WO2023004830A1 - 电池极片、电极组件、电池单体、电池及用电装置 - Google Patents

电池极片、电极组件、电池单体、电池及用电装置 Download PDF

Info

Publication number
WO2023004830A1
WO2023004830A1 PCT/CN2021/109917 CN2021109917W WO2023004830A1 WO 2023004830 A1 WO2023004830 A1 WO 2023004830A1 CN 2021109917 W CN2021109917 W CN 2021109917W WO 2023004830 A1 WO2023004830 A1 WO 2023004830A1
Authority
WO
WIPO (PCT)
Prior art keywords
active material
material layer
battery
pole piece
current collector
Prior art date
Application number
PCT/CN2021/109917
Other languages
English (en)
French (fr)
Inventor
车欢
陈威
许宝华
王梓
李世松
Original Assignee
宁德时代新能源科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to JP2023520500A priority Critical patent/JP2023543933A/ja
Priority to KR1020237011273A priority patent/KR20230061488A/ko
Priority to EP21951411.4A priority patent/EP4216305A1/en
Priority to CN202180073295.3A priority patent/CN116547829A/zh
Priority to PCT/CN2021/109917 priority patent/WO2023004830A1/zh
Publication of WO2023004830A1 publication Critical patent/WO2023004830A1/zh
Priority to US18/133,527 priority patent/US20230246199A1/en

