an electrolyte comprising an electrolyte salt and a solvent.
  • the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.
  • the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the electrolyte may further include additives, such as anode film-forming additives, cathode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, and additives that improve battery high or low temperature performance.
  • additives such as anode film-forming additives, cathode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, and additives that improve battery high or low temperature performance.
  • the battery further includes a separator.
  • the present application has no particular limitation on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation.
  • the materials of each layer can be the same or different, without particular limitation.
  • the isolation film has a thickness of 6 ⁇ m to 40 ⁇ m, and may be 12 ⁇ m to 20 ⁇ m.
  • the cathode electrode sheet 2 , the anode electrode sheet 1 , and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the battery may include an outer packaging, which may be used to encapsulate the electrode assembly and the electrolyte.
  • the outer packaging of the battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the battery may also be a soft package, such as a bag-type soft package.
  • the material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
  • the present application has no particular limitation on the shape of the secondary battery, which may be cylindrical, square, or any other shape.
  • the outer package may include a shell and a cover plate.
  • the shell may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell has an opening connected to the receiving cavity, and the cover plate can be covered on the opening to close the receiving cavity.
  • the cathode electrode sheet 2, the anode electrode sheet 1 and the isolation film can form an electrode assembly through a winding process or a lamination process.
  • the electrode assembly is encapsulated in the receiving cavity.
  • the electrolyte is infiltrated in the electrode assembly.
  • the number of electrode assemblies contained in the battery can be one or more, and those skilled in the art can select according to specific actual needs.
  • batteries may be assembled into a battery module.
  • the number of batteries contained in the battery module may be one or more. The specific number may be selected by those skilled in the art according to the application and capacity of the battery module.
  • the multiple batteries can be arranged in sequence along the length direction of the battery module. Of course, they can also be arranged in any other manner. Further, the multiple batteries can be fixed by fasteners.
  • the battery module may further include a housing having a receiving space, and the plurality of batteries are received in the receiving space.
  • the battery modules described above may also be assembled into a battery pack.
  • the battery pack may contain one or more battery modules, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.
  • the battery pack may include a battery box and a plurality of battery modules disposed in the battery box.
  • the battery box includes an upper box body and a lower box body, and the upper box body can be covered on the lower box body to form a closed space for accommodating the battery modules.
  • the plurality of battery modules can be arranged in the battery box in any manner.
  • the present application also provides an electric device 3, which includes at least one of the batteries, battery modules or battery packs provided in the present application.
  • the battery, battery module or battery pack can be used as a power source for the electric device 3, or as an energy storage unit for the electric device 3.
  • the electric device 3 may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited thereto.
  • a battery, a battery module or a battery pack can be selected according to its usage requirements.
  • Fig. 5 is an example of an electric device 3.
  • the electric device 3 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.
  • a battery pack or a battery module can be used.
  • the device may be a mobile phone, a tablet computer, a notebook computer, etc.
  • the device is usually required to be thin and light, and a battery may be used as a power source.
  • Embodiment 1 is a diagrammatic representation of Embodiment 1:
  • the compaction range design is achieved by the periodic change of the gap between the upper and lower rollers. The pole piece after drying is rolled with a roller press, and the length of the single battery pole piece is used as a rolling cycle. The compaction setting length range is 0% to 100% of the full length of the pole piece, the compaction range is 0.3g/ cm3 , and the pole piece thickness in the compaction design area changes continuously from 0.134mm to 0.161mm and then to 0.134mm.
  • the coated copper foil is placed in an oven and baked at 120°C for 30min, and the dried electrode is rolled with a roller press to a uniform thickness of 0.191mm.
  • the cathode and anode pole pieces and the separator are paired and wound, followed by pole ear shaping, laser welding of adapter pieces, top cover welding, liquid injection, and sealing pin welding to complete the battery cell assembly.
  • a partial schematic diagram of pairing the cathode pole piece and the anode pole piece of this embodiment to form an electrode assembly is shown in FIG1 .
  • test current and cut-off voltage can be modified according to actual measurement, application requirements, and the actual chemical system and health status of the battery cell.
  • the LFP battery cell was discharged to 2.5V at a rate of 1C, and the time required from discharge cut-off (i.e., discharge to 2.5V) to electrolyte level equilibrium (the unchanged electrolyte level before and after 2 hours represents liquid level equilibrium) was recorded.
  • the test results are shown in Table 1.
  • Embodiment 2 is a diagrammatic representation of Embodiment 1:
  • the same pole piece formula, coating process and battery cell assembly method as in Example 1 are used.
  • the anode pole piece compression setting length interval is 6% to 80% of the pole piece full length, the compression range is 0.3g/cm 3 , and the pole piece thickness in the compression design area changes continuously from 0.134mm to 0.161mm and then to 0.134mm; the cathode pole piece is rolled to a uniform thickness of 0.191mm by a roller press.
  • FIG2 A partial schematic diagram of the cathode pole piece and the anode pole piece of this embodiment when paired to form an electrode assembly is shown in FIG2 .
  • Embodiment 3 is a diagrammatic representation of Embodiment 3
  • the same pole piece formula, coating process and battery cell assembly method as those in Example 1 were used.
  • the anode pole piece was compacted to a length interval of 10% to 70% of the total length of the pole piece, the compaction range was 0.3 g/cm 3 , and the pole piece thickness in the compaction design area varied continuously from 0.134 mm to 0.161 mm and then to 0.134 mm.
  • the cathode pole piece was rolled to a uniform thickness of 0.191 mm by a roller press.
  • Embodiment 4 is a diagrammatic representation of Embodiment 4:
  • the same pole piece formula, coating process and battery cell assembly method as those in Example 1 were used.
  • the anode pole piece was compacted to a length interval of 20% to 50% of the total length of the pole piece, the compaction range was 0.3 g/cm 3 , and the pole piece thickness in the compaction design area varied continuously from 0.134 mm to 0.161 mm and then to 0.134 mm.
  • the cathode pole piece was rolled to a uniform thickness of 0.191 mm by a roller press.
  • Embodiment 5 is a diagrammatic representation of Embodiment 5:
  • the same pole piece formula, coating process and battery cell assembly method as those in Example 1 were used.
  • the anode pole piece was compacted to a length interval of 30% to 40% of the total length of the pole piece, the compaction range was 0.3 g/cm 3 , and the pole piece thickness in the compaction design area varied continuously from 0.134 mm to 0.161 mm and then to 0.134 mm.
  • the cathode pole piece was rolled to a uniform thickness of 0.191 mm by a roller press.
  • Embodiment 6 is a diagrammatic representation of Embodiment 6
  • Example 2 The same pole piece formula, coating process and battery cell assembly method as in Example 1 were used.
  • the anode pole piece was compacted to a length interval of 6% to 80% of the total length of the pole piece, the compaction range was 0.1 g/cm 3 , and the pole piece thickness in the compaction design area varied continuously from 0.134 mm to 0.161 mm and then to 0.134 mm.
  • the cathode pole piece was rolled to a uniform thickness of 0.191 mm by a roller press.
  • Embodiment 7 is a diagrammatic representation of Embodiment 7:
  • Example 2 The same pole piece formula, coating process and battery cell assembly method as in Example 1 were used.
  • the anode pole piece was compacted and set to a length interval of 6% to 80%, with a compaction range of 0.2 g/cm 3 .
  • the pole piece thickness in the compaction design area varied continuously from 0.134 mm to 0.161 mm and then to 0.134 mm.
  • the cathode pole piece was rolled to a uniform thickness of 0.191 mm by a roller press.
  • Embodiment 8 is a diagrammatic representation of Embodiment 8
  • the same pole piece formula, coating process and battery cell assembly method as in Example 1 were used.
  • the cathode pole piece compression setting length interval was 0% to 100%, the compression range was 0.3 g/cm 3 , and the pole piece thickness in the compression design area changed continuously from 0.213 mm to 0.191 mm and then to 0.213 mm.
  • the anode pole piece was rolled to a constant thickness of 0.134 mm by a roller press.
  • Embodiment 9 is a diagrammatic representation of Embodiment 9:
  • the same pole piece formula, coating process and battery cell assembly method as in Example 1 were used.
  • the cathode pole piece compression length interval was 6% to 80%, the compression range was 0.3 g/cm 3 , and the pole piece thickness in the compression design area changed continuously from 0.213 mm to 0.191 mm and then to 0.213 mm.
  • the anode pole piece was rolled to a constant thickness of 0.134 mm by a roller press.
  • Embodiment 10 is a diagrammatic representation of Embodiment 10:
  • the same pole piece formula, coating process and battery cell assembly method as in Example 1 were used.
