WO2024078336A1 - 一种极片、电化学装置及电子设备 - Google Patents

一种极片、电化学装置及电子设备 Download PDF

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Publication number
WO2024078336A1
WO2024078336A1 PCT/CN2023/121953 CN2023121953W WO2024078336A1 WO 2024078336 A1 WO2024078336 A1 WO 2024078336A1 CN 2023121953 W CN2023121953 W CN 2023121953W WO 2024078336 A1 WO2024078336 A1 WO 2024078336A1
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WO
WIPO (PCT)
Prior art keywords
groove
pole piece
along
active material
material layer
Prior art date
Application number
PCT/CN2023/121953
Other languages
English (en)
French (fr)
Inventor
刘芳
吴华
Original Assignee
宁德新能源科技有限公司
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Filing date
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Application filed by 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Publication of WO2024078336A1 publication Critical patent/WO2024078336A1/zh

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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
    • H01M4/13—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
    • 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
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the embodiments of the present application relate to the field of battery technology, and in particular to a pole piece, an electrochemical device, and an electronic device.
  • Ear glue is usually used in lithium-ion batteries.
  • the main function of the ear glue is to bond to the ear of the pole piece to prevent the welding burrs on the ear from piercing the isolation film on the battery cell during the winding and stacking of the pole piece.
  • the inventors of the embodiments of the present application discovered during the process of implementing the present application that the ear glue would adhere to the surface of the pole piece, thereby increasing the overall thickness of the pole piece and the thickness of the battery cell formed by winding or stacking the positive and negative pole pieces, which would have an adverse effect on the energy density, fast charging and cycle performance of the lithium-ion battery cell.
  • the embodiments of the present application provide a pole piece, an electrochemical device and an electronic device, which improve the problem that the above-mentioned pole ear glue adheres to the surface of the pole piece, resulting in an increase in the overall thickness of the pole piece, an increase in the thickness of the battery cell formed by winding or stacking the positive and negative pole pieces, and affects the energy density of the lithium-ion battery cell.
  • a pole piece which includes a current collector, an active material layer, a pole ear and a first insulating adhesive layer.
  • the active material layer is arranged on the surface of the current collector, the active material layer is provided with a first groove and a second groove that runs through the bottom of the first groove to the current collector, and the current collector is partially exposed and connected to the second groove.
  • the pole ear is received in the first groove and the second groove, and the pole ear is connected to the current collector.
  • the first insulating adhesive layer is arranged in the first groove.
  • the projection of the first insulating adhesive layer and the pole ear along the first direction is located in the first groove of the active material layer.
  • the first direction is the thickness direction of the pole piece.
  • the first insulating adhesive layer is arranged in the first groove, and the first insulating adhesive layer is received by the first groove, thereby reducing the direct adhesion of the first insulating adhesive layer to the surface of the pole piece and reducing the impact on the overall thickness of the pole piece.
  • the current collector includes a first surface and a second surface arranged opposite to each other, the active material layer includes a first active material layer and a second active material layer, the first active material layer is arranged on the first surface, the second active material layer is arranged on the second surface, and the first groove is located on the first active material layer.
  • the depth of the first groove along the first direction is T1
  • the thickness of the first insulating rubber layer along the first direction is T2
  • the thickness of the first active material layer along the first direction is T3, and T2 ⁇ T1 ⁇ T3
  • the first direction is a direction perpendicular to the bottom of the first groove.
  • the width of the second groove along the second direction is W1, the width of the first insulating rubber layer along the second direction is W2, and W1 ⁇ W2; the width of the first groove along the second direction is W3, and W2 ⁇ W3, and the second direction is perpendicular to the first direction.
  • the bottom of the first groove is divided by the second groove to form a discontinuous first area and a second area, the first area and the second area are arranged relative to each other, one end of the first insulating rubber layer is located in the first area, and the other end is located in the second area; or, when observed along the first direction, the bottom of the first groove is divided by the second groove to form a third area, and the third area is U-shaped.
  • the second active material layer is provided with a third groove and a fourth groove penetrating the bottom of the third groove to the current collector, the current collector is partially exposed in the fourth groove, the projections of the fourth groove and the second groove in the first direction overlap, the current collector is bent toward the fourth groove to form a bent portion, and the pole ear is connected to the bent portion;
  • the pole piece also includes a second insulating rubber layer, and the second insulating rubber layer is provided on the side of the third groove away from the current collector.
  • the second insulating rubber layer is accommodated by the third groove to reduce the second insulating rubber layer from directly adhering to the other surface of the pole piece, so as to reduce the impact on the overall thickness of the pole piece.
  • the depth of the third groove along the first direction is T4
  • the thickness of the second insulating adhesive layer along the first direction is T5
  • the thickness of the second active material layer along the first direction is T6, and T5 ⁇ T4 ⁇ T6.
  • the width of the fourth groove along the second direction is W4, the width of the second insulating rubber layer along the second direction is W5, and W4 ⁇ W5; the width of the third groove along the second direction is W6, and W5 ⁇ W6, and the second direction is perpendicular to the first direction.
  • the second insulating rubber layer is located in the third groove along the second direction, reducing the second insulating rubber layer protruding from the surface of the pole piece, thereby reducing the impact on the thickness of the pole piece.
  • the non-overlapping portion between the projections of the second groove and the fourth groove along the first direction can provide a certain displacement space for the active material layer, thereby reducing the influence of the active material layer on the thickness of the battery cell.
  • an electrochemical device includes an isolation membrane and a first pole piece and a second pole piece with opposite polarities located on both sides of the isolation membrane.
  • the first pole piece is the pole piece mentioned above.
  • a third insulating rubber layer is provided on the second pole piece, and the third insulating rubber layer is provided on the side of the active material layer on the second pole piece away from the current collector.
  • Two first step portions extend in the first groove of the first pole piece, and the two first step portions are arranged at intervals.
  • the first insulating rubber layer is located between the two first step portions, and a first step surface is provided on the first step portion.
  • the side of the third insulating rubber layer away from the active material layer abuts against the isolation film until the isolation film abuts against the first step surface, and the third insulating rubber layer is at least partially located in the first groove, thereby reducing the influence of the third insulating rubber layer on the thickness of the battery cell.
  • the thickness of the first step portion along the first direction is T7, the thickness of the first insulating rubber layer along the first direction is T2, and T2 ⁇ T7; the distance from the first step surface to the notch of the first groove is T8, the thickness of the third insulating rubber layer along the first direction is T9, and T9 ⁇ T8; the spacing distance between the two first step portions is W7, the width of the first insulating rubber layer along the second direction is W2, and W2 ⁇ W7.
  • a fourth insulating adhesive layer is provided on the second pole piece, and the fourth insulating adhesive layer is provided on the side of the active material layer on the second pole piece away from the current collector, and two second step portions extend in the third groove of the first pole piece, and the two second step portions are arranged at intervals.
  • the second insulating rubber layer is located between the two second step portions, and a second step surface is provided on the second step portion.
  • the side of the fourth insulating rubber layer facing away from the active material layer on the second pole piece abuts against the isolation film until the isolation film abuts against the second step surface, and the fourth insulating rubber layer is at least partially located in the third groove, thereby reducing the influence of the fourth insulating rubber layer on the thickness of the battery cell.
  • the thickness of the second step portion along the first direction is T10, the thickness of the second insulating rubber layer along the first direction is T5, and T5 ⁇ T10; the distance from the second step surface to the notch of the third groove is T11, the thickness of the fourth insulating rubber layer along the first direction is T12, and T12 ⁇ T11; the spacing distance between the two second step portions is W8, the width of the second insulating rubber layer along the second direction is W5, and W5 ⁇ W8.
  • an electronic device includes the electrochemical device as described above.