Links

Images

Classifications

    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • 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 energy storage devices, in particular to a battery pole piece, an electrode assembly, a battery cell, a battery and an electrical device.
  • Battery cells are widely used in electronic equipment, such as mobile phones, laptop computers, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.
  • the battery cells may include nickel-cadmium battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, secondary alkaline zinc-manganese battery cells, and the like.
  • the battery cell During the use of the battery cell, the battery cell often undergoes lithium precipitation, and the precipitated lithium will pierce the diaphragm and cause a short circuit, thereby causing a safety risk. Therefore, the problem of lithium analysis of battery cells needs to be solved urgently.
  • the present application provides a battery pole piece, an electrode assembly, a battery cell, a battery and an electrical device.
  • the active material layer and the insulating layer coated on the battery pole piece can form a clear boundary and reduce the risk of lithium precipitation. risk and improve product quality.
  • the first aspect of the embodiment of the present application provides a battery pole piece, the battery pole piece includes a current collector, at least one side of the current collector includes a connected coated area and an uncoated area, and the coated area is coated with an active material layer and an insulating layer,
  • the insulating layer is located on the side of the active material layer close to the uncoated region, wherein the insulating layer includes a connected first part and a second part, and the second part is located in an edge region of the insulating layer close to the side of the active material layer, and the active material layer is configured as The second part is covered and the first part is not covered, so that the active material layer and the insulating layer partially overlap along the thickness direction of the pole piece.
  • the second part is covered by the active material layer, and the second part will not penetrate to the upper surface of the active material layer, reducing the problem of blurred boundaries in the edge area of the insulating layer on the side close to the active material layer due to the mixing of the coating slurry, In this way, a clear boundary line is formed, and the misjudgment of the boundary of the active material layer is reduced, which causes the size of the active material layer of the positive electrode sheet and the active material layer of the negative electrode sheet to fail to meet the requirements, thereby reducing the problem of lithium analysis.
  • the thickness of the insulating layer is not greater than the thickness of the active material layer.
  • the thickness difference between the thickness of the active material layer and the thickness of the insulating layer reduces the risk of the active material layer and the slurry of the insulating layer being mixed and penetrating to the upper surface of the active material layer.
  • the thickness of the second portion is no greater than the thickness of the first portion.
  • the thickness of the insulating layer is small, which reduces the problem that the total thickness of the coating in the overlapping area of the active material layer and the second part increases significantly to form rims, and improves the consistency of the overall thickness of the battery pole piece.
  • the shortest distance between the surface of the second portion facing the current collector and the surface of the current collector is 0-90 ⁇ m.
  • the surface of the second part away from the current collector is an inclined plane, and the inclined plane gradually approaches the current collector along the direction in which the first part extends toward the active material layer.
  • the surface of the second part away from the current collector is inclined, which reduces the risk of forming rims due to an increase in the total thickness of the coating in the overlapping area of the active material layer and the second part. Moreover, during the drying process of the coating, the active material layer will slip along the inclined surface when shrinking, which reduces the penetration and mixing of the second part of the coating slurry into the active material layer.
  • the distance between the surface of the second portion away from the current collector and the outer surface of the active material layer is not less than 20 ⁇ m.
  • the setting of the distance between the surface of the second part away from the current collector and the outer surface of the active material layer can ensure that the second part is sufficiently far away from the outer surface of the active material layer, reducing the penetration of the coating slurry of the second part to the outer surface of the active material layer. superficial possibilities.
  • the second portion has a maximum thickness of 3-90 ⁇ m.
  • the thickness of the second part is set relatively small, so that the coating thickness change in the overlapping area of the active material layer and the second part will be relatively small, and the coating thickness in the overlapping area of the active material layer and the insulating layer will not be obvious increase to form a rim.
  • the width of the second portion is not greater than the width of the first portion.
  • a second aspect of the embodiments of the present application provides an electrode assembly, including the above-mentioned battery pole piece.
  • a third aspect of the embodiments of the present application provides a battery cell, including the above-mentioned electrode assembly.
  • a fourth aspect of the embodiments of the present application provides a battery, including a plurality of battery cells as described above.
  • a fifth aspect of the embodiments of the present application provides an electrical device, which is characterized by comprising the battery as described above, and the battery is used to provide electrical energy.
  • FIG. 1 is a schematic structural view of an electrical device provided by the present application in a specific embodiment
  • Fig. 2 is an exploded schematic view of the battery of some embodiments of the present application.
  • Fig. 3 is an exploded schematic diagram of a battery cell in some embodiments of the present application.
  • Fig. 4 is a schematic cross-sectional view of an electrode assembly according to a specific embodiment of the present application.
  • Figure 5 is a partial schematic diagram of the E-E cross-sectional view of the electrode assembly in Figure 4.
  • Fig. 6 is a partial expanded comparison diagram of the positive pole piece and the negative pole piece of some embodiments of the present application.
  • Fig. 7 is a cross-sectional view of a battery pole piece in an embodiment
  • Fig. 8 is an enlarged view of part I in Fig. 7;
  • Fig. 9 is a cross-sectional view of a battery pole piece in another embodiment
  • Fig. 10 is a cross-sectional view of a battery pole piece in another embodiment.
  • the battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack, and the like.
  • Batteries generally include a case for enclosing one or more battery cells. The box can prevent liquid or other foreign objects from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive pole piece, a negative pole piece and a separator.
  • a battery cell works primarily by moving metal ions between the positive and negative pole pieces.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer Fluid, the positive electrode current collector not coated with the positive electrode active material layer is used as the positive electrode tab.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the negative electrode current collector not coated with the negative electrode active material layer is used as the negative electrode tab.
  • the number of positive pole tabs is multiple and stacked together, and the number of negative pole tabs is multiple and stacked together.
  • an active material layer and an insulating layer are usually coated on the current collector of the pole piece of the battery cell.
  • the colors of the active material layer and the insulating layer are inconsistent.
  • the width of the active material layer can be determined by visually identifying the junction of the active material layer and the insulating layer.
  • the active material layer and the insulating layer were coated simultaneously, the active material layer and the insulating layer would infiltrate and blend at the boundary during the drying process, and the insulating layer penetrated to the surface of the active material layer, resulting in final drying. Afterwards, the boundaries between the active material layer and the insulating layer are blurred.
  • the active material of the negative electrode sheet should cover the active material of the positive electrode sheet, that is, the active material layer of the negative electrode sheet should be wider than that of the positive electrode sheet to avoid the problem of lithium precipitation.
  • the active material layer of the negative electrode sheet should be wider than that of the positive electrode sheet to avoid the problem of lithium precipitation.
  • a fuzzy boundary is generated, which makes the judgment of the position of the active material layer deviate, which may cause the positive pole piece in the electrode assembly to not be completely covered by the negative pole piece.
  • the situation of coating will lead to the lithium separation of the battery cell at this position, which will affect the performance of the battery cell.
  • the applicant improved the coating structure of the active material layer and the insulating layer coated on the battery pole piece, and partially overlapped the active material layer and the insulating layer to solve the above problems.
  • the embodiments of the present application are further described below.
  • FIG. 1 is a schematic structural diagram of a specific embodiment of an electrical device provided by the present application.
  • the embodiment of the present application provides a battery B and an electric device using the battery B as a power source.
  • Electric devices using battery B as a power source include equipment such as vehicles A, ships, and small aircraft.
  • the device uses battery B to provide electrical energy to generate driving force for driving the device.
