WO2022022525A1 - 一种双极性集流体、极片、电芯和二次电池 - Google Patents

一种双极性集流体、极片、电芯和二次电池 Download PDF

Info

Publication number
WO2022022525A1
WO2022022525A1 PCT/CN2021/108722 CN2021108722W WO2022022525A1 WO 2022022525 A1 WO2022022525 A1 WO 2022022525A1 CN 2021108722 W CN2021108722 W CN 2021108722W WO 2022022525 A1 WO2022022525 A1 WO 2022022525A1
Authority
WO
WIPO (PCT)
Prior art keywords
metal
negative electrode
region
positive electrode
metal layer
Prior art date
Application number
PCT/CN2021/108722
Other languages
English (en)
French (fr)
Inventor
张芹
Original Assignee
厦门海辰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 厦门海辰新能源科技有限公司 filed Critical 厦门海辰新能源科技有限公司
Publication of WO2022022525A1 publication Critical patent/WO2022022525A1/zh

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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134—Electrodes based on metals, Si or alloys
    • 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
    • H01M4/661—Metal or alloys, e.g. alloy coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • 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
    • 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
    • H01M2004/027—Negative electrodes
    • 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
    • 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
    • H01M2004/029—Bipolar 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 disclosure relates to the technical field of secondary batteries, and in particular, to a bipolar current collector, a pole piece, a battery cell and a secondary battery.
  • the negative electrode current collector usually forms a copper metal layer on both sides of the polymer layer
  • the positive electrode current collector usually forms an aluminum metal layer on both sides of the polymer layer, and then prepares the pole piece and the secondary battery.
  • the prior art provides a bipolar current collector.
  • a copper layer and an aluminum layer are respectively formed on the two surfaces of the insulating film layer. and preparation of secondary batteries.
  • it is easy to weld through the insulating film layer, so that the copper layer and the aluminum layer are in contact, and the problem of short circuit between the positive and negative electrodes occurs.
  • the purpose of the present disclosure is to provide a bipolar current collector, a pole piece, a battery cell and a secondary battery, which can, for example, improve the short circuit of positive and negative electrodes to a certain extent.
  • the present disclosure provides a bipolar current collector, comprising: an insulating film layer, a positive electrode metal layer and a negative electrode metal layer disposed on both surfaces of the insulating film layer.
  • the insulating film layer has a first region and a second region arranged in sequence.
  • the first surface of the first region has alternately arranged first blank regions and first metal regions covered by the positive metal layer, and the second surface of the first region has alternately arranged second regions.
  • the positive metal layer covering the first metal area is used to connect the positive electrode tab
  • the negative electrode metal layer covering the second metal area is used to connect the negative electrode tab
  • the projection of the first metal area in the thickness direction of the insulating film layer is located in the second blank area
  • the projection of the second metal region in the thickness direction of the insulating film layer is located in the first blank region.
  • the metal layers on the two surfaces of the first area are used to connect the tabs; on the first surface of the first area, the positive metal layer, the first blank area, the positive metal layer and the first blank area are alternately arranged; in the first area On the second surface, the second blank area, the negative metal layer, the second blank area, and the negative metal layer are alternately arranged, and at the first area, the metal areas on the two surfaces and the blank areas are arranged in a one-to-one correspondence.
  • the insulating film layer at the connection is inevitably damaged, since the backside of the negative electrode metal layer is the first blank area, the insulating film The damaged part of the film layer only has a negative electrode metal layer on one side, and no metal layer is provided on the other side. Even if the insulating film layer is damaged, there will be no contact between the positive electrode metal layer and the negative electrode metal layer on both surfaces of the insulating film layer. To a certain extent, the problem of short circuit of positive and negative electrodes is improved.
  • the width of the first metal region is smaller than the width of the corresponding second blank region, and the width of the second metal region is smaller than the width of the corresponding first blank region.
  • the positive metal layer on the first metal region may just come into contact with the negative metal layer on the second metal region, resulting in a short circuit between the positive and negative electrodes. Therefore, the above-mentioned limitation of the width can greatly reduce the occurrence of this phenomenon.
  • the periphery of the negative electrode metal layer on the second metal area also has If the solder mark is welded, and the insulation film is welded through by the solder mark, the negative metal layer on the second metal region may just come into contact with the positive metal layer on the first metal region, resulting in a short circuit between the positive and negative electrodes. Therefore, the above-mentioned limitation of the width can greatly reduce the occurrence of this phenomenon.
  • the two sides of the second blank area exceed the two sides of the projection of the corresponding first metal area on the second blank area, and the two sides of the first blank area
  • the projection of the second metal area beyond the corresponding second metal area is on both sides of the projection of the first blank area.
  • the projection of the first metal area on the second blank area is completely inside the second blank area, and the position of the blank area is too large. Even if the periphery of the positive metal layer on the first metal area is all soldered, the positive electrode can be effectively avoided.
  • the metal layer is in contact with the metal layer of the negative electrode to avoid short circuit of the positive and negative electrodes.
  • the projection of the second metal area on the first blank area is completely inside the first blank area, and the position of the blank area is too large. Even if the periphery of the negative metal layer on the second metal area is all welded, the positive electrode can be effectively avoided.
  • the metal layer is in contact with the metal layer of the negative electrode to avoid short circuit of the positive and negative electrodes.
  • the difference between the widths of the second blank area and the first metal area is 2-20 mm, and the difference between the widths of the first blank area and the second metal area is 2-20mm.
  • the width difference can effectively avoid the short circuit of the positive and negative electrodes, and can ensure the area of the metal layer in the tab area, so as to connect the tabs.
  • the perimeter shape of the first metal region corresponds to the perimeter shape of the second blank region (which may also be called, for example, an edge shape or a border shape or a perimeter shape), and the second The perimeter shape of the metal area corresponds to the perimeter shape of the first blank area, so that the projection of the first metal area on the negative electrode metal layer along the thickness direction of the insulating film layer is the same as the second blank area Coincidence, the projection of the second metal region on the positive electrode metal layer along the thickness direction of the insulating film layer coincides with the first blank region.
  • the positive electrode metal layer is a metal aluminum layer
  • the negative electrode metal layer is a metal copper layer or a metal nickel layer.
  • the metal aluminum layer is used as the positive electrode of the bipolar current collector, and the metal copper layer or the metal nickel layer is used as the negative electrode of the bipolar current collector.
  • the thickness of the positive electrode metal layer is 20-1500 nm, and the thickness of the negative electrode metal layer is 30-2500 nm.
  • the layer structure of the above-mentioned thickness can ensure the over-current capability, so that the electrical conductivity of the current collector is better.
  • the material of the insulating film layer includes at least one of the following: a polymer insulating material, a synthetic fiber insulating paper, and an insulating tape.
  • the present disclosure provides a pole piece including the above bipolar current collector, a positive electrode active material layer, a negative electrode active material layer, a positive electrode tab and a negative electrode tab.
  • the positive electrode active material layer is arranged on the positive electrode metal layer in the second area
  • the negative electrode active material layer is arranged on the negative electrode metal layer in the second area
  • a positive electrode tab is arranged on the positive electrode metal layer on the first metal area
  • a second A negative electrode tab is arranged on the negative electrode metal layer on the metal area.
  • the pole piece prepared by using the above bipolar current collector can effectively avoid the short circuit of the positive and negative poles when connecting the pole ears.
  • one of the positive electrode tabs is provided on the positive electrode metal layer on the one first metal region, including: the positive electrode tab and the positive electrode tab located on the first metal region
  • the positive metal layers are welded and connected.
  • one of the negative electrode tabs is disposed on the negative electrode metal layer on the one second metal region, including: the negative electrode tab and the negative electrode tab located on the second metal region.
  • the negative metal layers are connected by welding.
  • the projection of the first metal region along the thickness direction of the insulating film layer (on the negative metal layer) coincides with the second blank region and the second metal region is along the The projection of the thickness direction of the insulating film layer (on the positive electrode metal layer) coincides with the first blank area, and the positive electrode tab is welded on the positive electrode metal layer located on the first metal area along the edge of the positive electrode metal layer.