  • the beneficial effect of the embodiment of the present application is that, different from the prior art, the embodiment of the present application is provided with a current collector, an active material layer, a pole ear and a first insulating adhesive layer.
  • the active material layer is arranged on the surface of the current collector, and the active material layer is provided with a first groove and a second groove that passes through the bottom of the first groove to the current collector, the current collector is partially exposed in the second groove, the pole ear is accommodated in the first groove and the second groove, and the pole ear is connected to the current collector.
  • the first insulating rubber layer is arranged on the side of the first groove away from the current collector, and the projections of the first insulating rubber layer and the pole ear along the thickness direction of the current collector are located in the first groove of the active material layer. In this way, the first insulating rubber layer is bonded to the pole ear, which can prevent the welding burrs on the pole ear from piercing the isolation film on the battery cell.
  • the first insulating rubber layer is arranged in the first groove, and the first groove is used to accommodate the first insulating rubber layer, thereby reducing the direct adhesion of the first insulating rubber layer to the surface of the pole piece, affecting the overall thickness of the pole piece, and further reducing the influence of the first insulating rubber layer on the thickness of the battery cell formed by winding or stacking the positive and negative pole sheets, thereby improving the energy density of the battery cell, and at the same time improving the consistency of the battery cell thickness, improving the fast charging and cycle performance of the battery cell.
  • FIG1 is a schematic diagram of the overall structure of the pole piece of the embodiment of the present application, showing the top view of the pole piece. shape;
  • FIG2 is a side cross-sectional view of the overall structure of a pole piece according to an embodiment of the present application.
  • FIG3 is an enlarged schematic diagram of the structure at point A in FIG2 ;
  • FIG4 is another labeled schematic diagram of the structure at A in FIG2 ;
  • FIG5 is another annotated schematic diagram of the overall structure of the pole piece according to the embodiment of the present application.
  • FIG6 is a schematic diagram of the overall structure of another embodiment of the pole piece of the present application.
  • FIG7 is a schematic diagram of the overall structure of another embodiment of the pole piece of the present application.
  • FIG8 is a schematic diagram of a state of a pole piece according to an embodiment of the present application.
  • FIG9 is a schematic diagram of another state of the pole piece of the embodiment shown in FIG8 of the present application.
  • FIG10 is an exploded schematic diagram of the overall structure of the electrochemical device according to an embodiment of the present application.
  • FIG11 is a side cross-sectional view of a portion of an electrode assembly of an electrochemical device according to an embodiment of the present application.
  • FIG. 12 is an enlarged schematic diagram of the structure at point B in FIG. 11 .
  • the pole piece 1000 usually needs to be stacked or wound.
  • the pole piece 1000 can be set as a long sheet, and the pole piece 1000 has a length direction, a width direction and a thickness direction.
  • the pole piece 1000 is usually wound along the length direction of the pole piece 1000.
  • the length direction of the pole piece 1000 is the X direction in Figures 1 and 2
  • the width direction is the Y direction in Figure 1
  • the thickness direction is the Z direction in Figure 2.
  • the X direction and the Y direction are The A and Z directions are perpendicular to each other.
  • the pole piece 1000 includes a current collector 10, an active material layer 20, a pole tab 30, a first insulating adhesive layer 40, and a second insulating adhesive layer 50.
  • the active material layer 20 is disposed on the surface of the current collector 10, the pole tab 30 is connected to the current collector 10, and the first insulating adhesive layer 40 and the second insulating adhesive layer 50 are both disposed on the side of the active material layer 20 away from the current collector 10.
  • the current collector 10 is a pole piece 1000 which is a conductive substrate, one end of the pole tab 30 is connected to the current collector 10, and the other end of the pole tab 30 extends in the Y direction.
  • the pole piece 1000 generally includes a positive pole piece and a negative pole piece.
  • different materials can be selected as the current collector 10 of the pole piece 1000.
  • the positive pole piece can use aluminum foil as the current collector 10
  • the negative pole piece can use copper foil as the current collector 10.
  • the material of the pole tab 30 is different according to the different types of pole pieces.
  • the material of the pole tab 30 can be made of metal materials such as copper, nickel, and aluminum.
  • the current collector 10 includes a first surface and a second surface arranged opposite to each other, and the active material layer 20 can be coated on the first surface and the second surface.
  • the active material layer 20 may be disposed on at least one surface of the current collector 10. Since the current collector 10 is a conductive substrate of the pole piece 1000, its outer contour is usually in the shape of a long sheet. Therefore, usually, the active material layer 20 is coated on the first surface or the second surface of the pole piece 1000, or the first surface and the second surface of the pole piece 1000 are coated with the active material layer 20.
  • the active material layer 20 includes a first active material layer 201 and a second active material layer 202, wherein the first active material layer 201 is disposed on the first surface, and the second active material layer 202 is disposed on the second surface.
  • the active material layer 20 generally includes active materials, conductive agents, dispersants, additives and binders, etc. Different active materials can be selected for the active material layer 20 according to different types of pole pieces 1000.
  • its active material layer 20 can adopt some common positive active materials, such as: lithium cobalt oxide, lithium-rich manganese base, lithium iron phosphate, lithium iron phosphate manganese, nickel cobalt manganese ternary, lithium manganese oxide, polyanion compounds, Prussian blue, etc.
  • the active material layer 20 of the positive pole piece can select one or more of the above-mentioned positive active materials; for the negative pole piece, its active material layer 20 can select common negative active materials, such as: hard carbon, soft carbon, graphite, lithium metal, silicon carbon silicon oxygen, lithium titanate, etc.
  • the active material layer 20 of the negative pole piece can select one or more of the above-mentioned negative active materials.
  • the active material layer 20 is provided with a first groove 201a and a second groove 201b that penetrates the bottom of the first groove 201a to the current collector 10, the current collector 10 is partially exposed in the second groove 201b, the first insulating rubber layer 40 is provided on the side of the first groove 201a away from the current collector 10, and the first insulating rubber layer 40 and the tab 30 are arranged along the thickness direction of the current collector 10 (i.e., along the Z direction).
  • the projection of the first groove 201a in the active material layer 20 is located in the first groove 201a, and the first groove 201a is used to accommodate the first insulating adhesive layer 40, so as to reduce the direct adhesion of the first insulating adhesive layer 40 to the surface of the pole piece, thereby reducing the impact on the overall thickness of the pole piece.
  • the first groove 201a and the second groove 201b are located on the first active material layer 201.
  • the depth of the first groove 201a along the first direction is T1
  • the thickness of the first insulating rubber layer 40 along the first direction is T2
  • the thickness of the first active material layer 201 along the first direction is T3, and T2 ⁇ T1 ⁇ T3.
  • This arrangement can ensure that the first insulating rubber layer 40 does not exceed the notch edge of the first groove 201a along the Z direction, reducing the surface of the first insulating rubber layer 40 protruding from the pole piece to reduce the impact on the thickness of the pole piece.
  • the first direction is the direction perpendicular to the bottom of the first groove 201a.
  • the specific values of T1, T2 and T3 are not specifically limited. The specific values of T1, T2 and T3 can be set according to actual needs, as long as the relationship between T1, T2 and T3 meets the above conditions.
  • the width of the second groove 201b along the second direction is W1
  • the width of the first insulating rubber layer 40 along the second direction is W2
  • the width of the first groove 201a along the second direction is W3, and W1 ⁇ W2 ⁇ W3.
  • W1, W2 and W3 are not specifically limited. The specific values of W1, W2 and W3 can be set according to actual needs, as long as the relationship between W1, W2 and W3 meets the above conditions.
  • the bottom of the first groove 201a is separated by the second groove 201b to form a discontinuous first region 201aa and a second region 201ab.
  • the first region and the second region are arranged oppositely, and one end of the first insulating rubber layer 40 is located in the first region and the other end is located in the second region; or, when observing along the thickness direction of the current collector 10, the bottom of the first groove 201a is separated by the second groove 201b to form a third region 201ac, and the third region is U-shaped.