  • the device can also use electricity and other types of energy (such as fossil energy) at the same time to jointly generate driving force. All devices that can use the battery B as a power source are within the protection scope of the present application.
  • the electric device is vehicle A as an example, the vehicle A in the embodiment of the present application can be a new energy vehicle, the new energy vehicle can be a pure electric vehicle, or a hybrid vehicle or an extended-range vehicle, etc. .
  • a vehicle A includes a motor M, a controller C, and a battery B.
  • the battery B is installed horizontally at the bottom of the vehicle body.
  • the controller C controls the battery B to supply power to the motor M.
  • the motor M is connected to the wheels on the vehicle body through a transmission mechanism to drive the vehicle A forward.
  • the battery B may include a plurality of battery cells D, where the multiple battery cells D may be connected in series, in parallel or in parallel, and the hybrid connection refers to a mixture of series and parallel connections.
  • Battery B may also be referred to as a battery pack.
  • a plurality of battery cells D can be connected in series, parallel or mixed to form a battery module, and then a plurality of battery modules can be connected in series, parallel or mixed to form a battery B. That is to say, a plurality of battery cells D can directly form a battery B, or can first form a battery module, and then the battery module can form a battery B.
  • Fig. 2 is an exploded schematic view of battery B of some embodiments of the present application.
  • the battery B includes a case F and a battery cell D, and the battery cell D is accommodated in the case F.
  • the box F can be in various shapes, such as a cylinder, a cuboid, and the like. Of course, the box F can have various structures.
  • the box F may include an upper box F1 and a lower box F2 , and the upper box F1 and the lower box F2 cover each other to define an accommodating space for accommodating the battery cells D.
  • battery B there may be one or more battery cells D. If there are multiple battery cells D, the multiple battery cells D can be connected in series, in parallel, or in parallel.
  • the mixed connection means that the multiple battery cells D are both connected in series and in parallel.
  • FIG. 3 is an exploded schematic diagram of a battery cell D in some embodiments of the present application.
  • a battery cell D generally includes an electrode assembly 100 , a casing 200 and an end cap assembly 300 .
  • the end cap assembly 300 covers the opening of the casing 200 to provide a closed space for the electrode assembly 100 and the electrolyte.
  • the housing 200 can be in various shapes, such as a cylinder, a cuboid, and the like.
  • the shape of the case 200 may be determined according to the specific shape of the electrode assembly 100 . For example, if the electrode assembly 100 has a cylindrical structure, the casing 200 may be a cylindrical structure; if the electrode assembly 100 is a rectangular parallelepiped, the casing 100 may be a rectangular parallelepiped. It can be understood that the shape of the casing 200 and the shape of the electrode assembly 100 may also be different.
  • the housing 200 is a hollow cuboid structure with one end open.
  • the housing 200 may also be made of various materials, such as plastic, copper, iron, aluminum, stainless steel, aluminum alloy, etc., which are not particularly limited in this embodiment of the present application.
  • the end cap assembly 300 is used to close the opening of the housing 200 .
  • the electrode assembly 100 When assembling the battery cell D, first place the electrode assembly 100 in the case 200, then electrically connect and fix the electrode assembly 100 with the end cap assembly 300, and then fix the end cap assemblies 300 on both sides with the case 200 to complete Assembly of the battery cell D.
  • FIG. 4 is a schematic cross-sectional view of an electrode assembly 100 according to a specific embodiment of the present application.
  • an electrode assembly 100 in a specific embodiment of the present application is wound from a battery pole piece 1 and a separator 2 , the battery pole piece 1 includes a positive pole piece 1 a and a negative pole piece 1 b, and the separator 2 It is an insulator interposed between the positive pole piece 1a and the negative pole piece 1b.
  • FIG. 5 is a partial schematic diagram of the E-E cross-sectional view of the electrode assembly 100 in FIG. 4 .
  • the positive electrode sheet 1a includes a positive electrode current collector 11a and a positive electrode active material layer 12a, the positive electrode current collector 11a includes a coated area and an uncoated area, and the positive electrode active material layer 12a is coated on the positive electrode current collector 11a.
  • the uncoated area of the positive electrode collector 11a protrudes from the coated area to form a positive electrode tab 111a (see FIG. 6 ).
  • the material of the positive electrode current collector 11a may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate.
  • the positive electrode active material layer 12a can only be coated on one surface of the positive electrode current collector 11a, or can be coated with the positive electrode active material layer 12a on both surfaces of the positive electrode current collector 11a, the positive electrode shown in FIG. 4 Both surfaces of the current collector 11a are coated with the positive electrode active material layer 12a at the same time.
  • Negative electrode sheet 1b includes negative electrode current collector 11b and negative electrode active material layer 12b, negative electrode current collector 11b includes coated area and uncoated area, negative electrode active material layer 12b is coated on the surface of negative electrode current collector 11b, along the pole sheet width direction X, the uncoated area of the negative electrode current collector 11b protrudes from the coated area to form a positive electrode tab 111b (see FIG. 6 ).
  • the material of the negative electrode current collector 11b may be copper, and the negative electrode active material may be carbon or silicon.
  • the negative electrode active material layer 12b can only be coated on one surface of the negative electrode current collector 11b, or can be coated with the negative electrode active material layer 12b on both surfaces of the negative electrode current collector 11b.
  • the negative electrode shown in FIG. 4 Both surfaces of the current collector 11b are coated with the positive electrode active material layer 12a at the same time.
  • Fig. 6 is a partial expanded comparison diagram of the positive pole piece 1a and the negative pole piece 1b of some embodiments of the present application.
  • the electrode assembly 100 is wound from the positive pole piece 1a, the negative pole piece 1b, and the separator 2 interposed between the positive pole piece 1a and the negative pole piece 1b. After the electrode assembly 100 is unfolded, it is formed A structure in which the positive electrode sheet 1a, the separator 2, and the negative electrode sheet 1b are laminated.
  • Figure 5 shows a partial schematic view of the positive pole piece 1a and the negative pole piece 1b in the electrode assembly 100. In order to clearly show the size relationship between the positive pole piece 1a and the negative pole piece 1b, the expanded separator is not shown in Figure 6 2, and part of the negative pole piece 1b is removed on the right side of the dotted line in the figure to show the size state of the positive pole piece 1a.
  • the coating area of the positive pole piece 1a is coated with a positive electrode active material layer 12a, and the uncoated area forms a positive pole tab 111a, and the positive pole tab 111a is arranged at intervals along the length direction Y of the pole piece.
  • a plurality of positive electrode tabs 111a are overlapped.
  • the coated area of the negative pole piece 1b is coated with a negative electrode active material layer 12b, and the uncoated area forms a negative pole tab 111b, and the negative pole tabs 111b are arranged at intervals along the length direction Y of the pole piece.
  • the Electro assembly 100 is assembled, the Multiple negative tabs 111b overlap.
  • FIG. 6 does not show the full length of the positive pole piece 1a and the negative pole piece 1b, nor does it show all the positive pole tabs 111a and the negative pole tabs 111b.
  • the negative electrode active material layer 12b of the negative electrode sheet 1b should cover the positive electrode active material layer 12a of the positive electrode sheet 1a, that is, the width H1 of the positive electrode active material layer 12a should be smaller than the width H2 of the negative electrode active material layer 1b , so that the positive electrode active material layer 12a and the negative electrode active material layer 1b maintain at least a width difference ⁇ H.
  • the width difference ⁇ H is generally required to meet 0 ⁇ H ⁇ 2.5mm, so that the negative electrode activity of the negative electrode sheet 1b can be guaranteed
  • the material layer 12b covers the active material layer 12a of the positive pole piece, reducing the risk of lithium precipitation.
  • FIG. 7 is a cross-sectional view of the battery pole piece 1 in one embodiment.
  • the surface of both sides of the current collector 11 of the battery pole piece 1 of the present application along the thickness direction Z of the pole piece is coated with an active material layer 12 and an insulating layer 14, which is only one
  • the active material layer 12 and the insulating layer 14 may be coated on only one surface of the current collector 11 .
  • the battery pole piece 1 includes a current collector 11, at least one side of the current collector 11 includes a connected uncoated area and a coated area, and the coated area is coated with an active material layer 12 and an insulating layer 14, and the insulating layer 14 Located on the side of the active material layer 12 close to the uncoated area, the uncoated area forms a tab 111 .
  • the battery pole piece 1 may be a positive pole piece 1a, or a negative pole piece 1b, and both the positive pole piece 1a and the negative pole piece 1b are applicable to the structures in the following embodiments.
  • the current collector 11 is a positive pole current collector 11a
  • the tab 111 is a positive pole tab 111a
