WO2023082181A1 - 电化学装置及包括其的电子装置 - Google Patents

电化学装置及包括其的电子装置 Download PDF

Info

Publication number
WO2023082181A1
WO2023082181A1 PCT/CN2021/130344 CN2021130344W WO2023082181A1 WO 2023082181 A1 WO2023082181 A1 WO 2023082181A1 CN 2021130344 W CN2021130344 W CN 2021130344W WO 2023082181 A1 WO2023082181 A1 WO 2023082181A1
Authority
WO
WIPO (PCT)
Prior art keywords
insulating layer
pole piece
current collector
electrochemical device
thickness
Prior art date
Application number
PCT/CN2021/130344
Other languages
English (en)
French (fr)
Inventor
余舒娴
明帮生
Original Assignee
宁德新能源科技有限公司
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 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to PCT/CN2021/130344 priority Critical patent/WO2023082181A1/zh
Priority to CN202180021529.XA priority patent/CN115380411A/zh
Publication of WO2023082181A1 publication Critical patent/WO2023082181A1/zh
Priority to US18/660,768 priority patent/US20240297421A1/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
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
    • 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
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/653—Means for temperature control structurally associated with the cells characterised by electrically insulating or thermally conductive materials
    • 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
    • H01M50/593—Spacers; Insulating plates
    • 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
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • 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 present application relates to an electrochemical device and an electronic device including the same.
  • Li + is deintercalated from the positive electrode and intercalated into the negative electrode, but when some abnormal conditions (for example, the negative electrode has insufficient lithium intercalation space, the resistance of Li + to the negative electrode is too large, Li + is too fast to deintercalate from the positive electrode but cannot When an equal amount of intercalation into the negative electrode, etc.) occurs, Li + that cannot be inserted into the negative electrode can only obtain electrons on the surface of the negative electrode, thereby forming a silver-white metallic lithium element, which is precipitated on the surface of the negative electrode. This phenomenon is called lithium precipitation.
  • the present application provides an electrochemical device and an electronic device including the same to solve the problem of lithium separation in the slot.
  • An embodiment of the present application provides an electrochemical device, including an electrode assembly, where the electrode assembly includes a first pole piece, a separator, and a second pole piece.
  • the first pole piece includes a first current collector and a first active material layer disposed on the surface of the first current collector
  • the second pole piece includes a second current collector and a second active material layer disposed on the surface of the second current collector.
  • the first pole piece further includes a first groove formed by missing the first active material layer.
  • the first pole piece further includes a first pole lug, one end of the first pole lug is disposed in the first groove and electrically connected to the first current collector.
  • the second pole piece includes a first insulating layer disposed opposite to the first tab, and the first insulating layer is directly disposed on the surface of the second current collector.
  • the projected area of the first groove is smaller than the projected area of the first insulating layer, and the projection of the first groove is located within the projection of the first insulating layer.
  • Li + comes out of the positive pole piece, passes through the electrolyte and separator, and enters the opposite negative pole piece.
  • the first pole piece is a negative pole piece
  • the second pole piece is a positive pole piece. Since the first insulating layer is provided on the surface of the second current collector (positive current collector), the first insulating layer blocks electron conduction, LiCoO cannot escape e - to the second current collector (positive current collector), and the chemical reaction cannot conduct. Therefore, the second pole piece cannot escape Li + into the opposite first pole piece, which reduces the capacity of the positive electrode of the second pole piece, thereby effectively improving the phenomenon of lithium separation in the slot.
  • the second active material layer includes a first active region disposed on the surface of the second current collector and a second active region disposed on the surface of the first insulating layer, and the second active region is away from the surface of the first insulating layer.
  • the surface is provided with a first insulating member.
  • the first insulator is arranged on the surface of the second active area of the second pole piece, which is beneficial to reduce the risk of the first pole piece piercing the diaphragm and causing the first pole piece and the second pole piece to communicate and short circuit, and can also reduce the risk of the second active area.
  • the capacity is volatilized, thereby reducing the phenomenon of lithium precipitation.
  • the sum of the thicknesses of the first insulating layer and the second active region is equal to the thickness of the first active region.
  • Press coating the overall thickness of each region of the second pole piece remains consistent, so the sum of the thickness of the first insulating layer and the thickness of the second active region on its surface is equal to the thickness of the adjacent first active region. In this way, although a layer of the first insulating layer is added, the thickness of the second pole piece is not increased, and the influence on the energy density of the electrochemical device can be ignored.
  • the thickness of the first insulating layer is 5 ⁇ m ⁇ 20 ⁇ m. Setting the thickness of the first insulating layer within the range of 5 ⁇ m to 20 ⁇ m not only ensures the insulation effect, but also reduces the impact on the energy density of the electrochemical device.
  • the thickness of the first insulating layer is equal to the thickness of the second active material layer.
  • the direction in which the first tab protrudes from the first pole piece is defined as the first direction
  • the direction perpendicular to the first direction and the thickness direction of the electrode assembly is defined as the second direction.
  • the first insulating layer is connected to the second active material layer.
  • the second active material layer is not provided on the surface of the first insulating layer, so the second pole piece at the first insulating layer has no positive electrode capacity, and the first insulating member can be omitted, which is beneficial to the development of the electrochemical device. Increased energy density.
  • the first groove exposes part of the first current collector.
  • the exposed first current collector is more conducive to the heat dissipation of the electrochemical device in the state of high-rate charge and discharge; further, at the first current collector exposed by the first groove, the first tab is connected to the first current collector, The reliability of the electrical connection of the first tab is improved.
  • the second pole piece further includes a second groove, and the second groove is formed by missing the second active material layer.
  • the second pole piece further includes a second pole lug, one end of the second pole lug is disposed in the second groove and electrically connected to the second current collector.
  • the direction in which the second tab protrudes from the second pole piece is defined as the first direction, and the direction perpendicular to the first direction and the thickness direction of the electrode assembly is defined as the second direction.
  • the second pole piece is provided with a second insulating layer on both sides of the second groove, the second insulating layer is directly arranged on the surface of the second current collector, and the second insulating layer is connected to the second active electrode along the second direction. material layer.
  • a second insulating layer is provided on the surface of the second current collector near the second tab, and the second insulating layer blocks electron conduction, so LiCoO 2 cannot escape e- to the second current collector, and the chemical reaction cannot proceed. Therefore, the second pole piece cannot escape Li + into the opposite first pole piece, thereby effectively improving the phenomenon of lithium separation in the slot.