  • the concave shapes of the first groove 201a and the second groove 201b in the embodiment of the present application include but are not limited to rectangular parallelepiped, cube, cylinder, cone, etc.
  • the second active material layer 202 is provided with a third groove 202a and a fourth groove 202b that penetrates the bottom of the third groove 202a to the current collector 10, the current collector 10 is partially exposed in the fourth groove 202b, and the projection of the fourth groove 202b and the second groove 201b in the first direction overlaps, and the second insulating adhesive layer 50 is provided on the side of the third groove 202a away from the current collector 10, and the third groove 202a is used to accommodate the second insulating adhesive layer 50, thereby reducing the second The insulating adhesive layer 50 is directly adhered to the other surface of the pole piece to reduce the impact on the overall thickness of the pole piece.
  • the current collector 10 is bent toward the fourth groove 202b to form a bent portion 10a, which can be used to connect the pole ear 30.
  • the bent portion 10a can reduce the impact of the pole ear 30 on the thickness direction of the pole piece in the Z direction.
  • the depth of the third groove 202a along the first direction is T4
  • the thickness of the second insulating rubber layer 50 along the first direction is T5
  • the thickness of the second active material layer 202 along the first direction is T6, and T5 ⁇ T4 ⁇ T6.
  • T4, T5 and T6 are not specifically limited, and the specific values of T4, T5 and T6 can be set according to actual needs, as long as the relationship between T4, T5 and T6 meets the above conditions.
  • the width of the fourth groove 202b along the second direction is W4
  • the width of the second insulating rubber layer 50 along the second direction is W5
  • the width of the third groove 202a along the second direction is W6, and W4 ⁇ W5 ⁇ W6.
  • the number of the first groove 201a and the third groove 202a on the pole piece is not specifically limited in the embodiment of the present application.
  • the number of the first groove 201a and the third groove 202a can be set according to the number of pole ears 30 on the pole piece. For example, as shown in Figure 7, when the number of pole ears 30 is 2, the number of the first groove 201a can be set to 2 accordingly.
  • the formation process of the first groove 201a and the third groove 202a is not specifically limited in the embodiment of the present application. Taking the formation of the first groove 201a as an example, as shown in Figures 8 and 9, the first insulating adhesive layer 40 is coated on the first active material layer 201, and the second active material layer 202 is provided with a receiving groove 202c. After that, the electrode is subjected to processes such as pressurization.
  • the current collector 10 and the first active material layer 201 and the receiving groove 202c are projected and overlapped in the Z direction and are received in the receiving groove 202c, and the first insulating adhesive layer 40 moves toward the receiving groove 202c and is recessed on the first active material layer 201 to form the first groove 201a.
  • the first insulating adhesive layer 40 is located in the first groove 201a.
  • the formation process of the third groove 202a can refer to the formation process of the first groove 201a. It should be noted that: in order to enable the first insulating adhesive layer 40 to move toward the receiving groove 202c as a whole, the receiving groove 202c is disposed along the X direction. The width must be greater than or equal to the width of the first insulating adhesive layer 40 along the X direction, and the projection of the first insulating adhesive layer along the Z direction is located within the receiving groove 202 c.
  • the first insulating adhesive layer 40 and the second insulating adhesive layer 50 As shown in FIG3, the first insulating adhesive layer 40 is arranged on the side of the first groove 201a away from the current collector 10, and the second insulating adhesive layer 50 is arranged on the side of the third groove 202a away from the current collector 10, the first insulating adhesive layer 40 is partially bonded to the pole ear 30, and the second insulating adhesive layer 50 is partially bonded to the current collector 10, and the second insulating adhesive layer 50 and the first insulating adhesive layer 40 are at least partially overlapped in the projection along the thickness direction of the current collector 10, and the second insulating adhesive layer 50 and the first insulating adhesive layer 40 can prevent the welding burrs on the pole ear 30 from piercing the isolation film on the battery cell.
  • the manufacturing material of the first insulating adhesive layer 40 and the second insulating adhesive layer 50 includes at least one of polypropylene, polycarbonate, polyester resin, and polyamide.
  • a current collector 10, an active material layer 20, a tab 30 and a first insulating adhesive layer 40 are provided.
  • the active material layer 20 is provided on the surface of the current collector 10, the active material layer 20 is provided with a first groove 201a and a second groove 201b that penetrates through the bottom of the first groove 201a to the current collector 10, the current collector 10 is partially exposed in the second groove 201b, the tab 30 is accommodated in the first groove 201a and the second groove 201b, the tab 30 is connected to the current collector 10, and the first insulating adhesive layer 40 is provided on the side of the first groove 201a away from the current collector 10, and the projections of the first insulating adhesive layer 40 and the tab 30 along the thickness direction of the current collector 10 are located on the active material layer.
  • the first insulating rubber layer 40 is bonded to the pole ear 30, which can prevent the welding mark burrs on the pole ear 30 from piercing the isolation membrane on the battery cell, and at the same time, the first insulating rubber layer 40 is arranged in the first groove 201a, and the first groove 201a is used to accommodate the first insulating rubber layer 40, thereby reducing the first insulating rubber layer 40 directly adhering to the surface of the pole piece, affecting the overall thickness of the pole piece, and further reducing the influence of the first insulating rubber layer 40 on the thickness of the battery cell formed by the winding or stacking of the positive and negative pole sheets, thereby improving the energy density of the battery cell, while improving the consistency of the battery cell thickness, and improving the fast charging and cycle performance of the battery cell.
  • the non-overlapping portion between the projections of the second groove 201b and the fourth groove 202b along the first direction can provide a certain displacement space for the active material layer 20, thereby reducing the influence of the active material layer 20 on the thickness of the battery cell.
  • the electrochemical device 100 includes a housing 101 and an electrode assembly 102 located in the housing 101.
  • the electrode assembly 102 includes a separator 1021 and electrodes located on both sides of the separator 1021.
  • the first pole piece 1022 and the second pole piece 1023 have opposite polarities, and the first pole piece 1022 is the pole piece in the above embodiment.
  • the isolation film 1021 and the first pole piece 1022 and the second pole piece 1023 can be wound or stacked to form the electrode assembly 102.
  • the polarity of the first pole piece 1022 and the second pole piece 1023 is not specifically limited.
  • the first pole piece 1022 or the second pole piece 1023 can be a positive pole piece, and the first pole piece 1022 or the second pole piece 1023 can be a negative pole piece, as long as the polarity of the first pole piece 1022 and the second pole piece 1023 is opposite.
  • a third insulating rubber layer 1023a is provided on the second pole piece 1023.
  • the third insulating rubber layer 1023a is provided on the side of the active material layer on the second pole piece 1023 away from the current collector 10.
  • Two first step portions 2011 extend in the first groove 201a of the first pole piece 1022.
  • the two first step portions 2011 are arranged at intervals.
  • the first insulating rubber layer 40 is located between the two first step portions 2011.
  • a first step surface (not marked) is provided on the first step portion 2011.
  • the side of the third insulating rubber layer 1023a facing away from the active material layer abuts against the isolation film 1021 until the isolation film 1021 abuts against the first step surface, and the third insulating rubber layer 1023a is at least partially located in the first groove 201a, thereby reducing the influence of the third insulating rubber layer 1023a on the thickness of the battery cell.
  • the thickness of the first step portion 2011 along the first direction is T7
  • the thickness of the first insulating rubber layer 40 along the first direction is T2
  • T2 ⁇ T7 This configuration ensures that the thickness of the first insulating rubber layer 40 in the first direction does not exceed the thickness of the first step portion 2011.
  • the distance from the first step surface to the notch of the first groove 201a is T8, the thickness of the third insulating rubber layer 1023a along the first direction is T9, and T9 ⁇ T8.