  • the cathode pole piece compression length interval was 6% to 80%, the compression range was 0.1 g/cm 3 , and the pole piece thickness in the compression design area changed continuously from 0.198 mm to 0.191 mm and then to 0.198 mm.
  • the anode pole piece was rolled to a constant thickness of 0.134 mm by a roller press.
  • Embodiment 11 is a diagrammatic representation of Embodiment 11:
  • the same pole piece formula, coating process and battery cell assembly method as those in Example 1 were adopted.
  • the compression setting length intervals of the anode pole piece and the cathode pole piece were both 0% to 100%.
  • the compression range of the anode pole piece was 0.3 g/cm 3 , and the pole piece thickness in the compression design area changed continuously from 0.134 mm to 0.161 mm and then to 0.134 mm;
  • the compression range of the cathode pole piece was 0.3 g/cm 3 , and the pole piece thickness in the compression design area changed continuously from 0.213 mm to 0.191 mm and then to 0.213 mm.
  • Embodiment 12 is a diagrammatic representation of Embodiment 12
  • Example 2 The same pole piece formula, coating process and battery cell assembly method as those in Example 1 were adopted, the compression setting length intervals of the anode pole piece and the cathode pole piece were both 6% to 80%, the compression range of the anode pole piece was 0.3 g/cm 3 , and the pole piece thickness in the compression design area changed continuously from 0.134 mm to 0.161 mm and then to 0.134 mm; the compression range of the cathode pole piece was 0.3 g/cm 3 , and the pole piece thickness in the compression design area changed continuously from 0.213 mm to 0.191 mm and then to 0.213 mm.
  • Embodiment 13 is a diagrammatic representation of Embodiment 13:
  • the same pole piece formula, coating process and battery cell assembly method as in Example 1 are used.
  • the anode pole piece compression setting length interval is 6% to 80%, the total compression range is 0.3g/cm 3 , there are 3 gradients, and the compression difference of each gradient is 0.1g/cm 3.
  • the pole piece thickness in the compression design area changes from 0.134mm to 0.161mm and then to 0.134mm in a step-by-step manner; the cathode pole piece is rolled to a uniform thickness of 0.191mm by a roller press.
  • FIG3 A partial schematic diagram of the cathode pole piece and the anode pole piece of this embodiment when paired to form an electrode assembly is shown in FIG3 .
  • Embodiment 14 is a diagrammatic representation of Embodiment 14:
  • the cathode pole piece compression setting length interval is 6% to 80%, the total compression range is 0.3g/cm 3 , there are 3 gradients, and the compression difference of each gradient is 0.1g/cm 3.
  • the pole piece thickness in the compression design area changes from 0.213mm to 0.191mm and then to 0.213mm in a step-by-step manner; the anode pole piece is rolled to a uniform thickness of 0.134mm by a roller press.
  • FIG4 A partial schematic diagram of the cathode pole piece and the anode pole piece of this embodiment when paired to form an electrode assembly is shown in FIG4 .
  • Embodiment 15 is a diagrammatic representation of Embodiment 15:
  • the cathode pole piece compression setting length interval was 6% to 80%, the total compression range was 0.3 g/cm 3 , there were 3 gradients, the compression difference of each gradient was 0.1 g/cm 3 , and the pole piece thickness in the compression design area changed from 0.213 mm to 0.191 mm and then to 0.213 mm in a step-like manner; the total compression range of the anode pole piece was 0.3 g/cm 3 , there were 3 gradients, the compression difference of each gradient was 0.1 g/cm 3 , and the pole piece thickness in the compression design area changed from 0.134 mm to 0.161 mm and then to 0.134 mm in a step-like manner.
  • Embodiment 16 is a diagrammatic representation of Embodiment 16:
  • the same pole piece formula, coating process and battery cell assembly method as in Example 1 were used.
  • the anode pole piece compression length interval was 6% to 80%, the compression range was 0.6 g/cm 3 , and the pole piece thickness in the anode compression design area changed continuously from 0.127 mm to 0.188 mm and then to 0.127 mm.
  • the cathode pole piece was rolled to a constant thickness of 0.191 mm by a roller press.
  • Embodiment 17 is a diagrammatic representation of Embodiment 17:
  • the same pole piece formula, coating process and battery cell assembly method as those in Example 1 were used.
  • the anode pole piece compression length interval was 6% to 80%, the compression range was 0.7 g/cm 3 , and the pole piece thickness in the anode compression design area changed continuously from 0.121 mm to 0.188 mm and then to 0.121 mm.
  • the cathode pole piece was rolled to a constant thickness of 0.191 mm by a roller press.
  • Embodiment 18 is a diagrammatic representation of Embodiment 18:
  • Example 2 The same pole piece formula, coating process and battery cell assembly method as in Example 1 were used, the cathode pole piece compression setting length interval was 6% to 80%, the compression range was 0.8 g/cm 3 , and the pole piece thickness in the cathode compression design area continuously changed from 0.240 mm to 0.177 mm and then to 0.240 mm; the anode pole piece was rolled to a constant thickness of 0.134 mm by a roller press.
  • Embodiment 19 is a diagrammatic representation of Embodiment 19:
  • Example 2 The same pole piece formula, coating process and battery cell assembly method as in Example 1 were used, the cathode pole piece compression setting length interval was 6% to 80%, the compression range was 0.9 g/cm 3 , and the pole piece thickness in the cathode compression design area continuously changed from 0.240 mm to 0.172 mm and then to 0.240 mm; the anode pole piece was rolled to a constant thickness of 0.134 mm by a roller press.
  • Example 2 The same pole piece formula, coating process and battery cell assembly method as in Example 1 were used.
  • the anode pole piece was rolled to a uniform thickness of 0.134 mm using a roller press; the cathode pole piece was rolled to a uniform thickness of 0.191 mm using a roller press.
  • the same pole piece formula, coating process and battery cell assembly method as in Example 1 are used, and the anode pole piece compression setting length interval is 0% to 100% of the pole piece full length, and the compression range is 0.3g/cm 3.
  • Anode compression design the pole piece thickness in the 0% to 25% area of the pole piece full length changes continuously from 0.134mm to 0.161mm; the pole piece thickness in the 25% to 50% area of the pole piece full length changes continuously from 0.161mm to 0.134mm; the pole piece thickness in the 50% to 75% area of the pole piece full length changes continuously from 0.134mm to 0.161mm; the pole piece thickness in the 75% to 100% area of the pole piece full length changes continuously from 0.161mm to 0.134mm.
  • the cathode pole piece is rolled to a uniform thickness pole piece of 0.191mm by a roller press.
  • Example 1 of Table 1 the anode compaction design "1.65 ⁇ 1.35 ⁇ 1.65" means that the compaction density of the anode active material layer from one end to the other end within the compaction design length range gradually changes from 1.65g/cm 3 to 1.35g/cm 3 and then gradually changes to 1.65g/cm 3 ;
  • the thickness of the anode pole piece in the compaction design area "0.134 ⁇ 0.161 ⁇ 0.134” means that the thickness of the anode active material layer from one end to the other end within the compaction design length range gradually changes from 0.134mm to 0.161mm and then gradually changes to 0.134mm.
  • the meaning of " ⁇ " in the compaction design and pole piece thickness data of other embodiments and comparative examples is similar to that of Example 1.
  • Example 8 Example 11 and Comparative Example 1
  • the electrolyte infiltration rate of the battery can be effectively increased and the infiltration time can be shortened.
  • both the anode pole piece and the cathode pole piece are compacted, the electrolyte infiltration efficiency is higher and the infiltration time is shorter.
  • the infiltration rate of the electrolyte can be further improved.
  • the range of the compaction design area is reduced to 20% to 50% and 30% to 40% of the total length of the pole piece, respectively, and compared with Examples 1 to 3, the infiltration time is extended instead.
  • Example 12 Comparing Example 6 with Example 2, it can be seen that the compaction range in the compaction design area will also affect the electrolyte infiltration rate. From the test data of Example 12, it can be seen that when the compaction design area is 6% to 80% of the total length of the pole piece, the anode pole piece and the cathode pole piece are compacted, and the compaction range is set within a suitable range, the electrolyte infiltration rate can be significantly increased and the infiltration time can be significantly shortened. The infiltration time of Example 12 is only 390 minutes.

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Abstract

本申请涉及一种阳极极片，包括阳极集流体和设于阳极集流体表面的阳极活性材料层，阳极活性材料层具有第一压密设计区域；第一压密设计区域内阳极活性材料层的压实密度沿极片的延伸方向先逐渐减小再逐渐增大。还涉及一种阴极极片，包括阴极集流体和设于阴极集流体表面的阴极活性材料层，阴极活性材料层具有第二压密设计区域；第二压密设计区域内阴极活性材料层的压实密度沿阴极极片的延伸方向先逐渐增大再逐渐减小。并涉及相应的电极组件、电池和用电装置。通过对极片的活性材料层进行特定的压密设计，可以提高电池电解液浸润速率。

Description

极片、电极组件、电池和用电装置 技术领域
本申请涉及二次电池技术领域，尤其涉及一种极片、电极组件、电池和用电装置。
背景技术
近年来，随着二次离子电池的应用范围越来越广泛，二次电池广泛应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域。由于二次电池取得了极大的发展，因此对二次离子电池的性能也提出了更高的要求。
圆柱形电池单体中需要将阴极极片和阳极极片层叠卷绕形成圆柱卷绕结构的电极组件，该圆柱卷绕结构电极组件内部的极片膨胀力较大，从而导致在充放电过程中电池单体容易出现局部电解液浸润异常的问题，使得电池单体的电解液浸润速率较低。
因此，寻求能够有效地降低电池单体极片的膨胀力、提高电解液浸润速率的极片及电池单体结构，已经成为本领域技术人员重点关注的研究方向之一。
发明内容
本申请是鉴于上述课题而进行的，其目的之一在于，提供一种极片、电极组件、电池和用电装置，可以使包含该极片、电极组件的电池具有较快的电解液浸润速率。
为了达到上述目的，本申请的第一方面提供一种阳极极片，包括阳极集流体和设于所述阳极集流体表面的阳极活性材料层，所述阳极活性材料层具有第一压密设计区域；在所述第一压密设计区域，所述阳极活性材料层的压实密度沿所述极片的延伸方向先逐渐减小再逐渐增大。如此，可以减小阳极极片上的阳极活性材料层在电池充放电过程中的膨胀力，从而有效缓解局部电解液浸润异常的问题，提高电池的电解液浸润速率。
在任意实施方式中，所述第一压密设计区域覆盖所述阳极极片的全长。
在任意实施方式中，所述第一压密设计区域为所述阳极极片全长的6％长度位置至80％长度位置。如此设置，在相同的压密极差(即第一压密设计区域内最大压实密度与最小压实密度之差)的情况下可以更好地减小阳极极片上阳极活性材料层的膨胀力，更好地提高电解液的浸润速率。
在任意实施方式中，所述第一压密设计区域为所述阳极极片全长的10％长度位置至70％长度位置。如此，在相同的压密极差的情况下可进一步减小阳极极片上阳极活性材料层的膨胀力，进一步提高电解液浸润速率。
在任意实施方式中，在所述第一压密设计区域内，所述阳极活性材料层的压实密度沿所述阳极极片的延伸方向连续变化。采用这种压密设计，可以有效地减小阳极极片上阳极活性材料层的膨胀力，提高电解液的浸润速率的效果。
在任意实施方式中，在所述第一压密设计区域内，沿所述阳极极片的延伸方向所述阳极活性材料层的压实密度最大值和最小值之差为0.01g/cm 3～1.00g/cm 3。将第一压密设计区域内的压实密度之差设置在上述范围之内，可以较好地减小阳极极片上阳极活性材料层的膨胀力，提高电解液的浸润速率。
在任意实施方式中，在所述第一压密设计区域内，沿所述阳极极片的延伸方向所述阳极活性材料层的压实密度最大值和最小值之差为0.01 g/cm 3～0.60g/cm 3。如此，可以更好地减小阳极活性材料层的膨胀力，进一步提高电解液的浸润速率。
在任意实施方式中，沿所述阳极极片的延伸方向上，所述第一压密设计区域两端的阳极活性材料层的压实密度与位于所述第一压密设计区域之外的阳极活性材料层的压实密度连续变化。
在任意实施方式中，在所述第一压密设计区域内，所述阳极活性材料层的压实密度沿所述阳极极片的延伸方向呈梯度变化。采用这种压密设计，同样可以起到减小阳极极片上阳极活性材料层的膨胀力，提高电解液的浸润速率的效果。
在任意实施方式中，在所述第一压密设计区域内，所述阳极活性材料层的压实密度变化的梯度个数为3～15个，相邻梯度之间的压实密度差为0.01g/cm 3～0.30g/cm 3。如此，可以进一步提高电解液的浸润速率的效果。
在任意实施方式中，所述第一压密设计区域内，所述阳极活性材料层的压实密度连续减小的区域的长度与连续增大的区域的长度相等。这样，可以更好地提高电解液的浸润速率的效果。
本申请的第二方面提供一种阴极极片，包括阴极集流体和设于所述阴极集流体表面的阴极活性材料层，所述阴极活性材料层具有第二压密设计区域；在所述第二压密设计区域，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向先逐渐增大再逐渐减小。如此设置，当将该阴极极片与阳极极片配合形成电极组件时，该阴极极片的第二压密设计区域可以为阳极极片上的阳极活性材料层提供一定的膨胀空间，从而能够有效缓解局部电解液浸润异常的问题，提高电池的电解液浸润速率。
在任意实施方式中，所述第二压密设计区域覆盖所述阴极极片的全长。
在任意实施方式中，所述第二压密设计区域为所述阴极极片全长的6％长度位置至80％长度位置。如此设置，在相同的压密极差的情况下可以更 好地缓解局部电解液浸润异常的问题，提高电池的电解液浸润速率。
在任意实施方式中，所述第二压密设计区域为所述阴极极片全长的10％长度位置至70％长度位置。如此，可以更好地为阳极活性材料层提供膨胀空间，进一步提高电解液浸润速率。
在任意实施方式中，在所述第二压密设计区域内，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向连续变化。
在任意实施方式中，在所述第二压密设计区域内，沿所述阴极极片的延伸方向所述阴极活性材料层的压实密度最大值和最小值之差为0.01g/cm 3～1.50g/cm 3。将第二压密设计区域内的压实密度之差设置在上述范围之内，可以较好地为配套使用的阳极极片上的阳极活性材料层提供膨胀空间，提高电解液的浸润速率。
在任意实施方式中，在所述第二压密设计区域内，沿所述阴极极片的延伸方向所述阴极活性材料层的压实密度最大值和最小值之差为0.01g/cm 3～0.80g/cm 3。如此，可以更好地为阳极活性材料层提供膨胀空间，进一步提高电解液的浸润速率。
在任意实施方式中，沿所述阴极极片的延伸方向上，所述第二压密设计区域两端的阴极活性材料层的压实密度与位于所述第二压密设计区域之外的阴极活性材料层的压实密度连续变化。
在任意实施方式中，在所述第二压密设计区域内，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向呈梯度变化。
在任意实施方式中，在所述第二压密设计区域内，所述阴极活性材料层的压实密度变化的梯度个数为3～20个，相邻梯度之间的压实密度差为0.01g/cm 3～0.50g/cm 3。如此设置，可以进一步提高电解液的浸润速率。
在任意实施方式中，所述第二压密设计区域内，所述阴极活性材料层的压实密度连续增大的区域的长度与连续减小的区域的长度相等。可以进 一步提高电解液的浸润速率。
本申请的第三方面提供一种电极组件，包括阳极极片和阴极极片，所述阳极极片为本申请第一方面的阳极极片和/或所述阴极极片为本申请第二方面的阴极极片。可以有效地提高电池电解液的浸润速率。
在任意实施方式中，所述阳极极片为本申请第一方面的阳极极片，所述阴极极片为本申请第二方面的阴极极片，且所述阳极极片上的所述第一压密设计区域与所述阴极极片上的所述第二压密设计区域的位置相对应。如此，可以更好地提高电池电解液的浸润速率。
在任意实施方式中，所述电极组件为由所述阳极极片和所述阴极极片层叠卷绕形成的圆柱形电极组件。
本申请的第四方面提供一种电池，包括壳体、电极组件和电解液，所述电极组件包括本申请第三方面的电极组件，所述电极组件容纳于所述壳体的内腔中，所述电解液容纳于所述壳体的内腔中且浸润所述电极组件。该电池单体很好地解决了充放电过程中局部电解液浸润异常的问题，具有较高的电解液浸润速率。
本申请的第五方面提供一种用电装置，包括本申请第四方面的电池。
本申请的阳极极片，通过对阳极活性材料层的第一压密设计区域进行压实密度设计，使第一压密设计区域内阳极活性材料层的压实密度沿极片的延伸方向先逐渐减小再逐渐增大，可以减小阳极极片上的阳极活性材料层在电池充放电过程中的膨胀力，从而缓解局部电解液浸润异常的问题，提高电池的电解液浸润速率。
本申请的阴极极片，通过对阴极活性材料层的第二压密设计区域进行压实密度设计，使第二压密设计区域内阴极活性材料层的压实密度沿极片的延伸方向先逐渐增大再逐渐减小；当将该阴极极片与阳极极片配合(特别是第二压密设计区域与本申请阴极极片的第一压密设计区域配合)形成 电极组件时，该阴极极片的第二压密设计区域可以为阳极极片上的阳极活性材料层提供一定的膨胀空间，从而能够有效缓解局部电解液浸润异常的问题，提高电池的电解液浸润速率。
附图说明
图1是本申请实施例1中阳极极片与阴极极片配对的局部示意图。
图2是本申请实施例2中阳极极片与阴极极片配对的局部示意图。
图3是本申请实施例13中阳极极片与阴极极片配对的局部示意图。
图4是本申请实施例14中阳极极片与阴极极片配对的局部示意图。
图5是本申请一实施方式的电池用作电源的用电装置的示意图。
附图标记说明：
1、阳极极片；2、阴极极片；3、用电装置；11、阳极集流体；12、阳极活性材料层；13、第一压密设计区域；21、阴极集流体；22、阴极活性材料层；23、第二压密设计区域。
具体实施方式
以下，适当地参照附图详细说明具体公开了本申请的极片、电极组件、电池单体、二次电池和用电装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且 可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60～120和80～110的范围，理解为60～110和80～120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1～3、1～4、1～5、2～3、2～4和2～5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0～5”表示本文中已经全部列出了“0～5”之间的全部实数，“0～5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一 条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为真(或存在)。
圆柱形电池单体中需要将阴极极片和阳极极片层叠卷绕形成圆柱卷绕结构的电极组件，该电极组件内部的极片膨胀力较大，在充放电过程中容易出现局部电解液浸润异常的问题，使得电池的电解液浸润速率较低。因此，寻求能够有效地降低电池单体极片的膨胀力、提高电解液浸润速率的极片及电池结构，已经成为本领域技术人员重点关注的研究方向之一。
发明人研究发现一种极片，通过对集流体上的活性材料层按照特定方式进行压实密度设计，可以有效地减小极片膨胀力，解决充放电过程中出现局部电解液浸润异常的问题，从而能够提高电池的电解液浸润速率。
在一些实施方式中，本申请的第一方面提供了一种阳极极片，包括阳极集流体和设于所述阳极集流体表面的阳极活性材料层，所述阳极活性材料层具有第一压密设计区域；所述第一压密设计区域内，所述阳极活性材料层的压实密度沿所述极片的延伸方向先逐渐减小再逐渐增大。
本申请的阳极极片，通过在阳极活性材料层上设置第一压密设计区域，使该第一压密设计区域内的阳极活性材料层的压实密度沿着极片的延伸方向先逐渐减小再逐渐增大。即在该第一压密设计区域内，极片延伸方向上两端的阳极活性材料层的压实密度大于其中部的压实密度。由于在相同的涂布面密度下，压实密度与阳极活性材料层的厚度呈反比(h＝CW/PD，其中h为材料层的厚度，CW为涂布面密度，PD为压实密度)；相对应地，第一压密设计区域内两端的阳极活性材料层的厚度小于其中部的厚度。如此设置，可以减小阳极极片上的阳极活性材料层在电池充放电过程中的膨胀力，从而有效缓解局部电解液浸润异常的问题，提高电池的电解液浸润速率。
通过研究发现，阳极极片上的阳极活性材料层在充放电过程中沿极片 长度方向上靠近中部的区域的膨胀力会大一些，两端的膨胀力相对较小；相应地靠近中部的阳极活性材料层的膨胀率也相对大一些。通过使第一压密设计区域内的阳极活性材料层的压实密度沿着极片的延伸方向先逐渐减小再逐渐增大，可以更好地与活性材料的膨胀力变化趋势相符合，更好地提高电解液浸润速率。
需要说明的是，“压实密度沿着极片的延伸方向先逐渐减小再逐渐增大”，可以是先连续减小再连续增大，也可以是先按照一定的梯度减小再按照一定的梯度增大。
在任意实施方式中，上述的压密设计可以通过在阳极集流体的上下表面分别均匀涂布阳极活性材料并烘干之后，通过辊压设备对上下表面的阳极活性材料进行辊压形成。通过对辊压设备上下辊轮的间隙进行调节，可以调节各部位压实密度的大小。
在一些实施方式中，所述第一压密设计区域覆盖所述阳极极片的全长。即，所述第一压密设计区域贯穿整个阳极极片延伸度方向的起点至终点。换句话说，对阳极极片上的阳极活性材料层均按照上述的规律进行压实密度设计。
在一些实施方式中，所述第一压密设计区域为所述阳极极片全长的6％长度位置至80％长度位置。也就是说，第一压密设计区域只包括阳极极片全长的一部分；即只对从阳极极片长度方向起点的6％长度位置开始至80％长度位置为止的区域进行压实密度设计。
需要说明的是，阳极极片延伸方向起点位置定义为0％长度位置，终点位置定义为100％长度位置。
研究发现，在充放电过程中阳极极片上的阳极活性材料层各个部位的膨胀力大小并不是一致的，而是在阳极极片全长的6％长度位置至80％长度位置区域内阳极活性材料层的膨胀相对较大。通过将第一压密设计区域 相对应地设置为阳极极片全长的6％长度位置至80％长度位置，在相同的压密极差(即第一压密设计区域内最大压实密度与最小压实密度之差)情况下可以更好地减小阳极极片上阳极活性材料层的膨胀力，更好地提高电解液的浸润速率。
在一些实施方式中，所述第一压密设计区域为所述阳极极片全长的10％长度位置至70％长度位置。进一步研究发现，将第一压密设计区域设置为阳极极片全长的10％长度位置至70％长度位置，可以进一步减小阳极活性材料层的膨胀力，进一步提高电解液的浸润速率。
在任意实施方式中，所述第一压密设计区域占据所述阳极极片全宽。即第一压密设计区域布布满阳极极片的整个宽度。
在任意实施方式中，在所述第一压密设计区域内，所述阳极活性材料层的压实密度沿所述阳极极片的延伸方向连续变化。也就是说，在第一压密设计区域内阳极活性材料层沿阳极极片的延伸方向上压实密度是连续的，不存在压实密度突变的情况。具体来说，第一压密设计区域内的压实密度可以按照某种数学函数的方式进行变化，例如线性变化、二次函数变化等等。
在任意实施方式中，在所述第一压密设计区域内，沿所述阳极极片的延伸方向所述阳极活性材料层的压实密度之差(最大值和最小值之差，即压密极差)为0.01g/cm 3～1.00g/cm 3。换句话说，在第一压密设计区域内，阳极活性材料层压实密度最大处与最小处的压实密度之差为0.01g/cm 3～1.00g/cm 3。将第一压密设计区域内的压实密度之差设置在上述范围之内，可以较好地减小阳极极片上阳极活性材料层的膨胀力，提高电解液的浸润速率。
可以理解，在所述第一压密设计区域内，沿所述阳极极片的延伸方向所述阳极活性材料层的压实密度最大值和最小值之差可以为但不限于0.01 g/cm 3、0.05g/cm 3、0.10g/cm 3、0.20g/cm 3、0.30g/cm 3、0.40g/cm 3、0.50g/cm 3、0.60g/cm 3、0.70g/cm 3、0.80g/cm 3、0.90g/cm 3、1.00g/cm 3。
在一些实施方式中，在所述第一压密设计区域内，沿所述阳极极片的延伸方向所述阳极活性材料层的压实密度最大值和最小值之差为0.01g/cm 3～0.60g/cm 3。进一步研究发现，将第一压密设计区域内的压实密度之差设置在上述范围之内，可以更好地减小阳极活性材料层的膨胀力，进一步提高电解液的浸润速率。
在任意实施方式中，沿所述阳极极片的延伸方向上，所述第一压密设计区域两端的阳极活性材料层的压实密度与所述第一压密设计区域之外的阳极活性材料层的压实密度连续变化。换句话说，第一压密设计区域两端的阳极活性材料层的压实密度与第一压密设计区域之外的阳极活性材料层的压实密度之间连续过渡，不存在压实密度突变的情况。
在任意实施方式中，在所述第一压密设计区域内，所述阳极活性材料层的压实密度沿所述阳极极片的延伸方向呈梯度变化。也就是说，在第一压密设计区域内阳极活性材料层沿阳极极片的延伸方向上压实密度是不连续的，而是按照多个梯度进行变化，各个梯度的压实密度可以不相同。采用这种压密设计，同样可以起到减小阳极极片上阳极活性材料层的膨胀力，提高电解液的浸润速率的效果。
在任意实施方式中，在所述第一压密设计区域内，所述阳极活性材料层的压实密度变化的梯度个数为3～15个，相邻梯度之间的压实密度差为0.01g/cm 3～0.30g/cm 3。
可以理解，第一压密设计区域内阳极活性材料层的压实密度变化的梯度个数可以为但不限于3个、4个、5个、6个、7个、8个、9个、10个、11个、12个、13个、14个、15个。相邻梯度之间的压实密度差可以为但不限于0.01g/cm 3、0.02g/cm 3、0.05g/cm 3、0.08g/cm 3、0.10g/cm 3、0.12 g/cm 3、0.15g/cm 3、0.18g/cm 3、0.20g/cm 3、0.22g/cm 3、0.25g/cm 3、0.28g/cm 3、0.30g/cm 3。
在任意实施方式中，所述第一压密设计区域内，所述阳极活性材料层的压实密度连续减小的区域的长度与连续增大的区域的长度相等。进一步地，所述阳极活性材料层的压实密度沿垂直于所述阳极极片延伸方向的所述第一压密设计区域中截面对称分布。即位于第一压密设计区域中截面两侧的阳极活性材料层的压实密度相互对应，中截面两侧相同距离处的压实密度相等。
在一些实施方式中，本申请的第二方面提供了一种阴极极片，包括阴极集流体和设于所述阴极集流体表面的阴极活性材料层，所述阴极活性材料层具有第二压密设计区域；所述第二压密设计区域内，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向先逐渐增大再逐渐减小。
本申请的阴极极片，通过在阴极活性材料层上设置第二压密设计区域，使该第二压密设计区域内的阴极活性材料层的压实密度沿着极片的延伸方向先逐渐增大再逐渐减小。即在该第二压密设计区域内，极片延伸方向上两端的阴极活性材料层的压实密度小于其中部的压实密度。相对应地，第二压密设计区域内两端的阴极活性材料层的厚度大于其中部的厚度。如此设置，当将该阴极极片与阳极极片配合形成电极组件时，该阴极极片的第二压密设计区域可以为阳极极片上的阳极活性材料层提供一定的膨胀空间，从而能够有效缓解局部电解液浸润异常的问题，提高电池的电解液浸润速率。
需要说明的是，该阴极极片可以与本申请第一方面的阳极极片配套使用形成电极组件，也可以与普通的阳极极片配套形成电极组件。优选将该阴极极片与本申请第一方面的阳极极片配套使用，这样一方面第一压密设计区域内的压密设计可以减小阳极活性材料层的膨胀，同时第二压密设计 区域内的压密设计可以为阳极活性材料层提供一定的膨胀空间，这两方面共同作用可以更加有效地提高电池电解液的浸润速率。当将该阴极极片与本申请第一方面的阳极极片配套使用时，优选使第一压密设计区域和第二压密设计区域的位置相对应。
在任意实施方式中，上述的压密设计可以通过在阴极集流体的上下表面分别均匀涂布阴极活性材料并烘干之后，通过辊压设备对上下表面的阴极活性材料进行辊压形成。通过对辊压设备上下辊轮的间隙进行调节，可以调节各部位压实密度的大小。
在一些实施方式中，所述第二压密设计区域为所述阴极极片全长。即，所述第二压密设计区域贯穿整个阴极极片长度方向的起点至终点。也就是说，对阴极极片上的阴极活性材料层均按照上述的规律进行压实密度设计。
在一些实施方式中，所述第二压密设计区域为所述阴极极片全长的6％长度位置至80％长度位置。也就是说，第二压密设计区域只包括阴极极片全长的一部分；即只对从阴极极片长度方向起点的6％长度位置开始至80％长度位置为止的区域进行压实密度设计。
需要说明的是，阴极极片长度方向起点位置定义为0％长度位置，终点位置定义为100％长度位置。
在充放电过程中阳极极片上的阳极活性材料层各个部位的膨胀力大小并不是一致的，而是在阳极极片全长的6％长度位置至80％长度位置区域内阳极活性材料层的膨胀相对较大。通过将第二压密设计区域相对应地设置为阴极极片全长的6％长度位置至80％长度位置，在相同的压密极差(即第二压密设计区域内最大压实密度与最小压实密度之差)情况下可以更好地为与该阴极极片配套的阳极极片提供膨胀空间，更好地提高电解液的浸润速率。
在一些实施方式中，所述第二压密设计区域为所述阴极极片全长的10％ 长度位置至70％长度位置。将第二压密设计区域设置为阴极极片全长的10％长度位置至70％长度位置，可以更好地为阳极活性材料层提供膨胀空间，进一步提高电解液的浸润速率。
在任意实施方式中，所述第二压密设计区域占据所述阴极极片全宽。即第二压密设计区域布布满阴极极片的整个宽度。
在任意实施方式中，在所述第二压密设计区域内，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向连续变化。也就是说，在第二压密设计区域内阴极活性材料层沿阴极极片的延伸方向上压实密度是连续的，不存在压实密度突变的情况。具体来说，第二压密设计区域内的压实密度可以按照某种数学函数的方式进行变化，例如线性变化、二次函数变化等等。
在任意实施方式中，在所述第二压密设计区域内，沿所述阴极极片的延伸方向所述阴极活性材料层的压实密度最大值和最小值之差(即压密极差)为0.01g/cm 3～1.50g/cm 3。换句话说，在第二压密设计区域内，阴极活性材料层压实密度最大处与最小处的压实密度之差为0.01g/cm 3～1.50g/cm 3。将第二压密设计区域内的压实密度之差设置在上述范围之内，可以较好地为配套使用的阳极极片上的阳极活性材料层提供膨胀空间，提高电解液的浸润速率。
可以理解，在所述第二压密设计区域内，沿所述阴极极片的延伸方向所述阴极活性材料层的压实密度最大值和最小值之差可以为但不限于0.01g/cm 3、0.05g/cm 3、0.10g/cm 3、0.20g/cm 3、0.30g/cm 3、0.40g/cm 3、0.50g/cm 3、0.60g/cm 3、0.70g/cm 3、0.80g/cm 3、0.90g/cm 3、1.00g/cm 3、1.10g/cm 3、1.20g/cm 3、1.30g/cm 3、1.40g/cm 3、1.50g/cm 3。
在一些实施方式中，在所述第二压密设计区域内，沿所述阴极极片的延伸方向所述阴极活性材料层的压实密度最大值和最小值之差为0.01 g/cm 3～0.80g/cm 3。进一步研究发现，将第二压密设计区域内的压实密度之差设置在上述范围之内，可以更好地为阳极活性材料层提供膨胀空间，进一步提高电解液的浸润速率。
在任意实施方式中，沿所述阴极极片的延伸方向上，所述第二压密设计区域两端的阴极活性材料层的压实密度与所述第二压密设计区域之外的阴极活性材料层的压实密度连续变化。换句话说，第二压密设计区域两端的阴极活性材料层的压实密度与第二压密设计区域之外的阴极活性材料层的压实密度之间连续过渡，不存在压实密度突变的情况。
在任意实施方式中，在所述第二压密设计区域内，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向呈梯度变化。也就是说，在第二压密设计区域内阴极活性材料层沿阴极极片的延伸方向上压实密度是不连续的，而是按照多个梯度进行变化，各个梯度的压实密度可以不相同。采用这种压密设计，同样可以起到为阳极极片上的阳极活性材料层提供膨胀空间，提高电解液的浸润速率的效果。
在任意实施方式中，在所述第二压密设计区域内，所述阴极活性材料层的压实密度变化的梯度个数为3～20个，相邻梯度之间的压实密度差为0.01g/cm 3～0.50g/cm 3。
可以理解，第二压密设计区域内阴极活性材料层的压实密度变化的梯度个数可以为但不限于3个、4个、5个、6个、7个、8个、9个、10个、11个、12个、13个、14个、15个、16个、17个、18个、19个、20个。相邻梯度之间的压实密度差可以为但不限于0.01g/cm 3、0.02g/cm 3、0.05g/cm 3、0.08g/cm 3、0.10g/cm 3、0.12g/cm 3、0.15g/cm 3、0.18g/cm 3、0.20g/cm 3、0.22g/cm 3、0.25g/cm 3、0.28g/cm 3、0.30g/cm 3、0.32g/cm 3、0.34g/cm 3、0.36g/cm 3、0.38g/cm 3、0.40g/cm 3、0.42g/cm 3、0.45g/cm 3、0.48g/cm 3、0.50g/cm 3。
在任意实施方式中，所述第二压密设计区域内，所述阴极活性材料层的压实密度连续增大的区域的长度与连续减小的区域的长度相等。进一步地，所述阴极活性材料层的压实密度沿垂直于所述阴极极片延伸方向的所述第二压密设计区域中截面对称分布。即位于第二压密设计区域中截面两侧的阴极活性材料层的压实密度相互对应，中截面两侧相同距离处的压实密度相等。
在一些实施方式中，本申请的第三方面提供一种电极组件，包括阳极极片和阴极极片，所述阳极极片为本申请第一方面的阳极极片和/或所述阴极极片为本申请第二方面的阴极极片。
在一些实施方式中，该电极组件的阳极极片为本申请第一方面的阳极极片，而阴极极片采用普通的阴极极片，即阴极极片上的阴极活性材料层各处的压实密度一致。
在一些实施方式中，该电极组件的阳极极片采用普通的阳极极片，即阳极极片上的阳极活性材料层各处的压实密度一致。而阴极极片采用本申请第二方面的阴极极片。
在一些实施方式中，该电极组件的阳极极片采用本申请第一方面的阳极极片，并且阴极极片采用本申请第二方面的阴极极片。
通过将本申请第一方面的阳极极片和/或本申请第二方面的阴极极片配套组合形成电极组件，通过第一压密设计区域、第二压密设计区域内的压实密度设计，可以有效地提高电池电解液的浸润速率。优选将本申请第一方面的阳极极片和本申请第二方面的阴极极片配套组合形成电极组件，通过第一压密设计区域和第二压密设计区域的压实密度设计相配合，可以更好地提高电解液的浸润速率。
在任意实施方式中，所述电极组件为由所述阳极极片和所述阴极极片层叠卷绕形成的圆柱形电极组件。圆柱形电池单体中，充放电过程中电极 活性材料的膨胀更加容易造成局部电解液浸润异常的问题，在圆柱形电极组件中采用本申请的结构设计可以很好地缓解局部电解液浸润异常。
在一些实施方式中，本申请的第四方面提供一种电池，包括壳体、电极组件和电解液，所述壳体具有内腔，所述电极组件包括本申请第三方面的电极组件，所述电极组件容纳于所述壳体的内腔中，所述电解液容纳于所述壳体的内腔中且浸润所述电极组件。本申请的电池单体很好地解决了充放电过程中局部电解液浸润异常的问题，具有较高的电解液浸润速率。
在一些实施方式中，本申请的第五方面提供一种用电装置，包括本申请第四方面的电池，其中电池作为用电装置的电源，为用电装置提供电能。
以下适当参照附图对本申请的电池和用电装置进行说明。
通常情况下，电池包括阴极极片2、阳极极片1、电解液和隔离膜。在电池充放电过程中，活性离子在阴极极片2和阳极极片1之间往返嵌入和脱出。电解液在阴极极片2和阳极极片1之间起到传导离子的作用。隔离膜设置在阴极极片2和阳极极片1之间，主要起到防止阴阳极短路的作用，同时可以使离子通过。
[阴极极片]
阴极极片2包括阴极集流体21以及设置在阴极集流体21至少一个表面的阴极膜层(即阴极活性材料层22)，所述阴极膜层包括阴极活性材料。
作为示例，阴极集流体21具有在其自身厚度方向相对的两个表面，阴极膜层设置在阴极集流体21相对的两个表面的其中任意一者或两者上。
在一些实施方式中，所述阴极集流体21可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料形成在高分子材料基材上而形成。其中，金属材料包括但不限于铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等。高分子材料基材(如 聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)。
在一些实施方式中，阴极活性材料可包含本领域公知的用于电池的阴极活性材料。作为示例，阴极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池阴极活性材料的传统材料。这些阴极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO 2)、锂镍氧化物(如LiNiO 2)、锂锰氧化物(如LiMnO 2、LiMn 2O 4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi 1/3Co 1/3Mn 1/3O 2(也可以简称为NCM 333)、LiNi 0.5Co 0.2Mn 0.3O 2(也可以简称为NCM 523)、LiNi 0.5Co 0.25Mn 0.25O 2(也可以简称为NCM 211)、LiNi 0.6Co 0.2Mn 0.2O 2(也可以简称为NCM 622)、LiNi 0.8Co 0.1Mn 0.1O 2(也可以简称为NCM 811)、锂镍钴铝氧化物(如LiNi 0.85Co 0.15Al 0.05O 2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO 4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO 4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
所述阴极活性材料在阴极膜层中的重量比为80重量％～100重量％，基于阴极膜层的总重量计。
在一些实施方式中，阴极膜层还可选地包括粘结剂。作为示例，所述粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯酸酯树脂中的至少一种。所述粘结剂在阴极膜层中的重量比为0重量％～20重量％，基于阴极膜层的总重量计。
在一些实施方式中，阴极膜层还可选地包括导电剂。作为示例，所述导电剂可以包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。所述导电剂在阴极膜层中的重量比为0重量％～20重量％，基于阴极膜层的总重量计。
在一些实施方式中，可以通过以下方式制备阴极极片2：将上述用于制备阴极极片2的组分，例如阴极活性材料、导电剂、粘结剂和任意其他的组分分散于溶剂(例如N-甲基吡咯烷酮)中，形成阴极浆料，其中所述阴极浆料固含量为40wt％～80wt％，室温下的粘度调整到5000mPa·s～25000mPa·s，将阴极浆料涂覆在阴极集流体21的表面，烘干后经过冷轧机冷压后形成阴极极片2。
在一些实施方式中，在阴极极片2的阴极活性材料层22上还设置有第二压密设计区域23。在该第二压密设计区域23内按照本申请的特定方式进行压实密度设计。阴极极片2的一些示例如图1至图4所示。
[阳极极片]
阳极极片1包括阳极集流体11以及设置在阳极集流体11至少一个表面上的阳极膜层(即阳极活性材料层12)，所述阳极膜层包括阳极活性材料。
作为示例，阳极集流体11具有在其自身厚度方向相对的两个表面，阳极膜层设置在阳极集流体11相对的两个表面中的任意一者或两者上。
在一些实施方式中，所述阳极集流体11可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料形成在高分子材料基材上而形成。其中，金属材料包括但不限于铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等，高分子材料基材 包括但不限于聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等基材。
在一些实施方式中，阳极活性材料可采用本领域公知的用于电池的阳极活性材料。作为示例，阳极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。所述锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池阳极活性材料的传统材料。这些阳极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施方式中，阳极膜层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。所述粘结剂在阳极膜层中的重量比为0重量％～30重量％，基于阳极膜层的总重量计。
在一些实施方式中，阳极膜层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。所述导电剂在阳极膜层中的重量比为0重量％～20重量％，基于阳极膜层的总重量计。
在一些实施方式中，阳极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。所述其他助剂在阳极膜层中的重量比为0重量％～15重量％，基于阳极膜层的总重量计。
在一些实施方式中，可以通过以下方式制备阳极极片：将上述用于制备阳极极片的组分，例如阳极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成阳极浆料，其中所述阳极浆料固含 量为30wt％～70wt％，室温下的粘度调整到2000mPa·s～10000mPa·s；将所得到的阳极浆料涂覆在阳极集流体11上，经过干燥工序，冷压例如对辊，得到阳极极片1。
在一些实施方式中，在阳极极片1的阳极活性材料层12上还设置有第一压密设计区域13。在该第一压密设计区域13内按照本申请的特定方式进行压实密度设计。阳极极片1的一些示例如图1至图4所示。
[电解液]
电解液在阴极极片2和阳极极片1之间起到传导离子的作用。本申请对电解液的种类没有具体的限制，可根据需求进行选择。例如，电解液可以是液态的、凝胶态的或全固态的。
在一些实施方式中，所述电解液采用电解液。所述电解液包括电解液盐和溶剂。
在一些实施方式中，电解液盐可选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。
在一些实施方式中，溶剂可选自碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。
在一些实施方式中，所述电解液还可选地包括添加剂。例如添加剂可以包括阳极成膜添加剂、阴极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性 能的添加剂等。
[隔离膜]
在一些实施方式中，电池中还包括隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。
在一些实施方式中，所述隔离膜的厚度为6μm～40μm，可选为12μm～20μm。
在一些实施方式中，阴极极片2、阳极极片1和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施方式中，电池可包括外包装。该外包装可用于封装上述电极组件及电解液。
在一些实施方式中，电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。
在一些实施方式中，外包装可包括壳体和盖板。其中，壳体可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体具有与容纳腔连通的开口，盖板能够盖设于所述开口，以封闭所述容纳腔。阴极极片 2、阳极极片1和隔离膜可经卷绕工艺或叠片工艺形成电极组件。电极组件封装于所述容纳腔内。电解液浸润于电极组件中。电池所含电极组件的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
在一些实施方式中，电池可以组装成电池模块，电池模块所含电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
在电池模块中，多个电池可以是沿电池模块的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个电池进行固定。
可选地，电池模块还可以包括具有容纳空间的外壳，多个电池容纳于该容纳空间。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
在电池包中可以包括电池箱和设置于电池箱中的多个电池模块。电池箱包括上箱体和下箱体，上箱体能够盖设于下箱体，并形成用于容纳电池模块的封闭空间。多个电池模块可以按照任意的方式排布于电池箱中。
另外，本申请还提供一种用电装置3，所述用电装置3包括本申请提供的电池、电池模块或电池包中的至少一种。所述电池、电池模块或电池包可以用作所述用电装置3的电源，也可以用作所述用电装置3的能量存储单元。所述用电装置3可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。
作为所述用电装置3，可以根据其使用需求来选择电池、电池模块或 电池包。
图5是作为一个示例的用电装置3。该用电装置3为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置3对电池的高功率和高能量密度的需求，可以采用电池包或电池模块。
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用电池作为电源。
实施例
为了使本申请所解决的技术问题、技术方案及有益效果更加清楚，以下将结合实施例和附图对本申请进行进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本申请及其应用的任何限制。基于本申请中的实施例，本领域普通技术人员在没有付出创造性劳动前提下所获得的所有其他实施例都属于本申请保护的范围。
实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
实施例1：
(1)阳极极片制备
a.将石墨、导电剂、粘结剂、分散剂按97:0.5:1.5:1重量比例加入搅拌罐中，外加去离子水得到混合溶液，去离子水的加入量为石墨、导电剂、粘结剂、分散剂总质量的1倍；搅拌罐以1200r/min的转速高速旋转4h；将混匀的混合溶液用自动涂布机均匀的涂在铜箔上(涂布CW＝156mg/1540mm 2)；将涂好的铜箔放入烘箱中，在120℃温度下烘烤20min，极片预留等待后续进行压密设计。
b.压密梯度(PD)设计可以通过极片厚度(h)的变化来确认，计算公式为： h＝CW/PD。压密极差设计通过上下辊压辊轮的间隙周期性变化来实现，将烘干后的极片用辊压机进行辊压，以单电池极片长度作为一个辊压周期。压密设置长度区间为0％～100％极片全长，压密极差为0.3g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化。
(2)阴极极片制备
将磷酸铁锂、导电剂、粘结剂、分散剂按97:1:1.5:0.5重量比例加入搅拌罐中，外加去离子水得到混合溶液，去离子水的加入量为石墨、导电剂、粘结剂、分散剂总质量的0.6倍；搅拌罐以1200r/min的转速高速旋转4h；将混匀的混合溶液用自动涂布机均匀的涂在铝箔上(涂布CW＝340mg/1540mm 2)；将涂好的铜箔放入烘箱中，在120℃温度下烘烤30min，将烘干后的极片用辊压机辊压至0.191mm的等厚度极片。
(3)电池单体组装
将上述阴阳极极片和隔离膜配对卷绕，随后进行极耳整形、激光焊接转接片、顶盖焊接、注液以及密封钉焊接，完成电池单体装配。将本实施例的阴极极片和阳极极片配对形成电极组件时的局部示意图，如图1所示。
电池单体测试
浸润时间测试方法：测试电流和截止电压可根据实际测量、应用要求，以及电池单体实际化学体系和健康状态修改。本次实验，采用1C倍率下将LFP电池单体放电至2.5V，记录从放电截止(即放电至2.5V)到电解液液面平衡(2h前后的电解液液面高度不变代表液面平衡)所需时间。测试结果如表1所示。
实施例2：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为6％～80％极片全长，压密极差为0.3g/cm 3，压 密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。将本实施例的阴极极片和阳极极片配对形成电极组件时的局部示意图，如图2所示。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例3：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为10％～70％极片全长，压密极差为0.3g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例4：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为20％～50％极片全长，压密极差为0.3g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例5：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为30％～40％极片全长，压密极差为0.3g/cm 3，压 密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例6：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为6％～80％极片全长，压密极差为0.1g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例7：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为6％～80％，压密极差为0.2g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例8：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阴极极片压密设置长度区间为0％～100％，压密极差为0.3g/cm 3，压密设计区域极片厚度从0.213mm到0.191mm再到0.213mm连续变化；阳极极片用 辊压机辊压至0.134mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例9：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阴极极片压密设置长度区间为6％～80％，压密极差为0.3g/cm 3，压密设计区域极片厚度从0.213mm到0.191mm再到0.213mm连续变化；阳极极片用辊压机辊压至0.134mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例10：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阴极极片压密设置长度区间为6％～80％，压密极差为0.1g/cm 3，压密设计区域极片厚度从0.198mm到0.191mm再到0.198mm连续变化；阳极极片用辊压机辊压至0.134mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例11：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片和阴极极片的压密设置长度区间均为0％～100％，阳极极片压密极差为0.3g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化；阴极极片压密极差为0.3g/cm 3，压密设计区域极片厚度从 0.213mm到0.191mm再到0.213mm连续变化。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例12：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片和阴极极片压密设置长度区间均为6％～80％，阳极极片压密极差为0.3g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm连续变化；阴极极片压密极差为0.3g/cm 3，压密设计区域极片厚度从0.213mm到0.191mm再到0.213mm连续变化。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例13：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为6％～80％，总压密极差为0.3g/cm 3，共3个梯度，每个梯度压密差异0.1g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm呈阶梯变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。将本实施例的阴极极片和阳极极片配对形成电极组件时的局部示意图，如图3所示。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例14：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阴 极极片压密设置长度区间为6％～80％，总压密极差为0.3g/cm 3，共3个梯度，每个梯度压密差异0.1g/cm 3，压密设计区域极片厚度从0.213mm到0.191mm再到0.213mm呈阶梯变化；阳极极片用辊压机辊压至0.134mm的等厚度极片。将本实施例的阴极极片和阳极极片配对形成电极组件时的局部示意图，如图4所示。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例15：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阴极极片压密设置长度区间为6％～80％，总压密极差为0.3g/cm 3，共3个梯度，每个梯度压密差异0.1g/cm 3，压密设计区域极片厚度从0.213mm到0.191mm再到0.213mm呈阶梯变化；阳极极片总压密极差为0.3g/cm 3，共3个梯度，每个梯度压密差异0.1g/cm 3，压密设计区域极片厚度从0.134mm到0.161mm再到0.134mm呈阶梯变化。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例16：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为6％～80％，压密极差为0.6g/cm 3，阳极压密设计区域极片厚度从0.127mm到0.188mm再到0.127mm连续变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例17：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为6％～80％，压密极差为0.7g/cm 3，阳极压密设计区域极片厚度从0.121mm到0.188mm再到0.121mm连续变化；阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例18：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阴极极片压密设置长度区间为6％～80％，压密极差为0.8g/cm 3，阴极压密设计区域极片厚度从0.240mm到0.177mm再到0.240mm连续变化；阳极极片用辊压机辊压至0.134mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
实施例19：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阴极极片压密设置长度区间为6％～80％，压密极差为0.9g/cm 3，阴极压密设计区域极片厚度从0.240mm到0.172mm再到0.240mm连续变化；阳极极片用辊压机辊压至0.134mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
对比例1：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片用辊压机辊压至0.134mm的等厚度极片；阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
对比例2：
采用与实施例1相同的极片配方、涂布工艺和电池单体组装方法，阳极极片压密设置长度区间为0％～100％极片全长，压密极差为0.3g/cm 3。阳极压密设计：极片全长的0％～25％区域极片厚度从0.134mm到0.161mm连续变化；极片全长的25％～50％区域极片厚度从0.161mm到0.134mm连续变化；极片全长的50％～75％区域极片厚度从0.134mm到0.161mm连续变化；极片全长的75％～100％区域极片厚度从0.161mm到0.134mm连续变化。阴极极片用辊压机辊压至0.191mm的等厚度极片。
对组装后的电池单体的浸润时间进行测试，测试方法与实施例1相同，测试结果如表1所示。
表1
Figure PCTCN2022133693-appb-000001
Figure PCTCN2022133693-appb-000002
表1的实施例1中阳极压密设计“1.65～1.35～1.65”，表示在压密设计长度区间内的一端至另一端阳极活性材料层的压实密度由1.65g/cm 3逐渐变化至1.35g/cm 3再逐渐变化至1.65g/cm 3；压密设计区域阳极极片厚度“0.134～0.161～0.134”，表示在压密设计长度区间内的一端至另一端阳极活性材料层的厚度由0.134mm逐渐变化至0.161mm再逐渐变化至0.134mm。其他实施例和对比例的压密设计和极片厚度数据中“～”的意思与实施例1类似。
对比实施例1、实施例8、实施例11和对比例1的测试数据可知，通过对阳极极片上的阳极活性材料层的全长进行压密设计、对阴极极片上的阴极活性材料层的全长(0％～100％)进行压密设计，或者对阳极极片和阴极极片均进行压密设计，都可以有效提高电池的电解液浸润速率，缩短浸润时间。其中，对阳极极片和阴极极片均进行压密设计时的电解液浸润效率更高，浸润时间更短。
对比实施例1至实施例5的测试数据可知，将压密设计区域设置为极片全长的6％～80％位置时，浸润时间比压密设计区域为极片全长(0％～100％)时的浸润时间更短，说明压密设计区域为极片全长的6％～80％位置可以更好地提高电解液的浸润速率；进一步地，将压密设计区域设置为极片全长的10％～70％位置时，浸润时间比压密设计区域为极片全长的6％～80％位置时的浸润时间更短，说明压密设计区域为极片全长的10％～70％位置可以进一步地提高电解液的浸润速率。实施例4和实施例5中，压密设计区域的范围分别缩小至极片全长的20％～50％位置和30％～40％位置，相比于实施例1至实施例3，其浸润时间反而延长。
将实施例6与实施例2对比可知，压密设计区域内的压密极差大小同样会影响电解液的浸润速率。由实施例12的测试数据可以看出，当压密设计区域为极片全长的6％～80％位置、对阳极极片和阴极极片均进行压密设 计，且将压密极差设置在合适范围内，可以显著地提高电解液浸润速率，显著缩短浸润时间，实施例12的浸润时间仅为390min。
需要说明的是，本申请不限定于上述实施方式。上述实施方式仅为示例，在本申请的技术方案范围内具有与技术思想实质相同的构成、发挥相同作用效果的实施方式均包含在本申请的技术范围内。此外，在不脱离本申请主旨的范围内，对实施方式施加本领域技术人员能够想到的各种变形、将实施方式中的一部分构成要素加以组合而构筑的其它方式也包含在本申请的范围内。

Claims (21)

  1. 一种阳极极片，其特征在于，包括阳极集流体和设于所述阳极集流体表面的阳极活性材料层，所述阳极活性材料层具有第一压密设计区域；在所述第一压密设计区域，所述阳极活性材料层的压实密度沿所述极片的延伸方向先逐渐减小再逐渐增大。
  2. 根据权利要求1所述的阳极极片，其特征在于，所述第一压密设计区域覆盖所述阳极极片的全长；
    或，所述第一压密设计区域为所述阳极极片全长的6％长度位置至80％长度位置；可选地，所述第一压密设计区域为所述阳极极片全长的10％长度位置至70％长度位置。
  3. 根据权利要求1或2所述的阳极极片，其特征在于，在所述第一压密设计区域内，所述阳极活性材料层的压实密度沿所述阳极极片的延伸方向连续变化。
  4. 根据权利要求3所述的阳极极片，其特征在于，在所述第一压密设计区域内，沿所述阳极极片的延伸方向所述阳极活性材料层的压实密度最大值和最小值之差为0.01g/cm 3～1.00g/cm 3；
    可选地，在所述第一压密设计区域内，沿所述阳极极片的延伸方向所述阳极活性材料层的压实密度最大值和最小值之差为0.01g/cm 3～0.60g/cm 3。
  5. 根据权利要求1至4任一项所述的阳极极片，其特征在于，沿所述阳极极片的延伸方向上，所述第一压密设计区域两端的阳极活性材料层的压实密度与位于所述第一压密设计区域之外的阳极活性材料层的压实密度连续变化。
  6. 根据权利要求1或2所述的阳极极片，其特征在于，在所述第一压密设计区域内，所述阳极活性材料层的压实密度沿所述阳极极片的延伸方向呈梯度变化。
  7. 根据权利要求6所述的阳极极片，其特征在于，在所述第一压密设计区域内，所述阳极活性材料层的压实密度变化的梯度个数为3～15个，可选地，相邻梯度之间的压实密度差为0.01g/cm 3～0.30g/cm 3。
  8. 根据权利要求1至7任一项所述的阳极极片，其特征在于，所述第一压密设计区域内，所述阳极活性材料层的压实密度连续减小的区域的长度与连续增大的区域的长度相等。
  9. 一种阴极极片，其特征在于，包括阴极集流体和设于所述阴极集流体表面的阴极活性材料层，所述阴极活性材料层具有第二压密设计区域；在所述第二压密设计区域，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向先逐渐增大再逐渐减小。
  10. 根据权利要求9所述的阴极极片，其特征在于，所述第二压密设计区域覆盖所述阴极极片的全长；
    或，所述第二压密设计区域为所述阴极极片全长的6％长度位置至80％长度位置；可选地，所述第二压密设计区域为所述阴极极片全长的10％长度位置至70％长度位置。
  11. 根据权利要求9或10所述的阴极极片，其特征在于，在所述第二压密设计区域内，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向连续变化。
  12. 根据权利要求11所述的阴极极片，其特征在于，在所述第二压密设计区域内，沿所述阴极极片的延伸方向所述阴极活性材料层的压实密度最大值和最小值之差为0.01g/cm 3～1.50g/cm 3；
    可选地，在所述第二压密设计区域内，沿所述阴极极片的延伸方向所述阴极活性材料层的压实密度最大值和最小值之差为0.01g/cm 3～0.80g/cm 3。
  13. 根据权利要求9至12任一项所述的阴极极片，其特征在于，沿所述阴极极片的延伸方向上，所述第二压密设计区域两端的阴极活性材料层 的压实密度与位于所述第二压密设计区域之外的阴极活性材料层的压实密度连续变化。
  14. 根据权利要求9所述的阴极极片，其特征在于，在所述第二压密设计区域内，所述阴极活性材料层的压实密度沿所述阴极极片的延伸方向呈梯度变化。
  15. 根据权利要求14所述的阴极极片，其特征在于，在所述第二压密设计区域内，所述阴极活性材料层的压实密度变化的梯度个数为3～20个，可选地，相邻梯度之间的压实密度差为0.01g/cm 3～0.50g/cm 3。
  16. 根据权利要求9至15任一项所述的阴极极片，其特征在于，所述第二压密设计区域内，所述阴极活性材料层的压实密度连续增大的区域的长度与连续减小的区域的长度相等。
  17. 一种电极组件，其特征在于，包括阳极极片和阴极极片，所述阳极极片为权利要求1至8任一项所述的阳极极片和/或所述阴极极片为权利要求9至16任一项所述的阴极极片。
  18. 根据权利要求17所述的电极组件，其特征在于，所述阳极极片为权利要求1至8任一项所述的阳极极片，所述阴极极片为权利要求9至16任一项所述的阴极极片，且所述阳极极片上的所述第一压密设计区域与所述阴极极片上的所述第二压密设计区域的位置相对应。
  19. 根据权利要求17或18所述的电极组件，其特征在于，所述电极组件为由所述阳极极片和所述阴极极片层叠卷绕形成的圆柱形电极组件。
  20. 一种电池，其特征在于，包括壳体、电极组件和电解液，所述电极组件包括权利要求17至19任一项所述的电极组件，所述电极组件容纳于所述壳体的内腔中，所述电解液容纳于所述壳体的内腔中且浸润所述电极组件。
  21. 一种用电装置，其特征在于，包括权利要求20所述的电池。
PCT/CN2022/133693 2022-11-23 2022-11-23 极片、电极组件、电池和用电装置 WO2024108418A1 (zh)

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JP2007328977A (ja) * 2006-06-07 2007-12-20 Matsushita Electric Ind Co Ltd 非水系二次電池用電極板とその製造方法および非水系二次電池
CN108511787A (zh) * 2017-02-23 2018-09-07 松下知识产权经营株式会社 锂离子二次电池及其制造方法
CN217606851U (zh) * 2022-07-18 2022-10-18 宁德时代新能源科技股份有限公司 电极组件、电池单体、电池及用电装置

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JP2007328977A (ja) * 2006-06-07 2007-12-20 Matsushita Electric Ind Co Ltd 非水系二次電池用電極板とその製造方法および非水系二次電池
CN108511787A (zh) * 2017-02-23 2018-09-07 松下知识产权经营株式会社 锂离子二次电池及其制造方法
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