  • the second active material layer includes a first active region disposed on the surface of the second current collector and a third active region disposed on the surface of the second insulating layer, along the thickness direction of the electrode assembly, the second insulating
  • the sum of the thicknesses of the layer and the third active area is equal to the thickness of the first active area.
  • the thickness of the second insulating layer is 5 ⁇ m ⁇ 20 ⁇ m. In this way, the insulating effect is ensured, and the impact on the energy density of the electrochemical device is reduced.
  • the thickness of the second insulating layer is equal to the thickness of the second active material layer.
  • the second pole piece further includes a third insulating member disposed on the surface of the second tab, and along the thickness direction of the electrode assembly, the projection of the third insulating member at least partially overlaps the projection of the second insulating layer.
  • the third insulating member is beneficial to reduce the risk of the second tab piercing the diaphragm and causing a short circuit between the first pole piece and the second pole piece, and can also reduce the capacity volatilization of the second active material layer, thereby improving the lithium precipitation phenomenon.
  • the first pole piece further includes a fourth insulating member disposed opposite to the second tab, and the fourth insulating member is disposed on a surface of the first active material layer away from the first current collector.
  • the fourth insulating member is beneficial to reduce the risk of the second tab piercing the diaphragm and causing a short circuit between the first pole piece and the second pole piece.
  • the projection of the second insulating layer and the projection of the third insulating member cover the projection of the fourth insulating member. In this way, the lithium ions deintercalated from the second pole piece are received by the corresponding first active material layer on the first pole piece, which reduces the occurrence of lithium precipitation.
  • the first insulating layer includes an insulating material, and the insulating material includes at least one of polytetrafluoroethylene, polyvinylidene fluoride, or non-metallic silicate.
  • a functional coating is provided between the first insulating layer and the second active material layer.
  • the functional coating may be a ceramic coating; by providing the functional coating, electron conduction between the current collector and the active material layer can be blocked.
  • the present application also provides an electronic device, which includes a load and the above-mentioned electrochemical device, and the electrochemical device is used to supply power to the load.
  • the first insulating layer is directly arranged on the surface of the second current collector, which blocks the electron conduction of the second current collector, and the active material of the second active material layer (for example, including but not limited to LiCoO2 , etc.) cannot escape from the e- To the second current collector, the chemical reaction cannot proceed. Therefore, the second pole piece cannot escape Li + into the opposite first pole piece, which reduces the capacity of the positive electrode of the second pole piece, thereby effectively improving the phenomenon of lithium separation in the slot.
  • the active material of the second active material layer for example, including but not limited to LiCoO2 , etc.
  • FIG. 1 is a schematic structural diagram of an electrochemical device provided by an embodiment of the present application.
  • FIG. 2 is a schematic structural diagram of an electrode assembly provided by an embodiment of the present application.
  • Fig. 3 is an enlarged view of point A in Fig. 1 .
  • Fig. 4 is a schematic structural diagram of a first pole piece provided by an embodiment of the present application.
  • FIG. 5 is a schematic diagram of projections of the first groove and the first insulating layer on the first pole piece according to an embodiment of the present application.
  • FIG. 6 is a partially enlarged schematic view of the first tab provided by an embodiment of the present application.
  • FIG. 7 is a schematic structural diagram of a second pole piece provided by an embodiment of the present application.
  • FIG. 8 is an enlarged view of B in FIG. 1 .
  • FIG. 9 is a partially enlarged schematic view of a second tab provided in an embodiment of the present application.
  • FIG. 10 is a partially enlarged schematic diagram of a first tab provided in another embodiment of the present application.
  • FIG. 11 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.
  • the first active material layer 112 is the first active material layer 112
  • the first active area 1221 is the first active area 1221
  • the third active zone 1223 is the third active zone 1223
  • the electrochemical device 100 includes an electrode assembly 10 , a case 20 accommodating the electrode assembly 10 and an electrolyte (not shown).
  • the electrode assembly 10 includes a first pole piece 11 , a second pole piece 12 and a diaphragm 13 disposed between the first pole piece 11 and the second pole piece 12 .
  • Diaphragm 13 is used to prevent the first pole piece 11 and the second pole piece 12 from being in direct contact, and can make the ions in the electrolyte pass through.
  • the electrode assembly 10 has a wound structure and is arranged in a housing 20 , that is, the first pole piece 11 , the separator 13 and the second pole piece 12 are stacked and wound in sequence to form the electrode assembly 10 .
  • the electrode assembly 10 can also be stacked into a lamination structure by the first pole piece 11 , the diaphragm 13 and the second pole piece 12 , as shown in FIG. 2 .
  • the first pole piece 11 is a negative pole piece
  • the second pole piece 12 is a positive pole piece.
  • the first pole piece 11 includes a first current collector 111 and a first active material layer 112 disposed on the surface of the first current collector 111 .
  • the first current collector 111 can be a negative electrode current collector commonly used in the art, and the negative electrode current collector can use materials such as metal foils or porous metal plates, such as foils or porous metals such as copper, nickel, titanium or iron, or their alloys.
  • the board, such as copper foil, is not limited in this application.
  • the first active material layer 112 includes a positive electrode active material.
  • the positive electrode active material can be selected from various positive electrode active materials known in the art and can be used as an electrochemical device, which is not limited in this application.
  • the positive electrode active material may include at least one of lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, or lithium nickel manganese oxide.
  • the first pole piece 11 further includes a first groove 113 formed by missing the first active material layer 112 . Further, in some embodiments, the first groove 113 may reveal part of the first current collector 111 . The exposed first current collector 111 is more conducive to the heat dissipation of the electrochemical device 100 in a high-rate charging and discharging state.
  • the first pole piece 11 further includes a first pole lug 114 , one end of the first pole lug 114 is disposed in the first groove 113 and electrically connected to the first current collector 111 .
  • the first tab 114 is connected to the first current collector 111 , which can improve the reliability of the electrical connection of the first tab 114 .
  • the first tab 114 and the first current collector 111 may be connected by soldering and/or by conductive glue.
  • the second pole piece 12 includes a first insulating layer 31 disposed opposite to the first tab 114 , and the first insulating layer 31 is directly disposed on the surface of the second current collector 121 .
  • the opposite arrangement means that the first insulating layer 31 is arranged on the surface of the second current collector 121 adjacent to the first tab 114 in the thickness direction X, and, in the thickness direction X of the electrode assembly 10,
  • the projection of the first insulating layer 31 that is, the orthographic projection on the projection plane perpendicular to the thickness direction X of the electrode assembly 10) and the projection of the first tab 114 (that is, the projection plane perpendicular to the thickness direction X of the electrode assembly 10 Orthographic projection on ) at least partially overlap.