  • the third insulating rubber layer 1023a is accommodated in the first groove 201a, reducing the risk of the third insulating rubber layer 1023a protruding from the surface of the first pole piece 1022 after winding or stacking, reducing the influence of the third insulating rubber layer 1023a on the thickness of the battery cell, improving the energy density of the battery cell, and improving the consistency of the battery cell thickness.
  • the distance between the two first step portions 2011 is W7
  • the width of the first insulating adhesive layer 40 along the second direction is W2
  • W2 ⁇ W7 so that the first insulating adhesive layer 40 is accommodated between the two first step portions 2011 .
  • a fourth insulating adhesive layer 1023b is disposed on the second pole piece 1023, and the fourth insulating adhesive layer 1023b is disposed on a side of the active material layer on the second pole piece 1023 away from the current collector 10.
  • Two second step portions 2021 extend in the third groove 202a of the first pole piece 1022. The two second step portions 2021 are arranged at intervals, the second insulating rubber layer 50 is located between the two second step portions 2021, and a second step surface (not marked) is arranged on the second step portion 2021.
  • the side of the fourth insulating rubber layer 1023b facing away from the active material layer on the second pole piece 1023 abuts against the isolation film 1021 until the isolation film 1021 abuts against the second step surface, and the fourth insulating rubber layer 1023b is at least partially located in the third groove 202a, thereby reducing the influence of the fourth insulating rubber layer 1023b on the thickness of the battery cell.
  • the thickness of the second step portion 2021 along the first direction is T10
  • the thickness of the second insulating rubber layer 50 along the first direction is T5, and T5 ⁇ T10.
  • the distance from the second step surface to the notch of the third groove 202a is T11
  • the thickness of the fourth insulating rubber layer 1023b along the first direction is T12
  • T12 ⁇ T11 the fourth insulating rubber layer 1023b is accommodated in the third groove 202a, reducing the risk of the fourth insulating rubber layer 1023b protruding from the surface of the first pole piece 1022 after winding or stacking, reducing the influence of the fourth insulating rubber layer 1023b on the thickness of the battery cell, improving the energy density of the battery cell, and improving the consistency of the thickness of the battery cell.
  • the distance between the two second step portions 2021 is W8, the width of the second insulating adhesive layer 50 along the second direction is W5, and W5 ⁇ W8, so that the second insulating adhesive layer 50 is accommodated between the two second step portions 2021.
  • the present application also provides an embodiment of an electronic device, which includes the electrochemical device as described above.
  • the function and structure of the electrochemical device can be referred to the above embodiment, and will not be described in detail here.

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Abstract

电池技术领域，一种极片（1000）、电化学装置（100）及电子设备，包括：集流体（10）、活性物质层（20）、极耳（30）和第一绝缘胶层（40），所述活性物质层（20）设置于所述集流体（10）的表面，所述活性物质层（20）设置有第一凹槽（201a）及贯穿所述第一凹槽（201a）槽底至所述集流体（10）的第二凹槽（201b），所述集流体（10）部分裸露于所述第二凹槽（201b）内，所述极耳（30）收容于所述第一凹槽（201a）和第二凹槽（201b），所述极耳（30）与所述集流体（10）连接，所述第一绝缘胶层（40）设置于所述第一凹槽（201a）背离所述集流体（10）的一侧，所述第一绝缘胶层（40）及所述极耳（30）沿所述集流体（10）的厚度方向的投影位于所述活性物质层（20）的第一凹槽（201a）内。通过上述方式，能够减少第一绝缘胶层（40）对极片（1000）的整体厚度造成影响，改善电芯厚度一致性，提升电芯快充以及循环性能。

Description

一种极片、电化学装置及电子设备
相关申请的交叉参考
本申请要求于2022年10月13日提交中国专利局，申请号为202211252684.5，名称为“一种极片、电化学装置及电子设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及电池技术领域，特别是涉及一种极片、电化学装置及电子设备。
背景技术
目前，随着科学技术的不断进步，锂离子电池的应用领域也迅速扩展，已经从最初的手机、摄像机等便携式移动设备扩展至电动自行车、电动汽车等大功率高能量要求的大型电动设备。因此，对锂离子电池的设计和制作工艺的要求也越来越高。锂离子电池中通常用到极耳胶，极耳胶主要的作用是粘接在极片的极耳上，防止在极片卷绕、堆叠等加工过程中，极耳上的焊印毛刺刺穿电芯上的隔离膜。
本申请实施例的发明人在实现本申请的过程中，发现：极耳胶会粘附在极片的表面，从而导致极片的整体厚度增大，正负极片卷绕或堆叠形成的电芯厚度增大，对锂离子电池的电芯能量密度、电芯快充以及循环性能造成不利影响。
申请内容
鉴于上述问题，本申请实施例提供了一种极片、电化学装置及电子设备，改善了上述极耳胶粘附在极片的表面，导致极片的整体厚度增大，正负极片卷绕或堆叠形成的电芯厚度增大，影响锂离子电池的电芯能量密度等问题。
根据本申请实施例的一个方面，提供了一种极片，该极片包括集流体、活性物质层、极耳和第一绝缘胶层。其中，所述活性物质层设置于所述集流体的表面，所述活性物质层设置有第一凹槽及贯穿所述第一凹槽槽底至所述集流体的第二凹槽，所述集流体部分裸露与所述第二凹槽 内，所述极耳收容于所述第一凹槽和第二凹槽，所述极耳与所述集流体连接。所述第一绝缘胶层设置于所述第一凹槽。所述第一绝缘胶层及所述极耳沿第一方向的投影位于所述活性物质层的第一凹槽内。所述第一方向为极片的厚度方向。这样设置，第一绝缘胶层设置于所述第一凹槽内，利用第一凹槽收容第一绝缘胶层，从而减少所述第一绝缘胶层直接粘附在极片的表面，减少对极片的整体厚度造成影响。
在一种可选的方式中，所述集流体包括相对设置的第一表面和第二表面，所述活性物质层包括第一活性物质层和第二活性物质层，所述第一活性物质层设置于所述第一表面，所述第二活性物质层设置于所述第二表面，所述第一凹槽位于所述第一活性物质层上。
在一种可选的方式中，所述第一凹槽沿第一方向上的深度为T1，所述第一绝缘胶层沿第一方向上的厚度为T2，所述第一活性物质层沿第一方向上的厚度为T3，且T2≤T1＜T3，所述第一方向为垂直所述第一凹槽槽底的方向。这样设置，可使得第一绝缘胶层沿第一方向上不超出第一凹槽的槽口边缘，减少第一绝缘胶层凸出极片的表面，以减少对极片厚度造成影响。
在一种可选的方式中，至少满足以下条件之一：所述第二凹槽沿第二方向上的宽度为W1，所述第一绝缘胶层沿第二方向上的宽度为W2，且W1≤W2；所述第一凹槽沿第二方向上的宽度为W3，且W2≤W3，所述第二方向与所述第一方向垂直。这样设置，可使得极片在卷绕或堆叠过程中，第一绝缘胶层沿第二方向上均位于第一凹槽内，减少第一绝缘胶层凸出极片的表面。
在一种可选的方式中，沿所述第一方向观察，所述第一凹槽的槽底被所述第二凹槽分隔形成不连续的第一区域和第二区域，所述第一区域和第二区域相对设置，所述第一绝缘胶层的一端位于所述第一区域，另一端位于所述第二区域；或者，沿所述第一方向观察，所述第一凹槽的槽底被所述第二凹槽分隔形成第三区域，所述第三区域呈U型。
在一种可选的方式中，所述第二活性物质层设置有第三凹槽及贯穿所述第三凹槽槽底至所述集流体的第四凹槽，所述集流体部分裸露于所述第四凹槽内，所述第四凹槽和第二凹槽在第一方向上的投影重叠，所述集流体朝所述第四凹槽弯折形成弯折部，所述极耳连接于所述弯折部；所述极片还包括第二绝缘胶层，所述第二绝缘胶层设置于所述第三凹槽内背离所述集流体的一侧。利用第三凹槽收容第二绝缘胶层，减少第二绝缘胶层直接粘附在极片的另一表面，以减少对极片的整体厚度造成影响。
在一种可选的方式中，所述第三凹槽沿第一方向上的深度为T4，所述第二绝缘胶层沿第一方向上的厚度为T5，所述第二活性物质层沿第一方向上的厚度为T6，且T5≤T4＜T6。这样设置，可使得第二绝缘胶层沿第一方向上不超出第三凹槽的槽口边缘，减少第二绝缘胶层凸出极片的表面，以减少对极片厚度造成影响。
在一种可选的方式中，至少满足以下条件之一：所述第四凹槽沿第二方向上的宽度为W4，所述第二绝缘胶层沿第二方向上的宽度为W5，且W4≤W5；所述第三凹槽沿第二方向上的宽度为W6，且W5≤W6，所述第二方向与第一方向垂直。这样设置，可使得极片在卷绕或堆叠过程中，第二绝缘胶层沿第二方向上均位于第三凹槽内，减少第二绝缘胶层凸出极片的表面，以减少对极片厚度造成影响。
在一种可选的方式中，所述第二凹槽与所述第四凹槽沿第一方向上的投影存在不重合的部分，这样设置，在对极片进行加压等工序过程中，第二凹槽和第四凹槽沿第一方向上的投影未重合的部分可为活性物质层提供一定的位移空间，减少活性物质层对电芯的厚度的影响。
根据本申请实施例的另一个方面，提供了一种电化学装置，该电化学装置包括隔离膜以及位于所述隔离膜两侧且极性相反的第一极片和第二极片，所述第一极片为上述中的极片。
在一种可选的方式中，所述第二极片上设置有第三绝缘胶层，所述第三绝缘胶层设置于第二极片上的活性物质层背离集流体的一侧，第一极片的第一凹槽内延伸有两个第一阶梯部，两个第一阶梯部间隔设置，所述第一绝缘胶层位于所述两个第一阶梯部之间，所述第一阶梯部上设置有第一阶梯面，在第一极片和第二极片卷绕或堆叠时，所述第三绝缘胶层背离所述活性物质层的一侧抵接于所述隔离膜，直至所述隔离膜抵接于所述第一阶梯面，且所述第三绝缘胶层至少部分位于所述第一凹槽内，从而减少第三绝缘胶层对电芯的厚度造成影响。
在一种可选的方式中，至少满足以下条件之一：所述第一阶梯部沿第一方向上的厚度为T7，所述第一绝缘胶层沿第一方向上的厚度为T2，且T2≤T7；所述第一阶梯面到所述第一凹槽的槽口的距离为T8，所述第三绝缘胶层沿第一方向上的厚度为T9，且T9≤T8；所述两个第一阶梯部之间间隔距离为W7，所述第一绝缘胶层沿第二方向上的宽度为W2，且W2≤W7。
在一种可选的方式中，第二极片上设置有第四绝缘胶层，所述第四绝缘胶层设置于第二极片上的活性物质层背离集流体的一侧，第一极片的第三凹槽内延伸有两个第二阶梯部，两个第二阶梯部间隔设置，所述 第二绝缘胶层位于所述两个第二阶梯部之间，所述第二阶梯部上设置有第二阶梯面，在第一极片和第二极片卷绕或堆叠时，所述第四绝缘胶层背离第二极片上的活性物质层的一侧抵接于所述隔离膜，直至所述隔离膜抵接于所述第二阶梯面，且所述第四绝缘胶层至少部分位于所述第三凹槽内，从而减少第四绝缘胶层对电芯的厚度造成影响。
在一种可选的方式中，至少满足以下条件之一：所述第二阶梯部沿第一方向上的厚度为T10，所述第二绝缘胶层沿第一方向上的厚度为T5，且T5≤T10；所述第二阶梯面到所述第三凹槽的槽口的距离为T11，所述第四绝缘胶层沿第一方向上的厚度为T12，且T12≤T11；所述两个第二阶梯部之间间隔距离为W8，所述第二绝缘胶层沿第二方向上的宽度为W5，且W5≤W8。
根据本申请实施例的另一个方面，提供了一种电子设备，该电子设备包括如上所述的电化学装置。
本申请实施例的有益效果是：区别于现有技术的情况，本申请实施例通过设置有集流体、活性物质层、极耳和第一绝缘胶层。其中，所述活性物质层设置于所述集流体的表面，所述活性物质层设置有第一凹槽及贯穿所述第一凹槽槽底至所述集流体的第二凹槽，所述集流体部分裸露于所述第二凹槽内，所述极耳收容于所述第一凹槽和第二凹槽，所述极耳与所述集流体连接，此外，所述第一绝缘胶层设置于所述第一凹槽背离所述集流体的一侧，所述第一绝缘胶层及所述极耳沿所述集流体厚度方向的投影位于所述活性物质层的第一凹槽内，这样设置，所述第一绝缘胶层粘接在所述极耳上，可起到防止所述极耳上的焊印毛刺刺穿电芯上的隔离膜的作用，同时，所述第一绝缘胶层设置于所述第一凹槽内，利用第一凹槽收容所述第一绝缘胶层，从而减少所述第一绝缘胶层直接粘附在极片的表面，对极片的整体厚度造成影响，进一步，减少所述第一绝缘胶层对正负极片卷绕或堆叠形成的电芯厚度造成影响，提升电芯能量密度，同时改善电芯厚度一致性，提升电芯快充以及循环性能。
附图说明
为了更清楚地说明本申请具体实施例或现有技术中的技术方案，下面将对具体实施例或现有技术描述中所需要使用的附图作简单地介绍。在所有附图中，类似的元件或部分一般由类似的附图标记标识。附图中，各元件或部分并不一定按照实际的比例绘制。
图1是本申请实施例极片的整体结构示意图，示出了俯视角度的情 形；
图2是本申请实施例极片的整体结构侧面剖视图；
图3是图2中A处结构放大示意图；
图4是图2中A处结构另一标注示意图；
图5是本申请实施例极片的整体结构另一标注示意图；
图6是本申请极片的又一实施例整体结构示意图；
图7是本申请极片的另一实施例整体结构示意图；
图8是本申请实施例极片的一状态示意图；
图9是本申请图8所示实施例极片的另一状态示意图；
图10是本申请实施例电化学装置的整体结构爆炸示意图；
图11是本申请实施例电化学装置的电极组件部分组件侧面剖视图；
图12是图11中B处结构放大示意图。
具体实施方式
为了便于理解本申请，下面结合附图和具体实施例，对本申请进行更详细的说明。需要说明的是，当元件被表述“固定于”另一个元件，它可以直接在另一个元件上、或者其间可以存在一个或多个居中的元件。当一个元件被表述“连接”另一个元件，它可以是直接连接到另一个元件、或者其间可以存在一个或多个居中的元件。本说明书所使用的术语“垂直的”、“水平的”、“左”、“右”以及类似的表述只是为了说明的目的。
除非另有定义，本说明书所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。本说明书中在本申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是用于限制本申请。本说明书所使用的术语“和/或”包括一个或多个相关的所列项目的任意的和所有的组合。
此外，下面所描述的本申请不同实施例中所涉及的技术特征只要彼此之间未构成冲突就可以相互结合。
极片1000作为电极组件102的重要组成部件，其通常需要进行层叠或卷绕成型。为便于层叠或卷绕，极片1000可设置为长片状，且该极片1000具有长度方向、宽度方向和厚度方向，当极片1000进行卷绕成型时，通常是沿着极片1000的长度方向进行卷绕。根据图1和图2可知，上述极片1000的长度方向即为图1和图2中的X方向，宽度方向即为图1中的Y方向，厚度方向即为图2中的Z方向，X方向、Y方 向以及Z方向之间相互垂直。
请参阅图1和图2，所述极片1000包括集流体10、活性物质层20、极耳30、第一绝缘胶层40和第二绝缘胶层50。活性物质层20设置于集流体10的表面，极耳30与集流体10连接，第一绝缘胶层40和第二绝缘胶层50均设置于活性物质层20背离集流体10的一侧。
对于上述集流体10和极耳30，如图1所示，集流体10为极片1000为导电基材，极耳30的一端连接于集流体10，极耳30的另一端朝Y方向延伸。极片1000通常包括正极极片和负极极片，根据极片1000种类的不同，可选择不同的材料作为极片1000的集流体10，例如正极极片可采用铝箔作为集流体10，而负极极片可选择铜箔作为集流体10，极耳30的制作材料根据极片种类不同而不同，极耳30的制作此材料可为铜、镍、铝等金属材料。在一些实施例中，所述集流体10包括相对设置的第一表面和第二表面，所述第一表面和第二表面上可涂布活性物质层20。
对于上述活性物质层20，如图2和图3所示，活性物质层20可设置于集流体10的至少一个表面。由于集流体10为极片1000的导电基材，其外形轮廓通常也为长片状，因此，通常情况下，活性物质层20涂布于极片1000的第一表面或第二表面，或者极片1000的第一表面和第二表面均涂布活性物质层20。在一些实施例中，所述活性物质层20包括第一活性物质层201和第二活性物质层202，所述第一活性物质层201设置于所述第一表面，所述第二活性物质层202设置于所述第二表面。
活性物质层20通常包括活性物质、导电剂、分散剂、添加剂和粘结剂等，根据不同的极片1000类别，活性物质层20可选择不同的活性物质，对于正极极片，其活性物质层20可采用一些常见的正极活性物质，例如：钴酸锂、富锂锰基、磷酸铁锂、磷酸铁锂锰、镍钴锰三元、锰酸锂、聚阴离子化合物、普鲁士蓝等，正极极片的活性物质层20可选择上述正极活性物质中的一种或多种；对于负极极片，其活性物质层20可选择常见的负极活性物质，例如：硬碳、软碳、石墨、锂金属、硅碳硅氧、钛酸锂等，负极极片的活性物质层20可选择上述负极活性物质中的一种或多种。
在一些实施例中，活性物质层20设置有第一凹槽201a及贯穿第一凹槽201a槽底至集流体10的第二凹槽201b，集流体10部分裸露于第二凹槽201b内，第一绝缘胶层40设置于第一凹槽201a背离集流体10的一侧，且第一绝缘胶层40及极耳30沿集流体10厚度方向(即沿Z 方向)的投影位于活性物质层20的第一凹槽201a内，利用第一凹槽201a收容第一绝缘胶层40，减少第一绝缘胶层40直接粘附在极片的表面，以减少对极片的整体厚度造成影响。可选的，第一凹槽201a和第二凹槽201b位于第一活性物质层201上。
在一些实施例中，请一并参阅图4，第一凹槽201a沿第一方向(即沿Z方向)上的深度为T1，第一绝缘胶层40沿第一方向上的厚度为T2，第一活性物质层201沿第一方向上的厚度为T3，且T2≤T1＜T3，这样设置，可使得第一绝缘胶层40沿Z方向上不超出第一凹槽201a的槽口边缘，减少第一绝缘胶层40凸出极片的表面，以减少对极片厚度造成影响，第一方向为垂直第一凹槽201a槽底的方向。需要说明的是：本实施例中对T1、T2及T3的具体数值不作具体限定，T1、T2及T3的具体数值可根据实际需要进行设定，只要T1、T2及T3之间的关系满足上述条件即可。
在一些实施例中，第二凹槽201b沿第二方向(即沿X方向)上的宽度为W1，第一绝缘胶层40沿第二方向上的宽度为W2，第一凹槽201a沿第二方向上的宽度为W3，且W1≤W2≤W3，这样设置，可使得极片在卷绕或堆叠过程中，第一绝缘胶层40沿X方向上均位于第一凹槽201a内，减少第一绝缘胶层40凸出极片的表面，以减少对极片厚度造成影响。需要说明的是：本实施例中对W1、W2及W3的具体数值不作具体限定，W1、W2及W3的具体数值可根据实际需要进行设定，只要W1、W2及W3之间的关系满足上述条件即可。
在一些实施例中，请一并参阅图5和图6，沿集流体10的厚度方向(即沿Z方向)观察，第一凹槽201a的槽底被第二凹槽201b分隔形成不连续的第一区域201aa和第二区域201ab，第一区域和第二区域相对设置，第一绝缘胶层40的一端位于所述第一区域，另一端位于所述第二区域；或者，沿集流体10的厚度方向观察，第一凹槽201a的槽底被第二凹槽201b分隔形成第三区域201ac，第三区域呈U型。此外，对于第一凹槽201a及第二凹槽201b的的形状，本申请实施例中第一凹槽201a和第二凹槽201b的凹陷形状包括但不限于长方体、正方体、圆柱体、锥体等形状。
在一些实施例中，如图3所示，第二活性物质层202设置有第三凹槽202a及贯穿第三凹槽202a槽底至集流体10的第四凹槽202b，集流体10部分裸露于第四凹槽202b内，且第四凹槽202b和第二凹槽201b在第一方向上的投影重叠，第二绝缘胶层50设置于第三凹槽202a背离集流体10的一侧，利用第三凹槽202a收容第二绝缘胶层50，减少第二 绝缘胶层50直接粘附在极片的另一表面，以减少对极片的整体厚度造成影响。
在一些实施例中，集流体10朝第四凹槽202b弯折形成弯折部10a，弯折部10a可用于连接极耳30，弯折部10a可减少极耳30在Z方向对极片的厚度方向造成影响。
在一些实施例中，请一并参阅图4，第三凹槽202a沿第一方向上的深度为T4，第二绝缘胶层50沿第一方向上的厚度为T5，第二活性物质层202沿第一方向上的厚度为T6，且T5≤T4＜T6。这样设置，可使得第二绝缘胶层50沿Z方向上不超出第三凹槽202a的槽口边缘，减少第二绝缘胶层50凸出极片的表面，以减少对极片厚度造成影响。需要说明的是：本实施例中对T4、T5及T6的具体数值不作具体限定，T4、T5及T6的具体数值可根据实际需要进行设定，只要T4、T5及T6之间的关系满足上述条件即可。
在一些实施例中，第四凹槽202b沿第二方向(即沿X方向)上的宽度为W4，第二绝缘胶层50沿第二方向上的宽度为W5，第三凹槽202a沿第二方向上的宽度为W6，且W4≤W5≤W6，这样设置，可使得极片在卷绕或堆叠过程中，第二绝缘胶层50沿X方向上均位于第三凹槽202a内，减少第二绝缘胶层50凸出极片的表面，以减少对极片厚度造成影响。需要说明的是：本实施例中对W4、W5及W6的具体数值不作具体限定，W4、W5及W6的具体数值可根据实际需要进行设定，只要W4、W5及W6之间的关系满足上述条件即可。可以理解的是：对于第一凹槽201a以及第三凹槽202a在极片上的数量本申请实施例中不作具体限定，第一凹槽201a以及第三凹槽202a的数量可根据极片上极耳30的数量进行设定，例如，如图7所示，在极耳30数量为2个时，第一凹槽201a的数量可对应设置为2个。
此外，对于第一凹槽201a以及第三凹槽202a的形成过程，本申请实施例中不作具体限定，以第一凹槽201a的形成为例，如图8和图9所示，将第一绝缘胶层40涂覆于第一活性物质层201上，且第二活性物质层202上设置有收容槽202c，之后，对极片进行加压等工序，经过加压等工序过后，集流体10以及第一活性物质层201与收容槽202c在Z方向上投影重叠的部分收容于收容槽202c内，且第一绝缘胶层40朝收容槽202c方向移动，并在第一活性物质层201上凹陷形成第一凹槽201a，第一绝缘胶层40位于第一凹槽201a内。第三凹槽202a的形成过程可参阅第一凹槽201a的形成过程。需要说明的是：为使得第一绝缘胶层40整体可朝收容槽202c方向移动，收容槽202c沿X方向上的 宽度需大于或等于第一绝缘胶层40沿X方向上的宽度，且第一绝缘胶层在Z方向上投影位于收容槽202c内。
对于第一绝缘胶层40和第二绝缘胶层50，如图3所示，第一绝缘胶层40设置于第一凹槽201a背离集流体10的一侧，第二绝缘胶层50设置于第三凹槽202a内背离集流体10的一侧，所述第一绝缘胶层40部分粘接在极耳30上，所述第二绝缘胶层50部分粘接在集流体10上，第二绝缘胶层50与第一绝缘胶层40沿集流体10厚度方向上的投影至少部分重叠，第二绝缘胶层50和第一绝缘胶层40可起到防止极耳30上的焊印毛刺刺穿电芯上的隔离膜的作用。可选的，第一绝缘胶层40和第二绝缘胶层50的制作材料包括聚丙烯、聚碳酸酯、涤纶树脂、聚酰胺中的至少一种。
在本申请实施例中，通过设置有集流体10、活性物质层20、极耳30和第一绝缘胶层40。其中，所述活性物质层20设置于所述集流体10的表面，所述活性物质层20设置有第一凹槽201a及贯穿所述第一凹槽201a槽底至所述集流体10的第二凹槽201b，所述集流体10部分裸露于所述第二凹槽201b内，所述极耳30收容于所述第一凹槽201a和第二凹槽201b，所述极耳30与所述集流体10连接，此外，所述第一绝缘胶层40设置于所述第一凹槽201a背离所述集流体10的一侧，所述第一绝缘胶层40及所述极耳30沿所述集流体10厚度方向的投影位于所述活性物质层20的第一凹槽201a内，这样设置，所述第一绝缘胶层40粘接在所述极耳30上，可起到防止所述极耳30上的焊印毛刺刺穿电芯上的隔离膜的作用，同时，所述第一绝缘胶层40设置于所述第一凹槽201a内，利用第一凹槽201a收容所述第一绝缘胶层40，从而减少所述第一绝缘胶层40直接粘附在极片的表面，对极片的整体厚度造成影响，进一步，减少所述第一绝缘胶层40对正负极片卷绕或堆叠形成的电芯厚度造成影响，提升电芯能量密度，同时改善电芯厚度一致性，提升电芯快充以及循环性能。
此外，在一些实施例中，参照图3，所述第二凹槽201b与所述第四凹槽202b沿第一方向上的投影存在不重合的部分，这样设置，在对极片进行加压等工序过程中，第二凹槽201b和第四凹槽202b沿第一方向上的投影未重合的部分可为活性物质层20提供一定的位移空间，减少活性物质层20对电芯的厚度的影响。
本申请还提供了一种电化学装置100的实施例，如图10所示，该电化学装置100包括壳体101以及位于所述壳体101内的电极组件102，所述电极组件102包括隔离膜1021以及位于所述隔离膜1021两侧且极 性相反的第一极片1022和第二极片1023，所述第一极片1022为上述实施例中的极片。其中，隔离膜1021与第一极片1022和第二极片1023之间可通过卷绕或堆叠形成所述电极组件102。此外，需要说明的是：第一极片1022和第二极片1023的极性不作具体限定，第一极片1022或第二极片1023可为正极极片，第一极片1022或第二极片1023可为负极极片，只要保证第一极片1022和第二极片1023的极性相反即可。
在一些实施例中，请一并参阅图11和图12，第二极片1023上设置有第三绝缘胶层1023a，第三绝缘胶层1023a设置于第二极片1023上的活性物质层背离集流体10的一侧，第一极片1022的第一凹槽201a内延伸有两个第一阶梯部2011，两个第一阶梯部2011间隔设置，第一绝缘胶层40位于两个第一阶梯部2011之间，第一阶梯部2011上设置有第一阶梯面(未标示)。为减少第三绝缘胶层1023a对电芯的厚度造成影响，在第一极片1022和第二极片1023卷绕或堆叠时，第三绝缘胶层1023a背离活性物质层的一侧抵接于所述隔离膜1021，直至所述隔离膜1021抵接于所述第一阶梯面，且第三绝缘胶层1023a至少部分位于第一凹槽201a内，从而减少第三绝缘胶层1023a对电芯的厚度造成影响。
在一些实施例中，第一阶梯部2011沿第一方向上的厚度为T7，第一绝缘胶层40沿第一方向上的厚度为T2，且T2≤T7，这样设置，以使得第一绝缘胶层40在第一方向上的厚度不超过第一阶梯部2011的厚度，在第一极片1022和第二极片1023卷绕或堆叠时，减少第一绝缘胶层40与第三绝缘胶层1023a直接接触，降低第一绝缘胶层40将第三绝缘胶层1023a顶出第一凹槽201a的风险，进一步，以减少第三绝缘胶层1023a对电芯厚度的影响。
在一些实施例中，第一阶梯面到所述第一凹槽201a的槽口的距离为T8，第三绝缘胶层1023a沿第一方向上的厚度为T9，且T9≤T8，这样设置，在第一极片1022和第二极片1023卷绕或堆叠时，第三绝缘胶层1023a收容于第一凹槽201a内，降低第三绝缘胶层1023a因卷绕或堆叠后凸出于第一极片1022表面的风险，减少第三绝缘胶层1023a对电芯厚度的影响，提升电芯能量密度，同时改善电芯厚度一致性。
在一些实施例中，两个第一阶梯部2011之间间隔距离为W7，第一绝缘胶层40沿第二方向上的宽度为W2，且W2≤W7，以使得第一绝缘胶层40收容于两个第一阶梯部2011之间。
在一些实施例中，第二极片1023上设置有第四绝缘胶层1023b，第四绝缘胶层1023b设置于第二极片1023上的活性物质层背离集流体10的一侧，第一极片1022的第三凹槽202a内延伸有两个第二阶梯部2021， 两个第二阶梯部2021间隔设置，第二绝缘胶层50位于两个第二阶梯部2021之间，第二阶梯部2021上设置有第二阶梯面(未标示)，在第一极片1022和第二极片1023卷绕或堆叠时，第四绝缘胶层1023b背离第二极片1023上的活性物质层的一侧抵接于所述隔离膜1021，直至所述隔离膜1021抵接于所述第二阶梯面，且第四绝缘胶层1023b至少部分位于第三凹槽202a内，从而减少第四绝缘胶层1023b对电芯的厚度造成影响。
在一些实施例中，第二阶梯部2021沿第一方向上的厚度为T10，第二绝缘胶层50沿第一方向上的厚度为T5，且T5≤T10，在第一极片1022和第二极片1023卷绕或堆叠时，减少第二绝缘胶层50与第四绝缘胶层1023b直接接触，降低第一绝缘胶层40将第三绝缘胶层1023a顶出第三凹槽202a的风险，进一步，以减少第四绝缘胶层1023b对电芯厚度的影响。
在一些实施例中，所述第二阶梯面到所述第三凹槽202a的槽口的距离为T11，所述第四绝缘胶层1023b沿第一方向上的厚度为T12，且T12≤T11，这样设置，在第一极片1022和第二极片1023卷绕或堆叠时，第四绝缘胶层1023b收容于第三凹槽202a内，降低第四绝缘胶层1023b因卷绕或堆叠后凸出于第一极片1022表面的风险，减少第四绝缘胶层1023b对电芯厚度的影响，提升电芯能量密度，同时改善电芯厚度一致性。
在一些实施例中，所述两个第二阶梯部2021之间间隔距离为W8，所述第二绝缘胶层50沿第二方向上的宽度为W5，且W5≤W8，以使得第二绝缘胶层50收容于于两个第二阶梯部2021之间。
本申请还提供了一种电子设备的实施例，该电子设备包括如上所述的电化学装置，电化学装置的功能和结构可参阅上述实施例，此处不再一一赘述。
以上所述仅为本申请的实施例，并非因此限制本申请的专利范围，凡是利用本申请说明书及附图内容所作的等效结构或等效流程变换，或直接或间接运用在其他相关的技术领域，均同理包括在本申请的专利保护范围内。

Claims (16)

  1. 一种极片，包括集流体和活性物质层，所述活性物质层设置于所述集流体的表面，其特征在于，
    所述集流体包括相对设置的第一表面和第二表面，所述第一表面上设置有所述活性物质层，所述活性物质层设有第一凹槽及第二凹槽，所述第一表面部分裸露于所述第二凹槽内，沿第一方向，所述第二凹槽的投影位于所述第一凹槽的投影内，且所述第一凹槽和所述第二凹槽沿所述第一方向依次设置；
    所述集流体上设置有极耳和第一绝缘胶层，所述极耳收容于所述第一凹槽和第二凹槽，所述极耳与所述集流体连接；
    所述第一绝缘胶层设置于所述第一凹槽，所述第一绝缘胶层及所述极耳沿所述第一方向的投影位于所述第一凹槽内，所述第一方向为所述极片的厚度方向。
  2. 根据权利要求1所述的极片，其特征在于，
    所述活性物质层包括第一活性物质层和第二活性物质层，所述第一活性物质层设置于所述第一表面，所述第二活性物质层设置于所述第二表面，所述第一凹槽位于所述第一活性物质层上。
  3. 根据权利要求2所述的极片，其特征在于，
    所述第一凹槽沿所述第一方向上的深度为T1，所述第一绝缘胶层沿第一方向上的厚度为T2，所述第一活性物质层沿所述第一方向上的厚度为T3，且T2≤T1＜T3。
  4. 根据权利要求3所述的极片，其特征在于，
    所述极片至少满足以下条件之一：
    所述第二凹槽沿第二方向上的宽度为W1，所述第一绝缘胶层沿第二方向上的宽度为W2，且W1≤W2；
    所述第一凹槽沿第二方向上的宽度为W3，且W2≤W3，所述第二方向与所述第一方向垂直。
  5. 根据权利要求3所述的极片，其特征在于，
    沿所述第一方向观察，所述第一凹槽的槽底被所述第二凹槽分隔形 成不连续的第一区域和第二区域，所述第一区域和第二区域相对设置，所述第一绝缘胶层的一端位于所述第一区域，另一端位于所述第二区域；
    或者，
    沿所述第一方向观察，所述第一凹槽的槽底被所述第二凹槽分隔形成第三区域，所述第三区域呈U型。
  6. 根据权利要求3所述的极片，其特征在于，
    所述第二活性物质层设置有第三凹槽及贯穿所述第三凹槽槽底至所述集流体的第四凹槽，所述集流体部分裸露于所述第四凹槽内，所述第四凹槽和第二凹槽在第一方向上的投影重叠，所述集流体朝所述第四凹槽弯折形成弯折部，所述极耳连接于所述弯折部；
    所述极片还包括第二绝缘胶层，所述第二绝缘胶层设置于所述第三凹槽内背离所述集流体的一侧。
  7. 根据权利要求6所述的极片，其特征在于，
    所述第三凹槽沿第一方向上的深度为T4，所述第二绝缘胶层沿第一方向上的厚度为T5，所述第二活性物质层沿第一方向上的厚度为T6，且T5≤T4＜T6。
  8. 根据权利要求6所述的极片，其特征在于，
    至少满足以下条件之一：
    所述第四凹槽沿第二方向上的宽度为W4，所述第二绝缘胶层沿第二方向上的宽度为W5，且W4≤W5；
    所述第三凹槽沿第二方向上的宽度为W6，且W5≤W6，所述第二方向与第一方向垂直。
  9. 根据权利要求6-8任意一项所述的极片，其特征在于：所述第二凹槽与所述第四凹槽沿所述第一方向上的投影存在不重合的部分。
  10. 一种电化学装置，其特征在于，包括隔离膜以及位于所述隔离膜两侧且极性相反的第一极片和第二极片，所述第一极片为权利要求1-5任意一项所述的极片。
  11. 一种电化学装置，其特征在于，包括隔离膜以及位于所述隔离膜两侧且极性相反的第一极片和第二极片，所述第一极片为权利要求 6-8任意一项所述的极片。
  12. 根据权利要求11所述的电化学装置，其特征在于，
    所述第二极片上设置有第三绝缘胶层，所述第三绝缘胶层设置于第二极片上的活性物质层背离集流体的一侧；
    所述第一极片的第一凹槽内延伸有两个第一阶梯部，两个第一阶梯部间隔设置，所述第一绝缘胶层位于所述两个第一阶梯部之间，所述第一阶梯部上设置有第一阶梯面，在第一极片和第二极片卷绕或堆叠时，所述第三绝缘胶层背离所述活性物质层的一侧抵接于所述隔离膜，直至所述隔离膜抵接于所述第一阶梯面，且所述第三绝缘胶层至少部分位于所述第一凹槽内。
  13. 根据权利要求12所述的电化学装置，其特征在于，
    至少满足以下条件之一：
    所述第一阶梯部沿第一方向上的厚度为T7，所述第一绝缘胶层沿第一方向上的厚度为T2，且T2≤T7；
    所述第一阶梯面到所述第一凹槽的槽口的距离为T8，所述第三绝缘胶层沿第一方向上的厚度为T9，且T9≤T8；
    所述两个第一阶梯部之间间隔距离为W7，所述第一绝缘胶层沿第二方向上的宽度为W2，且W2≤W7。
  14. 根据权利要求11所述的电化学装置，其特征在于，
    所述第二极片上设置有第四绝缘胶层，所述第四绝缘胶层设置于第二极片上的活性物质层背离集流体的一侧；
    所述第一极片的第三凹槽内延伸有两个第二阶梯部，两个第二阶梯部间隔设置，所述第二绝缘胶层位于所述两个第二阶梯部之间，所述第二阶梯部上设置有第二阶梯面，在第一极片和第二极片卷绕或堆叠时，所述第四绝缘胶层背离第二极片上的活性物质层的一侧抵接于所述隔离膜，直至所述隔离膜抵接于所述第二阶梯面，且所述第四绝缘胶层至少部分位于所述第三凹槽内。
  15. 根据权利要求14所述的电化学装置，其特征在于，
    至少满足以下条件之一：
    所述第二阶梯部沿第一方向上的厚度为T10，所述第二绝缘胶层沿第一方向上的厚度为T5，且T5≤T10；
    所述第二阶梯面到所述第三凹槽的槽口的距离为T11，所述第四绝缘胶层沿第一方向上的厚度为T12，且T12≤T11；
    所述两个第二阶梯部之间间隔距离为W8，所述第二绝缘胶层沿第二方向上的宽度为W5，且W5≤W8。
  16. 一种电子设备，其特征在于，包括如权利要求10-15任一项所述的电化学装置。
PCT/CN2023/121953 2022-10-13 2023-09-27 一种极片、电化学装置及电子设备 WO2024078336A1 (zh)

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