WO2023159583A1 - 电化学装置及电子装置 - Google Patents

电化学装置及电子装置 Download PDF

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Publication number
WO2023159583A1
WO2023159583A1 PCT/CN2022/078352 CN2022078352W WO2023159583A1 WO 2023159583 A1 WO2023159583 A1 WO 2023159583A1 CN 2022078352 W CN2022078352 W CN 2022078352W WO 2023159583 A1 WO2023159583 A1 WO 2023159583A1
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WO
WIPO (PCT)
Prior art keywords
tab
electrode assembly
separator
electrochemical device
lug
Prior art date
Application number
PCT/CN2022/078352
Other languages
English (en)
French (fr)
Inventor
刘道林
何平
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/CN2022/078352 priority Critical patent/WO2023159583A1/zh
Priority to CN202280010455.4A priority patent/CN116868403A/zh
Publication of WO2023159583A1 publication Critical patent/WO2023159583A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • 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
    • 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
    • H01M50/183—Sealing members
    • H01M50/184—Sealing members characterised by their shape or structure
    • 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
    • H01M50/183—Sealing members
    • H01M50/186—Sealing members characterised by the disposition of the sealing members
    • 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
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs

Definitions

  • the present application relates to the field of electrochemistry, in particular to an electrochemical device and an electronic device.
  • the internal series high-voltage battery includes a casing and a plurality of series-connected electrode assemblies arranged in the casing, and the series-connected electrode assemblies are separated by separators.
  • the positive and negative tabs of multiple series-connected electrode assemblies usually protrude from the same side of the casing and are connected in series outside the casing. At this time, the reliability of the seal on this side will be insufficient, and there will be a safety risk.
  • the present application provides an electrochemical device and an electronic device to improve the sealing reliability of internal high-voltage batteries connected in series.
  • the first aspect of the present application provides an electrochemical device, including a first electrode assembly, a second electrode assembly, a case, and a separator.
  • the first electrode assembly includes a first tab.
  • the second electrode assembly includes a second tab.
  • the casing is provided with a first cavity and a second cavity, the first electrode assembly is arranged in the first cavity, and the second electrode assembly is arranged in the second cavity.
  • the separator is disposed between the first electrode assembly and the second electrode assembly, the separator includes a first sealing area, the first sealing area includes a first side, and the thickness of the separator is D.
  • both the first tab and the second tab extend out of the casing at the first side, and along the length direction of the first side, the minimum distance between the first tab and the second tab at the first side is It is L, and L/D ⁇ 15.
  • the offset arrangement of the first tab and the second tab can reduce the thickness difference of the seal at the first side and improve the reliability of the seal at the tab relative to the overlapping arrangement of the first tab and the second tab;
  • the bending degree of the separator between the tabs can be effectively reduced, so that the stress and strain it receives is small, and the separators at the side corners of the tabs can be better adhered to when sealing.
  • the other components connected with it are not easy to peel off when the tab is pulled by external stress to pull the separator, thereby further improving the reliability of the seal.
  • L/D ⁇ 100 the space utilization rate of the first side can be improved, and more electrode assemblies can be connected in series.
  • the thickness of the first tab is d1, L/d1 ⁇ 10; (2) the thickness of the second tab is d2, and L/d2 ⁇ 10 .
  • the degree of bending of the separator between the tabs can be further reduced, so that the stress and strain it receives is small, and the connection between the separator and other components at the side corners of the first tab and/or the second tab can be further improved. fit, thereby further improving seal reliability.
  • At least one of the following characteristics is satisfied: (3) L/(d1+D) ⁇ 5; (4) L/(d2+D) ⁇ 5; The degree of bending of the spacer makes it less stressed and strained, and further improves the fit between the spacer and other components at the side corners of the first lug and/or the second lug, thereby further improving the reliability of the seal sex.
  • d1 ⁇ 0.2 mm; and/or d2 ⁇ 0.2 mm are examples of dimensions.
  • the first electrode assembly further includes a third tab, and the third tab is located on the side of the first tab away from the second tab; In the length direction of the sides, the minimum distance between the first tab and the third tab at the first side is S1, and S1/L ⁇ 0.5;
  • the second electrode assembly also includes a fourth tab, the fourth The tab is located on the side of the second tab away from the first tab; along the length direction of the first side, the minimum distance between the second tab and the fourth tab at the first side is S2, and S2/L ⁇ 0.5.
  • S1 > 5 mm; and/or S2 > 5 mm.
  • the first lug is provided with a first lug glue, and along the length direction of the first side, the first end of the first lug close to the second lug exceeds the
  • the length of the first tab is H1;
  • the second tab is provided with a second tab glue, along the length direction of the first side, the second end of the second tab close to the first tab is on the first side
  • the length of the side beyond the second tab is H2; satisfying: (H1+H2)/L ⁇ 0.2. In this case, the sealing reliability at the side corners of the first tab and the second tab can be further improved.
  • H1 > 1 mm; and/or H2 > 1 mm.
  • the first tab is connected to the second tab, and the first tab and the second tab have different polarities.
  • the separator includes a substrate layer and an encapsulation layer located on the surface of the substrate layer.
  • the material of the encapsulation layer includes a first polymer material; the material of the substrate layer includes at least one of a metal material, a second polymer material, or a carbon material.
  • the first polymer material includes polypropylene, anhydride-modified polypropylene, polyethylene, ethylene-propylene copolymer, polyvinyl chloride, polystyrene, polyether nitrile, polyurethane, polyamide, polyester, non- A crystalline ⁇ -olefin copolymer or at least one of the derivatives of the above substances.
  • the metal material includes Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb , Pb, In, Zn, stainless steel (SUS) and their composition or alloy at least one.
  • the second polymer material includes polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyether ether ketone, polyimide , polyamide, polyethylene glycol, polyamideimide, polycarbonate, cyclic polyolefin, polyphenylene sulfide, polyvinyl acetate, polytetrafluoroethylene, polymethylene naphthalene, polyvinylidene fluoride , polypropylene carbonate, poly(vinylidene fluoride-hexafluoropropylene), poly(vinylidene fluoride-co-chlorotrifluoroethylene), silicone, vinylon, polypropylene, anhydride modified polypropylene, polypropylene At least one of ethylene, ethylene propylene copolymer, polyvinyl chloride, polystyrene, polyether nitrile, polyurethane, polyphenylene ether, polyester, polysulfone,
  • the carbon material includes at least one of carbon felt, carbon film, carbon black, acetylene black, fullerene, conductive graphite film, or graphene film.
  • the second aspect of the present application also provides an electronic device, including any one of the above electrochemical devices.
  • the first tab and the second tab are misaligned, relative to the first tab and the second tab.
  • the ear overlapping setting can reduce the thickness difference of the seal at the first side and improve the reliability of the seal at the tab; on the other hand, it can effectively reduce the bending degree of the partition between the tabs and make it less stressed and strained , and the separator at the side corner of the tab can better fit other parts connected to it during sealing, and it is not easy to peel off when the tab is pulled by external stress, thereby further improving the reliability of the seal.
  • Fig. 1 is the three-dimensional schematic diagram of the electrochemical device of the embodiment of the present application.
  • Fig. 2 is a schematic side view along the direction X of the electrochemical device of the embodiment of the present application
  • FIG. 3 is a schematic side view along the direction Z of the electrochemical device of the embodiment of the present application.
  • Fig. 4 is a schematic side view along the direction Z of the combination of the first lug, the second lug, the first lug glue and the second lug glue according to the embodiment of the present application; wherein, the separator is cut to expose the first side;
  • Fig. 5 is a schematic side view of the combination of the first lug, the second lug, the first lug glue and the second lug glue in the embodiment of the present application along the direction X; expose the first side;
  • Fig. 6 is a schematic side view along the direction X of the combination of the first tab, the second tab, the third tab, the fourth tab, the first tab glue and the second tab glue according to the embodiment of the present application; , the bulkhead is sectioned to expose the first side.
  • the internal series high-voltage battery includes a casing and a plurality of series-connected electrode assemblies arranged in the casing, and the series-connected electrode assemblies are separated by separators.
  • the positive and negative tabs of multiple series-connected electrode assemblies usually protrude from the same side of the casing and are connected in series outside the casing. At this time, the reliability of the seal on this side will be insufficient, and there will be a safety risk.
  • the present embodiment provides an electrochemical device 10 capable of improving the sealing reliability of internal series connected high-voltage batteries.
  • the electrochemical device 10 in this embodiment includes a first electrode assembly, a second electrode assembly, a casing 100 and a separator 200 .
  • the casing 100 is used to define a closed space for accommodating the first electrode assembly and the second electrode assembly.
  • the partition 200 serves to partition the inner space of the housing 100 , thereby increasing the number of independent spaces inside the housing 100 .
  • the electrochemical device 10 may include a separator 200 or may include a plurality of separators 200.
  • a separator 200 may divide the internal space of the casing 100 into two independent spaces.
  • the electrochemical device 10 includes a plurality of separators 200 , specifically two separators 200 , the two separators 200 can divide the inner space of the casing 100 into three independent spaces.
  • a partition 200 divides the inner space of the housing 100 into two independent spaces, called a first cavity and a second cavity, respectively.
  • the electrochemical device 10 may include two electrode assemblies or more than three electrode assemblies.
  • the electrochemical device 10 includes two electrode assemblies for illustration. And the two electrode assemblies are respectively referred to as the first electrode assembly and the second electrode assembly mentioned above.
  • the electrochemical device 10 has a separator 200, and the separator 200 separates the aforementioned two independent spaces, the first electrode assembly is arranged in the aforementioned first cavity, and the second electrode assembly is arranged in the aforementioned second cavity. cavity.
  • the first electrode assembly, the separator 200 and the second electrode assembly are distributed along the direction Z.
  • the first electrode assembly may include at least two tabs, and the polarities between the two tabs are different.
  • one tab of the first electrode assembly is referred to as the first tab 310 .
  • the first tab 310 may be a positive tab or a negative tab.
  • the second electrode assembly may include at least two tabs, and the polarities between the two tabs are different.
  • one of the tabs of the second electrode assembly is referred to as the second tab 320
  • the second tab 320 may be a positive tab or a negative tab.
  • the polarities of the first tab 310 and the second tab 320 may be the same or different.
  • the first tab 310 and the second tab 320 may or may not be electrically connected to each other.
  • the first tab 310 is a positive tab
  • the second tab 320 is a negative tab
  • the first tab 310 is electrically connected to the second tab 320 for illustration.
  • the separator 200 includes a first sealing area 210 , and when the electrochemical device 10 is packaged, the part of the separator 200 located in the sealing area 210 is sealed with other components. In other words, the portion of the sealing area 210 of the separator 200 is fixedly connected to other components (specifically, it may be thermally melted or bonded).
  • both side walls of the sealing area 210 of the separator 200 are connected to the casing 100 .
  • one side wall of the sealing area 210 of one separator 200 is connected to the other separator 200 , and the other side wall is connected to the casing 100 .
  • the number of partitions 200 is three or more, the wall surfaces on both sides of the sealing area 210 of the partition 200 in the middle are connected to other partitions 200 on both sides of the partition 200 .
  • the first sealing area 210 may be ring-shaped, and the first sealing area 210 may extend to the outer edge of the separator 200 , and the first sealing area 210 may also be separated from the outer edge of the separator 200 by a certain distance. Referring to FIG. 4 , in this embodiment, the first sealing area 210 is ring-shaped, and the outer edge of the first sealing area 210 is spaced apart from the outer edge of the separator 200 , and the distance between them depends on actual needs.
  • the first sealing area 210 includes a first side 211 , wherein both the first tab 310 and the second tab 320 extend out of the casing 100 at the first side 211 .
  • both the first tab 310 and the second tab 320 extend out of the casing 100 from both sides of the first side 211 .
  • the thickness of the separator 200 is D, that is, the thickness of the separator 200 is D along the direction Z in FIG. 5 .
  • the minimum distance between the first tab 310 and the second tab 320 at the first side 211 is L, and L/D ⁇ 15.
  • L/D may be 15, 20, 25, 30 or 100, etc. In a specific example, when D is 0.2mm, L ⁇ 3mm.
  • the inventors of the present application found that since the first tab 310 and the second tab 320 are located on both sides of the separator 200, on the one hand, the arrangement of the tabs will have a greater impact on the reliability of the seal.
  • the tab 310 and the second tab 320 are overlapped, and the first tab 310 and the second tab 320 are misplaced, which can reduce the difference in seal thickness at the first side 211 and improve the reliability of the seal at the tab; the other
  • the first tab 310 and the second tab 320 are misaligned, along the length direction of the first side 211 , the part of the separator 200 between the first tab 310 and the second tab 320 is bent. , the reliability of the seal there is affected.
  • the inventors of the present application have found through research that when the minimum distance L between the first tab 310 and the second tab 320 at the first side 211 and the thickness D of the separator 200 satisfy L/D ⁇ 15, the electrical The chemical device 10 has high sealing reliability. This is because, satisfying the above relationship can effectively reduce the bending degree of the separator between the tabs, so that the stress and strain it receives is small, and the separators at the side corners of the tabs can be better bonded when sealing Other components connected with it are not easy to peel off when the tab is pulled by external stress to pull the separator, thereby further improving the reliability of the seal.
  • L/D 100.
  • the space utilization rate of the first side 211 can be improved, and more electrode assemblies can be connected in series.
  • the electrochemical device 10 can satisfy at least one of the following characteristics: (1) the thickness of the first tab 310 is d1, L/d1 ⁇ 10; ( 2) The thickness of the second tab 320 is d2, and L/d2 ⁇ 10.
  • the degree of bending of the part of the separator 200 located between the first tab 310 and the second tab 320 can be further reduced, so that the stress and strain it receives is small, and further improves the stability of the separator between the first tab and/or the second tab 320. Or the fit between the corners of the side of the second tab and other components, thereby further improving the reliability of the seal.
  • L/d1 ⁇ 10 can also be made.
  • L/d2 ⁇ 10 is also required.
  • L/d1 ⁇ 10 and L/d2 ⁇ 10 are also required.
  • the thickness D of the separator 200 is 0.2mm, d1 is 0.1mm, and d2 is 0.1mm, under the condition of L/D ⁇ 15, the minimum value of L is 3mm; under the condition of L/d1 ⁇ 10 Under the condition, the minimum value of L is 1mm; under the condition of L/d2 ⁇ 10, the minimum value of L is 1mm, and the final minimum value of L is 3mm.
  • L/d1 ⁇ 10 and/or L/d2 ⁇ 10 are used to define the distance between the first tab 310 and the second tab 320 along the direction Y, the sealing reliability of the electrochemical device 10 can be further ensured.
  • the electrochemical device 10 can also satisfy at least one of the following characteristics: (3) L/(d1+D) ⁇ 5; (4) L/(d2+D) ⁇ 5; at this time, It can further reduce the degree of bending of the part of the separator 200 between the first tab 310 and the second tab 320, so that the stress and strain it receives is less, and further improve the stability of the separator between the first tab and/or the second tab. The fit between the corners of the side of the tab and other components further improves the reliability of the seal.
  • d1 ⁇ 0.2mm; and/or d2 ⁇ 0.2mm In one embodiment, d1 ⁇ 0.2mm; and/or d2 ⁇ 0.2mm.
  • the electrochemical device 10 satisfies conditions (3) and (4) at the same time.
  • D is 0.2mm
  • d1 is 0.2mm
  • d2 is 0.2mm
  • the minimum value of L is 3mm
  • the minimum value of L is The value is 2mm
  • the minimum value of L is 2mm. It is concluded that the final minimum value of L is 3mm.
  • L 3mm; and/or D ⁇ 0.3mm.
  • D the thickness of the separator 200 will not be too large, thereby preventing the separator 200 from occupying too much space of the electrochemical device 10 and reducing the energy density of the electrochemical device 10 .
  • the electrochemical device 10 satisfies at least one of the following features: (a) the first electrode assembly further includes a third tab 330, and the third tab 330 is located at the first tab 310 away from the second tab 320; along the length direction of the first side 211, the minimum distance between the first tab 310 and the third tab 330 at the first side 211 is S1, and S1/L ⁇ 0.5; (b) The two-electrode assembly also includes a fourth tab 340, which is located on the side of the second tab 320 away from the first tab 310; along the length direction of the first side 211, the second tab 320 is connected to the fourth tab 310.
  • the minimum distance between the tabs 340 at the first side 211 is S2, and S2/L ⁇ 0.5.
  • the side corners adjacent to the first tab 310 and the third tab 330 and/or the side corners between the second tab 320 and the second tab 330 Adjacent side corners of the quadrupole tab 340 will be subject to greater bending stress and strain, and have a higher risk of failure.
  • the sealing reliability at the side corner adjacent to the first tab 310 and the third tab 330 and/or at the side corner adjacent to the second tab 320 and the fourth tab 340 can be further improved. sex.
  • S1 ⁇ 5mm; and/or S2 ⁇ 5mm make the distance between the first tab 310 and the third tab 330 along the direction Y and/or the distance between the second tab 320 and the fourth tab 340 along the direction Y greater than or equal to 5 mm, on the one hand, when the first tab 310 and the third tab 330 and/or the polarities of the second tab 320 and the fourth tab 340 are different, the first tab 310 and the third tab 330 and/or the second tab 320 and the The fourth tab 340 is short-circuited due to the short distance. On the other hand, the part between the first tab 310 and the third tab 330 and/or the part between the second tab 320 and the fourth tab 340 can also be increased. The seal reliability of the intermediate parts.
  • the first tab 310 is provided with a first tab glue 410, and along the length direction of the first side 211, that is, the direction Y, the first tab glue 410 is close to the first side of the second tab 320.
  • the length of the end portion beyond the first tab 310 at the first side 211 is H1.
  • the second tab 320 is provided with a second tab glue 420, along the length direction of the first side 211, that is, the direction Y, the second end of the second tab glue 420 close to the first tab 310 is on the first side
  • the length of the side 211 beyond the second tab 320 is H2.
  • H1 and H2 satisfy: (H1+H2)/L ⁇ 0.2. In this solution, the sealing reliability at the side corners of the first tab 310 and the second tab 320 is further improved.
  • H1 ⁇ 1 mm; and/or H2 ⁇ 1 mm when H1 ⁇ 1 mm, the first tab glue 410 can well cover the side corner adjacent to the first tab 310 and the second tab 320 , improving the sealing reliability at the side corner.
  • the second tab glue 420 when H2 ⁇ 1 mm, can well cover the side corner of the second tab 320 adjacent to the first tab 310 , improving the sealing reliability at the side corner.
  • the present application also provides an electronic device, which includes the electrochemical device 10 provided in the present application.
  • the electronic device in this application is not particularly limited, and it may be any electronic device known in the prior art. Examples of electronic devices include, but are not limited to, notebook computers, pen-based computers, mobile computers, e-book players, cellular phones, portable fax machines, portable copiers, portable printers, headsets, VCRs, LCD televisions, portable Cleaners, portable CD players, mini discs, transceivers, electronic organizers, calculators, memory cards, portable recorders, radios, backup power supplies, electric motors, automobiles, motorcycles, power-assisted bicycles, bicycles, lighting fixtures, toys, game consoles , clocks, electric tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.
  • the method for preparing the electrochemical device of the present application is not particularly limited, and any method known in the art can be used.
  • the present application can be prepared by the following preparation method:
  • the negative electrode active material, binder and solvent are blended into a slurry, and stirred evenly.
  • the slurry is uniformly coated on the negative electrode current collector and dried to obtain a negative electrode sheet coated on one side.
  • the above steps were repeated on the other surface of the negative electrode collector to obtain a double-sided coated negative electrode sheet. Then, it is used after cold pressing and cutting.
  • the positive pole piece the positive active material, the binder, the conductive agent and the solvent are blended into a slurry and stirred evenly.
  • the slurry is uniformly coated on the positive electrode current collector and dried to obtain a positive electrode sheet coated on one side. Repeat the above steps on the other surface of the positive electrode collector to obtain a double-sided coated positive electrode sheet. Then, it is used after cold pressing and cutting.
  • the structure of the electrode assembly can be a winding structure or a laminated structure, wherein a plurality of negative electrode sheets, separators, and positive electrode sheets are stacked in sequence and fixed to form an electrode assembly with a laminated structure; Negative pole pieces, separators, and positive pole pieces are sequentially stacked and wound to form an electrode assembly with a wound structure; each electrode assembly includes a positive pole tab and a negative pole tab; multiple electrode assemblies can be obtained by repeating the above steps.
  • Electrode assembly assembly place the packaging case in the assembly jig, then place the electrode assembly and the separator at intervals, and lead all the tabs of the electrode assembly out of the packaging case for subsequent processing, and finally carry out top sealing and side sealing. Seal and leave the injection port.
  • Liquid injection packaging inject electrolyte into multiple cavities respectively, and seal them after hot pressing, chemical formation, and degassing.
  • the electrochemical device provided in the present application may contain two electrode assemblies, or may contain more than three electrode assemblies.
  • the preparation method of the electrochemical device containing two electrode assemblies or more than three electrode assemblies can refer to the preparation method of the above electrochemical device.
  • the top sealing position (the protruding side of the tab) is packaged
  • a sufficient amount of penetrant is sprayed on the top sealing position inside the packaging shell, and then the surrounding area is sealed, and then placed at room temperature for 24 hours, and the top seal is observed. Whether there is leakage of penetrant outside the sealing area, and judge the sealing reliability of the top sealing area.
  • the positive pole piece the positive active material lithium cobaltate (LiCoO 2 ), conductive carbon black (Super P), and polyvinylidene fluoride (PVDF) were mixed according to the weight ratio of 97.5:1.0:1.5, and N -Methylpyrrolidone (NMP), prepared into a slurry with a solid content of 75wt%, and stirred evenly.
  • the slurry is evenly coated on one surface of the positive electrode current collector aluminum foil, and dried to obtain a positive electrode sheet coated with a positive electrode active material layer on one side.
  • the above steps were repeated to obtain a positive electrode sheet coated with a positive electrode active material layer on both sides.
  • the positive pole piece was cut into a size of 38mm ⁇ 58mm for use.
  • each electrode assembly includes a positive pole lug and a negative pole lug, the positive pole lug is aluminum (Al) and the negative pole lug is nickel (Ni), the two pole lugs are arranged side by side, and the thickness d of the positive and negative pole lugs is equal to 0.2mm, the width of the lug is 5mm; the diaphragm is made of polyethylene (PE) film with a thickness of 15 ⁇ m.
  • PE polyethylene
  • Preparation of the separator uniformly disperse the packaging material polypropylene (PP, melting point 140°C) into the dispersant N-methylpyrrolidone (NMP) to prepare a PP suspension;
  • the aluminum layer with a thickness of 100 ⁇ m is coated with PP suspension on both sides, and then dried at 130°C.
  • the thickness of the PP packaging layer on one side of the aluminum layer is 50 ⁇ m, and the total thickness D of the separator is 0.2 mm.
  • Electrode assembly assembly Place the aluminum-plastic film (thickness 150 ⁇ m) formed by punching the pit in the assembly jig, with the pit face up, place the first electrode assembly in the pit, and place the first electrode assembly on the edge of the aluminum-plastic film.
  • the area corresponding to the tab of the electrode assembly is provided with a tab glue with a width of 9mm, wherein the shoulder width H1 of the tab glue is 2mm, and then the separator is placed on the first electrode assembly so that the edges are aligned, and an external force is applied to compress it to assemble Semi-finished products.
  • the distance L between the negative pole lug of the first electrode assembly and the positive pole lug of the second electrode assembly is 5mm; the distance S1 between the positive and negative pole lugs of the first electrode assembly is 5mm; The distance S2 between the positive and negative tabs is 5 mm.
  • Liquid injection packaging each cavity is injected with electrolyte solution, and sealed after hot pressing, chemical formation, and degassing.
  • Example 3 The difference between Example 3 and Example 1 is that L is adjusted to 4 mm; the thickness of the aluminum layer in the separator is 50 ⁇ m, the thickness of the single-layer PP packaging layer is 25 ⁇ m, and the total thickness D of the separator is 0.1 mm; d is 0.3 mm.
  • S1 and S2 are 0.2mm, in embodiment 8, S1 and S2 are 0.5mm, in embodiment 9, S1 and S2 are 10mm, in embodiment 10, S1 and S2 is 20mm.
  • Example 11-14 and Example 5 The difference between Examples 11-14 and Example 5 is that H1 and H2 are 0.1 mm in Example 11, H1 and H2 are 0.5 mm in Example 12, H1 and H2 are 1 mm in Example 13, and H1 in Example 14 and H2 is 1.5mm.
  • Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the negative electrode tab of the first electrode assembly and the positive electrode tab of the second electrode assembly are adjusted to overlap and lead out, that is, L is 0 mm.
  • Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that L is adjusted to 2 mm; the thickness of the aluminum layer in the separator is 200 ⁇ m, the thickness of the PP packaging layer on one side is 50 ⁇ m, and the total thickness D of the separator is 0.3 mm.
  • Comparative Example 3 The difference between Comparative Example 3 and Example 6 is that L is adjusted to 1 mm.
  • Example 5 and Example 9-10 with S1/L(S2/L) ⁇ 0.5 have better bending stability, which is due to the fact that when the first One lug is connected to the second lug, and when subjected to external stress and bent in the same direction, at this time, the side corners adjacent to the first lug and the third lug and/or the second lug and the fourth lug Adjacent side corners will be subject to greater bending stress and strain, with a higher risk of failure.
  • the bending stability of the side corner adjacent to the first tab and the third tab and/or the side corner adjacent to the second tab and the fourth tab can be further improved.
  • Example 5 and Example 11-14 By comparing Example 5 and Example 11-14, it can be seen that Example 5 and Example 13-14 with H1 ⁇ 1mm and H2 ⁇ 1mm have better bending stability, this is because, at this time, the tab The glue can well cover the side corners of the tabs, improving the sealing reliability at the side corners of the tabs.

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Abstract

本发明公开了一种电化学装置及电子装置，电化学装置包括第一电极组件、第二电极组件、壳体以及隔板。第一电极组件包括第一极耳。第二电极组件包括第二极耳。壳体设有第一腔体和第二腔体，第一电极组件设于第一腔体，第二电极组件设于第二腔体。隔板设于第一电极组件以及第二电极组件之间，隔板包括第一封印区，第一封印区包括第一侧边，隔板的厚度为D。其中，第一极耳以及第二极耳均于第一侧边处延伸出壳体，沿第一侧边的长度方向，第一极耳与第二极耳于第一侧边处的最小间距为L,且L/D≥15。相较于现有技术而言，本发明可以提高电化学装置的封印可靠性。

Description

电化学装置及电子装置 技术领域
本申请涉及电化学领域，特别是涉及一种电化学装置及电子装置。
背景技术
内部串联高电压电池在充放电时，可以有效降低电流，减少电池和用电器产热，降低温升，从而提高安全性；且相对于多个电池外部串联，可以降低电池成本，提高电池的能量密度。通常，内部串联高电压电池包括外壳及设置于外壳内的多个串联的电极组件，串联的电极组件之间通过隔板分隔开。多个串联的电极组件的正负极极耳通常自同一侧边伸出壳体，并在壳体外串联，此时，该侧边的封印可靠性会存在不足，存在安全风险。
发明内容
鉴于现有技术存在的上述问题，本申请提供一种电化学装置及电子装置，以提高内部串联高电压电池的封印可靠性。
具体地，本申请第一方面提供了一种电化学装置，包括第一电极组件、第二电极组件、壳体以及隔板。第一电极组件包括第一极耳。第二电极组件包括第二极耳。壳体设有第一腔体和第二腔体，第一电极组件设于第一腔体，第二电极组件设于第二腔体。隔板设于第一电极组件以及第二电极组件之间，隔板包括第一封印区，第一封印区包括第一侧边，隔板的厚度为D。其中，第一极耳以及第二极耳均于第一侧边处延伸出壳体，沿第一侧边的长度方向，第一极耳与第二极耳于第一侧边处的最小间距为L,且L/D≥15。一方面，第一极耳和第二极耳错位设置，相对于第一极耳和第二极耳重叠设置，能够降低第一侧边处的封印厚度差异，提高极耳处的封印可靠性；另一方面，通过满足上述关系，能够有效降低极耳之间隔板的弯折程度，使其受到的应力应变较小，且在极耳侧边拐角处的隔板在封印时能够更好的贴合与其连接的其他部件，在极耳受到外部应力拉扯隔板时，不容易剥离，从而进一步提高封印可靠性。
在一些实施方式中，L/D≤100。通过满足L/D≤100，能够提高第一侧边的空间利用率，便于串联更多的电极组件。
在一些实施方式中，满足以下特征中的至少一者：(1)第一极耳的厚度为d1，L/d1≥10；(2)第二极耳的厚度为d2，L/d2≥10。此时，能够进一步降低极耳之间隔板的弯折程度，使其受到的应力应变较小，并进一步改善隔板在第一极耳和/或第二极耳侧边拐角处与其他部件的贴合性，进而进一步提高封印可靠性。
在一些实施方式中，满足以下特征中的至少一者：(3)L/(d1+D)≥5；(4)L/(d2+D)≥5；此时，能够进一步降低极耳之间隔板的弯折程度，使其受到的应力应变较小，并进一步改善隔板在第一极耳和/或第二极耳侧边拐角处与其他部件的贴合性，进而进一步提高封印可靠性。
在一些实施方式中，d1≤0.2㎜；和/或d2≤0.2㎜。
在一些实施方式中，L≥3㎜；和/或D≤0.3㎜。
在一些实施方式中，满足以下特征中的至少一者：(a)第一电极组件还包括第三极耳，第三极耳位于第一极耳背离第二极耳的一侧；沿第一侧边的长度方向，第一极耳与第三极耳于第一侧边处的最小间距为S1,且S1/L≥0.5；(b)第二电极组件还包括第四极耳，第四极耳位于第二极耳背离第一极耳的一侧；沿第一侧边的长度方向，第二极耳与第四极耳于第一侧边处的最小间距为S2,且S2/L≥0.5。此时，在第一极耳和第二极耳受到外部应力朝同一方向弯曲时，第一极耳与第三极耳相邻的侧边拐角处和/或第二极耳与第四极耳相邻的侧边拐角处将受到较大的弯曲应力和应变，失效风险较高。通过满足上述关系，能够进一步提高第一极耳与第三极耳相邻的侧边拐角处和/或第二极耳与第四极耳相邻的侧边拐角处的封印可靠性。
在一些实施方式中，S1≥5mm；和/或S2≥5mm。
在一些实施方式中，第一极耳上设有第一极耳胶，沿第一侧边的长度方向，第一极耳胶靠近第二极耳的第一端部在第一侧边处超出第一极耳的长度为H1；第二极耳上设有第二极耳胶，沿第一侧边的长度方向，第二极耳胶靠近第一极耳的第二端部在第一侧边处超出第二极耳的长 度为H2；满足：(H1+H2)/L≥0.2。此时，能够进一步提高第一极耳和第二极耳侧边拐角处的封印可靠性。
在一些实施方式中，H1≥1mm；和/或H2≥1mm。
在一些实施方式中，第一极耳连接第二极耳，且第一极耳与第二极耳的极性相异。
在一些实施方式中，隔板包括基材层和位于基材层表面的封装层。
在一些实施方式中，封装层的材质包括第一高分子材料；基材层的材质包括金属材料、第二高分子材料或碳材料中的至少一种。
在一些实施方式中，第一高分子材料包括聚丙烯、酸酐改性聚丙烯、聚乙烯、乙烯丙烯共聚物、聚氯乙烯、聚苯乙烯、聚醚腈、聚氨酯、聚酰胺、聚酯、非晶态α-烯烃共聚物或上述物质衍生物中的至少一种。
在一些实施方式中，金属材料包括Ni、Ti、Cu、Ag、Au、Pt、Fe、Co、Cr、W、Mo、Al、Mg、K、Na、Ca、Sr、Ba、Si、Ge、Sb、Pb、I n、Zn、不锈钢(SUS)及其组合物或合金中的至少一种。
在一些实施方式中，第二高分子材料包括聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚萘二甲酸乙二醇酯、聚醚醚酮、聚酰亚胺、聚酰胺、聚乙二醇、聚酰胺酰亚胺、聚碳酸酯、环状聚烯烃、聚苯硫醚、聚乙酸乙烯酯、聚四氟乙烯，聚亚甲基萘、聚偏二氟乙烯、聚碳酸亚丙酯、聚(偏二氟乙烯-六氟丙烯)、聚(偏二氟乙烯-共-三氟氯乙烯)、有机硅、维尼纶、聚丙烯、酸酐改性聚丙烯、聚乙烯、乙烯丙烯共聚物、聚氯乙烯、聚苯乙烯、聚醚腈、聚氨酯、聚苯醚、聚酯、聚砜、非晶态α-烯烃共聚物或上述物质衍生物中的至少一种；
在一些实施方式中，碳材料包括碳毡、碳膜、炭黑、乙炔黑、富勒烯、导电石墨膜或石墨烯膜中的至少一种。
本申请的第二方面还提供了一种电子装置，包含上述任意一项电化学装置。
本申请提供的电化学装置，通过设置L/D≥15，相较于现有技术而言，一方面，第一极耳和第二极耳错位设置，相对于第一极耳和第二极耳重叠设置，能够降低第一侧边处的封印厚度差异，提高极耳处的封印可靠 性；另一方面，能够有效降低极耳之间隔板的弯折程度，使其受到的应力应变较小，且在极耳侧边拐角处的隔板在封印时能够更好的贴合与其连接的其他部件，在极耳受到外部应力拉扯隔板时，不容易剥离，从而进一步提高封印可靠性。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，还可以根据附图获得其他的附图。
图1是本申请实施例的电化学装置的立体示意图；
图2是本申请实施例的电化学装置的沿方向X的侧视示意图；
图3是本申请实施例的电化学装置的沿方向Z的侧视示意图；
图4是本申请实施例的第一极耳、第二极耳、第一极耳胶以及第二极耳胶组合的沿方向Z的侧视示意图；其中，对隔板进行了剖切，以露出第一侧边；
图5是本申请实施例的第一极耳、第二极耳、第一极耳胶以及第二极耳胶组合的沿方向X的侧视示意图；其中，对隔板进行了剖切，以露出第一侧边；
图6是本申请实施例的第一极耳、第二极耳、第三极耳、第四极耳、第一极耳胶以及第二极耳胶组合的沿方向X的侧视示意图；其中，对隔板进行了剖切，以露出第一侧边。
具体实施方式
为了便于理解本申请，下面结合附图和具体实施例，对本申请进行更详细的说明。需要说明的是，当元件被表述“固定于”另一个元件，它可以直接在另一个元件上、或者其间可以存在一个或多个居中的元件。当一个元件被表述“连接”另一个元件，它可以是直接连接到另一个元件、或者其间可以存在一个或多个居中的元件。本说明书所使用的术语“垂直的”、“水平的”、“左”、“右”以及类似的表述只是为了说明的目的。
除非另有定义，本说明书所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。在本申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是用于限制本申请。本说明书所使用的术语“和/或”包括一个或多个相关的所列项目的任意的和所有的组合。
内部串联高电压电池包括外壳及设置于外壳内的多个串联的电极组件，串联的电极组件之间通过隔板分隔开。多个串联的电极组件的正负极极耳通常自同一侧边伸出壳体，并在壳体外串联，此时，该侧边的封印可靠性会存在不足，存在安全风险。鉴于此，参见图1-6，本实施例提供了一种电化学装置10，该电化学装置10能够提高内部串联高电压电池的封印可靠性。具体地，本实施例中的电化学装置10包括第一电极组件、第二电极组件、壳体100以及隔板200。
本实施例中，壳体100用于限定出容纳第一电极组件以及第二电极组件的封闭空间。隔板200用于分隔壳体100的内部空间，从而增加壳体100内部的独立空间的数量。
电化学装置10可以包括一个隔板200也可以包括多个隔板200，当电化学装置10包括一个隔板200时，一个隔板200可以将壳体100的内部空间分隔成两个独立的空间。当电化学装置10包括多个隔板200、具体包括两个隔板200时，两个隔板200可以将壳体100的内部空间分隔成三个独立的空间。为了便于描述，以下实施例以电化学装置10包括一个隔板200来进行举例说明。一个隔板200将壳体100的内部空间分隔成两个独立的空间，分别称为第一腔体以及第二腔体。
电化学装置10可以包括两个电极组件也可以包括三个以上数量的电极组件。为了便于描述，以下实施例中，以电化学装置10包括两个电极组件来进行举例说明。且两个电极组件分别称为前述的第一电极组件以及第二电极组件。当电化学装置10具有一个隔板200，且该隔板200分隔出前述的两个独立的空间时，第一电极组件设置于前述的第一腔体，第二电极组件设置于前述的第二腔体。第一电极组件、隔板200以及第二电极组件沿方向Z分布。
第一电极组件可以包括至少两个极耳，两个极耳之间的极性相异。为了便于描述，本实施例将第一电极组件的其中一个极耳称为第一极耳310。第一极耳310可以为正极极耳也可以为负极极耳。同样地，第二电极组件可以包括至少两个极耳，两个极耳之间的极性相异。为了便于描述，本实施例将第二电极组件的其中一个极耳称为第二极耳320，第二极耳320可以为正极极耳也可以为负极极耳。第一极耳310以及第二极耳320的极性可以相同也可以不同。第一极耳310与第二极耳320可以相互电连接，也可以不相互连接。为了便于描述，以下实施例中，将第一极耳310为正极极耳、第二极耳320为负极极耳、第一极耳310与第二极耳320电连接来进行举例说明。
隔板200包括第一封印区210，电化学装置10进行封装时，隔板200的位于封印区210的部分与其他部件进行封印。换句话说，隔板200封印区210的部分与其他部件进行固定连接(具体可以为热熔连接或粘接)。当电化学装置10仅具有一个隔板200时，隔板200的封印区210的两侧壁面均与壳体100连接。当电化学装置10具有两个隔板200时，其中一个隔板200的封印区210的一侧壁面与另一个隔板200连接、另一侧壁面与壳体100连接。当隔板200的数量为三个或三个以上时，位于中间的隔板200的封印区210的两侧壁面均与位于该隔板200两侧的其他隔板200连接。
第一封印区210可以呈环形，且第一封印区210可以延伸至隔板200的外侧边沿位置，第一封印区210也可以与隔板200的外侧边沿间隔一定距离。参见图4，本实施例中，第一封印区210呈环形，且第一封印区210的外侧边缘与隔板200的外侧边沿间隔布置，间隔的距离视实际需求而定。
参见图4-6，本实施例中，第一封印区210包括第一侧边211,其中，第一极耳310以及第二极耳320均于第一侧边211处延伸出壳体100。具体地，第一极耳310以及第二极耳320均由第一侧边211的两侧延伸出壳体100。隔板200的厚度为D，即沿图5中的方向Z,隔板200的厚度为D。沿第一侧边211的长度方向，即沿方向Y，第一极耳310与第 二极耳320于第一侧边211处的最小间距为L,且L/D≥15。示例性地，L/D可以为15、20、25、30或100等。一种具体的举例中，当D为0.2㎜时，L≥3㎜。
本申请的发明人发现，由于第一极耳310以及第二极耳320位于隔板200的两侧，故一方面，极耳的设置方式会对封印可靠性造成较大影响，相对于第一极耳310和第二极耳320重叠设置，第一极耳310和第二极耳320错位设置，能够降低第一侧边211处的封印厚度差异，提高极耳处的封印可靠性；另一方面，当第一极耳310和第二极耳320错位设置时，沿第一侧边211的长度方向，隔板200位于第一极耳310以及第二极耳320之间的部分存在弯折，该处的封印可靠性受到影响。本申请的发明人通过研究发现，当第一极耳310与第二极耳320于第一侧边211处的最小间距L与隔板200的厚度D满足L/D≥15时，能够使得电化学装置10具有较高的封印可靠性。这是由于，满足上述关系，能够有效降低极耳之间隔板的弯折程度，使其受到的应力应变较小，且在极耳侧边拐角处的隔板在封印时能够更好的贴合与其连接的其他部件，在极耳受到外部应力拉扯隔板时，不容易剥离，从而进一步提高封印可靠性。
进一步地，在一些实施方式中，L/D≤100。通过满足L/D≤100，能够提高第一侧边211的空间利用率，便于串联更多的电极组件。
本申请的发明人还发现，第一极耳310以及第二极耳320沿方向Z的厚度尺寸与第一极耳310以及第二极耳320沿方向Y的间距之间满足特定关系可以进一步改善极耳侧边拐角处的隔板在封印时与其他部件的贴合性。鉴于此，参见图4-6，一种实施例中，可以使电化学装置10满足以下特征中的至少一者：(1)第一极耳310的厚度为d1，L/d1≥10；(2)第二极耳320的厚度为d2，L/d2≥10。此时，能够进一步降低隔板200位于第一极耳310以及第二极耳320之间部分的弯折程度，使其受到的应力应变较小，并进一步改善隔板在第一极耳和/或第二极耳侧边拐角处与其他部件的贴合性，进而进一步提高封印可靠性。
换句话说，一种实施例中，可以在L/D≥15的前提下，还使L/d1≥10。 或另一种实施例中，在L/D≥15的前提下，还使L/d2≥10。或又一种实施例中，在L/D≥15的前提下，还使L/d1≥10、L/d2≥10。
一种具体的举例中，当隔板200的厚度D为0.2㎜、d1为0.1㎜、d2为0.1㎜时，L/D≥15条件下，L最小值取3㎜；L/d1≥10条件下，L最小值取1㎜；L/d2≥10条件下，L最小值取1㎜，综合得出，L最终最小值取3㎜。当采用L/d1≥10和/或L/d2≥10来限定第一极耳310与第二极耳320沿方向Y的距离时，能够进一步保证电化学装置10的封印可靠性。
一种实施例中，电化学装置10还可以满足以下特征中的至少一者：(3)L/(d1+D)≥5；(4)L/(d2+D)≥5；此时，能够进一步降低隔板200位于第一极耳310以及第二极耳320之间部分的弯折程度，使其受到的应力应变较小，并进一步改善隔板在第一极耳和/或第二极耳侧边拐角处与其他部件的贴合性，进而进一步提高封印可靠性。
一种实施例中，d1≤0.2㎜；和/或d2≤0.2㎜。
一种具体的举例中，电化学装置10同时满足条件(3)、(4)。示例性地，当D为0.2㎜、d1为0.2㎜、d2为0.2㎜时，L/D≥15条件下，L最小值取3㎜；L/(d1+D)≥5条件下，L最小值取2㎜；L/(d2+D)≥5条件下，L最小值取2㎜。综合得出，L最终最小值取3㎜。
进一步的实施例中，L≥3㎜；和/或D≤0.3㎜。当D≤0.3㎜时，能够使隔板200的厚度不会过大，从而防止了隔板200占用电化学装置10过多的空间，从而降低电化学装置10的能量密度。
进一步的实施例中，电化学装置10满足以下特征中的至少一者：(a)第一电极组件还包括第三极耳330，第三极耳330位于第一极耳310背离第二极耳320的一侧；沿第一侧边211的长度方向，第一极耳310与第三极耳330于第一侧边211处的最小间距为S1,且S1/L≥0.5；(b)第二电极组件还包括第四极耳340，第四极耳340位于第二极耳320背离第一极耳310的一侧；沿第一侧边211的长度方向，第二极耳320与第四极耳340于第一侧边211处的最小间距为S2,且S2/L≥0.5。当第一极耳310和第二极耳320在受到外部应力朝同一方向弯曲时，第一极耳310 与第三极耳330相邻的侧边拐角处和/或第二极耳320与第四极耳340相邻的侧边拐角处将受到较大的弯曲应力和应变，失效风险较高。通过满足上述关系，能够进一步提高第一极耳310与第三极耳330相邻的侧边拐角处和/或第二极耳320与第四极耳340相邻的侧边拐角处的封印可靠性。
进一步的实施例中，S1≥5mm；和/或S2≥5mm。使第一极耳310与第三极耳330沿方向Y的距离和/或第二极耳320与第四极耳340沿方向Y的距离大于或等于5㎜，一方面，当第一极耳310与第三极耳330和/或第二极耳320与第四极耳340的极性相异时，能够降低第一极耳310与第三极耳330和/或第二极耳320与第四极耳340由于距离过近而短路的风险，另一方面，也能够提升第一极耳310与第三极耳330之间部分和/或第二极耳320与第四极耳340之间部分的封印可靠性。
一种实施例中，第一极耳310上设有第一极耳胶410，沿第一侧边211的长度方向，即方向Y，第一极耳胶410靠近第二极耳320的第一端部在第一侧边211处超出第一极耳310的长度为H1。第二极耳320上设有第二极耳胶420，沿第一侧边211的长度方向，即方向Y，第二极耳胶420靠近第一极耳310的第二端部在第一侧边211处超出第二极耳320的长度为H2。且H1、H2满足：(H1+H2)/L≥0.2。本方案中，进一步提高了第一极耳310和第二极耳320侧边拐角处的封印可靠性。
进一步的实施例中，H1≥1mm；和/或H2≥1mm。本方案中，H1≥1mm时，能够使得第一极耳胶410良好的包覆第一极耳310与第二极耳320相邻的侧边拐角，提高该侧边拐角处的封印可靠性。同样地，H2≥1mm时，能够使得第二极耳胶420良好的包覆第二极耳320与第一极耳310相邻的侧边拐角，提高该侧边拐角处的封印可靠性。
本申请还提供了一种电子装置，其包含本申请提供的电化学装置10。本申请的电子装置没有特别限定，其可以是现有技术中已知的任何电子装置。例如，电子装置包括但不限于笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、 便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、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。
制备本申请的电化学装置的方法没有特别限制，可以采用本领域公知的任何方法，例如，在一实施方式中，本申请可以采用如下制备方法制备：
(1)负极极片的制备：将负极活性材料、粘结剂和溶剂调配成浆料，并搅拌均匀。将浆料均匀涂覆在负极集流体上并烘干，得到单面涂覆的负极极片。在负极集流体的另一个表面上重复以上步骤，得到双面涂覆的负极极片。然后，经冷压、裁切后待用。
(2)正极极片的制备：将正极活性材料、粘结剂、导电剂和溶剂调配成浆料，并搅拌均匀。将浆料均匀涂覆在正极集流体上并烘干，得到单面涂覆的正极极片。在正极集流体的另一个表面上重复以上步骤，得到双面涂覆的正极极片。然后，经冷压、裁切后待用。
(3)电解液的制备：将锂盐和非水溶剂混合并搅拌均匀，得到电解液。
(4)电极组件的制备：电极组件的结构可以是卷绕结构或叠片结构，其中，将多个负极极片、隔膜、正极极片依次堆叠并固定可形成叠片结构的电极组件；将负极极片、隔膜、正极极片依次堆叠后并卷绕可形成卷绕结构的电极组件；每个电极组件包含一个正极极耳和一个负极极耳；重复上述步骤则可得到多个电极组件。
(5)隔板：可以采用本领域公知的任何隔板。
(6)电极组件组装：将包装壳置于组装夹具内，然后将电极组件与隔板间隔设置，并将电极组件的所有极耳引出包装壳外，以备后续加工，最后进行顶封和侧封，并留下注液口。
(7)注液封装：分别给多个腔体注入电解液，经热压、化成、脱气后密封。
(8)串联连接：将一个电极组件的正极极耳和另一个电极组件的负极极耳通过激光焊的方式焊接连接在一起，实现串联连接，即得到最终的电化学装置。
本申请提供的电化学装置中可以包含两个电极组件，也可以包含三个以上电极组件。含有两个电极组件或三个以上电极组件的电化学装置的制备方法均可参照上述电化学装置的制备方法。
本申请中所用的术语一般为本领域技术人员常用的术语，如果与常用术语不一致，以本申请中的术语为准。在本申请中，如果没有特别说明，“％”、“份”均以重量为基准。
测试方法：
封印可靠性测试：
电极组件组装步骤中，待顶封位置(极耳伸出侧)封装之后，将足量的渗透剂喷洒在包装壳内侧的顶封位置，然后将四周封装后，常温静置放置24h，观察顶封区外侧是否有渗透剂泄露，判断顶封区域的封印可靠性。
弯折稳定性测试：
将连接的两个极耳进行360°弯折测试，即极耳以隔板与包装壳的顶封封印区为轴，先向电化学装置的一侧X-Y面(X-Y面如图1所示)进行弯折，直至连接极耳与X-Y面贴合，记为一次弯折。然后反向弯折360°，与电化学装置另一侧X-Y面贴合，记为二次弯折。如此反复，直至极耳与包装壳封印外边缘处出现裂痕，记录此时对应的极耳弯折次数。
实施例1
(1)负极极片的制备：将负极活性材料人造石墨、导电炭黑(Super P)、丁苯橡胶(SBR)按照重量比96:1.5:2.5进行混合，加入去离子水，调配成固含量为70wt％的浆料，并搅拌均匀。将浆料均匀涂覆在负极集流体铜箔的一个表面上，烘干，得到单面涂覆有负极活性材料层的负极极片。在负极集流体铜箔的另一个表面上重复以上步骤，得到双面涂覆有负极活性材料层的负极极片。冷压后，将负极极片裁切成41mm×61mm的规格待用。
(2)正极极片的制备：将正极活性材料钴酸锂(LiCoO 2)、导电炭黑(Super P)、聚偏二氟乙烯(PVDF)按照重量比97.5:1.0:1.5进行混合，加入N-甲基吡咯烷酮(NMP)，调配成固含量为75wt％的浆料，并搅拌均匀。将浆料均匀涂覆在正极集流体铝箔的一个表面上，烘干，得到单面涂覆有正极活性材料层的正极极片。在正极集流体铝箔的另一个表面上，重复以上步骤，得到双面涂覆有正极活性材料层的正极极片。冷压后，将正极极片裁切成38mm×58mm的规格待用。
(3)电解液的制备：在干燥氩气气氛中，首先将有机溶剂碳酸乙烯酯(EC)、碳酸甲乙酯(EMC)和碳酸二乙酯(DEC)以质量比EC:EMC:DEC＝30:50:20混合，然后向有机溶剂中加入锂盐六氟磷酸锂(LiPF 6)溶解并混合均匀，得到基于电解液的质量，LiPF 6浓度为12.5％的电解液。
(4)第一电极组件和第二电极组件的制备：将隔膜、双面涂覆负极极片、隔膜、双面涂覆正极极片依次层叠设置组成叠片结构，然后将整个叠片结构的四个角固定好以备用。每个电极组件包含一个正极极耳和一个负极极耳，正极极耳为铝(Al)和负极极耳为镍(Ni)，两个极耳并排设置，正负极极耳的厚度d均为0.2mm，极耳的宽度为5mm；隔膜选用厚度为15μm的聚乙烯(PE)膜。
(5)隔板的制备：将封装层材料聚丙烯(PP，熔点为140℃)均匀分散到分散剂N-甲基吡咯烷酮(NMP)中，制备得到PP悬浊液；利用涂胶机，在厚度为100μm铝层两侧分别涂覆PP悬浊液；然后在130℃进行烘干处理，其中，铝层单侧PP封装层的厚度为50μm，隔板总厚度D为0.2mm。
(6)电极组件组装：将冲坑成型的铝塑膜(厚度为150μm)置于组装夹具内，坑面朝上，将第一电极组件置于坑内，并在铝塑膜的边缘处第一电极组件的极耳对应的区域设置宽度为9mm的极耳胶，其中，极耳胶肩宽H1为2mm，然后将隔板放置于第一电极组件上，使得边沿对齐，施加外力压紧得到组装半成品。将组装半成品置于组装夹具内，隔板一面朝上，将第二电极组件放置于隔板上，使得边沿对齐，施加外 力压紧，然后将另一个冲坑成型的铝塑膜坑面朝下覆盖于第二电极组件上，并在铝塑膜的边缘处第二电极组件的极耳对应的区域设置宽度为9mm的极耳胶，其中，极耳胶肩宽H2为2mm。将第一电极组件和第二电极组件的正负极极耳均引出铝塑膜外，采用热压的方式热封四周，得到组装电极组件。其中，第一电极组件的负极极耳和第二电极组件的正极极耳之间的间距L为5mm；第一电极组件的正负极极耳之间的距离S1为5mm；第二电极组件的正负极极耳之间的距离S2为5mm。
(7)注液封装：分别给每个腔体注入电解液，经热压、化成、脱气后密封。
(8)串联连接：将第一电极组件的负极极耳和第二电极组件的正极极耳通过激光焊的方式焊接连接在一起，实现串联连接，电池组装完成。
实施例2与实施例1的区别在于，调整L为3mm；d为0.1mm。
实施例3与实施例1的区别在于，调整L为4mm；隔板中铝层厚度为50μm，单层PP封装层的厚度为25μm，隔板总厚度D为0.1mm；d为0.3mm。
实施例4与实施例1的区别在于，调整L为4mm；d为0.3mm。
实施例5与实施例3的区别在于，调整L为10mm；d为0.1mm。
实施例6与实施例3的区别在于，调整L为3mm；d为0.2mm。
实施例7-10与实施例5的区别在于，实施例7中S1和S2为0.2mm、实施例8中S1和S2为0.5mm、实施例9中S1和S2为10mm、实施例10中S1和S2为20mm。
实施例11-14与实施例5的区别在于，实施例11中H1和H2为0.1mm、实施例12中H1和H2为0.5mm、实施例13中H1和H2为1mm、实施例14中H1和H2为1.5mm。
对比例1与实施例1的区别在于，调整第一电极组件的负极极耳和第二电极组件的正极极耳重叠引出，即L为0mm。
对比例2与实施例1的区别在于，调整L为2mm；隔板中铝层厚度为200μm，单侧PP封装层的厚度为50μm，隔板总厚度D为0.3mm。
对比例3与实施例6的区别在于，调整L为1mm。
表1 实施例1-14和对比例1-2封印可靠性和弯折稳定性测试结果
Figure PCTCN2022078352-appb-000001
通过表1中的实施例和对比例的比较可以看出，当L/D≥15时，所获得的内部串联高电压电池具有更优的封印可靠性和弯折稳定性。这是由于，一方面，第一极耳和第二极耳错位设置，相对于第一极耳和第二极耳重叠设置的对比例1，能够降低顶封处的封印厚度差异，提高极耳处的封印可靠性；另一方面，通过满足上述关系，能够有效降低极耳之间隔板的弯折程度，使其受到的应力应变较小，且在极耳侧边拐角处的隔板在封印时能够更好的贴合与其连接的其他部件，在极耳受到外部应力拉扯隔板时，不容易剥离，从而进一步提高封印可靠性。
通过比较实施例5、实施例7-10可以看出，S1/L(S2/L)≥0.5的实施例5、实施例9-10具有更优的弯折稳定性，这是由于，当第一极耳连接第二极耳，在受到外部应力朝同一方向弯曲时，此时，第一极耳与第三 极耳相邻的侧边拐角处和/或第二极耳与第四极耳相邻的侧边拐角处将受到较大的弯曲应力和应变，失效风险较高。通过满足上述关系，能够进一步提高第一极耳与第三极耳相邻的侧边拐角处和/或第二极耳与第四极耳相邻的侧边拐角处的弯折稳定性。
通过比较实施例5、实施例11-14可以看出，H1≥1mm和H2≥1mm的实施例5、实施例13-14具有更优的弯折稳定性，这是由于，此时，极耳胶能够良好的包覆极耳的侧边拐角，提高极耳侧边拐角处的封印可靠性。
需要说明的是，本申请的说明书及其附图中给出了本申请较佳的实施例，但是，本申请可以通过许多不同的形式来实现，并不限于本说明书所描述的实施例，这些实施例不作为对本申请内容的额外限制，提供这些实施例的目的是为了使本领域技术人员对本申请所公开内容的理解更加透彻全面。并且，对本领域普通技术人员来说，可以根据上述说明加以改进或变换，而所有这些改进和变换都应属于本申请所附权利要求的保护范围。

Claims (10)

  1. 一种电化学装置，其特征在于，包括：
    第一电极组件，所述第一电极组件包括第一极耳；
    第二电极组件，所述第二电极组件包括第二极耳；
    壳体，设有第一腔体和第二腔体，所述第一电极组件设于所述第一腔体，所述第二电极组件设于所述第二腔体；
    隔板，设于所述第一电极组件以及所述第二电极组件之间，所述隔板包括第一封印区，所述第一封印区包括第一侧边，所述隔板的厚度为D；
    其中，所述第一极耳以及所述第二极耳均于所述第一侧边处延伸出所述壳体，沿所述第一侧边的长度方向，所述第一极耳与所述第二极耳于所述第一侧边处的最小间距为L,且L/D≥15。
  2. 根据权利要求1所述的电化学装置，其特征在于，满足以下特征中的至少一者：
    (1)所述第一极耳的厚度为d1，L/d1≥10；
    (2)所述第二极耳的厚度为d2，L/d2≥10。
  3. 根据权利要求2所述的电化学装置，其特征在于，满足以下特征中的至少一者：
    (3)L/(d1+D)≥5；
    (4)L/(d2+D)≥5；
    (5)d1≤0.2㎜；
    (6)d2≤0.2㎜。
  4. 根据权利要求1所述的电化学装置，其特征在于，满足以下特征中的至少一者：
    (7)L≥3㎜；
    (8)D≤0.3㎜。
  5. 根据权利要求1所述的电化学装置，其特征在于，满足以下特征中的至少一者：
    (a)所述第一电极组件还包括第三极耳，所述第三极耳位于所述第一极耳背离所述第二极耳的一侧；沿所述第一侧边的长度方向，所述第一极耳与所述第三极耳于所述第一侧边处的最小间距为S1,且S1/L≥0.5；
    (b)所述第二电极组件还包括第四极耳，所述第四极耳位于所述第二极耳背离所述第一极耳的一侧；沿所述第一侧边的长度方向，所述第二极耳与所述第四极耳于所述第一侧边处的最小间距为S2,且S2/L≥0.5。
  6. 根据权利要求5所述的电化学装置，其特征在于，满足以下特征中的至少一者：
    (c)S1≥5mm；
    (d)S2≥5mm。
  7. 根据权利要求1所述的电化学装置，其特征在于，
    所述第一极耳上设有第一极耳胶，沿所述第一侧边的长度方向，所述第一极耳胶靠近所述第二极耳的第一端部在所述第一侧边处超出所述第一极耳的长度为H1；
    所述第二极耳上设有第二极耳胶，沿所述第一侧边的长度方向，所述第二极耳胶靠近所述第一极耳的第二端部在所述第一侧边处超出所述第二极耳的长度为H2；满足：(H1+H2)/L≥0.2。
  8. 根据权利要求7所述的电化学装置，其特征在于，
    H1≥1mm；和/或H2≥1mm。
  9. 根据权利要求1所述的电化学装置，其特征在于，
    所述第一极耳连接所述第二极耳，且所述第一极耳与所述第二极耳的极性相异。
  10. 一种电子装置，包含权利要求1至9中任意一项所述电化学装置。
PCT/CN2022/078352 2022-02-28 2022-02-28 电化学装置及电子装置 WO2023159583A1 (zh)

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CN1675783A (zh) * 2002-07-25 2005-09-28 株式会社东芝 非水电解质二次电池
JP2005209531A (ja) * 2004-01-23 2005-08-04 Toshiba Corp 非水電解質二次電池
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