  • the second current collector 121 in this application is a positive current collector, and the second current collector 121 can be made of Al foil, or other positive current collectors commonly used in the field.
  • the second current collector 121 may also include a substrate layer (for example, including but not limited to Al foil) and an undercoat layer disposed on the surface of the substrate layer (functions include but not limited to increasing the conductivity of the current collector, etc.).
  • the first insulating layer 31 is directly provided on the surface of the second current collector 121 means that when the second current collector 121 has only the substrate layer, the first insulating layer 31 is directly provided on the surface of the substrate layer; when When the second current collector 121 includes a substrate layer and an undercoat layer, the first insulating layer 31 is directly disposed on the surface of the undercoat layer. There is no intermediate layer between the first insulating layer 31 and the second current collector 121 .
  • the direction in which the first tab 114 protrudes from the first pole piece 11 is defined as the first direction Y, and the direction perpendicular to the first direction Y and the thickness direction X of the electrode assembly 10 is defined as the second direction Z.
  • the first direction Y can be the length direction of the first pole piece 11
  • the second direction Z can be the width direction of the first pole piece 11
  • the first direction Y can also be the width direction of the first pole piece 11
  • the second direction Z is the length direction of the first pole piece 11 .
  • the area of the projection of the first groove 113 (that is, the orthographic projection on the projection plane perpendicular to the thickness direction X of the electrode assembly 10) is smaller than that of the first insulating layer 31.
  • the area of the projection (that is, the orthographic projection on the projection plane perpendicular to the thickness direction X of the electrode assembly 10 ), and the projection of the first groove 113 is located within the projection of the first insulating layer 31 . In this way, it can be ensured that at the first groove 113 where the first active material layer 112 is missing, the corresponding second pole piece 12 does not have Li + come out.
  • the slot width of the first groove 113 along the second direction Z is 9 mm, and the length along the first direction Y is 20 mm; the width of the second insulating member 42 along the second direction Z is 9 mm. , the length along the first direction Y is 23 mm, and the projected area of the second insulating member 42 along the thickness direction X is slightly larger than the projected area of the first groove 113 along the thickness direction X.
  • the width of the first insulating layer 31 along the second direction Z may be 13mm to 18mm, then in the first direction, the length of the first pole piece 11 beyond the second pole piece 12 is 2mm to 4.5mm, and the length beyond 2mm Preferably, it can not only ensure that lithium is not separated, but also ensure that the capacity loss is small.
  • the size of the first insulating member 41 may be the same as that of the first insulating layer 31 .
  • the first insulating layer 31 includes an insulating material, and the insulating material includes at least one of polytetrafluoroethylene (Teflon, PTFE), polyvinylidene fluoride (PVDF), or non-metallic silicate.
  • Non-metallic silicates include, but are not limited to, glass, ceramic, cement, plastic, fiber, or rubber, among others.
  • the first insulating layer 31 is stable under high temperature and high pressure, and will not fail due to electrolyte immersion; the first insulating layer 31 is lighter and thinner, which is conducive to improving energy density; the size of the first insulating layer 31 can be flexibly set according to requirements.
  • the second pole piece 12 includes a second current collector 121 and a second active material layer 122 disposed on the surface of the second current collector 121 .
  • the second active material layer 122 includes a negative electrode active material.
  • the negative electrode active material may include at least one of carbonaceous material, silicon carbon material, alloy material, and lithium-containing metal composite oxide material, but is not limited thereto.
  • the negative electrode active material can be selected from Various conventionally known materials capable of electrochemically intercalating and deintercalating active ions that are known in the art and can be used as negative electrode active materials of electrochemical devices.
  • the second active material layer 122 includes a first active region 1221 disposed on the surface of the second current collector 121 and a second active region 1222 disposed on the surface of the first insulating layer 31, the second active region 1222 facing away from The surface of the first insulating layer 31 is provided with a first insulating member 41 .
  • the first insulator 41 is arranged on the surface of the second active area 1222 of the second pole piece 12, which is beneficial to reduce the risk of the first pole piece 114 piercing the diaphragm 13 and causing the first pole piece 11 and the second pole piece 12 to communicate and short circuit. It can reduce the capacity volatilization of the second active region, thereby reducing the phenomenon of lithium precipitation.
  • the first tab 114 is located in the first groove 113, and the surface of the first tab 114 generally needs to be attached with the second insulating member 42 to reduce the first tab 114 piercing the diaphragm 13 and causing the first pole piece 11 and the second Pole piece 12 communicates with the risk of short circuit.
  • the first insulator 41 and the second insulator 42 can be, but not limited to, adhesive tape commonly used in the field.
  • the sum of the thicknesses of the first insulating layer 31 and the second active region 1222 on its surface is equal to the thickness of the first active region 1221 .
  • the first insulating layer 31 is first provided, and then the first active region 1221 is provided on the surface of the second current collector 121 without the first insulating layer 31, and at the same time, the second active region is provided on the first insulating layer 31 1222, since the setting method is extrusion coating, the overall thickness of each area of the second pole piece 12 remains consistent, so the sum of the thickness of the first insulating layer 31 and the thickness of the second active region 1222 on its surface is equal to that of the adjacent first pole piece 1222.
  • the thickness of the active region 1221 . In this way, although a layer of the first insulating layer 31 is added, the thickness of the second pole piece 12 is not increased, and the influence on the energy density of the electrochemical device is negligible.
  • the thickness of the first insulating layer 31 may be 5 ⁇ m ⁇ 20 ⁇ m.
  • the thickness of the second active material layer 122 is approximately 50 ⁇ m, and the thickness of the first insulating layer 31 is set in the range of 5 ⁇ m to 20 ⁇ m, which not only ensures the insulating effect, but also The influence on the energy density of the electrochemical device 100 can be reduced.
  • the thickness of the first insulating layer 31 may also be equal to the thickness of the second active material layer 122, and the first insulating layer 31 is aligned with the second active material layer 122 along the second direction Z.
  • the second active material layers are connected.
  • the thickness of the second active material layer 122 is uniform, and there is no distinction between the first active region 1221 and the second active region 1222 .
  • the surface of the first insulating layer 31 is not provided with the second active material layer 122, the second pole piece 12 at the first insulating layer 31 does not have a positive electrode capacity to play, and the first insulating layer 31 can also play a role in reducing the first tab.
  • 114 punctures the diaphragm 13 and causes a short circuit, the first insulating member 41 shown in FIG. 3 can be omitted, which is beneficial to the improvement of the energy density of the electrochemical device 100 .
  • a functional coating layer may be provided between the first insulating layer 31 and the second active material layer 122 .
  • the functional coating can be a ceramic coating; by providing the functional coating, electron conduction between the current collector and the active material layer can be blocked.
  • the second pole piece 12 includes a second groove 123 formed by missing the second active material layer 122 .
  • the second pole piece 12 further includes a second pole lug 124 , one end of the second pole lug 124 is disposed in the second groove 123 and electrically connected to the second current collector 121 .