  • the negative electrode tabs are welded at the middle position along the length direction of the bipolar current collector of the negative electrode metal layer on the second metal region.
  • the edge of the insulating film layer is prevented from being welded through and the metal layers on the two surfaces are in contact, thereby improving the short circuit problem of the positive and negative electrodes to a certain extent.
  • the shapes of the positive electrode tabs and the negative electrode tabs are substantially trapezoidal, wherein the extension direction of the side of the positive electrode tabs close to the second region is in the direction of elongation.
  • the size or size (also referred to as extension or extension) is larger than the side away from the second area, and the dimension in the direction of extension of the side of the negative electrode tab close to the second area Or the size is larger than the side away from the second area.
  • the welding area between the tabs and the metal layer By making the welding area between the tabs and the metal layer larger, the welding of the tabs and the metal layer can be made stronger, and the welding area between the tabs and the connecting piece is smaller. increase the energy density of the battery.
  • the present disclosure provides a battery cell, comprising a plurality of the above-mentioned pole pieces and a plurality of separators, a separator is arranged between two adjacent pole pieces, and a positive electrode active material layer and a negative electrode active material layer are respectively arranged on both sides of the separator.
  • the battery cell can effectively avoid short circuit of positive and negative electrodes, and has high electrical performance.
  • the cell is a laminated cell stack, and each pole piece includes a positive electrode tab and a negative electrode tab.
  • the negative tabs of each pole piece overlap.
  • the cell stack can be used to prepare a laminated battery.
  • the positive electrode tabs and the negative electrode tabs on the same side are arranged at intervals, a plurality of positive electrode tabs are overlapped, and the overlapped positive electrode tabs are connected to the positive electrode connecting piece.
  • the plurality of negative electrode tabs are overlapped, and the overlapping negative electrode tabs are connected with the negative electrode connecting piece to obtain a laminated battery, and the structure of the battery is relatively simple.
  • the cell is a wound cell, and along the winding direction of the pole piece, the distance between two adjacent positive electrode tabs and the distance between two adjacent negative electrode tabs gradually increase , after winding the pole piece and the separator, a plurality of positive electrode tabs are overlapped, and a plurality of negative electrode tabs are overlapped. to get a wound battery.
  • the present disclosure provides a secondary battery including the above-mentioned battery cell.
  • the electrical performance of the secondary battery is better.
  • FIG. 1 is a schematic structural diagram of a bipolar current collector provided by an embodiment of the present disclosure
  • Fig. 2 is the II-II sectional view of Fig. 1;
  • Fig. 3 is the III-III sectional view of Fig. 1;
  • FIG. 4 is a schematic diagram of a first structure of a pole piece provided by an embodiment of the present disclosure
  • Fig. 5 is the V-V sectional view of Fig. 4;
  • Fig. 6 is the VI-VI sectional view in Fig. 4;
  • FIG. 7 is a schematic diagram of a second structure of a pole piece provided by an embodiment of the present disclosure.
  • FIG. 8 is a schematic diagram of a third structure of a pole piece provided by an embodiment of the present disclosure.
  • 100-bipolar current collector 110-insulating film layer; 120-positive metal layer; 130-negative metal layer; 111-first region; 112-second region; 1213-first metal region; 1214-first blank area; 1215-second metal area; 1216-second blank area; 200-pole piece; 210-positive electrode active material layer; 220-negative electrode active material layer; 230-positive electrode tab; 240-negative electrode Ear.
  • FIG. 1 is a schematic structural diagram of a bipolar current collector 100 provided by an embodiment of the present disclosure
  • FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1
  • FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1 .
  • the fluid 100 may include an insulating film layer 110 and a positive electrode metal layer 120 and a negative electrode metal layer 130 disposed on both surfaces of the insulating film layer 110 .
  • the extension dimension of the current collector 100 in the width direction is smaller than the extension in the length direction (also referred to as the "length of the current collector”).
  • the insulating film layer 110 may have a first region 111 and a second region 112 arranged in sequence, the first region 111 is located on one side of the second region 112, and there is, for example, no space therebetween. There is an overlap. As shown in FIG. 2 and FIG. 3 , the areas to the left of the dashed line 1 and the dashed line 2 are the first area 111 , and the area to the right of the dashed line 1 and the dashed line 2 is the second area 112 .
  • the material of the insulating film layer 110 may be a polymer insulating layer, such as polystyrene, polypropylene, polyester, polycarbonate, polytetrafluoroethylene, polyimide and other films;
  • the material can be synthetic fiber insulating paper, for example: aramid fiber paper, polyester fiber paper; the material of the insulating film layer 110 can be various insulating tapes and the like.
  • the first surface of the first region 111 may have alternately arranged first blank regions 1214 and first metal regions 1213 covered by the positive electrode metal layer 120 .
  • the second surface of a region 111 may have alternately arranged second blank regions 1216 and second metal regions 1215 covered by the negative metal layer 130 .
  • the first region 111 of the insulating film layer 110 , the positive electrode metal layer 120 and the negative electrode metal layer 130 on the first region 111 may be combined to form a tab region for arranging the tabs.
  • the positive electrode metal layer 120 may be entirely formed on the first surface of the second region 112
  • the negative electrode metal layer 130 may be entirely formed on the second surface of the second region 112 .
  • the second region 112 of the insulating film layer 110 and the positive electrode metal layer 120 and the negative electrode metal layer 130 on the second region 112 may be combined to form a coating region.
  • the positive electrode metal layer 120 may be a metal aluminum layer, and/or the negative electrode metal layer 130 may be a metal copper layer or a metal nickel layer.
  • the positive metal layer 120 may be a metal aluminum layer to conduct the conduction of the positive current; and/or, the negative metal layer 130 may be a metal copper layer to conduct the conduction of the negative current.
  • the positive electrode metal layer 120 is not limited to a metal aluminum layer, as long as the positive electrode metal layer that can be used as a current collector is within the protection scope of the present disclosure; and/or, the negative electrode metal layer 130 is not limited to a metal copper layer, As long as the metal layer of the negative electrode can be used as the current collector, it is within the protection scope of the present disclosure.
  • the thickness of the positive electrode metal layer 120 may be 20-1500 nm, and/or the thickness of the negative electrode metal layer 130 may be 30-2500 nm.
  • the layer structure of the above-mentioned thickness can ensure the over-current capability, so that the electrical conductivity of the current collector is better.
  • a positive electrode metal layer 120 may be deposited on one surface of the insulating film layer 110, and a negative electrode metal layer 130 may be deposited on the other surface of the insulating film layer 110, and then the bipolar One side of the current collector 100 serves as the tab region.
  • a first blank area 1214 and a second blank area 1216 can be formed by washing off part of the positive electrode metal layer 120 and part of the negative electrode metal layer 130 at the tab region, thereby obtaining the bipolar current collector 100 structure in FIG. 1 .
  • FIG. 4 is a schematic structural diagram of a pole piece 200 provided by an embodiment of the present disclosure
  • FIG. 5 is a cross-sectional view of V-V in FIG. 4
  • FIG. 6 is a cross-sectional view of VI-VI in FIG. 4
  • the pole piece 200 may include the bipolar current collector 100 , the positive electrode active material layer 210 , the negative electrode active material layer 220 , the positive electrode tab 230 and the negative electrode tab 240 .
  • the positive electrode active material layer 210 may be provided on the positive electrode metal layer 120 in the second region 112
  • the negative electrode active material layer 220 may be provided on the negative electrode metal layer 130 in the second region 112 .
  • a positive electrode tab 230 may be provided on the positive electrode metal layer 120 on a first metal region 1213 .
  • a negative electrode tab 240 may be disposed on the negative electrode metal layer 130 on a second metal region 1215 .
  • the positive electrode tabs 230 may be welded with the positive electrode metal layer 120 , and/or the negative electrode tabs 240 may be welded with the negative electrode metal layer 130 . Connecting the tabs by welding can make the connection between the tabs and the metal layer more firm. However, when the tabs are welded to the metal layer, the problem of welding through the insulating film layer 110 may easily occur.
  • the projection of the first metal region 1213 in the thickness direction of the insulating film layer 110 is located in the second blank region 1216 .
  • the top of the insulating film layer 110 is the positive metal layer 120
  • the lower surface of the insulating film layer 110 is the second blank area 1216 .
  • the damaged part of the insulating film layer 110 only has the positive metal layer 120 on one side, and no metal layer is provided on the other side.
  • the problem of contact and conduction between the positive electrode metal layer 120 and the negative electrode metal layer 130 can improve the short circuit problem of the positive electrode and the negative electrode to a certain extent.
  • the projection of the second metal region 1215 in the thickness direction of the insulating film layer 110 is located in the first blank region 1214 .
  • the lower part of the insulating film layer 110 is the negative electrode metal layer 130
  • the upper surface of the insulating film layer 110 is the first blank area 1214 .
  • the damaged part of the insulating film layer 110 only has the negative metal layer 130 on one side, and no metal layer is provided on the other side.
  • the problem of contact and conduction between the positive electrode metal layer 120 and the negative electrode metal layer 130 can improve the short circuit problem of the positive electrode and the negative electrode to a certain extent.
  • the peripheral shape of the first metal area 1213 corresponds to the peripheral shape of the second blank area 1216
  • the peripheral shape of the second metal area 1215 corresponds to the peripheral shape of the first blank area 1214
  • the first metal area The projection of 1213 on the negative electrode metal layer 130 along the thickness direction of the insulating film layer 110 coincides with the second blank area 1216
  • the projection of the second metal area 1215 on the positive electrode metal layer 120 along the thickness direction of the insulating film layer 110 coincides with the first blank area 1214 coincide.
  • the positive electrode metal layer 120 on the first metal region 1213 can be welded along the bipolar current collector. At the middle position in the length direction, and try not to weld at the edge position of the positive electrode metal layer 120 on the first metal region 1213 .
  • the negative electrode metal layer 130 on the second metal region 1215 can be welded along the length direction of the bipolar current collector.
  • the middle position of the negative electrode metal layer 130 on the second metal region 1215 try not to weld it at the edge position of the negative electrode metal layer 130, so as to prevent the edge of the insulating film layer 110 from being welded through and cause the metal layers on the two surfaces to contact, thereby improving to a certain extent.
  • the positive electrode metal layer 120 on the first metal region 1213 may just come into contact with the negative electrode metal layer 130 on the second metal region 1215 , resulting in a short circuit between the positive electrode and the negative electrode. Therefore, please continue to refer to FIG. 1 and FIG. 4 , in the embodiment of the present disclosure, along the length direction of the bipolar current collector 100 , the width of the first metal region 1213 may be smaller than the width of the corresponding second blank region 1216 .
  • the width of the area 1215 may be smaller than the width of the corresponding first blank area 1214 .
  • the above-mentioned limitation of the width can greatly reduce the occurrence of this phenomenon. Even if the insulating film layer 110 corresponding to the edge of the first metal layer is welded through, since the position of the corresponding blank area is wider, the conduction of the positive and negative electrodes can be effectively avoided.
  • both sides of the second blank area 1216 may exceed the corresponding first metal area 1213 in the second blank area 1216
  • the two sides of the first blank area 1214 may exceed the two sides of the projection of the corresponding second metal area 1215 on the first blank area 1214 .
  • the dotted line is the area of the second metal region 1215.
  • the region of the first metal region 1213 is smaller than the region of the second blank region 1216, and the first metal region 1213
  • the area is all inside the second blank area 1216
  • the area of the second metal area 1215 is smaller than the area of the first blank area 1214
  • the area of the second metal area 1215 is all inside the first blank area 1214 . It can effectively avoid the contact between the positive electrode metal layer 120 and the negative electrode metal layer 130 when welding the tabs, so as to avoid short circuit of the positive electrode and the negative electrode.
  • the difference between the widths of the second blank area 1216 and the first metal area 1213 may be 2-20 mm, and the difference between the widths of the first blank area 1214 and the second metal area 1215 may be 2-20 mm.
  • the difference can be 2-20mm.
  • the difference in width can effectively avoid short circuit of positive and negative electrodes, and can ensure the area of the metal layer in the tab area so as to connect the tabs.
  • one side of the projection of the first metal layer in the thickness direction of the insulating film layer 110 may correspond to the edge of the second blank area 1216, and the other side may be located in the second blank area 1216;
  • One side of the projection of the area 1215 in the thickness direction of the insulating film layer 110 corresponds to the edge of the first blank area 1214 , and the other side is located in the first blank area 1214 .
  • the present disclosure is not limited.
  • FIG. 7 is a schematic diagram of a second structure of the pole piece 200 according to an embodiment of the present disclosure.
  • the shapes of the positive electrode tabs 230 and the negative electrode tabs 240 may be substantially trapezoidal (along the length direction of the bipolar current collector 100 , a portion of the tabs close to the second region The size of the side of the tab is larger, and the size of the side of the tab away from the second area is smaller), and the welding area between the tab and the metal layer is larger, which can make the welding between the tab and the metal layer firmer, and the tab and the connecting piece.
  • the welding area is small, and the amount of tabs can be reduced and the energy density of the battery can be increased under the condition of ensuring the firmness of the welding.
  • the shapes of the first metal region 1213 and the second metal region 1215 correspond to the shapes of the positive electrode tab 230 and the negative electrode tab 240 respectively, so that the positive electrode tab 230 can be connected to the positive electrode metal layer 120 on the first metal region 1213,
  • the negative electrode tab 240 can be connected to the negative electrode metal layer 130 on the second metal region 1215 .
  • the above-mentioned pole piece 200 can be used to manufacture a secondary battery.
  • the secondary battery may be a laminated battery, a wound battery, or other secondary batteries, which are not limited in the present disclosure.
  • the pole piece 200 may be used to manufacture the battery cell first, and then the secondary battery may be manufactured by using the battery core.
  • the cell may include a plurality of the above-mentioned pole pieces 200 and a plurality of separators, a separator may be arranged between two adjacent pole pieces 200 , and a positive electrode active material layer 210 and a negative electrode active material layer 220 are respectively provided on both sides of the separator.
  • FIG. 8 is a schematic structural diagram of a battery pole piece 200 in a battery cell stack according to an embodiment of the present disclosure.
  • the cells are stacked cell stacks, wherein each pole piece 200 may include a positive electrode tab 230 and a negative electrode tab 240 .
  • the positive electrode tabs 230 of the plurality of pole pieces 200 are overlapped, and the negative electrode tabs 240 of the plurality of pole pieces 200 are overlapped.
  • a plurality of overlapping positive electrode tabs 230 are welded to the positive electrode connecting piece, and a plurality of overlapping negative electrode tabs 240 are connected to the negative electrode connecting piece, so as to manufacture a secondary battery.
  • the cell may be a wound cell, along the winding direction of the pole piece 200 , the distance between two adjacent positive electrode tabs 230 and the distance between two adjacent negative electrode tabs 240 Gradually increase (the diameter of the inner circle of the wound cell is small, and the diameter of the outer circle is large, so it is necessary to set different distances between the pole tabs), so that after the pole piece 200 is wound with the diaphragm, a plurality of positive pole tabs 230 overlap, The plurality of negative tabs 240 overlap.
  • a plurality of overlapping positive electrode tabs 230 are welded to the positive electrode connecting piece, and a plurality of overlapping negative electrode tabs 240 are connected to the negative electrode connecting piece, so as to manufacture a secondary battery.
  • both sides of the second blank area 1216 exceed the projection of the corresponding first metal area 1213 on the two sides of the second blank area 1216 , and both sides of the first blank area 1214 Both sides of the projection of the first blank area 1214 beyond the corresponding second metal area 1215 .
  • the conduction problem between the metal layer and the copper metal layer can effectively avoid the short circuit of the positive and negative electrodes.
  • the plurality of overlapping positive electrode tabs 230 are connected to the positive electrode connecting piece, and the plurality of overlapping negative electrode tabs 240 are connected to the negative electrode connecting piece, so as to manufacture the battery cell and the secondary battery, and the manufacture is relatively simple.
  • Embodiments of the present disclosure provide bipolar current collectors, pole pieces, cells, and secondary batteries, because the bipolar current collectors of embodiments of the present disclosure include alternately arranged first blank areas and are covered by the positive electrode metal layer The first metal area and the alternately arranged second blank area and the second metal area covered by the negative electrode metal layer, so even if the insulating film layer is damaged in the process of connecting the tabs, it can be avoided to a certain extent.
  • the conduction between the positive electrode metal layer and the negative electrode metal layer can improve the short circuit of the positive and negative electrodes to a certain extent; and since the two sides of the second blank area exceed the corresponding first metal area in the second blank area On both sides of the projection, the two sides of the first blank area exceed the corresponding second metal area on both sides of the projection of the first blank area, so it can also effectively avoid the positive and negative metal layers caused by the damage of the insulating film layer during the welding process. The conduction problem between them can effectively avoid the short circuit between the positive and negative electrodes.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Composite Materials (AREA)
  • Connection Of Batteries Or Terminals (AREA)
  • Secondary Cells (AREA)

Abstract

本公开提供一种双极性集流体、极片、电芯和二次电池。所述双极性集流体包括：绝缘膜层以及设置于所述绝缘膜层两表面的正极金属层和负极金属层；沿双极性集流体的宽度方向，绝缘膜层具有依次设置的第一区域和第二区域；沿双极性集流体的长度方向，第一区域的第一表面具有交替设置的第一空白区和被正极金属层覆盖的第一金属区，第一区域的第二表面具有交替设置的第二空白区和被负极金属层覆盖的第二金属区；覆盖第一金属区的正极金属层用于连接正极极耳，覆盖第二金属区的负极金属层用于连接负极极耳，第一金属区在第一绝缘膜层的厚度方向的投影位于第二空白区，第二金属区在第一绝缘膜层的厚度方向的投影位于第一空白区。所述双极性集流体可以在一定程度上改善二次电池的正负极短路的问题。

Description

一种双极性集流体、极片、电芯和二次电池
相关申请的交叉引用
本公开要求于2020年07月28日提交中国专利局的申请号为202021523469.0、名称为“一种双极性集流体、极片、电芯和二次电池”的中国专利申请的优先权，其全部内容通过引用结合在本公开中。
技术领域
本公开涉及二次电池技术领域，具体而言，涉及一种双极性集流体、极片、电芯和二次电池。
背景技术
复合集流体中，负极集流体通常是在高分子层的两侧形成铜金属层，正极集流体通常是在高分子层的两侧形成铝金属层，然后制备极片和二次电池。
为了进一步提高电池的能量密度，现有技术提供了一种双极性集流体，在绝缘膜层的两个表面分别形成铜层和铝层，然后铜层作为负极，铝层作为正极进行极片和二次电池的制备。但是，在焊接极耳的过程中，容易使绝缘膜层焊穿，从而造成铜层和铝层接触，出现正负极短路的问题。
发明内容
为了解决本领域已知存在的技术问题，本公开的目的在于提供一种双极性集流体、极片、电芯和二次电池，例如能够在一定程度上改善正负极短路的问题。本公开提供一种双极性集流体，包括：绝缘膜层以及设置于绝缘膜层两表面的正极金属层和负极金属层。沿双极性集流体的宽度方向，绝缘膜层具有依次设置的第一区域和第二区域。沿双极性集流体的长度方向，第一区域的第一表面具有交替设置的第一空白区和被正极金属层覆盖的第一金属区，第一区域的第二表面具有交替设置的第二空白区和被负极金属层覆盖的第二金属区。覆盖第一金属区的正极金属层用于连接正极极耳，覆盖第二金属区的负极金属层用于连接负极极耳，第一金属区在绝缘膜层的厚度方向的投影位于第二空白区，第二金属区在绝缘膜层的厚度方向的投影位于第一空白区。
第一区域的两个表面上的金属层用于连接极耳；在第一区域的第一表面，正极金属层、第一空白区、正极金属层、第一空白区交替设置；在第一区域的第二表面，第二空白区、负极金属层、第二空白区、负极金属层交替设置，在第一区域处，两个表面的金属区与空白区一一对应设置。
在将正极极耳与第一金属区上的正极金属层连接的时候，即使在连接处的绝缘膜层不可避免的遭到破坏，但是，由于正极金属层的背面是第二空白区，所以，绝缘膜层的破坏 处仅一面具有正极金属层，另一面没有设置金属层，即使绝缘膜层破坏，也不会存在绝缘膜层两表面的正极金属层和负极金属层接触导通的问题，可以在一定程度上改善正负极的短路的问题。
在将负极极耳与第一区域上的负极金属层连接的时候，即使在连接处的绝缘膜层不可避免的遭到破坏，但是，由于负极金属层的背面是第一空白区，所以，绝缘膜层的破坏处仅一面具有负极金属层，另一面没有设置金属层，即使绝缘膜层破坏，也不会存在绝缘膜层两表面的正极金属层和负极金属层接触导通的问题，可以在一定程度上改善正负极的短路的问题。
在本公开的实施方式中，沿双极性集流体的长度方向，第一金属区的宽度小于对应的第二空白区的宽度，第二金属区的宽度小于对应的第一空白区的宽度。
如果第一金属区和第二空白区刚好对应，则在第一金属区上的正极金属层上连接(例如：焊接)正极极耳的时候，在第一金属区上的正极金属层的周缘也有焊印，且该焊印使绝缘膜层被焊穿，则可能使第一金属区上的正极金属层可能会刚好与第二金属区上的负极金属层接触，从而导致正负极短路。所以，上述宽度的限定，可以大大降低该现象的产生。如果第二金属区和第一空白区刚好对应，则在第二金属区上的负极金属层上连接(例如：焊接)负极极耳的时候，在第二金属区上的负极金属层的周缘也有焊印，且该焊印使绝缘膜层被焊穿，则可能使第二金属区上的负极金属层可能会刚好与第一金属区上的正极金属层接触，从而导致正负极短路。所以，上述宽度的限定，可以大大降低该现象的产生。
在本公开的实施方式中，沿双极性集流体的长度方向，第二空白区的两侧超出对应的第一金属区在第二空白区的投影的两侧，第一空白区的两侧超出对应的第二金属区在第一空白区的投影的两侧。
第一金属区在第二空白区上的投影完全位于第二空白区内部，并且空白区的位置偏多，即使第一金属区上的正极金属层的周缘全部为焊印，也可以有效避免正极金属层与负极金属层的接触，以避免正负极的短路。第二金属区在第一空白区上的投影完全位于第一空白区内部，并且空白区的位置偏多，即使第二金属区上的负极金属层的周缘全部为焊印，也可以有效避免正极金属层与负极金属层的接触，以避免正负极的短路。
在本公开的实施方式中，沿双极性集流体的长度方向，第二空白区与第一金属区的宽度之差为2-20mm，第一空白区与第二金属区的宽度之差为2-20mm。
该宽度差可以有效避免正负极短路，且能够保证极耳区中金属层的面积，以便进行极耳的连接。
在本公开的实施方式中，所述第一金属区的周界形状与所述第二空白区的周界形状 (也可以例如称为边缘形状或边界形状或周缘形状)对应，所述第二金属区的周界形状与第一空白区的周界形状相对应，使得所述第一金属区沿所述绝缘膜层的厚度方向在所述负极金属层上的投影与所述第二空白区重合，所述第二金属区沿所述绝缘膜层的厚度方向在所述正极金属层上的投影与所述第一空白区重合。
在本公开的实施方式中，正极金属层为金属铝层，负极金属层为金属铜层或金属镍层。
金属铝层作为双极性集流体的正极，金属铜层或金属镍层作为双极性集流体的负极，可以使正负极的导流、汇流能力更好，且容易得到。
在本公开的实施方式中，所述正极金属层的厚度为20-1500nm，所述负极金属层的厚度为30-2500nm。
上述厚度的层结构能够保证过流能力，使集流体的导电能力更佳。
在本公开的实施方式中，所述绝缘膜层的材料至少包括以下之一：高分子绝缘材料、合成纤维绝缘纸、绝缘胶布。
本公开提供一种极片，包括上述双极性集流体、正极活性物质层、负极活性物质层、正极极耳和负极极耳。正极活性物质层设置于第二区域的正极金属层上，负极活性物质层设置于第二区域的负极金属层上，一个第一金属区上的正极金属层上设置一个正极极耳，一个第二金属区上的负极金属层上设置一个负极极耳。
使用上述双极性集流体制备的极片，在连接极耳的时候，可以有效避免正负极的短路。
在本公开的实施方式中，所述一个所述第一金属区上的所述正极金属层上设置一个所述正极极耳，包括：所述正极极耳与位于所述第一金属区上的所述正极金属层焊接连接。
在本公开的实施方式中，所述一个所述第二金属区上的所述负极金属层上设置一个所述负极极耳，包括：所述负极极耳与位于所述第二金属区上的所述负极金属层焊接连接。
在本公开的实施方式中，若所述第一金属区沿所述绝缘膜层的厚度方向(在负极金属层上)的投影与所述第二空白区重合以及所述第二金属区沿所述绝缘膜层的厚度方向(在正极金属层上)的投影与所述第一空白区重合，所述正极极耳焊接在位于所述第一金属区上的所述正极金属层的沿所述双极性集流体的长度方向的中部位置处，以及所述负极极耳焊接在位于所述第二金属区上的负极金属层的沿所述双极性集流体的长度方向的中部位置处。
以此避免绝缘膜层的边缘焊穿导致两表面的金属层接触，从而在一定程度上改善正负极的短路的问题。
在本公开的实施方式中，所述正极极耳和所述负极极耳的形状均为基本上的梯形 形状，其中，所述正极极耳靠近所述第二区域的一侧的延长度方向的尺寸或大小(也可以称为延伸范围或广延程度)相较于远离所述第二区域的一侧更大，所述负极极耳靠近所述第二区域的一侧的延长度方向的尺寸或大小相较于远离所述第二区域的一侧更大。
通过使极耳与金属层的焊接面积较大，可以令极耳与金属层的焊接更加牢固，极耳与连接片的焊接面积较小，在保证焊接牢固性的情况下，可以减少极耳的量，增大电池的能量密度。
本公开提供一种电芯，包括多个上述极片，以及多个隔膜，相邻两个极片之间设置一个隔膜，且隔膜的两侧分别设置正极活性物质层和负极活性物质层。该电芯能够有效避免正负极短路，电学性能高。
在本公开的实施方式中，电芯为叠片电芯堆，每个极片包括一个正极极耳和一个负极极耳，多个极片堆叠以后，多个极片的正极极耳重叠，多个极片的负极极耳重叠。
该电芯堆可以用来制备叠片电池，该叠片电池中，同一侧的正极极耳和负极极耳间隔设置，多个正极极耳重叠，重叠的正极极耳与正极连接片连接，多个负极极耳重叠，重叠的负极极耳与负极连接片连接，得到叠片电池，电池的结构较为简单。
在本公开的实施方式中，电芯为卷绕电芯，沿极片的卷绕方向，相邻两个正极极耳之间的距离以及相邻两个负极极耳之间的距离逐渐增大，使极片与隔膜卷绕以后，多个正极极耳重叠，多个负极极耳重叠。以得到卷绕电池。
本公开提供一种二次电池，包括上述电芯。该二次电池的电学性能更佳。
附图说明
为了更清楚地说明本公开实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本公开的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图也属于本公开的保护范围。
图1为本公开实施例提供的双极性集流体的结构示意图；
图2为图1的Ⅱ-Ⅱ剖视图；
图3为图1的Ⅲ-Ⅲ剖视图；
图4为本公开实施例提供的极片的第一结构示意图；
图5为图4的Ⅴ-Ⅴ剖视图；
图6为图4中Ⅵ-Ⅵ剖视图；
图7为本公开实施例提供的极片的第二结构示意图；
图8为本公开实施例提供的极片的第三结构示意图。
附图标记说明：100-双极性集流体；110-绝缘膜层；120-正极金属层；130-负极金属层；111-第一区域；112-第二区域；1213-第一金属区；1214-第一空白区；1215-第二金属区；1216-第二空白区；200-极片；210-正极活性物质层；220-负极活性物质层；230-正极极耳；240-负极极耳。
具体实施方式
为使本公开实施例的目的、技术方案和优点更加清楚，下面将结合本公开实施例中的附图，对本公开实施例中的技术方案进行描述。
图1为本公开实施例提供的双极性集流体100的结构示意图，图2为图1的Ⅱ-Ⅱ剖视图；图3为图1的Ⅲ-Ⅲ剖视图。请参阅图1-图3，本公开实施例中，沿双极性集流体100的垂直于图1中所示的宽度方向和长度方向的厚度方向，即垂直于页面的方向，双极性集流体100可以包括绝缘膜层110以及设置于绝缘膜层110两表面的正极金属层120和负极金属层130。在本实施例中，集流体100沿宽度方向的延伸尺寸(也可称为“集流体的宽度”)小于沿长度方向的延伸尺寸(也可称为“集流体的长度”)，当然这并不是限制性的，在其他实施方式中的适应性改变是允许的。沿双极性集流体100的宽度方向，绝缘膜层110可以具有依次设置的第一区域111和第二区域112，第一区域111位于第二区域112的一侧，且两者之间例如不存在交叠部分。如图2和图3，虚线1和虚线2左侧的区域为第一区域111，虚线1和虚线2右侧的区域为第二区域112。
可选地，绝缘膜层110的材料可以是高分子绝缘层，例如：聚苯乙烯、聚丙烯、聚酯、聚碳酸酯、聚四氟乙烯、聚酰亚胺等薄膜；绝缘膜层110的材料可以是合成纤维绝缘纸，例如：芳香族聚酰胺纤维纸、聚酯纤维纸；绝缘膜层110的材料可以是各种绝缘胶布等。
本公开实施例中，沿双极性集流体100的长度方向，第一区域111的第一表面可以具有交替设置的第一空白区1214和被正极金属层120覆盖的第一金属区1213，第一区域111的第二表面可以具有交替设置的第二空白区1216和被负极金属层130覆盖的第二金属区1215。绝缘膜层110的第一区域111、第一区域111上的正极金属层120和负极金属层130可以组合形成用于设置极耳的极耳区。在第二区域112的第一表面可以全部形成正极金属层120，第二区域112的第二表面可以全部形成负极金属层130。绝缘膜层110的第二区域112、以及第二区域112上的正极金属层120和负极金属层130可以组合形成涂覆区。
可选地，正极金属层120可以为金属铝层，和/或，负极金属层130可以为金属铜层或金属镍层。可选地，正极金属层120可以为金属铝层，以进行正极电流的导流；和/或，负极金属层130可以为金属铜层，以进行负极电流的导流。本公开中，正极金属层120不限定为金属铝层，只要能够作为集流体的正极的金属层均在本公开的保护范围之内；和/或，负极金属层130不限定为金属铜层，只要能够作为集流体的负极的金属层均在本公开的保 护范围之内。
可选地，正极金属层120的厚度可以为20-1500nm，和/或，负极金属层130的厚度可以为30-2500nm。上述厚度的层结构能够保证过流能力，使集流体的导电能力更佳。
为了形成上述双极性集流体100结构，可选地，可以在绝缘膜层110的一表面沉积正极金属层120，在绝缘膜层110的另一表面沉积负极金属层130，然后选择双极性集流体100的一侧作为极耳区。例如可以通过在极耳区处分别洗掉部分正极金属层120和部分负极金属层130，形成第一空白区1214和第二空白区1216，从而得到图1中的双极性集流体100结构。
图4为本公开实施例提供的极片200的结构示意图；图5为图4的Ⅴ-Ⅴ剖视图；图6为图4中Ⅵ-Ⅵ剖视图。请参阅图4-图6，本公开实施例中，极片200可以包括上述双极性集流体100、正极活性物质层210、负极活性物质层220、正极极耳230和负极极耳240。正极活性物质层210可以设置于第二区域112的正极金属层120上，负极活性物质层220可以设置于第二区域112的负极金属层130上。一个第一金属区1213上的正极金属层120上可以设置一个正极极耳230。一个第二金属区1215上的负极金属层130上可以设置一个负极极耳240。
可选地，正极极耳230可以与正极金属层120焊接，和/或，负极极耳240可以与负极金属层130焊接。以焊接的方式连接极耳，可以使极耳与金属层的连接更加牢固。但是，在极耳与金属层焊接的时候，可能容易出现绝缘膜层110焊穿的问题。
所以，本公开实施例中，第一金属区1213在绝缘膜层110的厚度方向的投影位于第二空白区1216。如图2所示，虚线1的左边，绝缘膜层110的上方为正极金属层120，绝缘膜层110的下表面为第二空白区1216。在将正极极耳230与正极金属层120连接的时候，即使在连接处的绝缘膜层110不可避免的遭到破坏(焊接时绝缘膜层110被焊穿)，但是，由于正极金属层120的背面是第二空白区1216，所以，绝缘膜层110的破坏处仅一面具有正极金属层120，另一面没有设置金属层，即使绝缘膜层110破坏，也不会存在绝缘膜层110两表面的正极金属层120和负极金属层130接触导通的问题，可以在一定程度上改善正负极的短路的问题。
本公开实施例中，第二金属区1215在绝缘膜层110的厚度方向的投影位于第一空白区1214。如图3所示，虚线2的左边，绝缘膜层110的下方为负极金属层130，绝缘膜层110的上表面为第一空白区1214。在将负极极耳240与负极金属层130连接的时候，即使在连接处的绝缘膜层110不可避免的遭到破坏(焊接时绝缘膜层110被焊穿)，但是，由于负极金属层130的背面是第一空白区1214，所以，绝缘膜层110的破坏处仅一面具有负极金属层130，另一面没有设置金属层，即使绝缘膜层110破坏，也不会存在绝缘膜层110两表面 的正极金属层120和负极金属层130接触导通的问题，可以在一定程度上改善正负极的短路的问题。
可选地，第一金属区1213的周界形状与第二空白区1216的周界形状对应，第二金属区1215的周界形状与第一空白区1214的周界形状对应，第一金属区1213沿绝缘膜层110的厚度方向在负极金属层130的投影与第二空白区1216重合，第二金属区1215沿绝缘膜层110的厚度方向在正极金属层120的投影与第一空白区1214重合。
可选地，在将正极极耳230与第一金属区1213上的正极金属层120焊接的时候，可以焊接在第一金属区1213上的正极金属层120的沿所述双极性集流体的长度方向的中部位置处，而尽量不焊接在第一金属区1213上的正极金属层120的边缘位置处。
可选地，负极极耳240与第二金属区1215上的负极金属层130焊接的时候，可以焊接在第二金属区1215上的负极金属层130的沿所述双极性集流体的长度方向的中部位置处，而尽量不焊接在第二金属区1215上的负极金属层130的边缘位置处，从而避免绝缘膜层110的边缘焊穿导致两表面的金属层接触，从而在一定程度上改善正负极的短路的问题。
在第一金属区1213上的正极金属层120上连接(例如：焊接)正极极耳230的时候，如果第一金属区1213上的正极金属层120的周缘也有焊印，且该焊印使绝缘膜层110被焊穿，则可能使第一金属区1213上的正极金属层120可能会刚好与第二金属区1215上的负极金属层130接触，从而导致正负极短路。所以，请继续参阅图1和图4，本公开实施例中，沿双极性集流体100的长度方向，第一金属区1213的宽度可以小于对应的第二空白区1216的宽度，第二金属区1215的宽度可以小于对应的第一空白区1214的宽度。上述宽度的限定，可以大大降低该现象的产生。即使将第一金属层的边缘对应的绝缘膜层110焊穿，但是，由于对应的空白区的位置更广，也可以有效避免正负极的导通。
请继续参阅图1和图4，本公开实施例中，沿双极性集流体100的长度方向，第二空白区1216的两侧可以超出对应的第一金属区1213在第二空白区1216的投影的两侧，第一空白区1214的两侧可以超出对应的第二金属区1215在第一空白区1214的投影的两侧。其中，图1和图4中，虚线部分为第二金属区1215的区域，从图中可以看出，第一金属区1213的区域小于第二空白区1216的区域，且第一金属区1213的区域全部在第二空白区1216的内部，第二金属区1215的区域小于第一空白区1214的区域，且第二金属区1215的区域全部在第一空白区1214的内部。可以有效避免焊接极耳的时候，正极金属层120与负极金属层130的接触，以避免正负极的短路。
可选地，沿双极性集流体100的长度方向，第二空白区1216与第一金属区1213的宽度之差可以为2-20mm，第一空白区1214与第二金属区1215的宽度之差可以为2-20mm。该宽度差可以有效避免正负极短路，且能够保证极耳区中金属层的面积，以便进行极耳的 连接。
在其他实施例中，还可以第一金属层在在绝缘膜层110的厚度方向的投影的一侧与第二空白区1216的边缘对应，另一侧位于第二空白区1216内；第二金属区1215在绝缘膜层110的厚度方向的投影的一侧与第一空白区1214的边缘对应，另一侧位于第一空白区1214内。本公开不做限定。
图7为本公开实施例提供的极片200的第二结构示意图。请参阅图7，在其他实施例中，正极极耳230和负极极耳240的形状可以为基本上的梯形形状(沿双极性集流体100的长度方向，极耳的靠近第二区域的一侧的尺寸更大，极耳的远离第二区域的一侧的尺寸更小)，极耳与金属层的焊接面积较大，可以使极耳与金属层的焊接更加牢固，极耳与连接片的焊接面积较小，在保证焊接牢固性的情况下，可以减少极耳的量，增大电池的能量密度。第一金属区1213和第二金属区1215的形状分别与正极极耳230和负极极耳240的形状相对应，使正极极耳230能够连接在第一金属区1213上的正极金属层120上，负极极耳240能够连接在第二金属区1215上的负极金属层130上。
上述极片200可以用来制作二次电池。二次电池可以是叠片电池，或卷绕电池，或其他二次电池，本公开不做限定。在制作二次电池的时候，可以先使用极片200制作电芯，然后再使用电芯来制作二次电池。
电芯可以包括多个上述极片200，以及多个隔膜，相邻两个极片200之间可以设置一个隔膜，且隔膜的两侧分别设置正极活性物质层210和负极活性物质层220。
图8为本公开实施例提供的电芯堆中一个电池极片200的结构示意图。请参阅图8，电芯为叠片电芯堆，其中每个极片200可以包括一个正极极耳230和一个负极极耳240。多个极片200经堆叠以后，多个极片200的正极极耳230重叠，多个极片200的负极极耳240重叠。多个重叠的正极极耳230与正极连接片焊接，多个重叠的负极极耳240与负极连接片连接，以进行二次电池的制作。
在另一实施方式中，电芯可以为卷绕电芯，沿极片200的卷绕方向，相邻两个正极极耳230之间的距离以及相邻两个负极极耳240之间的距离逐渐增大(卷绕电芯的内圈的直径小，外圈的直径大，所以，需要设置不同的极耳距离)，使极片200与隔膜卷绕以后，多个正极极耳230重叠，多个负极极耳240重叠。多个重叠的正极极耳230与正极连接片焊接，多个重叠的负极极耳240与负极连接片连接，以进行二次电池的制作。
本公开实施例提供的双极性集流体100及极片200的有益效果例如包括：
(1)在第一金属区1213上的正极金属层120与正极极耳230连接或在第二金属区1215上的负极金属层130与负极极耳240连接(例如焊接)的时候，即使由于连接过程对绝缘膜层110进行了破坏，但是由于极耳连接处背面的空白区的设置，也可以在一定程度上避 免铝金属层和铜金属层之间的导通，从而可以在一定程度上改善正负极的短路的问题。
(2)沿双极性集流体100的长度方向，第二空白区1216的两侧超出对应的第一金属区1213在第二空白区1216的投影的两侧，第一空白区1214的两侧超出对应的第二金属区1215在第一空白区1214的投影的两侧。即使第一金属区1213上的正极金属层120全部形成焊印，第二金属区1215上的负极金属层130全部形成焊印，也可以有效避免由于焊接过程中绝缘膜层110的破坏而导致铝金属层和铜金属层之间的导通的问题，从而有效避免正负极短路。
(3)重叠的多个正极极耳230与正极连接片连接，重叠的多个负极极耳240与负极连接片连接，从而进行电芯以及二次电池的制作，制作较为简单。
以上所述仅为本公开的一部分实施例而已，并不用于限制本公开，对于本领域的技术人员来说，本公开可以有各种更改和变化。凡在本公开的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本公开的保护范围之内。
工业实用性
本公开实施例提供了双极性集流体、极片、电芯和二次电池，由于本公开实施例的双极性集流体包含了交替设置的第一空白区和被所述正极金属层覆盖的第一金属区以及交替设置的第二空白区和被所述负极金属层覆盖的第二金属区，因而即使在连接极耳的过程中对绝缘膜层进行了破坏，也可以一定程度上避免正极金属层和负极金属层之间的导通，从而实现在一定程度上改善正负极的短路的问题；以及由于第二空白区的两侧超出对应的第一金属区在第二空白区的投影的两侧，第一空白区的两侧超出对应的第二金属区在第一空白区的投影的两侧，因此也可以有效避免由于焊接过程中绝缘膜层的破坏而导致正负金属层之间的导通的问题，从而有效避免正负极短路。

Claims (17)

  1. 一种双极性集流体，其特征在于，包括：绝缘膜层以及设置于所述绝缘膜层两表面的正极金属层和负极金属层；
    沿所述双极性集流体的宽度方向，所述绝缘膜层具有依次设置的第一区域和第二区域；
    沿所述双极性集流体的长度方向，所述第一区域的第一表面具有交替设置的第一空白区和被所述正极金属层覆盖的第一金属区，所述第一区域的第二表面具有交替设置的第二空白区和被所述负极金属层覆盖的第二金属区；
    覆盖所述第一金属区的所述正极金属层用于连接正极极耳，覆盖所述第二金属区的所述负极金属层用于连接负极极耳，所述第一金属区在所述绝缘膜层的厚度方向的投影位于所述第二空白区，所述第二金属区在所述绝缘膜层的厚度方向的投影位于所述第一空白区。
  2. 根据权利要求1所述的双极性集流体，其特征在于，沿所述双极性集流体的长度方向，所述第一金属区的宽度小于对应的所述第二空白区的宽度，所述第二金属区的宽度小于对应的所述第一空白区的宽度。
  3. 根据权利要求1或2所述的双极性集流体，其特征在于，沿所述双极性集流体的长度方向，所述第二空白区的两侧超出对应的所述第一金属区在所述第二空白区的投影的两侧，所述第一空白区的两侧超出对应的所述第二金属区在所述第一空白区的投影的两侧。
  4. 根据权利要求1至3中任一项所述的双极性集流体，其特征在于，沿所述双极性集流体的长度方向，所述第二空白区与第一金属区的宽度之差为2-20mm，所述第一空白区与所述第二金属区的宽度之差为2-20mm。
  5. 根据权利要求1所述的双极性集流体，其特征在于，还包括：所述第一金属区的周界形状与所述第二空白区的周界形状相对应，所述第二金属区的周界形状与第一空白区的周界形状相对应，使得所述第一金属区沿所述绝缘膜层的厚度方向在所述负极金属层上的投影与所述第二空白区重合，所述第二金属区沿所述绝缘膜层的厚度方向在所述正极金属层上的投影与所述第一空白区重合。
  6. 根据权利要求1至5中任一项所述的双极性集流体，其特征在于，所述正极金属层为金属铝层，所述负极金属层为金属铜层或金属镍层。
  7. 根据权利要求1至6中任一项所述的双极性集流体，其特征在于，所述正极金属层的厚度为20-1500nm，所述负极金属层的厚度为30-2500nm。
  8. 根据权利要求1至7中任一项所述的双极性集流体，其特征在于，所述绝缘膜层的材料至少包括以下之一：高分子绝缘材料、合成纤维绝缘纸、绝缘胶布。
  9. 一种极片，其特征在于，包括：
    权利要求1-8任一项所述的双极性集流体；
    正极活性物质层，所述正极活性物质层设置于所述第二区域的正极金属层上；
    负极活性物质层，所述负极活性物质层设置于所述第二区域的负极金属层上；
    正极极耳，一个所述第一金属区上的所述正极金属层上设置一个所述正极极耳；
    负极极耳，一个所述第二金属区上的所述负极金属层上设置一个所述负极极耳。
  10. 根据权利要求9所述的极片，其特征在于，所述一个所述第一金属区上的所述正极金属层上设置一个所述正极极耳，包括：所述正极极耳与位于所述第一金属区上的所述正极金属层焊接连接。
  11. 根据权利要求9或10所述的极片，其特征在于，所述一个所述第二金属区上的所述负极金属层上设置一个所述负极极耳，包括：所述负极极耳与位于所述第二金属区上的所述负极金属层焊接连接。
  12. 根据权利要求9至11中任一项所述的极片，其特征在于，若所述第一金属区沿所述绝缘膜层的厚度方向在所述负极金属层上的投影与所述第二空白区重合以及所述第二金属区沿所述绝缘膜层的厚度方向在所述正极金属层上的投影与所述第一空白区重合，所述正极极耳焊接在位于所述第一金属区上的所述正极金属层的沿所述双极性集流体的长度方向的中部位置处，以及所述负极极耳焊接在位于所述第二金属区上的负极金属层的沿所述双极性集流体的长度方向的中部位置处。
  13. 根据权利要求9至12中任一项所述的极片，其特征在于，所述正极极耳和所述负极极耳的形状均为基本上的梯形形状，其中，所述正极极耳靠近所述第二区域的一侧的沿所述长度方向的尺寸比远离所述第二区域的一侧的沿所述长度方向的尺寸大，所述负极极耳靠近所述第二区域的一侧的沿所述长度方向的尺寸比远离所述第二区域的一侧的沿所述长度方向的尺寸大。
  14. 一种电芯，其特征在于，包括多个权利要求6所述的极片，以及多个隔膜，相邻两个所述极片之间设置一个所述隔膜，且所述隔膜的两侧分别设置所述正极活性物质层和所述负极活性物质层。
  15. 根据权利要求14所述的电芯，其特征在于，所述电芯为叠片电芯堆，每个所述极片包括一个所述正极极耳和一个所述负极极耳，多个所述极片堆叠以后，多个所述极片的所述正极极耳重叠，多个所述极片的所述负极极耳重叠。
  16. 根据权利要求14所述的电芯，其特征在于，所述电芯为卷绕电芯，沿所述极片 的卷绕方向，相邻两个所述正极极耳之间的距离以及相邻两个所述负极极耳之间的距离逐渐增大，使所述极片与所述隔膜卷绕以后，多个所述正极极耳重叠，多个所述负极极耳重叠。
  17. 一种二次电池，其特征在于，包括权利要求14至16中任一项所述的电芯。
PCT/CN2021/108722 2020-07-28 2021-07-27 一种双极性集流体、极片、电芯和二次电池 WO2022022525A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202021523469.0U CN212659568U (zh) 2020-07-28 2020-07-28 一种双极性集流体、极片、电芯和二次电池
CN202021523469.0 2020-07-28

Publications (1)

Publication Number Publication Date
WO2022022525A1 true WO2022022525A1 (zh) 2022-02-03

Family

ID=74770696

Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/CN2021/106893 WO2022022303A1 (zh) 2020-07-28 2021-07-16 双极性集流体、极片、电芯和二次电池
PCT/CN2021/108722 WO2022022525A1 (zh) 2020-07-28 2021-07-27 一种双极性集流体、极片、电芯和二次电池

Family Applications Before (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/106893 WO2022022303A1 (zh) 2020-07-28 2021-07-16 双极性集流体、极片、电芯和二次电池

Country Status (4)

Country Link
US (1) US20230035287A1 (zh)
EP (1) EP4191713A1 (zh)
CN (1) CN212659568U (zh)
WO (2) WO2022022303A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN212659568U (zh) * 2020-07-28 2021-03-05 深圳市海鸿新能源技术有限公司 一种双极性集流体、极片、电芯和二次电池
CN114122327B (zh) * 2022-01-29 2022-07-15 宁德时代新能源科技股份有限公司 一种极片及具备其的二次电池

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100646551B1 (ko) * 2005-11-03 2006-11-14 삼성에스디아이 주식회사 음극 및 양극 일체형 이차 전지 및 그 형성 방법
US20130260205A1 (en) * 2012-04-03 2013-10-03 Samsung Electronics Co., Ltd. Flexible secondary battery
CN103594736A (zh) * 2012-08-17 2014-02-19 迪吉亚节能科技股份有限公司 单卷芯、具有单卷芯的锂电池及单卷芯的连续卷绕方法
CN108390068A (zh) * 2018-02-09 2018-08-10 合肥国轩高科动力能源有限公司 一种双极性集流体及其制备方法
CN208336372U (zh) * 2018-03-20 2019-01-04 宁德时代新能源科技股份有限公司 电极极片、电极组件及二次电池
CN109980234A (zh) * 2019-03-29 2019-07-05 宁德新能源科技有限公司 复合集流体与包含其的复合极片及电化学装置
CN111584823A (zh) * 2019-02-19 2020-08-25 宁德新能源科技有限公司 极片、电芯以及电池
CN212659570U (zh) * 2020-07-28 2021-03-05 深圳市海鸿新能源技术有限公司 一种双极性集流体、极片及电芯
CN212659568U (zh) * 2020-07-28 2021-03-05 深圳市海鸿新能源技术有限公司 一种双极性集流体、极片、电芯和二次电池
CN212659571U (zh) * 2020-07-28 2021-03-05 深圳市海鸿新能源技术有限公司 一种双极性集流体、极片及二次电池

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5400268B2 (ja) * 2006-01-26 2014-01-29 パナソニック株式会社 リチウム二次電池
JP2010251197A (ja) * 2009-04-17 2010-11-04 Sharp Corp リチウムイオン電池
CN108400385A (zh) * 2018-01-17 2018-08-14 柔电（武汉）科技有限公司 使用活性自支撑极片制备高能量密度软包锂电池的方法
CN108376759A (zh) * 2018-01-17 2018-08-07 柔电（武汉）科技有限公司 一种提高能量密度的软包锂电池制备方法
CN108598359B (zh) * 2018-05-12 2020-08-28 山东金品能源有限公司 一种提高方形聚合物锂离子电芯极片活性物质涂覆量的方法

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100646551B1 (ko) * 2005-11-03 2006-11-14 삼성에스디아이 주식회사 음극 및 양극 일체형 이차 전지 및 그 형성 방법
US20130260205A1 (en) * 2012-04-03 2013-10-03 Samsung Electronics Co., Ltd. Flexible secondary battery
CN103594736A (zh) * 2012-08-17 2014-02-19 迪吉亚节能科技股份有限公司 单卷芯、具有单卷芯的锂电池及单卷芯的连续卷绕方法
CN108390068A (zh) * 2018-02-09 2018-08-10 合肥国轩高科动力能源有限公司 一种双极性集流体及其制备方法
CN208336372U (zh) * 2018-03-20 2019-01-04 宁德时代新能源科技股份有限公司 电极极片、电极组件及二次电池
CN111584823A (zh) * 2019-02-19 2020-08-25 宁德新能源科技有限公司 极片、电芯以及电池
CN109980234A (zh) * 2019-03-29 2019-07-05 宁德新能源科技有限公司 复合集流体与包含其的复合极片及电化学装置
CN212659570U (zh) * 2020-07-28 2021-03-05 深圳市海鸿新能源技术有限公司 一种双极性集流体、极片及电芯
CN212659568U (zh) * 2020-07-28 2021-03-05 深圳市海鸿新能源技术有限公司 一种双极性集流体、极片、电芯和二次电池
CN212659571U (zh) * 2020-07-28 2021-03-05 深圳市海鸿新能源技术有限公司 一种双极性集流体、极片及二次电池

Also Published As

Publication number Publication date
CN212659568U (zh) 2021-03-05
US20230035287A1 (en) 2023-02-02
EP4191713A1 (en) 2023-06-07
WO2022022303A1 (zh) 2022-02-03

Similar Documents

Publication Publication Date Title
CN212659570U (zh) 一种双极性集流体、极片及电芯
WO2022022324A1 (zh) 双极性集流体、极片及二次电池
WO2022141161A1 (zh) 电极组件和电化学装置
WO2022022525A1 (zh) 一种双极性集流体、极片、电芯和二次电池
WO2023088428A1 (zh) 极片和电池
WO2020078081A1 (zh) 叠片电芯及其制作方法、锂电池
WO2018099168A1 (zh) 阴极极片、阳极极片及电芯
WO2020168879A1 (zh) 极片、电芯以及电池
JP2024520156A (ja) 電池用電極板、電池及び電池用電極板の製作方法
WO2023071835A1 (zh) 一种电芯、电池及电子设备
WO2023088434A1 (zh) 极片和电池
CN112864350A (zh) 电芯及电池
WO2024120551A1 (zh) 极片及电芯
CN112821014A (zh) 电芯、电芯组件及电池
WO2022022337A1 (zh) 一种双极性集流体及二次电池
CN219800919U (zh) 一种极片、电芯及电池
CN112490596A (zh) 一种电芯及其制备方法、单电池
CN107293806B (zh) 卷绕式电芯
CN219180539U (zh) 一种极片、电芯及电池
CN218160737U (zh) 一种全极耳电芯结构与锂离子电池
CN217114709U (zh) 一种电池
JP6987983B2 (ja) 捲回型電池セル
CN217485538U (zh) 一种卷绕式电芯
CN214280146U (zh) 一种电芯、单电池及二次电池
CN116802921A (zh) 电化学装置及用电设备

Legal Events

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

Ref document number: 21848752

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 06/07/2023)

122 Ep: pct application non-entry in european phase

Ref document number: 21848752

Country of ref document: EP

Kind code of ref document: A1