  • the current collector 11 is a negative current collector 11b
  • the tab 111 is the negative tab 111b.
  • the insulating layer 14 includes a connected first portion 141 and a second portion 142, the second portion 142 is located at the edge region of the insulating layer 14 near the active material layer 12, and the active material layer 12 is configured to cover the second The portion 142 does not cover the first portion 141 , so that the projections of the active material layer 12 and the insulating layer 14 along the thickness direction Z of the pole piece overlap.
  • the edge of the active material layer 12 is in contact with the first portion 141 to form a boundary line 15 .
  • the second part 142 is covered by the active material layer 12, and the second part 142 will not penetrate to the upper surface of the active material layer 12, and will not be in the edge area of the insulating layer 14 near the active material layer 12 due to mixing of the coating slurry. The problem of blurred boundaries due to fusion, thus forming a clear boundary line15.
  • Fig. 8 is an enlarged view of part I in Fig. 7 .
  • the thickness w1 of the insulating layer 14 is not greater than the thickness w2 of the active material layer 12 , ie w1 ⁇ w2 .
  • the thickness w1 of the insulating layer 14 refers to the maximum thickness of the insulating layer 14 .
  • the preferred range of the thickness w2 of the active material layer 12 is 50-400 microns ( ⁇ m), the preferred range of the thickness w1 of the insulating layer is 3-90 ⁇ m, when the active material layer 12 covers the second part 142, the coating slurry of the second part 142 material is in contact with the coating slurry inside the active material layer 12, because there is a large thickness difference between the thickness w2 of the active material layer 12 and the thickness w1 of the insulating layer 14, even if the coating slurry of the second part 142 is in contact with the active material The coating slurry inside the layer 12 is mixed, and the mixed slurry will not seep to the upper surface of the active material layer 12 .
  • the thickness w3 of the second portion 142 is not greater than the thickness w4 of the first portion 141 , ie w3 ⁇ w4.
  • the thickness w3 of the second part 142 is smaller than the thickness w4 of the first part 141 outside the exposed active material layer 12, so that the second part 142 with a smaller thickness extends into the inside of the active material layer 12, and the thickness w3 of the second part is smaller , the coating thickness of the area where the active material layer 12 covers the second part 142 will not be significantly increased to form a rim, so that the overall thickness of the battery pole piece 1 is guaranteed to be consistent, and the coated battery pole piece 1 is rolled When being wound into a pole piece coil material, the risk of the battery pole piece 1 bursting and breaking due to the bulging of the battery pole piece 1 during winding is reduced.
  • the range of the shortest distance w5 between the surface of the second part 142 facing the current collector 11 and the surface of the current collector 11 should satisfy 0 ⁇ w5 ⁇ 0.9 ⁇ w2, that is, the surface of the second part 142 facing the current collector 11 and
  • the shortest distance w5 on the surface of the current collector 11 should be less than or equal to 0.9 times the thickness w2 of the active material layer 12 .
  • the shortest distance w5 between the surface 1421 of the second portion 142 facing the current collector 11 and the surface of the current collector 11 is 0-90 ⁇ m.
  • the surface of the second part 142 facing the current collector 11 is the lower surface of the second part 142 along the thickness direction Z of the pole piece, and the surface of the second part 142 away from the current collector 11 is the upper surface of the second part 142 along the thickness direction Z of the pole piece.
  • the second part 142 extends into the active material layer 12.
  • the active material layer 12 can cover the upper surface and the lower surface of the second part 142 along the pole piece thickness direction Z, and the second part 142 extends into the active material layer along the pole piece width direction X.
  • the end surface inside the substance layer 12 can also only cover the upper surface and the end surface of the second part 142 along the thickness direction Z of the pole piece.
  • the shortest distance w5 between the surface of the second part 142 facing the current collector 11 and the surface of the current collector 11 is 0, That is, the surface of the second part 142 facing the current collector 11 is directly coated on the current collector 11 .
  • the setting of the shortest distance w5 between the surface of the second part 142 facing the current collector 11 and the surface of the current collector 11 can ensure that the second part 142 is sufficiently close to the current collector 11 and away from the outer surface of the active material layer 12, reducing the size of the second part 142.
  • the distance w6 between the surface of the second portion 142 away from the current collector 11 and the outer surface of the active material layer 12 should satisfy 0.01 ⁇ w2 ⁇ w6 ⁇ 0.9 ⁇ w2. In a specific embodiment, the distance w6 between the surface of the second portion 142 away from the current collector 11 and the outer surface of the active material layer 12 is not less than 20 ⁇ m.
  • the setting of the distance w6 between the second part 142 away from the surface of the current collector 11 and the outer surface of the active material layer 12 can ensure that the second part 142 is sufficiently far away from the outer surface of the active material layer 12, reducing the coating slurry of the second part 142 Possibility of penetration into the outer surface of the active material layer 12 .
  • the thickness w3 of the second portion 142 should satisfy 0.01 ⁇ w2 ⁇ w3 ⁇ 0.9 ⁇ w2. In a specific embodiment, the thickness w3 of the second portion 142 is 3-90 ⁇ m.
  • the thickness w3 of the second part 142 is set relatively small, so that the coating thickness change in the overlapping area of the active material layer 12 and the second part 142 will be relatively small, and the overlapping of the active material layer 12 and the insulating layer 142 will not be
  • the thickness of the coating in the area is significantly increased to form a bulge, so that the overall thickness of the battery pole piece 1 is guaranteed to be consistent. risk.
  • the tab 111 is obtained by die-cutting the base material of the battery pole piece 1, and the die-cutting position of the tab 111 needs to be located on the insulating layer 14, so the insulating layer 14 needs to have a certain width.
  • the first part 141 The range of the width L1 is 0.1-15 millimeters (mm), so as to ensure that the die-cutting position of the tab 111 is located on the first part 141 .
  • the width L2 of the second portion 142 is not greater than the width L1 of the first portion 141 , ie L2 ⁇ L1.
  • the width L2 of the second portion 142 is in the range of 0.01-2mm, so as to ensure that the projections of the active material layer 12 and the second portion 142 overlap in the thickness direction Z of the pole piece, and avoid the second portion 142 from overlapping with the first The overlapping width of the coating layer 12 is too wide.
  • FIG. 9 is a cross-sectional view of another embodiment of the battery pole piece 1 .
  • the surface of the second portion 142 away from the current collector 11 is a slope 1421 , and the slope 1421 gradually approaches the current collector 11 along the direction in which the first portion 141 extends toward the active material layer 12 .
  • the projection of the active material layer 12 along the thickness direction of the pole piece overlaps with the second part 142, and the thickness w3 of the second part 142 gradually decreases from the position where it meets the first part 141 along the opposite direction of the width direction X of the pole piece. This reduces the risk of bulging due to an increase in the total thickness of the coating in the overlapping region of the active material layer 12 and the second portion 142 .
  • the active material layer 12 will slip along the inclined slope 1421 when shrinking, reducing the coating of the second part 142.
  • the slurry penetrates into the active material layer 12 and blends.
  • the thickness w4 of the first portion 141 is equal to the thickness w2 of the active material layer, which is just an example.
  • Fig. 10 is a cross-sectional view of a battery pole piece 1 in another embodiment.
  • the surface of the second portion 142 away from the current collector 11 is a slope 1421 , and along the thickness direction Z of the pole piece, the thickness w4 of the first portion 141 is smaller than the thickness w2 of the active material layer.
  • the insulating layer 14 has a thickness smaller than that of the active material layer 12, the mixing of the coating slurry can be reduced, resulting in a significant increase in the coating thickness in the overlapping region of the active material layer 12 and the insulating layer 142. And form the problem of drum edge.
  • the shape of the second part 142 in the present application is not limited to the situation described in the above embodiments, and it may be a combination of various structural shapes of the various embodiments in the present application.
  • the battery pole piece 1 provided by the present application is coated with an active material layer 12 and an insulating layer 14.
  • the insulating layer 14 includes a connected first part 141 and a second part 142.
  • the second part 142 is located on the insulating layer 14 close to the active material.
  • the active material layer 12 is configured to cover the second part 142, so that the active material layer 12 overlaps with the projection part of the insulating layer 14 along the thickness direction Z of the pole piece, and the second part 142 will not penetrate into the
  • the upper surface of the active material layer 12 does not have the problem of blurred interface due to the mixing of the coating slurry in the edge region of the insulating layer 14 near the active material layer 12 , thus forming a clear boundary line 15 .
  • the battery cell D and the battery B can ensure that the negative pole piece 1b covers the positive pole piece 1a, reduces the risk of lithium deposition in the battery, and improves the safety performance of the battery.

Abstract

本申请涉及一种电池极片、电极组件、电池单体、电池及用电装置，电池极片包括集流体，集流体至少一面包括相连的涂覆区和未涂覆区，涂覆区涂敷有活性物质层和绝缘层，绝缘层位于活性物质层靠近未涂覆区一侧，其中，绝缘层包括相连的第一部分和第二部分，第二部分位于绝缘层靠近活性物质层一侧的边缘区域，活性物质层被配置为覆盖第二部分，以使活性物质层与绝缘层沿极片厚度方向部分重叠。本申请提供一种电池极片、电极组件、电池单体、电池及用电装置，电池极片上涂敷的活性物质层和绝缘层能够形成清晰的边界，提高产品优率。

Description

电池极片、电极组件、电池单体、电池及用电装置 技术领域
本申请涉及储能器件技术领域，尤其涉及一种电池极片、电极组件、电池单体、电池及用电装置。
背景技术
电池单体广泛用于电子设备，例如手机、笔记本电脑、电瓶车、电动汽车、电动飞机、电动轮船、电动玩具汽车、电动玩具轮船、电动玩具飞机和电动工具等等。电池单体可以包括镉镍电池单体、氢镍电池单体、锂离子电池单体和二次碱性锌锰电池单体等。
在电池单体的使用过程中，电池单体时常发生析锂，析出的锂会刺破隔膜造成短路，从而引发安全风险。因此，电池单体的析锂问题亟需解决。
发明内容
为了解决上述问题，本申请提供一种电池极片、电极组件、电池单体、电池及用电装置，电池极片上涂敷的活性物质层和绝缘层能够形成清晰的边界，减小析锂的风险，提高产品优率。
本申请实施例第一方面提供一种电池极片，电池极片包括集流体，集流体至少一面包括相连的涂覆区和未涂覆区，涂覆区涂敷有活性物质层和绝缘层，绝缘层位于活性物质层靠近未涂覆区一侧，其中，绝缘层包括相连的第一部分和第二部分，第二部分位于绝缘层靠近活性物质层一侧的边缘区域，活性物质层被配置为覆盖第二部分且未覆盖所述第一部分，以使活性物质层与绝缘层沿极片厚度方向部分重叠。
第二部分被活性物质层覆盖，第二部分不会渗透至活性物质层的上表 面，减小绝缘层靠近活性物质层一侧的边缘区域由于涂层浆料混融而产生界线模糊的问题，从而形成清晰的边界线，减小对活性物质层边界误判造成正极极片活性物质层和负极极片活性物质层的尺寸不满足要求，从而析锂的问题。
在一些实施例中，绝缘层的厚度不大于活性物质层的厚度。
活性物质层的厚度与绝缘层的厚度的存在厚度差，减小活性物质层与绝缘层浆料混融并渗透至活性物质层的上表面的风险。
在一些实施例中，第二部分的厚度不大于第一部分的厚度。
绝缘层的厚度较小，减小活性物质层与第二部分的重叠区域的涂层总厚度明显增加而形成鼓边的问题，提高电池极片的整体厚度的一致性。
在一些实施例中，沿厚度方向，第二部分朝向集流体的表面与集流体表面的最短距离为0-90μm。
在一些实施例中，第二部分远离集流体的表面为斜面，且斜面沿着第一部分向活性物质层延伸的方向，逐渐靠近集流体。
第二部分远离集流体的表面为斜面，减小了活性物质层与第二部分的重叠区域的涂层总厚度增加而形成鼓边的风险。并且，在涂层干燥过程中，活性物质层收缩时会沿倾斜的表面产生滑移，减小了第二部分的涂层浆料向活性物质层的渗透混融。
在一些实施例中，沿极片厚度方向，第二部分远离集流体的表面与活性物质层外表面的距离不小于20μm。
第二部分远离集流体的表面与活性物质层外表面的距离的设置，能够保证第二部分充分远离活性物质层的外表面，减小第二部分的涂层浆料渗透至活性物质层的外表面的可能性。
在一些实施例中，第二部分的最大厚度为3-90μm。
将第二部分的厚度设置的相对较小，使活性物质层与第二部分重叠区域的涂层厚度变化也会相对较小，不会使活性物质层与绝缘层的重叠区域的 涂层厚度明显增加而形成鼓边。
在一些实施例中，沿活性物质层与绝缘层排列的方向，第二部分的宽度不大于第一部分的宽度。
通过第一部分的宽度与第二部分的宽度的设置能够避免第二部分与活性物质层的重叠宽度过宽。
本申请实施例的第二方面提供一种电极组件，包括如上所述的电池极片。
本申请实施例的第三方面提供一种电池单体，包括如上所述的电极组件。
本申请实施例的第四方面提供一种电池，包括多个如上所述的电池单体。
本申请实施例的第五方面提供一种用电装置，其特征在于，包括如上所述的电池，所述电池用于提供电能。
应当理解的是，以上的一般描述和后文的细节描述仅是示例性的，并不能限制本申请。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需使用的附图作简单地介绍，显而易见，以下描述的附图仅仅是本申请的具体实施例，本领域技术人员在不付出创造性劳动的前提下，可以根据以下附图获得其他实施例。
图1为本申请所提供的用电装置在一种具体实施例中的结构示意图；
图2为本申请一些实施例的电池的分解示意图；
图3为本申请一些实施例的电池单体的分解示意图；
图4为本申请一种具体实施例的电极组件的截面示意图；
图5为图4中的电极组件的E-E向剖视图的局部示意图；
图6为本申请一些实施例的正极极片与负极极片局部展开对比图；
图7为电池极片在一个实施例中的剖视图；
图8为图7中的Ⅰ部放大图；
图9为电池极片在另一个实施例中的剖视图；
图10为电池极片在又一个实施例中的剖视图。
附图标记：
A-车辆；
B-电池；
C-控制器；
D-电池单体；
F-箱体；
F1-上箱体；
F2-下箱体；
M-马达；
100-电极组件；
200-壳体；
300-端盖组件；
1-电池极片；
1a-正极极片；
1b-负极极片；
11-集流体；
11a-正极集流体；
11b-负极集流体；
111-极耳；
111a-正极极耳；
111b-负极极耳；
12-活性物质层；
12a-正极活性物质层；
12b-负极活性物质层；
14-绝缘层；
141-第一部分；
142-第二部分；
15-边界线；
2-隔离膜；
X-极片宽度方向；
Y-极片长度方向；
Z-极片厚度方向。
此处的附图被并入说明书中并构成本说明书的一部分，示出了符合本申请的实施例，并与说明书一起用于解释本申请的原理。
具体实施方式
为了更好的理解本申请的技术方案，下面结合附图对本申请实施例进行详细描述。
应当明确，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。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其它实施例，都属于本申请保护的范围。
在本申请实施例中使用的术语是仅仅出于描述特定实施例的目的，而非旨在限制本申请。在本申请实施例和所附权利要求书中所使用的单数形式的“一种”、“所述”和“该”也旨在包括多数形式，除非上下文清楚地表示其他含义。
应当理解，本文中使用的术语“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A， 同时存在A和B，单独存在B这三种情况。另外，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
需要注意的是，本申请实施例所描述的“上”、“下”、“左”、“右”等方位词是以附图所示的角度来进行描述的，不应理解为对本申请实施例的限定。此外，在上下文中，还需要理解的是，当提到一个元件连接在另一个元件“上”或者“下”时，其不仅能够直接连接在另一个元件“上”或者“下”，也可以通过中间元件间接连接在另一个元件“上”或者“下”。
本申请的实施例所提到的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。例如，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
电池单体包括电极组件和电解液，电极组件由正极极片、负极极片和隔离膜组成。电池单体主要依靠金属离子在正极极片和负极极片之间移动来工作。正极极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂覆正极活性物质层的正极集流体凸出于已涂覆正极活性物质层的正极集流体，未涂覆正极活性物质层的正极集流体作为正极极耳。负极极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂覆负极活性物质层的负极集流体凸出于已涂覆负极活性物质层的负极集流体，未涂覆负极活性物质层的负极集流体作为负极极耳。为了保证通过大电流而不发生熔断，正极极耳的数量为多个且层叠在一起，负极极耳的数量为多个且层叠在一起。
在现有技术中，通常电池单体的极片的集流体上涂布活性物质层和绝缘层。活性物质层和绝缘层颜色不一致，涂布完成后，通过视觉识别活性物质层和绝缘层的交界位置，以确定活性物质层的宽度。
申请人发现，在活性物质层与绝缘层同步涂布时，活性物质层与绝缘层在干燥过程中，会在边界位置产生相互渗透混融，而且绝缘层向活性物质层表面渗透，导致最终干燥后的活性物质层和绝缘层的边界位置界线模糊。
在电池单体中，要求负极极片的活性物质要包覆正极极片的活性物质，即负极极片的活性物质层要比正极极片的活性物质层宽，避免析锂的问题。活性物质层与绝缘层在干燥过程中，由于产生相互渗透混融，产生模糊的边界，使活性物质层位置的判断产生偏差，可能会造成电极组件内的正极极片未能被负极极片完全包覆的情况，从而导致电池单体在该位置析锂，影响电池单体的性能。
基于申请人发现的上述问题，申请人对电池极片涂敷的活性物质层和绝缘层的涂层结构进行改进，将活性物质层和绝缘层部分重叠设置以解决上述问题。下面对本申请实施例进行进一步描述。
图1为本申请所提供用电装置在一种具体实施例中的结构示意图。
如图1所示，本申请实施例提供一种电池B，以及使用该电池B作为电源的用电装置。使用电池B作为电源的用电装置包括车辆A、船舶、小型飞机等设备，该装置采用电池B提供电能，产生驱动该装置的驱动力。该装置也可以同时使用电能和其他类型的能源(例如化石能源)，共同产生驱动力。只要能够使用电池B作为电源的装置均在本申请的保护范围内。
如图1所示，用电装置以车辆A为例，本申请实施例中的车辆A可为新能源汽车，该新能源汽车可为纯电动汽车，也可为混合动力汽车或增程式汽车等。比如，车辆A包括马达M、控制器C和电池B。电池B水平设置于车辆主体的底部，控制器C控制电池B为马达M供电，马达M通过传动机构与车辆主体上的车轮连接，从而驱动车辆A行进。
为了满足不同的使用电力需求，电池B可以包括多个电池单体D，其中，多个电池单体D之间可以串联或并联或混联，混联是指串联和并联的混合。电池B也可以称为电池包。可选地，多个电池单体D可以先串联或并联或混联组成电池模块，多个电池模块再串联或并联或混联组成电池B。也就是说，多个电池单体D可以直接组成电池B，也可以先组成电池模块，电池模块再组成电池B。
图2为本申请一些实施例的电池B的分解示意图。
如图2所示，电池B包括箱体F和电池单体D，电池单体D容纳于箱体F内。箱体F可以是多种形状，比如，圆柱体、长方体等。当然，箱体F可以是多种结构。
在一些实施例中，箱体F可以包括上箱体F1和下箱体F2，上箱体F1与下箱体F2相互盖合，以限定出用于容纳电池单体D的容纳空间。
在电池B中，电池单体D可以是一个、也可以是多个。若电池单体D为多个，多个电池单体D之间可串联或并联或混联，混联是指多个电池单体D中既有串联又有并联。
图3为本申请一些实施例的电池单体D的分解示意图。
如图3所示，电池单体D一般包括电极组件100、壳体200和端盖组件300，端盖组件300盖合于壳体200的开口，以为电极组件100和电解液提供一个密闭空间。壳体200可以是多种形状，比如，圆柱体、长方体等。壳体200的形状可根据电极组件100的具体形状来确定。比如，若电极组件100为圆柱体结构，壳体200则可选用为圆柱体结构；若电极组件100为长方体结构，壳体100则可选用长方体结构。可以理解的是，壳体200的形状与电极组件100的形状也可以不同。
示例性的，在图3中，壳体200为一端开口的空心长方体结构。壳体200的材质也可以是多种，比如，塑料、铜、铁、铝、不锈钢、铝合金等，本申请实施例对此不作特殊限制。
如图3所示，端盖组件300用于封闭壳体200的开口。组装电池单体D时，先将电极组件100置于壳体200内，再将电极组件100与端盖组件300电连接并固定后，将两侧端盖组件300与壳体200固定连接，完成电池单体D的组装。
图4为本申请一种具体实施例的电极组件100的截面示意图。
如图4所示，本申请一种具体实施例中的电极组件100由电池极片1和隔离膜2卷绕而成，电池极片1包括正极极片1a和负极极片1b，隔离膜2是介于正极极片1a和负极极片1b的绝缘体。
图5为图4中的电极组件100的E-E向剖视图的局部示意图。
如图5所示，正极极片1a包括正极集流体11a和正极活性物质层12a，正极集流体11a包括涂覆区和未涂覆区，正极活性物质层12a涂覆于正极集流体11a涂覆区的表面，沿极片宽度方向X，正极集流体11a的未涂覆区凸出于涂覆区形成正极极耳111a(见图6)。以锂离子电池为例，正极集流体11a的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。沿极片厚度方向Z，正极活性物质层12a可以只涂覆正极集流体11a的一个表面，也可以在正极集流体11a两个表面同时涂覆正极活性物质层12a，图4中所显示的正极集流体11a两个表面同时涂覆正极活性物质层12a。
负极极片1b包括负极集流体11b和负极活性物质层12b，负极集流体11b包括涂覆区和未涂覆区，负极活性物质层12b涂覆于负极集流体11b的表面，沿极片宽度方向X，负极集流体11b的未涂覆区凸出于涂覆区形成正极极耳111b(见图6)。负极集流体11b的材料可以为铜，负极活性物质可以为碳或硅等。沿极片厚度方向Z，负极活性物质层12b可以只涂覆负极集流体11b的一个表面，也可以在负极集流体11b两个表面同时涂覆负极活性物质层12b，图4中所显示的负极集流体11b两个表面同时涂覆正极活性物质层12a。
图6为本申请一些实施例的正极极片1a与负极极片1b局部展开对比图。
在一些实施例中，电极组件100由正极极片1a和负极极片1b，以及介于正极极片1a和负极极片1b之间的隔离膜2卷绕而成，电极组件100展开后，形成正极极片1a、隔离膜2、和负极极片1b层叠的结构。图5中显示了电极组件100中的正极极片1a和负极极片1b展开的局部示意图，为了清楚表示正极极片1a和负极极片1b的尺寸关系，图6中并未显示展开的隔离膜2，并在图中虚线的右侧去除了部分负极极片1b，以显示正极极片1a的尺寸状态。
如图6所示，正极极片1a的涂覆区上涂覆有正极活性物质层12a，未涂覆区形成正极极耳111a，正极极耳111a沿极片长度方向Y间隔设置，在进行电极组件100的卷芯时，使多个正极极耳111a重叠。负极极片1b的涂覆 区上涂覆有负极活性物质层12b，未涂覆区形成负极极耳111b，负极极耳111b沿极片长度方向Y间隔设置，在组装成电极组件100时，使多个负极极耳111b重叠。图6中并未显示正极极片1a和负极极片1b的全长，也未显示全部的正极极耳111a和负极极耳111b。
沿极片宽度方向X，负极极片1b的负极活性物质层12b要包覆正极极片1a的正极活性物质层12a，即正极活性物质层12a的宽度H1要小于负极活性物质层1b的宽度H2，从而使正极活性物质层12a与负极活性物质层1b至少保持宽度差ΔH，为满足电池的性能需要，宽度差ΔH一般要求满足0≤ΔH≤2.5mm，从而能够保证负极极片1b的负极活性物质层12b包覆正极极片活性物质层12a，减小产生析锂问题的风险。
图7为电池极片1在一个实施例中的剖视图。
如图7所示，在一个具体实施例中，本申请的电池极片1的集流体11沿极片厚度方向Z的两侧表面均涂覆有活性物质层12和绝缘层14，这只是一个示例，也可以只在集流体11的一个表面上涂覆活性物质层12和绝缘层14。
在一些实施例中，电池极片1包括集流体11，集流体11至少一面包括相连的未涂覆区和涂覆区，涂覆区涂敷有活性物质层12和绝缘层14，绝缘层14位于活性物质层12靠近未涂覆区一侧，未涂覆区形成极耳111。电池极片1可以是正极极片1a，也可以是负极极片1b，正极极片1a及负极极片1b均可适用以下实施例中的结构。当电池极片1为正极极片1a时，集流体11为正极集流体11a，极耳111为正极极耳111a，当电池极片1为负极极片1b时，集流体11为负极集流体11b，极耳111为负极极耳111b。
如图7所示，绝缘层14包括相连的第一部分141和第二部分142，第二部分142位于绝缘层14靠近活性物质层12一侧的边缘区域，活性物质层12被配置为覆盖第二部分142且未覆盖第一部分141，以使活性物质层12与绝缘层14沿极片厚度方向Z的投影部分重叠。
活性物质层12的边缘与第一部分141相接，并形成边界线15。第二部分142被活性物质层12覆盖，第二部分142的不会渗透至活性物质层12的 上表面，不会在绝缘层14靠近活性物质层12一侧的边缘区域由于涂层浆料混融而产生界线模糊的问题，从而形成清晰的边界线15。
图8为图7中的Ⅰ部放大图。
如图8所示，沿极片厚度方向Z，绝缘层14的厚度w1不大于活性物质层12的厚度w2，即w1≤w2。本实施例中，绝缘层14的厚度w1是指绝缘层14的最大厚度。活性物质层12的厚度w2的优选范围为50-400微米(μm)，绝缘层的厚度w1优选范围3-90μm，在活性物质层12覆盖第二部分142时，第二部分142的涂层浆料与活性物质层12内部的涂层浆料接触，由于活性物质层12的厚度w2与绝缘层14的厚度w1的存在较大的厚度差，即使第二部分142的涂层浆料与活性物质层12内部的涂层浆料发生混融，也不会导致混融的浆料渗出至活性物质层12的上表面。
在一个具体实施例中，第一部分141的厚度w4即为绝缘层14的最大厚度，即w4＝w1。
第二部分142的厚度w3不大于第一部分141的厚度w4，即w3≤w4。第二部分142的厚度w3小于外露的活性物质层12外部的第一部分的141的厚度w4，使具有更小厚度的第二部分142伸入活性物质层12内部，第二部分的厚度w3较小，不会使活性物质层12覆盖第二部分142的区域的涂层厚度明显增加而形成鼓边，从而使电池极片1的整体厚度保证一致，在将涂布后的电池极片1进行卷绕成极片卷料时，减小了由于电池极片1存在鼓边而使电池极片1在收卷时发生胀破断带的风险。
沿极片厚度方向Z，第二部分142朝向集流体11的表面与集流体11表面的最短距离w5的范围应满足0≤w5≤0.9×w2，即第二部分142朝向集流体11的表面与集流体11表面的最短距离w5应小于等于0.9倍的活性物质层12的厚度w2。在一个具体实施例中，第二部分142朝向集流体11的表面1421与集流体11表面的最短距离w5为0-90μm。
第二部分142朝向集流体11的表面即第二部分142沿极片厚度方向Z的下表面，第二部分142远离集流体11的表面即第二部分142沿极片厚度方 向Z的上表面。
第二部分142伸入活性物质层12内部，活性物质层12可以包覆第二部分142沿极片厚度方向Z的上表面和下表面，以及第二部分142沿极片宽度方向X伸入活性物质层12内部的端面。活性物质层12也可以只包覆第二部分142沿极片厚度方向Z的上表面和端面，此时，第二部分142朝向集流体11的表面与集流体11表面的最短距离w5为0，即第二部分142朝向集流体11的表面直接涂覆在集流体11上。
第二部分142朝向集流体11的表面与集流体11表面的最短距离w5的设置，能够保证第二部分142充分靠近集流体11，并远离活性物质层12的外表面，减小第二部分142的涂层浆料渗透至活性物质层12的外表面的可能性。
在一些实施例中，沿极片厚度方向Z，第二部分142远离集流体11的表面与活性物质层12外表面的距离w6的范围应满足0.01×w2≤w6≤0.9×w2。在一个具体实施例中，第二部分142远离集流体11的表面与活性物质层12外表面的距离w6不小于20μm。
第二部分142远离集流体11的表面与活性物质层12外表面的距离w6的设置，能够保证第二部分142充分远离活性物质层12的外表面，减小第二部分142的涂层浆料渗透至活性物质层12的外表面的可能性。
在一些实施例中，第二部分142的厚度w3范围应满足0.01×w2≤w3≤0.9×w2。在一个具体实施例中，第二部分142的厚度w3为3-90μm。
将第二部分142的厚度w3设置的相对较小，使活性物质层12与第二部分142重叠区域的涂层厚度变化也会相对较小，不会使活性物质层12与绝缘层142的重叠区域的涂层厚度明显增加而形成鼓边，从而使电池极片1的整体厚度保证一致，在将电池极片1进行电极组件100的卷绕时，减小了由于电池极片1鼓边的风险。
通常极耳111是通过对电池极片1的基材模切得到，极耳111的模切位置需位于绝缘层14上，因此绝缘层14需要具有一定宽度，在一些实施例中，第一部分141的宽度L1的范围为0.1-15毫米(mm)，以确保极耳111的模切 位置位于第一部分141上。
沿活性物质层12与绝缘层14排列的方向(极片宽度方向X)，第二部分142的宽度L2不大于第一部分141的宽度L1，即L2≤L1。在一些实施例中，第二部分142的宽度L2的范围为0.01-2mm，确保活性物质层12与第二部分142在极片厚度方向Z的投影重叠，又能够避免第二部分142与第一涂层12的重叠宽度过宽。
图9为电池极片1在另一个实施例中的剖视图。
如图9所示，在一些实施例中，第二部分142远离集流体11的表面为斜面1421，且斜面1421沿着第一部分141向活性物质层12延伸的方向，逐渐靠近集流体11。此时，活性物质层12沿极片厚度方向的投影与第二部分142重叠，第二部分142的厚度w3从与第一部分141交接的位置沿极片宽度方向X的反方向逐渐减小，减小了活性物质层12与第二部分142的重叠区域的涂层总厚度增加而形成鼓边的风险。并且，在同时涂覆活性物质层12和第二部分142后，在涂层干燥过程中，活性物质层12收缩时会沿倾斜的斜面1421产生滑移，减小了第二部分142的涂层浆料向活性物质层12的渗透混融。
图9中，沿极片厚度方向Z，第一部分141的厚度w4等于活性物质层的厚度w2，这只是一个示例。
图10为电池极片1在又一个实施例中的剖视图。
如图10所示，在另一些实施例中，第二部分142远离集流体11的表面为斜面1421，且沿极片厚度方向Z，第一部分141的厚度w4小于活性物质层的厚度w2。在这些实施例中，由于绝缘层14具有比活性物质层12更小的厚度，能够减小涂层浆料混融而导致在活性物质层12与绝缘层142的重叠区域的涂层厚度明显增加而形成鼓边的问题。
当然本申请中的第二部分142的形状并不限于上述实施例中描述的情况，其可以是本申请中各实施例的各种结构形状的组合。
本申请的提供的电池极片1，其上涂覆有活性物质层12和绝缘层14，绝缘层14包括相连的第一部分141和第二部分142，第二部分142位于绝缘 层14靠近活性物质层12一侧的边缘区域，活性物质层12被配置为覆盖第二部分142，以使活性物质层12与绝缘层14沿极片厚度方向Z的投影部分重叠，第二部分142不会渗透至活性物质层12的上表面，不会在绝缘层14靠近活性物质层12一侧的边缘区域由于涂层浆料混融而产生界面模糊的问题，从而形成清晰的边界线15。
使用本申请的电池极片1所组成的电极组件100、电池单体D及电池B，能够确保负极极片1b包覆正极极片1a，减小电池析锂的风险，提高电池的安全性能。
以上所述仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (12)

  1. 一种电池极片，其特征在于，
    所述电池极片包括集流体，
    所述集流体至少一面包括相连的涂覆区和未涂覆区，所述涂覆区涂敷有活性物质层和绝缘层，所述绝缘层位于所述活性物质层靠近所述未涂覆区一侧，
    其中，所述绝缘层包括相连的第一部分和第二部分，所述第二部分位于所述绝缘层靠近所述活性物质层一侧的边缘区域，所述活性物质层被配置为覆盖所述第二部分且未覆盖所述第一部分，以使所述活性物质层与所述绝缘层沿极片厚度方向部分重叠。
  2. 根据权利要求1所述的电池极片，其特征在于，所述绝缘层的最大厚度小于或等于所述活性物质层的最大厚度。
  3. 根据权利要求1所述的电池极片，其特征在于，所述第二部分的最大厚度小于或等于所述第一部分的最大厚度。
  4. 根据权利要求1所述的电池极片，其特征在于，沿极片厚度方向，所述第二部分朝向所述集流体的表面与所述集流体表面的最短距离为0-90μm。
  5. 根据权利要求1所述的电池极片，其特征在于，所述第二部分远离所述集流体的表面为斜面，且所述斜面沿着从所述第一部分向所述活性物质层延伸的方向，逐渐靠近所述集流体。
  6. 根据权利要求1所述的电池极片，其特征在于，沿所述极片厚度方向， 所述第二部分远离所述集流体的表面与所述活性物质层外表面的距离不小于20μm。
  7. 根据权利要求1所述的电池极片，其特征在于，所述第二部分的最大厚度为3-90μm。
  8. 根据权利要求1-7任一项所述的电池极片，其特征在于，沿所述活性物质层与绝缘层排列的方向，所述第二部分的最大宽度小于或等于所述第一部分的最大宽度。
  9. 一种电极组件，其特征在于，包括如权利要求1-8任一项所述的电池极片。
  10. 一种电池单体，其特征在于，包括如权利要求9所述的电极组件。
  11. 一种电池，其特征在于，包括多个如权利要求10所述的电池单体。
  12. 一种用电装置，其特征在于，包括如权利要求11所述的电池，所述电池用于提供电能。
PCT/CN2021/109917 2021-07-30 2021-07-30 电池极片、电极组件、电池单体、电池及用电装置 WO2023004830A1 (zh)

Priority Applications (6)

Application Number Priority Date Filing Date Title
JP2023520500A JP2023543933A (ja) 2021-07-30 2021-07-30 電池極板、電極アセンブリ、電池セル、電池及び電力消費装置
KR1020237011273A KR20230061488A (ko) 2021-07-30 2021-07-30 배터리 극판, 전극 어셈블리, 배터리 셀, 배터리 및 전기 장치
EP21951411.4A EP4216305A1 (en) 2021-07-30 2021-07-30 Battery pole, electrode assembly, battery cell, battery, and electrical apparatus
CN202180073295.3A CN116547829A (zh) 2021-07-30 2021-07-30 电池极片、电极组件、电池单体、电池及用电装置
PCT/CN2021/109917 WO2023004830A1 (zh) 2021-07-30 2021-07-30 电池极片、电极组件、电池单体、电池及用电装置
US18/133,527 US20230246199A1 (en) 2021-07-30 2023-04-12 Battery plate, electrode assembly, battery cell, battery and power consuming device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2021/109917 WO2023004830A1 (zh) 2021-07-30 2021-07-30 电池极片、电极组件、电池单体、电池及用电装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/133,527 Continuation US20230246199A1 (en) 2021-07-30 2023-04-12 Battery plate, electrode assembly, battery cell, battery and power consuming device

Publications (1)

Publication Number Publication Date
WO2023004830A1 true WO2023004830A1 (zh) 2023-02-02

Family

ID=85087383

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/109917 WO2023004830A1 (zh) 2021-07-30 2021-07-30 电池极片、电极组件、电池单体、电池及用电装置

Country Status (6)

Country Link
US (1) US20230246199A1 (zh)
EP (1) EP4216305A1 (zh)
JP (1) JP2023543933A (zh)
KR (1) KR20230061488A (zh)
CN (1) CN116547829A (zh)
WO (1) WO2023004830A1 (zh)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109244362A (zh) * 2018-11-05 2019-01-18 宁德新能源科技有限公司 正极极片、电化学装置及包含其的电子装置
CN109449478A (zh) * 2018-11-05 2019-03-08 宁德新能源科技有限公司 电化学装置
CN111326711A (zh) * 2020-04-02 2020-06-23 宁德新能源科技有限公司 电极极片、电化学装置及包含其的电子装置
WO2020203658A1 (ja) * 2019-03-29 2020-10-08 株式会社エンビジョンＡｅｓｃエナジーデバイス リチウムイオン二次電池用の正極電極、リチウムイオン二次電池用の正極電極シート、および、その製造方法
CN112310409A (zh) * 2019-08-14 2021-02-02 宁德时代新能源科技股份有限公司 电极组件和二次电池

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109244362A (zh) * 2018-11-05 2019-01-18 宁德新能源科技有限公司 正极极片、电化学装置及包含其的电子装置
CN109449478A (zh) * 2018-11-05 2019-03-08 宁德新能源科技有限公司 电化学装置
WO2020203658A1 (ja) * 2019-03-29 2020-10-08 株式会社エンビジョンＡｅｓｃエナジーデバイス リチウムイオン二次電池用の正極電極、リチウムイオン二次電池用の正極電極シート、および、その製造方法
CN112310409A (zh) * 2019-08-14 2021-02-02 宁德时代新能源科技股份有限公司 电极组件和二次电池
CN111326711A (zh) * 2020-04-02 2020-06-23 宁德新能源科技有限公司 电极极片、电化学装置及包含其的电子装置

Also Published As

Publication number Publication date
EP4216305A1 (en) 2023-07-26
CN116547829A (zh) 2023-08-04
KR20230061488A (ko) 2023-05-08
US20230246199A1 (en) 2023-08-03
JP2023543933A (ja) 2023-10-18

Similar Documents

Publication Publication Date Title
US8734985B2 (en) Jelly-roll type battery unit and winding method thereof and lithium secondary battery comprising the same
JP6061162B2 (ja) パウチ型二次電池およびバッテリーパック
JP6613082B2 (ja) リチウムイオン二次電池
CN114583097A (zh) 极片、卷绕电芯以及电池
US20230052005A1 (en) Electrode assembly including disconnection preventing layer and method for manufacturing the same
WO2023004823A1 (zh) 卷绕式电极组件、电池单体、电池及用电设备
US20230238540A1 (en) Electrode assembly, battery cell, battery, and method and device for manufacturing electrode assembly
KR102188429B1 (ko) 전극 활물질 미코팅부를 포함하는 젤리-롤형 전극조립체
US20200373549A1 (en) Pouch type lithium secondary battery preventing internal short circuit
WO2023004830A1 (zh) 电池极片、电极组件、电池单体、电池及用电装置
CN216529252U (zh) 一种电池单体、电池及用电装置
WO2023004829A1 (zh) 电池单体、电池、用电装置及电池单体的制造方法和设备
CN213340472U (zh) 卷芯、电池以及电子产品
CN114586217A (zh) 电化学装置及包括该电化学装置的电子装置
CN214254468U (zh) 电芯及电池
US20230361429A1 (en) Electrode assembly, battery cell, battery, and electrical apparatus
CN112563681B (zh) 非水电解质二次电池
WO2023130237A1 (zh) 电极组件、电池单体、电池以及用电装置
WO2024077602A1 (zh) 电极组件、电池单体、电池及用电设备
US20230369728A1 (en) Electrode assembly, method and system for manufacturing same, battery cell, battery, and electric apparatus
CN219321573U (zh) 电池单体、电池及用电设备
WO2023206949A1 (zh) 圆柱电极组件、电池单体、电池、用电设备和制造方法
JP7468635B2 (ja) 二次電池
CN215989140U (zh) 电池单体、电池以及用电装置
WO2024098340A1 (zh) 电池单体及其制造方法、电池及用电设备

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21951411

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20237011273

Country of ref document: KR

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2023520500

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2021951411

Country of ref document: EP

Effective date: 20230417

WWE Wipo information: entry into national phase

Ref document number: 202180073295.3

Country of ref document: CN

NENP Non-entry into the national phase

Ref country code: DE