  • the second groove 123 may expose part of the surface of the second current collector 121 .
  • the exposed second current collector 121 is more conducive to the heat dissipation of the electrochemical device 100 in a state of high-rate charge and discharge.
  • the second tab 124 is connected to the second current collector 121 , which can improve the reliability of the electrical connection of the second tab 124 .
  • the second tab 124 and the second current collector 121 can be connected by soldering and/or by conductive glue.
  • the direction in which the second pole lug 124 protrudes from the second pole piece 12 is defined as the first direction Y (consistent with the direction in which the first pole lug 114 protrudes from the first pole piece 11), perpendicular to the first direction Y and
  • the direction of the thickness direction X of the electrode assembly 10 is the second direction Z.
  • the second pole piece 12 is provided with a second insulating layer 32 on both sides of the second groove 123 along the second direction Z, and the second insulating layer 32 is provided on the second current collector 121 (there is no intermediate layer between the second insulating layer 32 and the second current collector 121 ), the second insulating layer 32 is connected to the second active material layer 122 along the second direction Z.
  • the second insulating layer 32 is provided on the surface of the second current collector 121 near the second tab 124, and the second insulating layer 32 blocks electron conduction, LiCoO 2 cannot escape from e- to the second current collector 121, and the chemical reaction cannot proceed. Therefore, the second pole piece 12 cannot escape Li + into the opposite first pole piece 11, thereby further improving the phenomenon of lithium precipitation in the slot.
  • the second insulating layer 32 includes an insulating material, and the insulating material includes at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), or non-metallic silicate.
  • PTFE polytetrafluoroethylene
  • PVDF polyvinylidene fluoride
  • Non-metallic silicates include, but are not limited to, glass, ceramic, cement, plastic, fiber or rubber, and the like.
  • the second insulating layer 32 is stable under high temperature and high pressure, and will not fail due to electrolyte immersion; the second insulating layer 32 is lighter and thinner, which is conducive to improving energy density; the size of the second insulating layer 32 can be flexibly set according to requirements.
  • the second active material layer 122 includes a first active region 1221 disposed on the surface of the second current collector 121 and a third active region 1223 disposed on the surface of the second insulating layer 32 ,
  • the sum of the thicknesses of the second insulating layer 32 and the third active region 1223 on its surface is equal to the thickness of the first active region 1221 .
  • the second insulating layer 32 is first provided, and then the first active region 1221 is provided on the surface of the second current collector 121 without the second insulating layer 32, and the third active region is provided on the second insulating layer 32 at the same time.
  • the overall thickness of each area of the second pole piece 12 remains consistent, so the sum of the thickness of the second insulating layer 32 and the thickness of the third active region 1223 on its surface is equal to that of the adjacent first pole piece 1223.
  • the thickness of the active region 1221 is equal to that of the adjacent first pole piece 1223. In this way, although a second insulating layer 32 is added, the thickness of the second pole piece 12 is not increased, and the influence on the energy density of the electrochemical device is negligible.
  • the thickness of the second insulating layer is 5 ⁇ m ⁇ 20 ⁇ m. In this way, the insulating effect is ensured, and the energy density of the electrochemical device will not be affected.
  • the second pole piece 12 further includes a third insulating member 43 disposed on the surface of the second tab 124 , along the thickness direction X of the electrode assembly 10 , the projection of the third insulating member 43 is the same as The projections of the second insulating layer 32 at least partially overlap.
  • the third insulator 43 is beneficial to reduce the risk of the second tab 124 piercing the diaphragm 13 to cause a short circuit between the first pole piece 11 and the second pole piece 12, and can also reduce the capacity volatilization of the second active material layer 122, thereby improving the analytical performance. Lithium phenomenon.
  • the third insulating member 43 may be, but not limited to, adhesive tape commonly used in this field.
  • the first pole piece 11 further includes a fourth insulating member 44 disposed opposite to the second tab 124, and the fourth insulating member 44 is disposed on the first active material layer 112 away from the first set. The surface of the fluid 111.
  • the relative arrangement means that the fourth insulating member 44 is arranged on the surface of the first pole piece 11 adjacent to the second tab 124 in the thickness direction X, and, in the thickness direction X of the electrode assembly 10,
  • the fourth insulating member 44 is beneficial to reduce the risk of the second tab 124 piercing the diaphragm 13 and causing a short circuit between the first pole piece 11 and the second pole piece 12 .
  • the projection of the second insulating layer 32 and the projection of the third insulating member 43 cover the projection of the fourth insulating member 44 .
  • the lithium ions deintercalated from the second pole piece 12 are received by the corresponding first active material layer 112 on the first pole piece 11, which reduces the occurrence of lithium precipitation.
  • the fourth insulating member 44 can be, but not limited to, adhesive tape commonly used in the field.
  • the thickness of the second insulating layer 32 may be equal to the thickness of the second active material layer 122 .
  • the thickness of the second active material layer 122 is uniform, and there is no distinction between the first active region 1221 and the third active region 1223 .
  • the surface of the second tab 124 can also be provided with a third insulating member 43
  • the first pole piece 11 can also include a fourth insulating member 44 opposite to the second tab 124, the projection of the second insulating layer 32 and the third insulating member
  • the projection of 43 covers the projection of the fourth insulating element 44 .
  • the first insulating member 41 (see FIG. 3 ) on the surface of the second active material layer 122 can be replaced by the second insulating layer 32, because the second insulating layer 32
  • the performance is more stable than gummed paper, etc., and it will not fail due to electrolyte immersion.
  • the settings in Figure 10 can also improve the role of lithium separation in the slot.
  • the present application also provides an electronic device 1000 , which includes a load (not shown) and the above-mentioned electrochemical device 100 , and the electrochemical device 100 is used to supply power to the load.
  • the electronic device 1000 of the present application may be, but not limited to, mobile phones, notebook computers, electronic notebooks, calculators, memory cards, radios, backup power supplies, motors, lighting appliances, toys, game machines, clocks, Power tools, flashlights, cameras, large household storage batteries and lithium-ion capacitors, etc.
  • the electronic conduction of the second current collector 121 is blocked, and the active material of the second active material layer 122 (for example, including but not limited to LiCoO2 , etc.) Unable to escape e - to the second current collector 121, so that the chemical reaction cannot be carried out. Therefore, the second pole piece 12 cannot escape Li + into the opposite first pole piece 11, which reduces the capacity of the positive electrode of the second pole piece 12, thereby effectively improving the phenomenon of lithium precipitation in the slot.
  • the active material of the second active material layer 122 for example, including but not limited to LiCoO2 , etc.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Composite Materials (AREA)
  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请提供一种电化学装置及包括其的电子装置，电化学装置包括第一极片、隔膜和第二极片。第一极片包括第一凹槽和一端设于第一凹槽的第一极耳，第二极片包括与第一极片的第一极耳相对设置的第一绝缘层，第一绝缘层直接设于第二集流体的表面。在电极组件的厚度方向上，第一凹槽的投影面积小于第一绝缘层的投影面积，且第一凹槽的投影位于第一绝缘层的投影内。本申请通过在第二集流体的表面设置第一绝缘层，阻隔了第二集流体的电子传导，第二活性物质层的活性材料无法脱出e -到第二集流体，使化学反应无法进行。因此，第二极片无法脱出Li +进入对面的第一极片，降低了第二极片的正极容量发挥，从而有效改善了槽位析锂现象。

Description

电化学装置及包括其的电子装置 技术领域
本申请涉及一种电化学装置及包括其的电子装置。
背景技术
锂离子电池在充电时，Li +从正极脱嵌并嵌入负极，但是当一些异常情况(例如，负极嵌锂空间不足、Li +嵌入负极阻力太大、Li +过快的从正极脱嵌但无法等量的嵌入负极等)发生时，无法嵌入负极的Li +只能在负极表面得电子，从而形成银白色的金属锂单质，析出在负极表面，这种现象叫做析锂。
目前，电池多为极耳中置或多极耳结构，容易出现槽位析锂。
发明内容
有鉴于此，本申请提供一种电化学装置及包括其的电子装置以解决槽位析锂的问题。
本申请一实施方式提供一种电化学装置，包括电极组件，该电极组件包括第一极片、隔膜和第二极片。第一极片包括第一集流体以及设于第一集流体的表面的第一活性物质层，第二极片包括第二集流体以及设于第二集流体的表面的第二活性物质层。第一极片还包括第一凹槽，第一凹槽由第一活性物质层缺失形成。第一极片还包括第一极耳，第一极耳的一端设于第一凹槽并电连接第一集流体。第二极片包括与第一极耳相对设置的第一绝缘层，第一绝缘层直接设于第二集流体的表面。在电极组件的厚度方向上，第一凹槽的投影面积小于第一绝缘层的投影面积，且第一凹槽的投影位于第一绝缘层的投影内。
电化学装置充电时需要进行如下化学反应：正极：LiCoO 2＝Li 1-xCoO 2+x Li ++x e -；负极：6C+x Li ++x e -＝Li xC 6。充电时，Li +从正极极片上脱出，经过电解液和隔膜，进入到对面的负极极片。本申请中，第一极片为负极极片，第二极片为正极极片。由于在第二集流体(正极集流体)的表面设置了第一绝缘层，该第一绝缘层阻隔了电子传导，LiCoO 2无法脱出 e -到第二集流体(正极集流体)，化学反应无法进行。因此，第二极片无法脱出Li +进入对面的第一极片，降低了第二极片的正极容量发挥，从而有效改善了槽位析锂现象。
一种实施方式中，第二活性物质层包括设于第二集流体的表面的第一活性区和设于第一绝缘层的表面的第二活性区，第二活性区背离第一绝缘层的表面设有第一绝缘件。在第二极片的第二活性区表面设置第一绝缘件，有利于降低第一极耳刺破隔膜导致第一极片和第二极片连通短路的风险，还能减少第二活性区的容量挥发，进而减少析锂现象。
一种实施方式中，沿电极组件的厚度方向，第一绝缘层与第二活性区的厚度之和等于第一活性区的厚度。在第二集流体上先设置第一绝缘层再在未设第一绝缘层的第二集流体表面设置第一活性区且同时在第一绝缘层上设置第二活性区，由于设置方式为挤压涂布，第二极片各区域的整体厚度保持一致，因此第一绝缘层的厚度与其表面的第二活性区的厚度之和等于相邻的第一活性区的厚度。如此，虽然增加了一层第一绝缘层，但第二极片的厚度并未增加，对电化学装置的能量密度的影响可以忽略不计。
一种实施方式中，沿电极组件的厚度方向，第一绝缘层的厚度为5μm～20μm。将第一绝缘层的厚度设置在5μm～20μm的范围内，既保证了绝缘效果，又降低了对电化学装置的能量密度的影响。
一种实施方式中，沿电极组件的厚度方向，第一绝缘层的厚度等于第二活性物质层的厚度。定义第一极耳伸出第一极片的方向为第一方向，垂直于第一方向以及电极组件厚度方向的方向为第二方向。沿第二方向，第一绝缘层与第二活性物质层相连接。本实施方式中，第一绝缘层的表面并未设置第二活性物质层，则第一绝缘层处的第二极片并没有正极容量发挥，可以省略第一绝缘件，有利于电化学装置的能量密度的提升。
一种实施方式中，第一凹槽显露出部分第一集流体。显露出的第一集流体更利于电化学装置在大倍率充放电状态下的散热；进一步地，在第一凹槽显露出的第一集流体处，第一极耳与第一集流体连接，提高第一极耳电连接的可靠性。
一种实施方式中，第二极片还包括第二凹槽，第二凹槽由第二活性物质层缺失形成。第二极片还包括第二极耳，第二极耳的一端设于第二凹槽并电连接第二集流体。定义第二极耳伸出第二极片的方向为第一方向，垂直于第一方向以及电极组件的厚度方向的方向为 第二方向。沿第二方向，第二极片在第二凹槽的两侧设有第二绝缘层，第二绝缘层直接设于第二集流体的表面，第二绝缘层沿第二方向连接第二活性物质层。在第二极耳附近的第二集流体表面设置第二绝缘层，该第二绝缘层阻隔了电子传导，LiCoO 2无法脱出e -到第二集流体，化学反应无法进行。因此，第二极片无法脱出Li +进入对面的第一极片，从而有效改善了槽位析锂现象。
一种实施方式中，第二活性物质层包括设于第二集流体的表面的第一活性区和设于第二绝缘层的表面的第三活性区，沿电极组件的厚度方向，第二绝缘层与第三活性区的厚度之和等于第一活性区的厚度。在第二集流体上先设置第二绝缘层再在未设第二绝缘层的第二集流体表面设置第一活性区且同时在第二绝缘层上设置第三活性区，由于设置方式为挤压涂布，第二极片各区域的整体厚度保持一致，因此第二绝缘层的厚度与其表面的第三活性区的厚度之和等于相邻的第一活性区的厚度。如此，虽然增加了一层第二绝缘层，但第二极片的厚度并未增加，对电化学装置的能量密度的影响可以忽略不计。
一种实施方式中，第二绝缘层的厚度为5μm～20μm。如此，既保证了绝缘效果，又降低了对电化学装置的能量密度的影响。
一种实施方式中，沿电极组件的厚度方向，第二绝缘层的厚度等于第二活性物质层的厚度。
一种实施方式中，第二极片还包括设于第二极耳的表面的第三绝缘件，沿电极组件的厚度方向，第三绝缘件的投影与第二绝缘层的投影至少部分重叠。第三绝缘件有利于降低第二极耳刺破隔膜导致第一极片和第二极片连通短路的风险，还能减少第二活性物质层的容量挥发，进而改善析锂现象。
一种实施方式中，第一极片还包括与第二极耳相对设置的第四绝缘件，第四绝缘件设于第一活性物质层背离第一集流体的表面。第四绝缘件有利于减少第二极耳刺破隔膜导致第一极片和第二极片连通短路的风险。在电极组件的厚度方向上，第二绝缘层的投影和第三绝缘件的投影覆盖第四绝缘件的投影。如此，第二极片脱嵌的锂离子在第一极片上都有对应的第一活性物质层接收，减少了析锂现象的发生。
一种实施方式中，第一绝缘层包括绝缘材料，绝缘材料包括聚四氟乙烯、聚偏氟乙烯或非金属硅酸盐中的至少一种。
一种实施方式中，沿电极组件的厚度方向，第一绝缘层和第二活性物质层之间设有功能涂层。根据本申请的一种实施方式，该功能涂层可以是陶瓷涂层；通过设置该功能涂层，可以阻隔集流体和活性物质层之间的电子传导。
本申请还提供一种电子装置，其包括负载和如上所述的电化学装置，电化学装置用于为负载供电。
本申请通过在第二集流体的表面直接设置第一绝缘层，阻隔了第二集流体的电子传导，第二活性物质层的活性材料(例如，包括但不限于LiCoO 2等)无法脱出e -到第二集流体，使化学反应无法进行。因此，第二极片无法脱出Li +进入对面的第一极片，降低了第二极片的正极容量发挥，从而有效改善了槽位析锂现象。
附图说明
图1为本申请一实施方式提供的电化学装置的结构示意图。
图2为本申请一实施方式提供的电极组件的结构示意图。
图3为图1中A处的放大图。
图4为本申请一实施方式提供的第一极片的结构示意图。
图5为本申请一实施方式提供的第一凹槽和第一绝缘层在第一极片上的投影示意图。
图6为本申请一实施方式提供的第一极耳处的局部放大示意图。
图7为本申请一实施方式提供的第二极片的结构示意图。
图8为图1中B处的放大图。
图9为本申请一实施方式提供的第二极耳处的局部放大示意图。
图10为本申请另一实施方式提供的第一极耳处的局部放大示意图。
图11为本申请一实施方式提供的电子装置的结构示意图。
主要元件符号说明
电化学装置                           100
电子装置                             1000
电极组件                             10
壳体                                 20
第一极片                             11
第二极片                             12
隔膜                                 13
第一集流体                           111
第一活性物质层                       112
第一凹槽                             113
第一极耳                             114
第二集流体                           121
第二活性物质层                       122
第二凹槽                             123
第二极耳                             124
第一绝缘层                           31
第二绝缘层                           32
第一绝缘件                           41
第二绝缘件                           42
第三绝缘件                           43
第四绝缘件                           44
第一活性区                           1221
第二活性区                           1222
第三活性区                           1223
厚度方向                             X
第一方向                             Y
第二方向                              Z
如下具体实施方式将结合上述附图进一步说明本申请实施例。
具体实施方式
除非另有定义，本文所使用的所有的技术和科学术语与属于本申请实施例的技术领域的技术人员通常理解的含义相同。本文中所使用的术语只是为了描述具体的实施方式的目的，不是旨在于限制本申请实施例。
需要说明，本申请实施例中所有方向性指示(诸如上、下、左、右、前、后……)仅用于解释在某一特定姿态(如附图所示)下各部件之间的相对位置关系、运动情况等，如果该特定姿态发生改变时，则该方向性指示也相应地随之改变。
另外，在本申请中如涉及“第一”“第二”等的描述仅用于描述目的，而不能理解为指示或暗示其相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”“第二”的特征可以明示或者隐含地包括至少一个该特征。在本申请的描述中，“多个”的含义是至少两个，例如两个，三个等，除非另有明确具体的限定。
下面结合附图，对本申请的一些实施方式作详细说明。在不冲突的情况下，下述的实施方式及实施方式中的特征可以相互组合。
为改善槽位析锂的现象，通常在负极极片上贴短、窄胶纸，对位的正极极片上贴长、宽胶纸，使得负极极片的活性物质层在长度和宽度方向上都大于正极极片的活性物质层。
但是，由于胶纸长期在电解液中浸泡，会失去部分粘性，失粘的胶纸无法抑制正极极片脱嵌出Li +，导致负极胶纸边缘的负极活性物质层要承受正对位的正极极片脱嵌的Li +和附近胶纸无法抑制的Li +。负极极片无法嵌入过多的Li +，锂枝晶析出在负极极片表面，导致槽位出现越来越多的锂析出，循环衰减和膨胀恶化。
为改善槽位析锂的现象，本申请一实施方式提供一种电化学装置100。请参阅图1，该电化学装置100包括电极组件10、收容电极组件10的壳体20和电解液(图未示)。电极组件10包括第一极片11、第二极片12以及设置于第一极片11和第二极片12之间的隔膜13。隔膜13用于防止第一极片11和第二极片12直接接触，并能使电解液中的离子通 过。图1中，电极组件10为卷绕结构并设置于壳体20内，即，第一极片11、隔膜13和第二极片12依次层叠卷绕形成电极组件10。当然，电极组件10还可以由第一极片11、隔膜13和第二极片12堆叠成叠片结构，如图2所示。本申请中，第一极片11为负极极片，第二极片12为正极极片。
请参阅图3，第一极片11包括第一集流体111以及设于第一集流体111的表面的第一活性物质层112。第一集流体111可以是本领域常用的负极集流体，负极集流体可以使用金属箔材或多孔金属板等材料，例如使用铜、镍、钛或铁等金属或它们的合金的箔材或多孔板，如铜箔，本申请并不作限制。第一活性物质层112包括正极活性材料，正极活性材料可选用本领域公知的各种可被用作电化学装置的正极活性材料，本申请并不作限制。例如，正极活性材料可包括钴酸锂、锰酸锂、磷酸铁锂、磷酸锰铁锂、镍钴锰酸锂、镍钴铝酸锂或镍锰酸锂中的至少一种，上述正极活性材料可以经过掺杂和/或包覆处理。第一极片11还包括第一凹槽113，第一凹槽113由第一活性物质层112缺失形成。进一步地，在一些实施例中，第一凹槽113可显露出部分第一集流体111。显露出的第一集流体111更利于电化学装置100在大倍率充放电状态下的散热。第一极片11还包括第一极耳114，第一极耳114的一端设于第一凹槽113并电连接第一集流体111。在第一凹槽113显露出的第一集流体111处，第一极耳114与第一集流体111连接，能提高第一极耳114电连接的可靠性。第一极耳114与第一集流体111可通过焊印连接和/或通过导电胶连接。
如图3所示，第二极片12包括与第一极耳114相对设置的第一绝缘层31，第一绝缘层31直接设于第二集流体121的表面。所述相对设置指的是，第一绝缘层31设置在与第一极耳114在厚度方向X上相邻设置的第二集流体121的表面，并且，在电极组件10的厚度方向X上，第一绝缘层31的投影(即在垂直于电极组件10的厚度方向X的投影面上的正投影)与第一极耳114的投影(即在垂直于电极组件10的厚度方向X的投影面上的正投影)至少部分重叠。可以理解，本申请中第二集流体121为正极集流体，第二集流体121可以采用Al箔，也可以采用本领域常用的其它正极集流体。第二集流体121还可以包括基材层(例如，包括但不限于Al箔)和设置于基材层表面的底涂层(作用包括但不限于增大集流体的导电能力等)。本申请中，第一绝缘层31直接设于第二集流体121的 表面指的是，当第二集流体121只有基材层时，第一绝缘层31直接设于基材层的表面；当第二集流体121包含基材层和底涂层时，第一绝缘层31直接设于底涂层的表面。第一绝缘层31和第二集流体121之间并不存在中间层。
请参阅图4，定义第一极耳114伸出第一极片11的方向为第一方向Y，垂直于第一方向Y以及电极组件10的厚度方向X的方向为第二方向Z。可以理解，第一方向Y可为第一极片11的长度方向，则第二方向Z为第一极片11的宽度方向；第一方向Y也可为第一极片11的宽度方向，则第二方向Z为第一极片11的长度方向。
请参阅图5，在电极组件10的厚度方向X上，第一凹槽113的投影(即在垂直于电极组件10的厚度方向X的投影面上的正投影)面积小于第一绝缘层31的投影(即在垂直于电极组件10的厚度方向X的投影面上的正投影)面积，且第一凹槽113的投影位于第一绝缘层31的投影内。如此，能保证在缺失第一活性物质层112的第一凹槽113处，对应的第二极片12并没有Li +脱出。
电化学装置充电时需要进行如下化学反应：正极：LiCoO 2＝Li 1-xCoO 2+x Li ++x e -；负极：6C+x Li ++x e -＝Li xC 6。充电时，Li +从正极极片上脱出，经过电解液和隔膜，进入到对面的负极极片。本申请中，由于在第二集流体(正极集流体)的表面设置了第一绝缘层，该第一绝缘层阻隔了电子传导，LiCoO 2无法脱出e -到第二集流体(正极集流体)，化学反应无法进行。因此，第二极片(正极极片)无法脱出Li +进入对面的第一极片(负极极片)，降低了第二极片的正极容量发挥，从而有效改善了槽位析锂现象。
进一步地，在一实施例中，第一凹槽113沿第二方向Z的槽位宽度为9mm，沿第一方向Y的长度为20mm；第二绝缘件42沿第二方向Z的宽度为9mm，沿第一方向Y的长度23mm，第二绝缘件42沿厚度方向X的投影面积略大于第一凹槽113沿厚度方向X的投影面积。此时，第一绝缘层31沿第二方向Z的宽度可为13mm至18mm，则在第一方向上，第一极片11超出第二极片12的长度为2mm至4.5mm，以超出2mm为佳，既可保证不析锂又可保证容量损失较小。第一绝缘件41的尺寸可与第一绝缘层31的尺寸相同。
一些实施例中，第一绝缘层31包括绝缘材料，绝缘材料包括聚四氟乙烯(铁氟龙，PTFE)、聚偏氟乙烯(PVDF)或非金属硅酸盐中的至少一种。非金属硅酸盐包括但不限 于玻璃、陶瓷、水泥、塑料、纤维或橡胶等。第一绝缘层31在高温高压下稳定，不会因电解液浸泡失效；第一绝缘层31较轻薄，有利于提升能量密度；第一绝缘层31的尺寸可以根据需求灵活设置。
请继续参阅图3，第二极片12包括第二集流体121以及设于第二集流体121的表面的第二活性物质层122。第二活性物质层122包括负极活性材料，负极活性材料可包含碳质材料、硅碳材料、合金材料、含锂金属复合氧化物材料中的至少一种，但不限于此，负极活性材料可选用本领域技术公知的各种可被用作电化学装置的负极活性材料的能够电化学性地嵌入、脱嵌活性离子的传统公知的材料。一些实施例中，第二活性物质层122包括设于第二集流体121的表面的第一活性区1221和设于第一绝缘层31的表面的第二活性区1222，第二活性区1222背离第一绝缘层31的表面设有第一绝缘件41。在第二极片12的第二活性区1222表面设置第一绝缘件41，有利于降低第一极耳114刺破隔膜13导致第一极片11和第二极片12连通短路的风险，还能减少第二活性区的容量挥发，进而减少析锂现象。第一极耳114设于第一凹槽113，第一极耳114的表面一般需要贴附第二绝缘件42，以减少第一极耳114刺破隔膜13导致第一极片11和第二极片12连通短路的风险。第一绝缘件41和第二绝缘件42可为但不限于本领域常用的胶纸等。
图3中，沿电极组件10的厚度方向X，第一绝缘层31与其表面的第二活性区1222的厚度之和等于第一活性区1221的厚度。在第二集流体121上先设置第一绝缘层31再在未设第一绝缘层31的第二集流体121表面设置第一活性区1221且同时在第一绝缘层31上设置第二活性区1222，由于设置方式为挤压涂布，第二极片12各区域的整体厚度保持一致，因此第一绝缘层31的厚度与其表面的第二活性区1222的厚度之和等于相邻的第一活性区1221的厚度。如此，虽然增加了一层第一绝缘层31，但第二极片12的厚度并未增加，对电化学装置的能量密度的影响可以忽略不计。
进一步地，一些实施例中，沿电极组件10的厚度方向X，第一绝缘层31的厚度可为5μm～20μm。本实施方式中，第二活性物质层122的厚度(第一活性区1221的厚度)大致为50μm，将第一绝缘层31的厚度设置在5μm～20μm的范围内，既保证了绝缘效果，又能降低对电化学装置100的能量密度的影响。
请参阅图6，另一些实施例中，沿电极组件10的厚度方向X，第一绝缘层31的厚度也可等于第二活性物质层122的厚度，第一绝缘层31沿第二方向Z与第二活性物质层相连接。本实施方式中，第二活性物质层122的厚度均一，并无第一活性区1221和第二活性区1222之分。第一绝缘层31的表面并未设置第二活性物质层122，第一绝缘层31处的第二极片12并没有正极容量发挥，且第一绝缘层31也能起到降低第一极耳114刺破隔膜13导致短路的风险，则图3中所示的第一绝缘件41可省略，有利于电化学装置100的能量密度的提升。
一些实施例中，沿电极组件10的厚度方向X，第一绝缘层31和第二活性物质层122之间可设有功能涂层。进一步地，该功能涂层可以是陶瓷涂层；通过设置该功能涂层，可以阻隔集流体和活性物质层之间的电子传导。
请参阅图7，第二极片12包括第二凹槽123，第二凹槽123由第二活性物质层122缺失形成。第二极片12还包括第二极耳124，第二极耳124的一端设于第二凹槽123并电连接第二集流体121。进一步地，在一些实施例中，第二凹槽123可显露出部分第二集流体121的表面。显露出的第二集流体121更利于电化学装置100在大倍率充放电状态下的散热。在第二凹槽123显露出的第二集流体121处，第二极耳124与第二集流体121连接，能提高第二极耳124电连接的可靠性。第二极耳124与第二集流体121可通过焊印连接和/或通过导电胶连接。
图7中，定义第二极耳124伸出第二极片12的方向为第一方向Y(和第一极耳114伸出第一极片11的方向一致)，垂直于第一方向Y以及电极组件10的厚度方向X的方向为第二方向Z。
请参阅图8，一些实施例中，第二极片12在第二凹槽123沿第二方向Z的两侧设有第二绝缘层32，且第二绝缘层32设于第二集流体121的表面(第二绝缘层32与第二集流体121之间无中间层)，第二绝缘层32沿第二方向Z连接第二活性物质层122。在第二极耳124附近的第二集流体121表面设置第二绝缘层32，该第二绝缘层32阻隔了电子传导，LiCoO 2无法脱出e -到第二集流体121，化学反应无法进行。因此，第二极片12无法脱出Li +进入对面的第一极片11，从而进一步改善了槽位析锂现象。
一些实施例中，第二绝缘层32包括绝缘材料，绝缘材料包括聚四氟乙烯(铁氟龙，PTFE)、聚偏氟乙烯(PVDF)或非金属硅酸盐中的至少一种。非金属硅酸盐包括但不限于玻璃、陶瓷、水泥、塑料、纤维或橡胶等。第二绝缘层32在高温高压下稳定，不会因电解液浸泡失效；第二绝缘层32较轻薄，有利于提升能量密度；第二绝缘层32的尺寸可以根据需求灵活设置。
如图8所示，一些实施例中，第二活性物质层122包括设于第二集流体121的表面的第一活性区1221和设于第二绝缘层32的表面的第三活性区1223，沿电极组件10的厚度方向X，第二绝缘层32与其表面的第三活性区1223的厚度之和等于第一活性区1221的厚度。在第二集流体121上先设置第二绝缘层32再在未设第二绝缘层32的第二集流体121表面设置第一活性区1221且同时在第二绝缘层32上设置第三活性区1223，由于设置方式为挤压涂布，第二极片12各区域的整体厚度保持一致，因此第二绝缘层32的厚度与其表面的第三活性区1223的厚度之和等于相邻的第一活性区1221的厚度。如此，虽然增加了一层第二绝缘层32，但第二极片12的厚度并未增加，对电化学装置的能量密度的影响可以忽略不计。
进一步地，一些实施例中，第二绝缘层的厚度为5μm～20μm。如此，既保证了绝缘效果，又不会对电化学装置的能量密度产生影响。
如图8所示，一些实施例中，第二极片12还包括设于第二极耳124表面的第三绝缘件43，沿电极组件10的厚度方向X，第三绝缘件43的投影与第二绝缘层32的投影至少部分重叠。第三绝缘件43有利于降低第二极耳124刺破隔膜13导致第一极片11和第二极片12连通短路的风险，还能减少第二活性物质层122的容量挥发，进而改善析锂现象。第三绝缘件43可为但不限于本领域常用的胶纸等。
请继续参阅图8，一些实施例中，第一极片11还包括与第二极耳124相对设置的第四绝缘件44，第四绝缘件44设于第一活性物质层112背离第一集流体111的表面。所述相对设置指的是，第四绝缘件44设置在与第二极耳124在厚度方向X上相邻设置的第一极片11的表面，并且，在电极组件10的厚度方向X上，第四绝缘件44的投影(即在垂直于电极组件10的厚度方向X的投影面上的正投影)与第二极耳124的投影(即在垂直于 电极组件10的厚度方向X的投影面上的正投影)至少部分重叠。第四绝缘件44有利于减少第二极耳124刺破隔膜13导致第一极片11和第二极片12连通短路的风险。在电极组件10的厚度方向X上，第二绝缘层32的投影和第三绝缘件43的投影覆盖第四绝缘件44的投影。如此，第二极片12脱嵌的锂离子在第一极片11上都有对应的第一活性物质层112接收，减少了析锂现象的发生。第四绝缘件44可为但不限于本领域常用的胶纸等。
请参阅图9，另一些实施例中，沿电极组件10的厚度方向X，第二绝缘层32的厚度可等于第二活性物质层122的厚度。本实施方式中，第二活性物质层122的厚度均一，并无第一活性区1221和第三活性区1223之分。第二极耳124表面也可设置第三绝缘件43，第一极片11也可包括与第二极耳124相对设置的第四绝缘件44，第二绝缘层32的投影和第三绝缘件43的投影覆盖第四绝缘件44的投影。
请参阅图10，一些实施例中，可将第二活性物质层122表面的第一绝缘件41(参图3)，也即胶纸替换为第二绝缘层32，由于第二绝缘层32的性能相较于胶纸等更稳定，不会因电解液浸泡而失效，图10中的设置也可起到改善槽位析锂的作用。
请参阅图11，本申请还提供一种电子装置1000，其包括负载(图未示)和如上所述的电化学装置100，电化学装置100用于为负载供电。在一实施方式中，本申请的电子装置1000可以是，但不限于手机、笔记本电脑、电子记事本、计算器、存储卡、收音机、备用电源、电机、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。
本申请通过在第二集流体121的表面直接设置第一绝缘层31，阻隔了第二集流体121的电子传导，第二活性物质层122的活性材料(例如，包括但不限于LiCoO 2等)无法脱出e -到第二集流体121，使化学反应无法进行。因此，第二极片12无法脱出Li +进入对面的第一极片11，降低了第二极片12的正极容量发挥，从而有效改善了槽位析锂现象。
以上说明是本申请一些具体实施方式，但在实际的应用过程中不能仅仅局限于这些实施方式。对本领域的普通技术人员来说，根据本申请的技术构思做出的其他变形和改变，都应该属于本申请的保护范围。

Claims (15)

  1. 一种电化学装置，包括电极组件，所述电极组件包括第一极片、隔膜和第二极片，所述第一极片包括第一集流体以及设于所述第一集流体的表面的第一活性物质层，所述第二极片包括第二集流体以及设于所述第二集流体的表面的第二活性物质层，其特征在于，
    所述第一极片还包括第一凹槽，所述第一凹槽由所述第一活性物质层缺失形成；所述第一极片还包括第一极耳，所述第一极耳的一端设于所述第一凹槽；所述第二极片包括与所述第一极耳相对设置的第一绝缘层，所述第一绝缘层直接设于所述第二集流体的表面；在所述电极组件的厚度方向上，所述第一凹槽的投影面积小于所述第一绝缘层的投影面积，且所述第一凹槽的投影位于所述第一绝缘层的投影内。
  2. 如权利要求1所述的电化学装置，其特征在于，所述第二活性物质层包括设于所述第二集流体的表面的第一活性区和设于所述第一绝缘层的表面的第二活性区，所述第二活性区背离所述第一绝缘层的表面设有第一绝缘件。
  3. 如权利要求2所述的电化学装置，其特征在于，沿所述电极组件的厚度方向，所述第一绝缘层与所述第二活性区的厚度之和等于所述第一活性区的厚度。
  4. 如权利要求3所述的电化学装置，其特征在于，沿所述电极组件的厚度方向，所述第一绝缘层的厚度为5μm～20μm。
  5. 如权利要求1所述的电化学装置，其特征在于，沿所述电极组件的厚度方向，所述第一绝缘层的厚度等于所述第二活性物质层的厚度；定义所述第一极耳伸出所述第一极片的方向为第一方向，垂直于所述第一方向以及所述电极组件的厚度方向的方向为第二方向；沿所述第二方向，所述第一绝缘层与所述第二活性物质层相连接。
  6. 如权利要求1所述的电化学装置，其特征在于，所述第一凹槽显露出部分所述第一集流体的表面。
  7. 如权利要求1所述的电化学装置，其特征在于，所述第二极片还包括第二凹槽，所述第二凹槽由所述第二活性物质层缺失形成，所述第二极片还包括第二极耳，所述第二极 耳的一端设于所述第二凹槽；定义所述第二极耳伸出所述第二极片的方向为第一方向，垂直于所述第一方向以及所述电极组件的厚度方向的方向为第二方向；
    沿所述第二方向，所述第二极片在所述第二凹槽的两侧设有第二绝缘层，所述第二绝缘层设于所述第二集流体的表面，所述第二绝缘层沿所述第二方向连接所述第二活性物质层。
  8. 如权利要求7所述的电化学装置，其特征在于，沿所述电极组件的厚度方向，所述第二绝缘层的厚度等于所述第二活性物质层的厚度。
  9. 如权利要求7所述的电化学装置，其特征在于，所述第二活性物质层包括设于所述第二集流体的表面的第一活性区和设于所述第二绝缘层的表面的第三活性区，沿所述电极组件的厚度方向，所述第二绝缘层与所述第三活性区的厚度之和等于所述第一活性区的厚度。
  10. 如权利要求9所述的电化学装置，其特征在于，所述第二绝缘层的厚度为5μm～20μm。
  11. 如权利要求7所述的电化学装置，其特征在于，所述第二极片还包括设于所述第二极耳的表面的第三绝缘件，沿所述电极组件的厚度方向，所述第三绝缘件的投影与所述第二绝缘层的投影至少部分重叠。
  12. 如权利要求11所述的电化学装置，其特征在于，所述第一极片还包括与所述第二极耳相对设置的第四绝缘件，所述第四绝缘件设于所述第一活性物质层背离所述第一集流体的表面；在所述电极组件的厚度方向上，所述第二绝缘层的投影和所述第三绝缘件的投影覆盖所述第四绝缘件的投影。
  13. 如权利要求1所述的电化学装置，其特征在于，所述第一绝缘层包括绝缘材料，所述绝缘材料包括聚四氟乙烯、聚偏氟乙烯或非金属硅酸盐中的至少一种。
  14. 如权利要求1所述的电化学装置，其特征在于，所述第一绝缘层和所述第二活性物质层之间设有功能涂层。
  15. 一种电子装置，其特征在于，包括负载和如权利要求1-14中任一项所述的电化学装置；所述电化学装置用于为所述负载供电。
PCT/CN2021/130344 2021-11-12 2021-11-12 电化学装置及包括其的电子装置 WO2023082181A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
PCT/CN2021/130344 WO2023082181A1 (zh) 2021-11-12 2021-11-12 电化学装置及包括其的电子装置
CN202180021529.XA CN115380411A (zh) 2021-11-12 2021-11-12 电化学装置及包括其的电子装置
US18/660,768 US20240297421A1 (en) 2021-11-12 2024-05-10 Electrochemical apparatus and electronic apparatus containing same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2021/130344 WO2023082181A1 (zh) 2021-11-12 2021-11-12 电化学装置及包括其的电子装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/660,768 Continuation US20240297421A1 (en) 2021-11-12 2024-05-10 Electrochemical apparatus and electronic apparatus containing same

Publications (1)

Publication Number Publication Date
WO2023082181A1 true WO2023082181A1 (zh) 2023-05-19

Family

ID=84060791

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/130344 WO2023082181A1 (zh) 2021-11-12 2021-11-12 电化学装置及包括其的电子装置

Country Status (3)

Country Link
US (1) US20240297421A1 (zh)
CN (1) CN115380411A (zh)
WO (1) WO2023082181A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116544345A (zh) * 2023-06-28 2023-08-04 宁德新能源科技有限公司 二次电池及电子装置

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116053714A (zh) * 2022-12-31 2023-05-02 宁德新能源科技有限公司 电极组件、电池和用电设备
CN116581243B (zh) * 2023-07-12 2023-11-21 宁德时代新能源科技股份有限公司 电极极片、其制备方法、二次电池和用电装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130130065A1 (en) * 2011-11-17 2013-05-23 Kyung-ho Park Rechargeable battery pack
CN203733894U (zh) * 2014-01-17 2014-07-23 宁德新能源科技有限公司 锂离子电池
CN110729447A (zh) * 2019-10-09 2020-01-24 惠州锂威新能源科技有限公司 一种电芯极片及电芯
CN211507765U (zh) * 2020-04-03 2020-09-15 珠海冠宇电池股份有限公司 卷芯结构
CN113381058A (zh) * 2021-06-09 2021-09-10 珠海冠宇电池股份有限公司 一种锂离子电池

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101772418B1 (ko) * 2015-02-03 2017-08-29 주식회사 엘지화학 절연층을 포함하는 단위 전극의 제조방법
KR101950086B1 (ko) * 2016-03-15 2019-02-19 가부시끼가이샤 도시바 비수전해질 전지, 전지 팩 및 차량
CN113544876B (zh) * 2020-03-31 2024-07-05 宁德新能源科技有限公司 电化学装置以及电子装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130130065A1 (en) * 2011-11-17 2013-05-23 Kyung-ho Park Rechargeable battery pack
CN203733894U (zh) * 2014-01-17 2014-07-23 宁德新能源科技有限公司 锂离子电池
CN110729447A (zh) * 2019-10-09 2020-01-24 惠州锂威新能源科技有限公司 一种电芯极片及电芯
CN211507765U (zh) * 2020-04-03 2020-09-15 珠海冠宇电池股份有限公司 卷芯结构
CN113381058A (zh) * 2021-06-09 2021-09-10 珠海冠宇电池股份有限公司 一种锂离子电池

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116544345A (zh) * 2023-06-28 2023-08-04 宁德新能源科技有限公司 二次电池及电子装置
CN116544345B (zh) * 2023-06-28 2023-09-19 宁德新能源科技有限公司 二次电池及电子装置

Also Published As

Publication number Publication date
CN115380411A (zh) 2022-11-22
US20240297421A1 (en) 2024-09-05

Similar Documents

Publication Publication Date Title
WO2023082181A1 (zh) 电化学装置及包括其的电子装置
KR100870349B1 (ko) 보호회로기판의 접속단자 및 그를 이용한 이차전지
US9972868B2 (en) Curved electrode stack and battery pack including the same
CN113544876B (zh) 电化学装置以及电子装置
JP5212470B2 (ja) 電極体、全固体型電池素子および全固体型電池
US11121439B2 (en) Secondary battery
KR100289537B1 (ko) 리튬 이차전지
WO2012111061A1 (ja) 電池および電池の製造方法
CN113557625B (zh) 电芯、电池及电子装置
KR102332343B1 (ko) 전지 모듈
JP3821434B2 (ja) 電池用電極群およびそれを用いた非水電解液二次電池
JP5288452B2 (ja) 非水電解液二次電池
WO2024104110A1 (zh) 一种电极构件、电池单体、电池及用电装置
JP2011082039A (ja) 非水電解質電池及び組電池
JP2023530349A (ja) 高い比エネルギー密度を有するリチウムイオン電池
JP2005310577A (ja) コイン形二次電池
CN114335407A (zh) 一种极片及电池
JP4718812B2 (ja) 二次電池パック
WO2023279298A1 (zh) 电化学装置及包括该电化学装置的电子装置
TW201444147A (zh) 非水電解質二次電池
CN215896641U (zh) 电化学装置及电子装置
CN213636041U (zh) 正极片、卷芯、电池以及电子产品
WO2022126634A1 (zh) 电极组件及其制造方法和制造系统、电池单体、电池及用电装置
KR20060087179A (ko) 파우치형 리튬 이차 전지
JP2023529881A (ja) 特定の高いエネルギー密度を有するリチウムイオンセル

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: 21963630

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE