WO2023159610A1 - 用于电化学装置的隔板、电化学装置及用电设备 - Google Patents

用于电化学装置的隔板、电化学装置及用电设备 Download PDF

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Publication number
WO2023159610A1
WO2023159610A1 PCT/CN2022/078428 CN2022078428W WO2023159610A1 WO 2023159610 A1 WO2023159610 A1 WO 2023159610A1 CN 2022078428 W CN2022078428 W CN 2022078428W WO 2023159610 A1 WO2023159610 A1 WO 2023159610A1
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Prior art keywords
layer
separator
sealing layer
electrochemical device
barrier layer
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PCT/CN2022/078428
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English (en)
French (fr)
Inventor
张楠
关晓静
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宁德新能源科技有限公司
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Application filed by 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to CN202280005246.0A priority Critical patent/CN115956324A/zh
Priority to PCT/CN2022/078428 priority patent/WO2023159610A1/zh
Publication of WO2023159610A1 publication Critical patent/WO2023159610A1/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
    • H01M10/06—Lead-acid accumulators
    • H01M10/18—Lead-acid accumulators with bipolar electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—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
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with 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

Definitions

  • the present application relates to the field of electrochemistry, in particular to a separator for an electrochemical device, an electrochemical device and electrical equipment.
  • Electrochemical devices such as lithium-ion batteries have many advantages such as large volume and mass energy density, long cycle life, high nominal voltage, low self-discharge rate, small size, and light weight, and have a wide range of applications in the field of consumer electronics.
  • the electrochemical device adopts the method of connecting multiple cells in series, which can effectively increase the output voltage. At the same time, it also has many advantages such as reducing the total heat production of the cells, reducing the temperature rise, and being compatible with winding and laminated structures.
  • the ionic insulation function of each series cavity of the electrochemical device is realized through the separator.
  • the separator needs to be connected with the outer package of the electrochemical device, and the ionic insulation of the separator itself and the connection between the separator and the outer package will be It affects the ion insulation effect of two adjacent cavities in the electrochemical device.
  • Embodiments of the present application provide a separator for an electrochemical device, an electrochemical device, and electrical equipment, which can solve the problem that it is difficult to achieve ionic insulation between two adjacent cavities in the electrochemical device.
  • an embodiment of the present application provides a separator for an electrochemical device, including:
  • the sealing layer includes a middle part, an edge part surrounding and connected to the periphery of the middle part, the middle part is accommodated in the inner space of the outer package of the electrochemical device, and the edge part is used for sealing with the outer package connect.
  • the sealing layer includes a thermoplastic polymer, so that the separator can be directly connected to the outer packaging of the electrochemical device after heat-melting the sealing layer, effectively improving the seal strength of the connection between the separator and the outer packaging .
  • the melting point range of the thermoplastic polymer is 100°C to 200°C; the thermoplastic polymer polymer includes: polypropylene, polyethylene, polyester plastic, ⁇ -phthaloyl At least one of imino- ⁇ -hydroxybutyric acid, anhydride-modified polypropylene, ethylene and its copolymers, cast polypropylene, polyimide, polytetrafluoroethylene, polyvinylidene fluoride and its derivatives .
  • the separator further includes at least one barrier layer, the barrier layer has ion insulation, and the barrier layer is arranged on at least one side of the sealing layer; In the thickness direction of the stack of layers and the barrier layer, the projection of the barrier layer covers at least the projection of the middle part.
  • the number of the barrier layer is two layers, and the two layers of the barrier layer are respectively arranged on two opposite surfaces of the sealing layer.
  • the area of the middle part is S
  • the area of the barrier layer is S1
  • the area of the sealing layer is The area
  • the separator satisfies S ⁇ S1 ⁇ S2 or S ⁇ S1 ⁇ S2.
  • the length of the middle part of the sealing layer is a and the width is b
  • the length of the barrier layer is a1 and the width is b1
  • the length of the sealing layer is a2 and the width b2
  • the separator satisfies: a ⁇ a1 ⁇ a2, b ⁇ b1 ⁇ b2, or a ⁇ a1 ⁇ a2, b ⁇ b1 ⁇ b2.
  • the barrier layer is chemically bonded to the sealing layer by at least one of atomic layer deposition, molecular layer deposition, chemical vapor deposition, physical vapor deposition, electrodeposition or 3D printing.
  • the surface can effectively improve the strength of the connection between the sealing layer and the barrier layer, so that the sealing layer and the barrier layer will not be easily peeled off.
  • the barrier layer includes at least one of an oxide layer, a nitride layer, a metal layer, and an organic polymer;
  • the oxide layer includes at least one of an aluminum oxide layer, a zinc oxide layer, a zirconium oxide layer, a silicon oxide layer, and a silicon-aluminum oxide layer;
  • the nitride layer includes at least one of an aluminum nitride layer, a zinc nitride layer, a zirconium nitride layer, a silicon nitride layer, and a silicon aluminum nitride layer;
  • the metal layer includes: containing Si, Zn, Al, Zr, Ti, V, Mg, Ni, Pr, Ce, Mn, Ta, In, Zn, Ga, Sn, Cd, Pb, Ni, Ti, Cu, Ag, Au , at least one metal material or alloy material in Pt, Fe, Co, Cr, W;
  • Organic polymers include: vinylidene chloride-methyl acrylate, polyethylene, polypropylene, polyethylene terephthalate, random copolymers of ethylene vinyl alcohol, resins, polyacrylonitrile, polyvinylidene chloride , polyamide, polyimide-amide, polyurethane, polythiourea, polyethylene glycol, or at least one organometallic polymer.
  • the separator has at least one of the following characteristics:
  • the thickness of the sealing layer is H, and the range of H is 14 ⁇ m to 304 ⁇ m; the thickness of the barrier layer is h, and the range of h is 5 nm to 2000 nm;
  • the sealing layer comprises an ion barrier sheet, and the ion barrier sheet includes at least one of sheet-like graphene, hydrotalcite nanosheets, and boehmite sheets;
  • the sealing layer also includes a leveling layer, the leveling layer is connected to the barrier layer, the leveling layer has a low roughness relative to the surface of the barrier layer, and the leveling layer includes a ring One or more of polymer materials such as epoxy resin, polypropylene resin, and polyacrylate;
  • the separator further includes a reinforcing layer on the surface of the sealing layer or the barrier layer, the reinforcing layer is arranged on the surface of the barrier layer and/or the sealing layer, and the reinforcing layer includes a polymer layer , at least one of a glass fiber layer, a carbon material layer, an elastic polymer layer, and an oxide layer.
  • an electrochemical device including:
  • the partition is arranged in the outer packaging, and the partition is connected to the outer packaging, so as to separate the inner space of the outer packaging into a plurality of first chambers;
  • a plurality of electrode assemblies are correspondingly arranged in each of the first chambers in contact with the electrolyte.
  • the outer packaging includes a connection layer
  • the connection layer is connected to the edge portion of the separator
  • the connection layer includes a polymer
  • the polymer includes: polypropylene, polypropylene Ethylene, polyester plastic, ⁇ -phthalimido- ⁇ -hydroxybutyric acid, anhydride-modified polypropylene, ethylene and its copolymers, cast polypropylene, polyimide, polytetrafluoroethylene, poly At least one of vinylidene fluoride and its derivatives.
  • an embodiment of the present application provides an electrical device, including the above-mentioned electrochemical device.
  • the sealing layer of the separator is connected to the outer package of the electrochemical device, and the sealing connection between the separator and the outer package of the electrochemical device is improved. stability, thereby effectively improving the service life of the electrochemical device.
  • the thickness of the prepared separator can also be effectively reduced, and the energy density of the electrochemical device can be improved.
  • Fig. 1 is a cross-sectional view of a barrier layer of a separator provided on one side of a sealing layer according to an embodiment of the present application;
  • Fig. 2 is a cross-sectional view of the barrier layer of the separator provided on both sides of the sealing layer according to an embodiment of the present application;
  • Fig. 3 is a cross-sectional view of a partition connected to an outer package according to an embodiment of the present application
  • Figure 4a is a front view of the sealing layer of the separator of an embodiment of the present application.
  • Figure 4b is a front view of a partition of an embodiment of the present application.
  • Fig. 5 is a cross-sectional view of a barrier layer completely covering a sealing layer according to an embodiment of the present application
  • Fig. 6 is a cross-sectional view of a separator with a leveling layer according to an embodiment of the present application
  • Fig. 7 is a cross-sectional view of a separator with a reinforcement layer according to an embodiment of the present application.
  • FIG. 8 is a schematic diagram of the three-dimensional structure of an electrochemical device according to an embodiment of the present application.
  • FIG. 9 is an exploded view of an electrochemical device according to an embodiment of the present application.
  • FIG. 10 is a partial cross-sectional view of an electrochemical device according to an embodiment of the present application.
  • electrode assembly 200, electrode assembly; 210, first electrode assembly; 220, second electrode assembly;
  • the barrier layer is usually made of metal material, and the sealing layer is often made of polymer, which can meet the requirements of barrier and tensile strength, but at the same time, it is necessary to pay attention to the thickness of the superimposed separator to prevent the separator Occupying more space leads to an increase in the proportion of inactive substances in the electrochemical device, which in turn leads to a lower overall energy density (ED). In addition, attention must be paid to the sealing layer and barrier layer, separator and outer packaging, etc.
  • embodiments of the present application provide a separator for an electrochemical device, an electrochemical device, and electrical equipment.
  • the present application is explained by taking the lithium-ion battery as an example of the electrochemical device, but the electrochemical device of the present application is not limited to the lithium-ion battery, as shown in Figure 1 and Figure 2 , is a schematic structural diagram of a separator 100 used in an electrochemical device 10 according to an embodiment of the present application.
  • the separator 100 includes a sealing layer 110 and at least one barrier layer 120 .
  • the sealing layer 110 includes a middle part 101, an edge part 102 surrounding and connected to the periphery of the middle part 101, as shown in FIG. Package 700 seals the connection.
  • the middle part 101 and the edge part 102 are integrally formed with the same material.
  • Each barrier layer 120 is ion-insulating, and the barrier layer 120 is disposed on at least one side of the sealing layer 110 to directly connect the barrier layer 120 to the sealing layer 110 .
  • the projection of the barrier layer 120 at least covers the projection of the middle part 101, so that the barrier layer 120 is in the cavity of the outer package 700, and The barrier layer 120 is placed on the surface of the separator 100 to prevent ion migration in two adjacent chambers.
  • the edge portion 102 of the sealing layer 110 surrounds the periphery of the middle portion 101, and the outer packaging 700 is connected to the entire edge portion 102 of the sealing layer 110, so that when the outer packaging 700 is connected with the separator 100, the middle portion 101 of the sealing layer 110
  • the periphery forms a fully enclosed structure, so that any two adjacent first chambers 700a divided by the partition 100 in the outer package 700 are independent from each other.
  • the shape of the separator 100 in the embodiment of the present application is selected based on the shape of the electrochemical device 10 , for example, the shape of the separator 100 may be quadrilateral, circular or other heterogeneous structures.
  • the separator 100 is rectangular in shape
  • the middle part 101 of the sealing layer 110 is rectangular in shape
  • the edge part 102 is a rectangular frame surrounding the middle part 101 .
  • the separator 100 satisfies the conditional formula (1) S ⁇ S1 ⁇ S2 or S ⁇ S1 ⁇ S2, within the area range of the above conditional formula (1), after the separator 100 is connected with the outer package 700, it can meet the requirements of ion barrier and the separator 100 The requirement for a sealed connection with the outer packaging 700.
  • the area requirements of the above conditional formula (1) are not limited to when the sealing layer 110 is rectangular, as long as the barrier layer 120 completely covers the middle part 101 of the sealing layer 110 in the thickness direction, any shape
  • the separators 100 all satisfy the requirement of the above conditional formula (1).
  • the sealing layer 110 when the sealing layer 110 is rectangular, the length of the middle part 101 of the sealing layer 110 is a, the width is b, the length of the barrier layer 120 is a1, the width is b1, and the length of the sealing layer 110 is a2, the width is b2, and the separator 100 satisfies: a ⁇ a1 ⁇ a2, b ⁇ b1 ⁇ b2, or a ⁇ a1 ⁇ a2, b ⁇ b1 ⁇ b2, that is, for example, the thickness of the separator 100 direction, the projection of the barrier layer 120 can overlap with the projection of the middle part 101 of the sealing layer 110; or, as shown in FIG.
  • the projection of the edge portion 102 of the sealing layer 110 makes the barrier layer 120 also between the edge portion 102 of the sealing layer 110 and the outer package 700 , so as to effectively improve the ionic insulation of the connection between the separator 100 and the outer package 700 .
  • the sealing layer 110 includes a polymer that can be heat-sealed and connected to the outer packaging 700, so that the edge portion 102 of the sealing layer 110 can be hot-melted and connected to the outer packaging 700.
  • the process is difficult and the feasibility is high.
  • the packaging reliability is high, for example, the edge portion 102 of the sealing layer 110 is placed between two layers of outer packaging 700, and then the edge portion 102 of the sealing layer 110 is connected to the outer packaging 700 by hot rolling, so that The chamber in the outer package 700 is divided into a plurality of independent first chambers 700a.
  • the barrier layer 120 When the number of the barrier layer 120 is one layer, the barrier layer 120 is connected to one side of the sealing layer 110 .
  • the two layers of barrier layers 120 are separately arranged on the two opposite surfaces of the sealing layer 110. In the thickness direction of the separator 100, the projections of the two layers of barrier layers 120 can be completely overlapped or partially overlapped. Overlapping, the embodiment of the present application does not specifically limit the shape of the two barrier layers 120, as long as the projection of the barrier layer 120 covers the projection of the middle part 101 of the sealing layer 110 in the thickness direction of the separator 100, and the above conditional formula is satisfied The area requirement of (1) is enough.
  • the barrier layer 120 includes at least one of an oxide layer, a nitride layer, a metal layer, and an organic polymer, and these compounds make the barrier layer 120 have ion insulation. It can also make the barrier layer 120 at the edge portion 102 of the sealing layer 110 interfere less with the hot-melt connection of the sealing layer 110 and the outer packaging 700 when the sealing layer 110 is hot-melt connected to the outer package 700 .
  • the oxide layer in the barrier layer 120 includes at least one of an aluminum oxide layer, a zinc oxide layer, a zirconium oxide layer, a silicon oxide layer, and a silicon aluminum oxide layer.
  • the nitride layer in the barrier layer 120 includes at least one of an aluminum nitride layer, a zinc nitride layer, a zirconium nitride layer, a silicon nitride layer, and a silicon aluminum nitride layer.
  • the metal layer in the barrier layer 120 includes: containing Si, Zn, Al, Zr, Ti, V, Mg, Ni, Pr, Ce, Mn, Ta, In, Zn, Ga, Sn, Cd, Pb, A metal compound composed of at least one element of Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W.
  • the organic polymer in the barrier layer 120 includes: random copolymer of vinylidene chloride-methyl acrylate, polyethylene, polypropylene, polyethylene terephthalate, ethylene vinyl alcohol, resin, At least one of polyacrylonitrile, polyvinylidene chloride, polyamide, polyimide-amide, polyurethane, polythiourea, polyethylene glycol or organometallic polymers, organometallic polymers such as methylaluminum, etc. .
  • the melting point range of the polymer in the sealing layer 110 is 100°C to 200°C, preferably 120°C to 160°C
  • the polymer layer includes: polypropylene, polyethylene, polyester plastic, ⁇ -phthalo At least one of imido- ⁇ -hydroxybutyric acid, anhydride-modified polypropylene, ethylene and its copolymers, cast polypropylene, polyimide, polytetrafluoroethylene, polyvinylidene fluoride and its derivatives kind.
  • the barrier layer 120 is chemically bonded to the surface of the sealing layer 110 to improve the connection stability between the sealing layer 110 and the barrier layer 120, so that the barrier layer 120 and the sealing layer 110 will not be easily damaged. peel off. And the barrier layer 120 is directly connected to the sealing layer 110, no other bonding structure needs to be arranged between the sealing layer 110 and the barrier layer 120, the thickness of the separator 100 is reduced as much as possible, and the proportion of ineffective substances is reduced , the energy density of the electrochemical device 10 can be increased. In the case that the separator 100 is thinner, the separator 100 can be made flexible at the same time, and the bending resistance of the separator 100 can be improved. In the bending area, the flexible partition 100 will not be easily bent and damaged.
  • the barrier layer 120 adopts at least one of atomic layer deposition (ALD), molecular layer deposition (MLD), chemical vapor deposition (CVD), physical vapor deposition (PVD), electrodeposition or 3D printing.
  • ALD atomic layer deposition
  • MLD molecular layer deposition
  • CVD chemical vapor deposition
  • PVD physical vapor deposition
  • the surface of the sealing layer 110 is chemically bonded in several ways.
  • the material in the barrier layer 120 is deposited on the surface of the sealing layer 110 for the first time, it reacts with the functional group of the polymer in the sealing layer 110 to form a chemical bond, so that the materials on the surfaces of the sealing layer 110 and the barrier layer 120 facing each other are cross-linked, which can realize When both the sealing layer 110 and the barrier layer 120 are of relatively thin thickness, the separator 100 thus obtained can be made to have higher density to block separators.
  • the chemical bonding connection between the sealing layer 110 and the barrier layer 120 can be observed by transmission electron microscopy and energy spectrum analysis.
  • the first water vapor transmission rate M1 of the separator 100 is Satisfy: M1 ⁇ 10 ⁇ 3 g/(day ⁇ m 2 ).
  • a simulated bending experiment can be carried out to obtain the bent separator 100, and the bent separator 100 is put into a water vapor transmission rate tester, and the first temperature of the bent separator 100 is tested at 38° C. and 90% RH humidity.
  • Two water vapor transmission rate M2 to further test the water permeability of the separator 100.
  • the second water vapor transmission rate M2 of the bent separator 100 satisfies: M2 ⁇ 10 ⁇ 1 g/(day ⁇ m 2 ).
  • the separator 100 of the embodiment of the present application has good ion insulation and sealing performance under the condition that the first water vapor transmission rate M1 and the second water vapor transmission rate M2 are satisfied at the same time.
  • the simulated bending test method includes: cutting the separator 100 into a 10cm*10cm square, turning it over and folding it in half along the diagonal 180 degrees, applying an external force of 300N on the covering diagonal to press the bent separator 100, and removing the external force And flatten the separator 100 to obtain the bent separator 100; or, cut the separator 100 into a square of 10cm*10cm, use a tool to apply a force of 300N to the surface of the separator 100, and draw three scratches, Each scratch has a width of 1 mm and a length of 10 cm to obtain a bent separator 100 .
  • the thickness of the sealing layer 110 is H
  • the thickness of the barrier layer 120 is h
  • H>h so that the sealing layer 110 has sufficient thickness to provide support for the barrier layer 120, and make the obtained
  • the separator 100 is flexible and not easy to be bent and damaged.
  • the two parameters of H and h satisfy the conditional formula (2): 0 ⁇ h/H ⁇ 0.1, further, the two parameters of H and h satisfy the conditional formula (3): 0.001 ⁇ h/H ⁇ 0.01, the control
  • the thickness of the sealing layer 110 and the thickness of the barrier layer 120 are within an appropriate range, so that the barrier layer 120 will not be too thick, resulting in the overall rigidity of the obtained separator 100 and weak bending resistance; nor will the barrier layer 120 The thickness is too thin to meet the ion barrier requirements.
  • the range of H is 10 ⁇ m to 300 ⁇ m (and including 10 ⁇ m and 300 ⁇ m), further, the range of H is 30 ⁇ m to 100 ⁇ m.
  • the range of h is 5nm to 2000nm (and including 5nm and 2000nm), further, the range of h is 50nm to 200nm.
  • the thickness of the separator 100 is M.
  • the range of L is 14 ⁇ m to 304 ⁇ m (and including 14 ⁇ m and 304 ⁇ m), further, the range of M is 34 ⁇ m to 104 ⁇ m.
  • the sealing layer 110 may further include an ion barrier sheet 110a, and the ion barrier sheet 110a also has ion insulation.
  • the polymer and the ion barrier sheet 110a can be mixed together to prepare the sealing layer 110.
  • the ion-blocking sheet 110a is a plate-like structure with smaller particles obtained by crushing the ion-blocking material, so that the ion-blocking sheet 110a can be uniformly mixed with the polymer to obtain the sealing layer 110 .
  • the ion blocking sheet includes at least one of sheet-like graphene, hydrotalcite nanosheets, and boehmite sheets.
  • the sealing layer 110 includes a sealing layer 111 and a leveling layer 112 connected to the sealing layer 111.
  • the sealing layer 111 is used to connect to the outer package 700, that is, the sealing layer 111 includes Polymer in outer packaging 700.
  • the leveling layer 112 is connected to the barrier layer 120, the surface of the leveling layer 112 for connecting the barrier layer 120 has low roughness, the leveling layer 112 includes polyether modified dimethyl polysiloxane copolymer, the leveling layer 112 The chemical bonding is connected to the leveling layer 112 .
  • the projection of the leveling layer 112 completely covers the projection of the barrier layer 120 .
  • the ion blocking sheet 110a is distributed in the polymer of the sealing layer 111 .
  • the leveling layer 112 can be provided on the surface of the sealing layer 111 by means of spraying, scraping, depositing and the like.
  • the leveling layer 112 may include one or more polymer materials such as epoxy resin, polypropylene resin, polyacrylate and the like.
  • the thickness of the leveling layer 112 ranges from 3 nm to 10 ⁇ m.
  • the separator 100 may also include a reinforcement layer 130 located on the outer layer, and the reinforcement layer 130 is connected to the surface of the barrier layer 120 and/or the sealing layer 110 to further adjust the structural strength and Ionic insulation.
  • the reinforcing layer 113 can be provided on the surface of the barrier layer 120 by means of spraying, scraping, depositing and the like.
  • the reinforcing layer 113 may include one or more of (photo/thermal etc.) curable polymer layer, glass fiber layer, carbon material layer, elastic polymer layer, oxide layer.
  • the reinforcement layer 113 has a thickness of 2 ⁇ m to 100 ⁇ m.
  • the number of reinforcement layers 130 can be one or two layers. When the number of reinforcement layers 130 is two layers, in the thickness direction of the separator 100, two layers of reinforcement layers 130 are arranged opposite to each other, and the sealing layer 110 and the barrier layer 120 are sandwiched between between the two barrier layers 120 .
  • an embodiment of the present application also provides an electrochemical device 10 , including an outer package 700 , an electrolyte solution, a plurality of electrode assemblies 200 and the above separator 100 .
  • the partition 100 is arranged in the outer packaging 700, the middle part 101 of the sealing layer 110 of the partition 100 is used to accommodate the inner space of the outer packaging 700, and the edge part 102 of the sealing layer 110 of the partition 100 is used for Sealed connection with the outer package 700 to separate the inner space of the outer package 700 into a plurality of independent first chambers 700a, each first chamber 700a has an electrode assembly 200 and electrolyte to form an independent electrochemical unit.
  • the outer packaging 700 includes an outer structural layer 710 and a connecting layer 720
  • the outer structural layer 710 can be made of packaging materials such as aluminum-plastic film
  • the outer structural layer 710 is used to define the inner space of the outer packaging 700
  • the connecting layer 720 It is disposed on the inner surface of the outer structure layer 710
  • the connection layer 720 is used for connecting with the separator 100 , for example, the connection layer 720 is hot-melt connected with the separator 100 .
  • the material of the connection layer 720 is the same as that of the sealing layer 110 , which improves the connection strength between the outer package 700 and the separator 100 .
  • the connection layer 720 can be set to completely cover the outer structure layer 710 , or the edge portion 102 of the connection layer 720 corresponding to the sealing layer 110 can be set to partially cover the outer structure layer 710 .
  • the electrode assembly includes a positive electrode sheet 310, a negative electrode sheet 320 and a diaphragm 400, and the diaphragm 400 is arranged between the positive electrode sheet 310 and the negative electrode sheet 320 to block the positive electrode sheet 310 and the negative electrode sheet 320, and prevent the positive electrode sheet 310 and the negative electrode sheet 320 from contacting and causing a short circuit. catch.
  • the positive electrode sheet 310 includes a positive current collector 311 and a positive active material 312, the positive active material 312 is arranged on the surface of the positive current collector 311, the negative electrode sheet 320 includes a negative current collector 321 and a negative active material 322, and the negative active material 322 is arranged on the negative current collector 321
  • the positive electrode sheet 310 and the negative electrode sheet 320 can be spaced apart from the separator 400 or attached to the separator 400 .
  • the electrolyte is in contact with both the positive electrode sheet 310 and the negative electrode sheet 320 , and the electrolyte solution penetrates into the separator 400 .
  • Each electrode assembly can lead out a positive tab 510 and a negative tab 520 , the positive tab 510 is electrically connected to the positive current collector 311 , and the negative tab 520 is electrically connected to the negative current collector 321 .
  • the positive tab 510 of the first electrode assembly 210 is connected in series with the negative tab 520 of the second electrode assembly 220, and the negative tab 520 of the first electrode assembly 210 and the second electrode assembly
  • the positive tab 510 of 220 is the output tab, and the output voltage is the sum of the output voltages of the two electrochemical cells.
  • the positive tab 510 and the negative tab 520 of the electrode assembly 200 can be connected in series inside or outside the outer package 700 by direct welding or wire welding.
  • the positive electrode sheet 310, the negative electrode sheet 320 and the separator 400 of the electrode assembly 200 can be in a wound structure or a laminated structure, and the structures of the electrode assemblies 200 in each first cavity 700a can be the same or different.
  • the two electrochemical cells located on opposite sides of the separator 400 may be symmetrical or asymmetrical.
  • the outer package 700 of the electrochemical device 10 can be made of hard or flexible material, and the positive electrode sheet 310 , the negative electrode sheet 320 and the separator 400 can be glued and fixed in the outer package 700 .
  • the positive electrode sheet 310 of the present application is not particularly limited, the positive current collector 311 can be any positive current collector 311 known in the art, such as aluminum foil, aluminum alloy foil or composite current collector, etc., and the positive electrode active material 312 can be any positive electrode in the prior art
  • the active material 312, the positive electrode active material 312 includes at least one of NCM811, NCM622, NCM523, NCM111, NCA, lithium iron phosphate, lithium cobaltate, lithium manganate, lithium manganese iron phosphate or lithium titanate.
  • the negative electrode sheet 320 of the present application is not particularly limited.
  • the negative current collector 321 can be any negative current collector 321 known in the art, such as copper foil, aluminum foil, aluminum alloy foil or a composite current collector.
  • the negative active material 322 can be an existing Any negative electrode active material 322 of technology, and the negative electrode active material 322 includes at least one of graphite, hard carbon, soft carbon, silicon, silicon carbon, or silicon oxide.
  • the electrolyte solution of the present application is not particularly limited, and any electrolyte solution known in the art can be used, and the electrolyte solution can be any of gel state, solid state and liquid state.
  • the electrolytic solution is a liquid electrolytic solution
  • the liquid electrolytic solution includes a lithium salt and a non-aqueous solvent.
  • Lithium salt is not particularly limited, any lithium salt known in the art can be used, as long as the purpose of the application can be realized, for example, lithium salt can include LiPF6, LiBF4, LiAsF6, LiClO4, LiB(C6H5)4, LiCH3SO3, LiCF3SO3, At least one of LiN(SO2CF3)2, LiC(SO2CF3)3 or LiPO2F2, etc.
  • Non-aqueous solvent is not particularly limited, as long as the purpose of this application can be realized, for example, non-aqueous solvent can comprise at least one in carbonate compound, carboxylate compound, ether compound, nitrile compound or other organic solvent etc.
  • carbonic acid Ester compounds may include diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), ethylmethyl carbonate (MEC ), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinyl ethylene carbonate (VEC), fluoroethylene carbonate (FEC), 1,2-carbonate Difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro- 2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-d
  • the separator 400 of the present application is not particularly limited, for example, the separator 400 may be made of a material stable to the electrolyte of the present application.
  • the separator 400 should have ion conductivity, so that ions pass through the separator 400 and move between the positive electrode sheet 310 and the negative electrode sheet 320.
  • the separator 400 should also have electronic insulation to prevent the positive electrode sheet 310 from contacting the negative electrode sheet 320. Prevent the positive electrode sheet 310 and the negative electrode sheet 320 from being short-circuited.
  • the embodiment of the present application also provides that the embodiment of the present application provides an electric device, including the above electrochemical device 10 , for example, the electric device may include a car and the like.
  • electrochemical device 10 as a lithium ion battery as an example, and further describe the present application in detail in conjunction with specific embodiments.
  • the positive electrode sheet 310, the negative electrode sheet 320, and the separator 400 are wound or laminated, and the positive electrode tab 510 is electrically connected to the positive current collector 311 of the positive electrode sheet 310, and the negative electrode tab 520 is connected to the negative collector of the negative electrode sheet 320.
  • the fluid 321 is electrically connected to make the electrode assembly 200, and prepare two electrode assemblies 200 (one of which is the first electrode assembly 210 and the other is the second electrode assembly 220), and the two electrode assemblies 200 are reversed in length and width The dimensions in the direction and the thickness direction are the same.
  • the positive tab 510 is made of aluminum
  • the negative tab 520 is made of nickel
  • the positive tab 510 and the negative tab 520 are arranged facing the same side.
  • Preparation of the separator 100 Provide a PP film with a hot-melt encapsulation function and a thickness of 10 ⁇ m as the sealing layer 110, and use trimethylaluminum and H 2 O as precursors to deposit on the opposite surfaces of the sealing layer 110, among which trimethylaluminum and H 2 O
  • the base aluminum reacts with the functional groups on the surface of PP, so that trimethylaluminum can be deposited on the surface of PP, water further reacts with the trimethylaluminum deposited on the surface of PP, and -OH replaces the trimethyl group, and the cyclic reaction produces Al2O 3 , thereby forming the barrier layer 120 .
  • each barrier layer 120 formed on the surface of the sealing layer 110 is 0.05 ⁇ m.
  • the total thickness of the separator 100 is 10.05 ⁇ m, and the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.005.
  • Assembly of the electrochemical device 10 two outer packages 700 are provided, and the outer packages 700 are stamped from an aluminum-plastic film with a thickness of 150 ⁇ m to form a structure with pits.
  • the first electrode assembly 210 is placed in the pit of one of the outer packaging 700, the separator 100 covers the first electrode assembly 210, and the edge portion 102 of the sealing layer 110 of the separator 100 is connected to the outer packaging 700, and pressure is applied to close the
  • the separator 100 and the outer package 700 are preliminarily pressed and formed to obtain a semi-finished product.
  • the second electrode assembly 220 on the semi-finished separator 100, and cover the second electrode assembly 220 with another outer package 700 facing down, so that the edge portion 102 of the sealing layer 110 of the separator 100 is placed in the two outer packages.
  • pressure is applied to the two outer packages 700 corresponding to the edge portion 102 of the sealing layer 110 , and the edge portion 102 of the sealing layer 110 is hot-pressed at 150° C. to be sealed and connected to the two outer packages 700 .
  • the partition 100 divides the spaces inside the two outer packages 700 into two independent first chambers 700a. Both the positive tab 510 and the negative tab 520 of the two electrode assemblies protrude from the outer package 700 to obtain a preformed product.
  • Liquid injection encapsulation through the openings of the outer packages 700 , inject electrolyte solution into the first chambers 700a respectively, and seal the openings of the outer packages 700 after the liquid injection is completed.
  • the positive tab 510 of one electrode assembly is bonded to the negative tab 520 of the other electrode assembly and fixed by welding to connect the two electrode assemblies in series to obtain an electrochemical device 10 with two electrochemical units.
  • the electrochemical device 10 can be charged and discharged by connecting the unwelded positive tab 510 and the negative tab 520 in the electrochemical device 10 .
  • the voltage in the electrochemical device 10 can be monitored by connecting the two tabs welded together.
  • Example 1 The difference from Example 1 is that the thickness of the PP film is 30 ⁇ m.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0017.
  • Example 1 The difference from Example 1 is that the thickness of the PP film is 80 ⁇ m.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0006.
  • Example 1 The difference from Example 1 is that the thickness of the PP film is 100 ⁇ m.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0005.
  • Example 2 The difference from Example 1 is that the thickness of the PP film is 300 ⁇ m.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0002.
  • the barrier layer 120 has a thickness of 0.005 ⁇ m.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0001.
  • the barrier layer 120 has a thickness of 0.1 ⁇ m.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0013.
  • the barrier layer 120 has a thickness of 0.2 ⁇ m.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0025.
  • Example 1 The difference from Example 1 is that the thickness of the PP film is 76 ⁇ m, and the thickness of the barrier layer 120 is 2 ⁇ m.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0263.
  • the difference from Example 1 is that the thickness of the PP film is 80 ⁇ m, the thickness of the barrier layer 120 is 0.1 ⁇ m, the area S of the middle part 101 of the sealing layer 110, the area S1 of the barrier layer 120, and the area S2 of the sealing layer 110.
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0013.
  • Example 10 The difference from Example 10 is that the three parameters of the area S of the middle part 101 of the sealing layer 110 , the area S1 of the barrier layer 120 , and the area S2 of the sealing layer 110 satisfy the conditional formula: S ⁇ S1 ⁇ S2.
  • the sealing layer 111 is made of a PE film with a thickness of 80 ⁇ m
  • the thickness of the barrier layer 120 is 0.1 ⁇ m
  • the edge portion 102 of the sealing layer 110 is hot-pressed at 120° C. to be sealed and connected to the two outer packages 700 .
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0013.
  • Example 13 The difference from Example 13 is that: a polystyrene film with a thickness of 80 ⁇ m is used as the sealing layer 111 , and the edge portion 102 of the sealing layer 110 is hot-pressed at 240° C. to seal and connect to the two outer packages 700 .
  • Example 1 The difference from Example 1 is that: a PP film with a thickness of 80 ⁇ m is used as the sealing layer 111, and Al with a thickness of 0.1 ⁇ m is deposited on the surface of the sealing layer 110 to form the barrier layer 120, and the edge portion 102 of the sealing layer 110 is heated at 150° C. Press until it is airtightly connected to the two outer packages 700 .
  • the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0013.
  • Example 15 The difference from Example 15 is that in the thickness direction of the sealing layer 110, a layer of Al 2 O 3 is molecularly deposited on the surface of the sealing layer 110, and then polyimide is deposited on the surface of the Al 2 O 3 so that the surface of the sealing layer 110 A barrier layer 120 is formed.
  • the barrier layer 120 formed of Al 2 O 3 and polyimide had a thickness of 0.1 ⁇ m.
  • Embodiment 7 The difference with Embodiment 7 is: in the thickness direction of the sealing layer 110, epoxy resin is sprayed on the two opposite surfaces of the sealing layer 110, so as to generate leveling layers 112 and leveling layers respectively on the two opposite surfaces of the sealing layer 110.
  • 112 has a thickness of 10 nm.
  • a barrier layer 120 is then deposited on the surface of each leveling layer 112 respectively.
  • Example 7 The difference from Example 7 is that in the thickness direction of the sealing layer 110, a layer of urethane acrylate is sprayed on the surface of each barrier layer 120 to form a reinforcement layer 130 on the surface of the barrier layer 120, and the thickness of the reinforcement layer 130 is 10 ⁇ m.
  • Example 13 The difference from Example 13 is that boehmite flakes are mixed into the raw materials for preparing the PP film to obtain a sealing layer 110 with a thickness of 80 ⁇ m, and the edge portion 102 of the sealing layer 110 is hot-pressed at 150° C. to be sealed and connected to the 700 for two outer packages.
  • Embodiment 13 The difference from Embodiment 13 is that a barrier layer 120 is provided on one side of the sealing layer 110 .
  • Example 13 The difference from Example 13 is that three electrode assemblies and two layers of separators 100 are provided, and the electrode assemblies and separators 100 are alternately placed between two outer packages 700, and the edge portions 102 of the sealing layers 110 of each separator 100 are uniform. Placed between two outer packages 700 , and the edge portion 102 of each sealing layer 110 is hot-pressed at 150° C. to be sealed and connected to the two outer packages 700 .
  • Example 1 The difference from Example 1 is that the PP material in the hot melt state is uniformly dispersed in the dispersant N-methylpyrrolidone (NMP) to obtain a suspension, and the suspension is coated on the opposite side of the Al film by using a glue applicator. Dry the dispersant NMP in the suspension at 150°C to obtain the encapsulation layer connected to the surface of the Al film, that is, the preparation of the separator 100 is completed.
  • the encapsulation layer is used for hot-melt connection with the outer packaging 700, and the Al film It has ionic insulation.
  • the total thickness of the separator 100 is 120 ⁇ m
  • the total thickness of the two layers of encapsulation layers is 80 ⁇ m
  • the thickness of the Al film is 40 ⁇ m
  • the thickness of the Al film is the same as the total thickness of the two layers of encapsulation layers.
  • Example 1 The difference from Example 1 is that the PP film is used as the separator 100 alone, and the total thickness of the separator 100 is 80 ⁇ m. Among them, the PP film has ionic insulation, and is hot-melt connected with the outer package 700 at 150°C.
  • Example 1 The difference from Example 1 is that Al alone is used as the separator 100 , the total thickness of the separator 100 is 80 ⁇ m, the Al separator 100 has ion insulation, and the Al separator 100 is directly connected to the outer package 700 by encapsulation glue.
  • Example 2 The difference from Example 1 is that the thickness of the PP film is 80 ⁇ m, the thickness of the barrier layer 120 is 0.05 ⁇ m, and the ratio of the thickness of the barrier layer 120 to the thickness of the sealing layer 110 is 0.0006.
  • the edge portion 102 of the sealing layer 110 of the partition 100 is connected to the outer package 700 by hot rolling.
  • the separator 100 for the electrochemical device 10 and the electrochemical device 10 in each embodiment and comparative example were tested using the following method:
  • Seal strength test remove the part where the outer package 700 is hot-melt connected with the separator 100 from the electrochemical device 10, and cut it into a test strip with a width of 8mm to ensure that the outer package 700 on both sides of the test strip is intact, and obtain the test strip to be tested.
  • Sample Using a high-speed rail tensile machine, the outer packages 700 on both sides of the sample to be tested are torn apart at an angle of 180°, so that the two layers of outer packages 700 are separated from each other. The stable pulling force when the above two layers of outer packaging 700 are separated is recorded, and based on this, the packaging strength is calculated.
  • the number of internal series electrode assemblies is n
  • the electrochemical device 10 is left at 25°C for 30 minutes, charged at a constant current at a charging rate of 0.05C to a voltage of 4.45*nV, and then the electrochemical device 10 is charged at a rate of 0.05C.
  • the device 10 was discharged to 3.00*nV, and the above charging/discharging steps were repeated for 3 cycles to complete the formation of the electrochemical device 10 to be tested.
  • Drop test drop the 6 sides and 4 corners of the electrochemical device 10 from a height of 1.5m, one round for each of the 6 sides and 4 corners, a total of five rounds, that is, 50 times, no heat generation, no leakage, no swelling,
  • the non-ignited cell is the passing cell, and the other is the non-passing cell, so as to determine the proportion of the passing cell.

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Abstract

本申请公开了一种用于电化学装置的隔板、电化学装置及用电设备。隔板包括密封层，密封层包括中间部分、围设并连接于中间部分外围的边缘部分，中间部分容置于电化学装置的外包装的内部空间，边缘部分用于与外包装密封连接。本申请由隔板的密封层与电化学装置的外包装连接，提高隔板与电化学装置的外包装密封连接的稳定性，从而有效提高电化学装置的使用寿命。另外，还可有效减少制得的隔板的厚度，提高电化学装置的能量密度。

Description

用于电化学装置的隔板、电化学装置及用电设备 技术领域
本申请涉及电化学领域，尤其涉及一种用于电化学装置的隔板、电化学装置及用电设备。
背景技术
电化学装置例如锂离子电池具有体积和质量能量密度大、循环寿命长、标称电压高、自放电率低、体积小、重量轻等许多优点，在消费电子领域具有广泛的应用。电化学装置采用多电芯内部串联的方法可有效提高输出电压，同时还具有减小电芯总产热，降低温升，并兼容卷绕和叠片结构等诸多优点。
在对多个电芯做串联组装时，需要实现各串联腔体间的离子绝缘功能，避免填充电解液后不同腔体内的阴阳极发生短路，同时规避液态电解液在高电压下分解失效后对相邻腔体的干扰。相关技术中，通过隔板实现电化学装置各串联腔体的离子绝缘功能，隔板需与电化学装置的外包装连接，隔板自身以及隔板与外包装连接处的离子绝缘性，都将影响电化学装置内相邻两个腔体的离子绝缘效果。
发明内容
本申请实施例提供一种用于电化学装置的隔板、电化学装置及用电设备，能够解决电化学装置内难以实现相邻两个腔体离子绝缘的问题。
第一方面，本申请实施例提供了一种用于电化学装置的隔板，包括：
密封层，包括中间部分、围设并连接于所述中间部分外围的边缘部分，所述中间部分容置于电化学装置的外包装的内部空间，所述边缘部分用于与所述外包装密封连接。
在一些示例性的实施例中，所述密封层包括热塑性聚合物，以使隔板能够通过密封层热熔后直接与电化学装置的外包装连接，有效提高隔板与外包装连接的封印强度。在一些示例性的实施例中，所述热塑性聚合物的熔点范围为100℃至200℃；所述热塑性聚合物聚合物包括：聚丙烯、聚乙烯、聚酯塑料、γ-邻苯二甲酰亚氨基-α-羟基丁酸、酸酐改性聚丙烯、乙烯及其共聚物、流延聚丙烯、聚酰亚胺、聚四氟乙烯、聚偏二氟乙烯及其衍生物中的至少一种。
在一些示例性的实施例中，所述隔板还包括至少一层的阻隔层，所述阻隔层具有离子绝缘性，所述阻隔层设置于所述密封层的至少一侧；在所述密封层与所述阻隔层的层叠的厚度方向上，所述阻隔层的投影至少覆盖所述中间部分的投影。
在一些示例性的实施例中，所述阻隔层的数量为两层，两层所述阻隔层分设于所述密封 层相对的两个表面。
在一些示例性的实施例中，在垂直于所述密封层与所述阻隔层层叠方向的平面内，所述中间部分的面积为S，所述阻隔层的面积为S1，所述密封层的面积为S2，所述隔板满足S＜S1≤S2或S≤S1＜S2。
在一些示例性的实施例中，所述密封层的所述中间部分的长度为a、宽度为b，所述阻隔层的长度为a1、宽度为b1，所述密封层的长度为a2、宽度为b2，所述隔板满足：a＜a1≤a2、b＜b1≤b2，或a≤a1＜a2、b≤b1＜b2。
在一些示例性的实施例中，所述阻隔层采用原子层沉积、分子层沉积、化学气相沉积、物理气相沉积、电沉积或3D打印中的至少一种方式化学键合连接于所述密封层的表面，有效提高密封层与阻隔层连接的强度，使密封层与阻隔层不会轻易被剥离。
在一些示例性的实施例中，所述阻隔层包括氧化物层、氮化物层、金属层、有机聚合物中的至少一种；
所述氧化物层包括氧化铝层、氧化锌层、氧化锆层、氧化硅层、硅铝氧化物层中的至少一种；
所述氮化物层包括氮化铝层、氮化锌层、氮化锆层、氮化硅层、硅铝氮化物层中的至少一种；
金属层包括：含Si、Zn、Al、Zr、Ti、V、Mg、Ni、Pr、Ce、Mn、Ta、In、Zn、Ga、Sn、Cd、Pb、Ni、Ti、Cu、Ag、Au、Pt、Fe、Co、Cr、W中的至少一种金属材料或合金材料；
有机聚合物包括：偏氯乙烯-丙烯酸甲酯、聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯、乙烯一乙烯醇的无规共聚物、树脂、聚丙烯腈、聚偏二氯乙烯、聚酰胺、聚酰亚胺-酰胺、聚氨酯、聚硫脲、聚乙二醇或有机金属聚合物中的至少一种。
在一些示例性的实施例中，所述隔板具有以下特征中的至少一个：
(a)所述隔板的第一水汽透过率M1满足M1≤10 -3g/(day·m 2)；
(b)所述密封层的厚度为H，H的范围为14μm至304μm；所述阻隔层的厚度为h，h的范围为5nm至2000nm；
(c)所述密封层包含离子阻隔片，所述离子阻隔片包括片状石墨烯、水滑石纳米片、勃姆石片中的至少一种；
(d)所述密封层还包括流平层，所述流平层连接于所述阻隔层，所述流平层相对于所述阻隔层的表面具有低粗糙度，所述流平层包括环氧树脂、聚丙烯树脂、聚丙烯酸酯等聚合物材料中的一种或多种；
(e)所述隔板还包括位于所述密封层或阻隔层表面的加强层，所述加强层设置于所述 阻隔层和/或所述密封层的表面，所述加强层包括聚合物层、玻璃纤维层、碳材料层、弹性聚合物层、氧化物层的至少一种。
第二方面，本申请实施例提供了一种电化学装置，包括：
如上所述的隔板；
外包装，所述隔板设于所述外包装内，且所述隔板连接于所述外包装，以将所述外包装的内部空间分隔出多个第一腔室；
电解液，设于各所述第一腔室；及
多个电极组件，对应设于各所述第一腔室与所述电解液相接触。
在一些示例性的实施例中，所述外包装包括连接层，所述连接层与所述隔板的边缘部分相连接，所述连接层包括聚合物，所述聚合物包括：聚丙烯、聚乙烯、聚酯塑料、γ-邻苯二甲酰亚氨基-α-羟基丁酸、酸酐改性聚丙烯、乙烯及其共聚物、流延聚丙烯、聚酰亚胺、聚四氟乙烯、聚偏二氟乙烯及其衍生物中的至少一种。
第三方面，本申请实施例提供了一种用电设备，包括如上所述的电化学装置。
基于本申请实施例的用于电化学装置的隔板、电化学装置及用电设备，由隔板的密封层与电化学装置的外包装连接，提高隔板与电化学装置的外包装密封连接的稳定性，从而有效提高电化学装置的使用寿命。另外，还可有效减少制得的隔板的厚度，提高电化学装置的能量密度。
附图说明
为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域技术人员来讲，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的附图。
图1为本申请一种实施例的隔板的阻隔层设于密封层单侧的剖视图；
图2为本申请一种实施例的隔板的阻隔层设于密封层双侧的剖视图；
图3为本申请一种实施例的隔板连接于外包装的剖视图；
图4a为本申请一种实施例的隔板的密封层的主视图；
图4b为本申请一种实施例的隔板的主视图；
图5为本申请一种实施例的阻隔层全部覆盖密封层的剖视图；
图6为本申请一种实施例的隔板具有流平层的剖视图；
图7为本申请一种实施例的隔板具有加强层的剖视图；
图8为本申请一种实施例的电化学装置的立体结构示意图；
图9为本申请一种实施例的电化学装置的爆炸图；
图10为本申请一种实施例的电化学装置的局部剖视图。
附图标记：
用电设备
10、电化学装置；
100、隔板；110、密封层；120、阻隔层；130、加强层；
101、中间部分；102、边缘部分；
111、密封层；112、流平层；110a、阻隔片；
200、电极组件；210、第一电极组件；220、第二电极组件；
310、正极片；311正集流体；312正极活性材料；
320、负极片；321负集流体；322负极活性材料；
400、隔膜；
510、正极耳；520、负极耳；
700、外包装；710、外部结构层；720、连接层；700a、第一腔室。
具体实施方式
为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本申请，并不用于限定本申请。
发明人发现，电化学装置中，单独采用金属层作为隔板时，隔板容易与其连接的结构剥离，且金属层的拉伸强度低，存在撕扯断裂的风险，导致电芯内部短路；单独采用聚合物作为隔板时，聚合物本身的阻隔性能有限，难以发挥有效的阻隔效果。若采用密封层与阻隔层叠加，阻隔层常选用金属材料，密封层常选用聚合物，则可兼顾阻隔性和抗拉伸强度需求，但同时还需注意叠加后的隔板厚度，防止隔板占用较多的空间导致电化学装置内的非活性物质占比增大，进而导致整体能量密度(ED)较低，另外，同时还需注意密封层与阻隔层、隔板与外包装等多处的粘接强度，防止粘接力有限存在老化剥离的风险，进而导致电解液渗透至剥离后的两层结构之间，甚至渗透到外部，存在安全隐患，影响电化学装置的使用寿命。为解决上述问题，本申请实施例提供了一种用于电化学装置的隔板、电化学装置及用电设备。
需要说明的是，本申请的具体实施方式中，以锂离子电池作为电化学装置的例子来解释本申请，但是本申请的电化学装置并不仅限于锂离子电池，如图1和图2所示，为本申请一种实施例的用于电化学装置10的隔板100的结构示意图，隔板100包括密封层110和至少一层的阻隔层120。
密封层110包括中间部分101、围设并连接于中间部分101外围的边缘部分102，如图3所示，中间部分101用于容置于外包装700的内部空间，边缘部分102用于与外包装700密封连接。其中，中间部分101与边缘部分102采用相同的材质一体成型。
各阻隔层120具有离子绝缘性，阻隔层120设置于密封层110的至少一侧，将阻隔层120直接连接于密封层110。在密封层110与阻隔层120层叠的厚度方向(也即隔板100的厚度方向)上，阻隔层120的投影至少覆盖中间部分101的投影，使阻隔层120处于外包装700的腔室内，并使阻隔层120处于隔板100表层阻隔相邻两个腔室内的离子迁移。
其中，密封层110的边缘部分102围绕中间部分101的外围，外包装700连接于密封层110全部的边缘部分102，以在外包装700与隔板100连接时，在密封层110的中间部分101的外围形成全封闭的结构，以使外包装700内被隔板100分割出的任一相邻两个第一腔室700a相互独立。
本申请实施例的隔板100的形状基于电化学装置10的形状进行选择，例如，隔板100的形状可为四边形、圆形或其他异性结构。以电化学装置10为锂离子电池为例，示例性的，隔板100的形状为矩形，密封层110的中间部分101的形状为矩形，边缘部分102则为围绕中间部分101的矩形框。
在垂直于密封层110与阻隔层120层叠方向的平面内，密封层110的中间部分101的面积为S，阻隔层120的面积为S1，密封层110的面积为S2，隔板100满足条件式(1)S＜S1≤S2或S≤S1＜S2，在上述条件式(1)的面积范围内，隔板100与外包装700连接后，既可满足离子阻隔要求，又可满足隔板100与外包装700密封连接的要求。需要说明的是，上述条件式(1)的面积要求也可不局限于密封层110为矩形时，只要在厚度方向上阻隔层120全部覆盖密封层110的中间部分101的情况下，任一形状的隔板100均满足上述条件式(1)的要求。
如图4a和图4b所示，当密封层110为矩形时，密封层110的中间部分101的长度为a、宽度为b，阻隔层120的长度为a1、宽度为b1，密封层110的长度为a2、宽度为b2，隔板100满足：a＜a1≤a2、b＜b1≤b2，或a≤a1＜a2、b≤b1＜b2，也即，示例性地，在隔板100的厚度方向，阻隔层120的投影可与密封层110的中间部分101的投影重叠；或者，如图5所示，阻隔层120的投影可在覆盖密封层110的中间部分101的投影情况下，同时覆盖密封层110的边缘部分102的投影，使阻隔层120也处于密封层110的边缘部分102与外包装700之间，以有效提高隔板100与外包装700连接处的离子绝缘性。
在一些示例性的实施例中，密封层110包括能够热封连接于外包装700的聚合物，使密封层110的边缘部分102可热熔后与外包装700连接，工艺难度底，可行性高，且封装可靠性高，例如，将密封层110的边缘部分102置于两层外包装700之间，再采用热轧的方式将 密封层110的边缘部分102与外包装700连接在一起，从而将外包装700内的腔室分隔为多个独立的第一腔室700a。
当阻隔层120的数量为一层时，阻隔层120连接于密封层110的其中一侧。当阻隔层120的数量为两层时，两层阻隔层120分设于密封层110相对的两个表面，在隔板100的厚度方向上，两层阻隔层120的投影可完全重叠，也可部分重叠，本申请实施例对两层阻隔层120的形状不做具体限定，只要使得在隔板100厚度方向上，阻隔层120的投影覆盖密封层110的中间部分101的投影，且满足上述条件式(1)的面积要求即可。
在一些示例性的实施例中，阻隔层120包括氧化物层、氮化物层、金属层、有机聚合物中的至少一种，并通过这些化合物使制得阻隔层120具有离子绝缘性。还可使得密封层110热熔连接于外包装700时，处于密封层110的边缘部分102的阻隔层120对密封层110和外包装700的热熔连接干扰较小。
示例性地，阻隔层120中的氧化物层包括氧化铝层、氧化锌层、氧化锆层、氧化硅层、硅铝氧化物层中的至少一种。
示例性地，阻隔层120中的氮化物层包括氮化铝层、氮化锌层、氮化锆层、氮化硅层、硅铝氮化物层中的至少一种。
示例性地，阻隔层120中的金属层包括：含Si、Zn、Al、Zr、Ti、V、Mg、Ni、Pr、Ce、Mn、Ta、In、Zn、Ga、Sn、Cd、Pb、Ni、Ti、Cu、Ag、Au、Pt、Fe、Co、Cr、W中的至少一种元素组成的金属化合物。
示例性地，阻隔层120中的有机聚合物包括：偏氯乙烯-丙烯酸甲酯、聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯、乙烯一乙烯醇的无规共聚物、树脂、聚丙烯腈、聚偏二氯乙烯、聚酰胺、聚酰亚胺-酰胺、聚氨酯、聚硫脲、聚乙二醇或有机金属聚合物中的至少一种，有机金属聚合物例如甲基铝等。
示例性地，密封层110中的聚合物的熔点范围为100℃至200℃，优选为120℃至160℃，聚合物层包括：聚丙烯、聚乙烯、聚酯塑料、γ-邻苯二甲酰亚氨基-α-羟基丁酸、酸酐改性聚丙烯、乙烯及其共聚物、流延聚丙烯、聚酰亚胺、聚四氟乙烯、聚偏二氟乙烯及其衍生物中的至少一种。
本申请所述的隔板100，阻隔层120化学键合连接于密封层110的表面，以提高密封层110与阻隔层120之间的连接稳定性，使阻隔层120与密封层110不会轻易被剥离。并且阻隔层120直接连接于密封层110，无需再在密封层110和阻隔层120之间设置其他粘接结构，尽可能地减少了制得的隔板100的厚度，降低了非有效物质的比例，可提高电化学装置10的能量密度。在制得的隔板100较薄的情况下，同时还可使隔板100具有柔性，提高隔板100的抗弯折性能，例如，在隔板100与外包装700连接处附近的高频率弯折区域，具有柔性的 隔板100不会轻易弯折破损。
在一些示例性的实施例中，阻隔层120采用原子层沉积(ALD)、分子层沉积(MLD)、化学气相沉积(CVD)、物理气相沉积(PVD)、电沉积或3D打印中的至少一种方式化学键合连接于密封层110的表面。阻隔层120内的材料首次沉积于密封层110表面时，与密封层110内聚合物的官能团反应形成化学键，使密封层110和阻隔层120朝向彼此的表面内的材料相互交联，可实现在密封层110和阻隔层120均处于较薄厚度的情况下，即可使制得的隔板100具有较高的致密性以阻隔离子。密封层110与阻隔层120之间化学键合连接可通过透射电子显微镜和能谱分析观察到。
将制得的隔板100放入水汽透过率测试仪，于38℃、90％RH湿度下检测隔板100的水汽透过率，示例性地，隔板100的第一水汽透过率M1满足：M1≤10 -3g/(day·m 2)。通过限制隔板100的第一水汽透过率M1，防止隔板100相邻两侧腔室电解液内的水分子互串导致的腔室内水含量超标。优选地，M1≤10 -4g/(day·m 2)。
进一步地，可进行模拟弯折实验，获得弯折隔板100，并将弯折隔板100放入水汽透过率测试仪，于38℃、90％RH湿度下检测弯折隔板100的第二水汽透过率M2，以进一步检测隔板100的透水性。示例性地，弯折隔板100的第二水汽透过率M2满足：M2≤10 -1g/(day·m 2)。本申请实施例的隔板100在同时满足第一水汽透过率M1和第二水汽透过率M2的情况下，具有良好的第离子绝缘性和密封性。
模拟弯折实验方法包括：将隔板100裁切成10cm*10cm的方块，沿对角线180度翻转对折，覆盖对角线处施加300N的外力按压弯折后的隔板100，移除外力并展平隔板100，即获得弯折隔板100；或者，将隔板100裁切成10cm*10cm的方块，采用工具施加300N的作用力于隔板100表面，并划出三条划纹，各划纹的宽度为1mm、长度为10cm，以获得弯折隔板100。
在一些示例性的实施例中，密封层110的厚度为H，阻隔层120的厚度为h，且H>h，使密封层110具有足够的厚度为阻隔层120提供支撑，并使制得的隔板100具有柔性，不易弯折破损。进一步地，H和h两个参数满足条件式(2)：0＜h/H≤0.1，更进一步地，H和h两个参数满足条件式(3)：0.001≤h/H≤0.01，控制密封层110的厚度和阻隔层120的厚度处于合适的范围内，使阻隔层120不至于过厚，而导致制得的隔板100整体较硬抗弯折能力弱；也不至于使阻隔层120的厚度过薄难以满足离子阻隔要求。
示例性的，H的范围为10μm至300μm(且包括10μm和300μm)，进一步地，H的范围为30μm至100μm。示例性的，h的范围为5nm至2000nm(且包括5nm和2000nm)，进一步地，h的范围为50nm至200nm。隔板100的厚度为M，示例性的，L的范围为14μm至304μm(且包括14μm和304μm)，进一步地，M的范围为34μm至104μm。
在一些示例性的实施例中，密封层110内还可包含离子阻隔片110a，离子阻隔片110a也具有离子绝缘性。在制备密封层110时，可将聚合物与离子阻隔片110a混匀后一起制得密封层110。需要说明的是，离子阻隔片110a是将离子阻隔材料破碎后获得的颗粒较小的片状结构，以便于离子阻隔片110a能够与聚合物混合均匀后制得密封层110。离子阻隔片包括片状石墨烯、水滑石纳米片、勃姆石片中的至少一种。
为使阻隔层120能够更加致密地形成在密封层110上，以提高离子绝缘性，密封层110用于连接阻隔层120的表面越光滑越好。示例性地，如图6所示，密封层110包括密封层111、连接于密封层111的流平层112，密封层111用于连接于外包装700，也即密封层111包括能够热封连接于外包装700的聚合物。流平层112连接于阻隔层120，流平层112用于连接阻隔层120的表面具有低粗糙度，流平层112包括聚醚改性二甲基聚硅氧烷共聚物，流平层112化学键合连接于流平层112。在隔板100的厚度方向，流平层112的投影全部覆盖阻隔层120的投影。当密封层110内具有离子阻隔片110a时，离子阻隔片110a分部于密封层111的聚合物内。
示例性地，可采用喷涂、刮涂、沉积等方式将流平层112设于密封层111表面。流平层112可包括环氧树脂、聚丙烯树脂、聚丙烯酸酯等聚合物材料中的一种或多种。流平层112厚度范围为3nm至10μm。
如图7所示，隔板100还可包括位于外层的加强层130，加强层130连接阻隔层120和/或密封层110的表面，以进一步地调节制得的隔板100的结构强度和离子绝缘性。示例性地，可采用喷涂、刮涂、沉积等方式将加强层113设于阻隔层120表面。加强层113可包括(光/热等)固化类聚合物层、玻璃纤维层、碳材料层、弹性聚合物层、氧化物层中的一种或多种。加强层113的厚度为2μm至100μm。
加强层130的数量可为一层或两层，当加强层130的数量为两层时，在隔板100厚度方向，两层加强层130相对设置，将密封层110和阻隔层120夹设于两层阻隔层120之间。
如图8和图9所示，本申请实施例还提供了一种电化学装置10，包括外包装700、电解液、多个电极组件200以及如上所述的隔板100。请再参图3，隔板100设于外包装700内，隔板100密封层110的中间部分101用于容置于外包装700的内部空间，隔板100密封层110的边缘部分102用于与外包装700密封连接，以将外包装700的内部空间分隔出多个独立的第一腔室700a，各第一腔室700a中具有一个电极组件200和电解液，形成独立的电化学单元。
如图10所示，外包装700包括外部结构层710和连接层720，外部结构层710可由铝塑膜等包装材料制得，外部结构层710用于限定出外包装700的内部空间，连接层720设于外部结构层710的内表面，且连接层720用于与隔板100连接，例如连接层720与隔板100热 熔连接。进一步地，连接层720的材质与密封层110的材质相同，提高外包装700与隔板100的连接强度。可设置连接层720全部覆盖外部结构层710，也可设置连接层720对应密封层110的边缘部分102局部覆盖外部结构层710。
电极组件包括正极片310、负极片320和隔膜400，隔膜400设于正极片310和负极片320之间，以阻隔正极片310和负极片320，防止正极片310和负极片320相接触而短接。正极片310包括正集流体311和正极活性材料312，正极活性材料312设于正集流体311表面，负极片320包括负集流体321和负极活性材料322，负极活性材料322设于负集流体321表面，正极片310和负极片320可与隔膜400间隔设置或与隔膜400贴合。电解液与正极片310、负极片320均相接触，且电解液渗透至隔膜400内。各电极组件可引出一个正极耳510和一个负极耳520，正极耳510与正集流体311电连接，负极耳520与负集流体321电连接。
示例性地，相邻两个电极组件200中，第一电极组件210的正极耳510与第二电极组件220的负极耳520串联在一起，第一电极组件210的负极耳520和第二电极组件220的正极耳510为输出极耳，输出电压为两个电化学单元输出电压之和。电极组件200的正极耳510和负极耳520可以通过直接焊接或者导线焊接的方式，在外包装700内部或者外部实现串联。
电极组件200的正极片310、负极片320和隔膜400可呈绕卷式结构或叠片式结构，各第一腔体700a内，电极组件200的结构可相同或不同。位于隔膜400相对两侧的两个电化学单元可对称或不对称。电化学装置10的外包装700可由硬质或具有柔性的材质制得，正极片310、负极片320和隔膜400可粘接固定于外包装700内。
本申请的正极片310没有特别限制，正集流体311可以为本领域公知的任何正集流体311，如铝箔、铝合金箔或复合集流体等，正极活性材料312可以为现有技术的任何正极活性材料312，正极活性材料312包括NCM811、NCM622、NCM523、NCM111、NCA、磷酸铁锂、钴酸锂、锰酸锂、磷酸锰铁锂或钛酸锂中的至少一种。
本申请的负极片320也没有特别限制，负集流体321可以为本领域公知的任何负集流体321，如铜箔、铝箔、铝合金箔或复合集流体等，负极活性材料322可以为现有技术的任何负极活性材料322，负极活性材料322包括石墨、硬碳、软碳、硅、硅碳或硅氧化物等中的至少一种。
本申请的电解液也没有特别限制，可以使用本领域公知的任何电解液，电解液可以是凝胶态、固态和液态中的任一种。当电解液为液态电解液时，液态电解液包括锂盐和非水溶剂。锂盐没有特别限制，可以使用本领域公知的任何锂盐，只要能实现本申请的目的即可，例如，锂盐可以包括LiPF6、LiBF4、LiAsF6、LiClO4、LiB(C6H5)4、LiCH3SO3、LiCF3SO3、LiN(SO2CF3)2、LiC(SO2CF3)3或LiPO2F2等中的至少一种。非水溶剂没有特别限定，只要能实现本申请的目的即可，例如，非水溶剂可以包括碳酸酯化合物、羧酸酯化合物、醚化合 物、腈化合物或其它有机溶剂等中的至少一种，碳酸酯化合物可以包括碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸甲乙酯(MEC)、碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)、碳酸乙烯基亚乙酯(VEC)、碳酸氟代亚乙酯(FEC)、碳酸1,2-二氟亚乙酯、碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯或碳酸三氟甲基亚乙酯等中的至少一种。
本申请的隔膜400没有特别限制，例如，隔膜400可包括由对本申请的电解液稳定的材料制得。隔膜400应当具有离子传导性，使离子从隔膜400穿过在正极片310和负极片320之间活动，同时，隔膜400还应当具有电子绝缘性，以阻隔正极片310和负极片320相接触，防止正极片310和负极片320短接。
本申请实施例还提供了本申请实施例提供了一种用电设备，包括如上的电化学装置10，例如，用电设备可包括汽车等。
以下将以电化学装置10为锂离子电池为例，结合具体实施例对本申请作进一步详细的说明。
实施例1
电极组件200制备：将正极片310、负极片320和隔膜400卷绕或者叠片设置，并设置正极耳510与正极片310的正集流体311电连接，负极耳520与负极片320的负集流体321电连接，以制得电极组件200，并制备两个电极组件200(其中一个为第一电极组件210、另一个为第二电极组件220)，两个电极组件200在长度反向、宽度方向、厚度方向尺寸均相同。正极耳510由铝制得，负极耳520由镍制得，正极耳510和负极耳520朝向同侧设置。
隔板100制备：提供具有热熔封装功能、厚度为10μm的PP薄膜作为密封层110，以三甲基铝和H 2O作为反映前驱体沉积于密封层110相对的两表面，其中，三甲基铝与PP表面的官能团发生反应，使三甲基铝能够沉积在PP表面，水进一步与沉积在PP表面的三甲基铝反应，-OH取代三甲基，如此循环反应，生成Al 2O 3，从而形成阻隔层120。在密封层110表面生成的各阻隔层120厚度为0.05μm。其中，隔板100总厚度为10.05μm，阻隔层120厚度与密封层110厚度比为0.005。在厚度方向，阻隔层120的投影与密封层110的投影重叠，也即，S1＝S2。
电化学装置10组装：提供两个外包装700，外包装700由厚度为150μm的铝塑膜冲压形成具有凹坑的结构。将第一电极组件210置于其中一个外包装700的凹坑内，隔板100覆盖第一电极组件210，且使隔板100的密封层110的边缘部分102与外包装700连接，并施加压力将隔板100与外包装700初步压制成型，获得半成品。再将第二电极组件220置于半成品的隔板100上，将另一个外包装700凹坑朝下覆盖第二电极组件220，使隔板100密封 层110的边缘部分102置于两个外包装700之间，对应密封层110的边缘部分102施加压力作用于两个外包装700，将密封层110的边缘部分102在150℃热压至密封连接于两个外包装700。隔板100将两个外包装700内部的空间分隔为两个独立的第一腔室700a。两个电极组件的正极耳510和负极耳520均伸出外包装700，获得预成型产品。
注液封装：通过各外包装700上的开口向各第一腔室700a内分别独注入电解液，待注液结束后，封装外包装700的开口。
串接：将其中一个电极组件的正极耳510与另一个电极组件的负极耳520贴合且焊接固定，以将两个电极组件串接，获得具有两个电化学单元的电化学装置10。连接电化学装置10内未焊接的正极耳510和负极耳520，可对电化学装置10充放电。连接焊接在一起的两个极耳，可监测电化学装置10内的电压。
实施例2
与实施例1的区别在于：PP薄膜的厚度为30μm。阻隔层120厚度与密封层110厚度比为0.0017。
实施例3
与实施例1的区别在于：PP薄膜的厚度为80μm。阻隔层120厚度与密封层110厚度比为0.0006。
实施例4
与实施例1的区别在于：PP薄膜的厚度为100μm。阻隔层120厚度与密封层110厚度比为0.0005。
实施例5
与实施例1的区别在于：PP薄膜的厚度为300μm。阻隔层120厚度与密封层110厚度比为0.0002。
实施例6
与实施例3的区别在于：阻隔层120的厚度为0.005μm。阻隔层120厚度与密封层110厚度比为0.0001。
实施例7
与实施例3的区别在于：阻隔层120的厚度为0.1μm。阻隔层120厚度与密封层110厚度比为0.0013。
实施例8
与实施例3的区别在于：阻隔层120的厚度为0.2μm。阻隔层120厚度与密封层110厚度比为0.0025。
实施例9
与实施例1的区别在于：PP薄膜的厚度为76μm，阻隔层120的厚度为2μm。阻隔层120厚度与密封层110厚度比为0.0263。
实施例10
与实施例1的区别在于：PP薄膜的厚度为80μm，阻隔层120的厚度为0.1μm，密封层110的中间部分101的面积S、阻隔层120的面积S1、密封层110的面积S2三个参数满足条件式：S＜S1＝S2。阻隔层120厚度与密封层110厚度比为0.0013。
实施例11
与实施例10的区别在于：密封层110的中间部分101的面积S、阻隔层120的面积S1、密封层110的面积S2三个参数满足条件式：S＜S1＜S2。
实施例12
与实施例10的区别在于：密封层110的中间部分101的面积S、阻隔层120的面积S1、两个参数满足条件式：S＝S1。
实施例13
与实施例1的区别在于：由厚度为80μm的PE薄膜作为密封层111，阻隔层120的厚度为0.1μm，以及将密封层110的边缘部分102120℃热压至密封连接于两个外包装700。阻隔层120厚度与密封层110厚度比为0.0013。
实施例14
与实施例13的区别在于：由厚度为80μm的聚苯乙烯薄膜作为密封层111，以及将密封层110的边缘部分102240℃热压至密封连接于两个外包装700。
实施例15
与实施例1的区别在于：由厚度为80μm的PP薄膜作为密封层111，在密封层110表面沉积厚度为0.1μm的Al，以形成阻隔层120，以及将密封层110的边缘部分102150℃热压至密封连接于两个外包装700。阻隔层120厚度与密封层110厚度比为0.0013。
实施例16
与实施例15的区别在于：在密封层110厚度方向，先在密封层110表面分子沉积一层Al 2O 3后，再在Al 2O 3表面沉积聚酰亚胺，以在密封层110表面形成阻隔层120。由Al 2O 3和聚酰亚胺形成的阻隔层120的厚度为0.1μm。
实施例17
与实施例7的区别在于：在密封层110厚度方向，先将环氧树脂喷涂于密封层110相对的两表面，以在密封层110相对的两个表面分别生成流平层112，流平层112的厚度为10nm。再在各流平层112表面分别沉积一层阻隔层120。
实施例18
与实施例7的区别在于：在密封层110厚度方向，在各阻隔层120表面分别喷涂一层聚氨酯丙烯酸酯，以在阻隔层120表面形成加强层130，加强层130的厚度为10μm。
实施例19
与实施例13的区别在于：在制备PP薄膜的原料内混入勃姆石片，以制得厚度为80μm的密封层110，以及将密封层110的边缘部分102于150℃热压至密封连接于两个外包装700。
实施例20
与实施例13的区别在于：在密封层110单侧设置阻隔层120。
实施例21
与实施例13的区别在于：提供三个电极组件、两层隔板100，将电极组件和隔板100交替置于两个外包装700之间，各隔板100密封层110的边缘部分102均置于两个外包装700之间，并将各密封层110的边缘部分102150℃热压至密封连接于两个外包装700。
对比例1
与实施例1的区别在于：将热熔状态的PP材料均匀分散到分散剂N-甲基吡咯烷酮(NMP)中，得到悬浊液，利用涂胶机，将悬浊液涂布至Al薄膜相对的两表面，150℃烘干悬浊液内的分散剂NMP，获得连接于Al薄膜表面的封装层，即完成了隔板100的制备，封装层用于与外包装700热熔连接，Al薄膜具有离子绝缘性。本对比例将两层封装层连接于Al薄膜相对的两个表面，隔板100总厚度为120μm，两层封装层总厚度为80μm，Al薄膜厚度为40μm，Al薄膜厚度与两层封装层总厚度比为0.5，此时封装层面积S2＝阻隔层面积S1。
对比例2
与实施例1的区别在于：单独以PP薄膜作为隔板100，隔板100总厚度为80μm。其中，PP薄膜具有离子绝缘性，同时与外包装700于150℃热熔连接。
对比例3
与实施例1的区别在于：单独以Al作为隔板100，隔板100总厚度为80μm，Al隔板100具有离子绝缘性，且Al隔板100直接与外包装700采用封装胶连接。
对比例4
与实施例1的区别在于：PP薄膜的厚度为80μm，阻隔层120的厚度为0.05μm，阻隔层120厚度与密封层110厚度比为0.0006。将隔板100沿其对角线折叠后，再将隔板100密封层110的边缘部分102与外包装700热轧连接。
使用下述方法对各实施例和对比例中的用于电化学装置10的隔板100、电化学装置10进行测试：
封印强度测试：从电化学装置10取下外包装700与隔板100热熔连接的部分，并裁剪为宽度为8mm的试条，保证此试条两侧的外包装700完好无损，得到待检样。使用高铁拉力机， 以180°角将待检样两侧的外包装700撕开，使得两层外包装700相互分离。记录上述两层外包装700分离时的稳定拉力，并以此为基础计算得到封装强度。
50cls容量保持率：内部串联电极组件个数为n，将电化学装置10在25℃环境下，以2C的充电速率从3.0*nV充电至4.45*nV，再以0.2C的放电速率放电至3.0*n V，确定此次的放电容量为首次放电容量，重复上述充放电循环50次，测定第50次放电的放电容量，50cls容量保持率＝第50次放电容量/首次放电容量。
能量密度测试：内部串联电极组件个数为n，将电化学装置10在25℃下静置30分钟，以0.05C充电速率恒流充电至电压4.45*nV，随后再以0.05C倍率将电化学装置10放电至3.00*nV，重复上述充/放电步骤3个循环以完成待测的电化学装置10的化成。完成电化学装置10的化成后，以0.1C充电速率恒流充电至电压至4.45*nV，随后以0.1C放电倍率将电化学装置10放电至3.00*nV，记录其放电容量，随后计算其0.1C放电时的能量密度：能量密度(Wh/L)＝放电容量(Wh)/电化学装置10体积尺寸(L)。
跌落测试：将电化学装置10的6面4角分别从高度1.5m处跌落，6面4角各一次为一轮，共五轮，即50次，视无发热、无漏液、无鼓胀、无着火电芯为通过电芯，其他属未通过电芯，从而确定通过电芯的比例。
上述各实施例和对比例的参数设置请见表1，测试结果请见表2。
表1
Figure PCTCN2022078428-appb-000001
Figure PCTCN2022078428-appb-000002
表2
Figure PCTCN2022078428-appb-000003
Figure PCTCN2022078428-appb-000004
由表1可知，相较于对比例1至3，本申请实施例1-21(除实施例5外)的电化学装置能量密度增大，可以看出应用本申请实施例的隔板制得的电化学装置，相较于应用中间层为阻隔层两侧为封装层的隔板、单独采用聚合物的隔板、以及单独采用阻隔层的隔板，制得的电化学装置，本申请实施例制得的电化学装置所用的隔板厚度更薄，极大减少电芯内部非活性物质占比，且隔板阻隔性能和粘接性能更好，导致容量发挥更高，从而实现高能量密度的技术效果。
相较于对比例1至4，本申请实施例1-21(除实施例1、2和6外)的电化学装置50次循环后的放电容量与首次放电容量的比值基本不发生变化，说明本申请实施例具有高的电解液阻隔性能，保证两个电化学腔体的有效分隔，同时，该方案的隔板与包装袋边缘具有良好的封装，可以有效防止外部水氧的入侵，从而具有良好的循环性。
通过实施例3至21和对比例3可以看出，本申请的电化学装置跌落破损比例明显降低，说明本申请制备的隔板具有良好的柔韧性，在外部作用下，不易发生断裂而造成短路，应用于电化学装置中可以很好的抗跌落损坏。
通过实施例3至21和对比例3可以看出，本申请的电化学装置的外包装与隔板的封印强度明显提升，说明本申请制备的隔板的封装方法可靠，应用于电化学装置中可起很好的封装 效果。
本实施例的附图中相同或相似的标号对应相同或相似的部件；在本申请的描述中，需要理解的是，若有术语“上”、“下”、“左”、“右”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此附图中描述位置关系的用语仅用于示例性说明，不能理解为对本专利的限制，对于本领域的普通技术人员而言，可以根据具体情况理解上述术语的具体含义。
以上所述仅为本申请的较佳实施例而已，并不用以限制本申请，凡在本申请的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本申请的保护范围之内。

Claims (10)

  1. 一种用于电化学装置的隔板，其特征在于，包括：
    密封层，包括中间部分、围设并连接于所述中间部分外围的边缘部分，所述中间部分容置于电化学装置的外包装的内部空间，所述边缘部分用于与所述外包装密封连接。
  2. 根据权利要求1所述的用于电化学装置的隔板，其特征在于，所述密封层包括热塑性聚合物，所述热塑性聚合物的熔点范围为100℃至200℃；
    所述热塑性聚合物包括：聚丙烯、聚乙烯、聚酯塑料、γ-邻苯二甲酰亚氨基-α-羟基丁酸、酸酐改性聚丙烯、乙烯及其共聚物、流延聚丙烯、聚酰亚胺、聚四氟乙烯、聚偏二氟乙烯及其衍生物中的至少一种。
  3. 根据权利要求1所述的用于电化学装置的隔板，其特征在于，所述隔板还包括阻隔层，各所述阻隔层具有离子绝缘性，所述阻隔层设置于所述密封层的至少一侧；
    在所述密封层与所述阻隔层的层叠的厚度方向上，所述阻隔层的投影至少覆盖所述中间部分的投影。
  4. 根据权利要求3所述的用于电化学装置的隔板，其特征在于：
    在垂直于所述密封层与所述阻隔层层叠方向的平面内，所述中间部分的面积为S，所述阻隔层的面积为S1，所述密封层的面积为S2，所述隔板满足S＜S1≤S2或S≤S1＜S2；和/或，
    所述密封层的所述中间部分的长度为a、宽度为b，所述阻隔层的长度为a1、宽度为b1，所述密封层的长度为a2、宽度为b2，所述隔板满足：a＜a1≤a2、b＜b1≤b2，或a≤a1＜a2、b≤b1＜b2。
  5. 根据权利要求3所述的用于电化学装置的隔板，其特征在于，所述阻隔层采用原子层沉积、分子层沉积、化学气相沉积、物理气相沉积、电沉积或3D打印中的至少一种方式化学键合连接于所述密封层的表面。
  6. 根据权利要求3所述的用于电化学装置的隔板，其特征在于，所述阻隔层包括氧化物层、氮化物层、金属层、有机聚合物中的至少一种；
    所述氧化物层包括氧化铝层、氧化锌层、氧化锆层、氧化硅层、硅铝氧化物层中的至少一种；
    所述氮化物层包括氮化铝层、氮化锌层、氮化锆层、氮化硅层、硅铝氮化物层中的至少一种；
    金属层包括：Si、Zn、Al、Zr、Ti、V、Mg、Ni、Pr、Ce、Mn、Ta、In、Zn、Ga、Sn、Cd、Pb、Ni、Ti、Cu、Ag、Au、Pt、Fe、Co、Cr、W中的至少一种金属材料或合金材料；
    有机聚合物包括：偏氯乙烯-丙烯酸甲酯、聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯、乙烯一乙烯醇的无规共聚物、树脂、聚丙烯腈、聚偏二氯乙烯、聚酰胺、聚酰亚胺-酰胺、聚氨酯、聚硫脲、聚乙二醇或有机金属聚合物中的至少一种。
  7. 根据权利要求3-6中任一项所述的用于电化学装置的隔板，其特征在于，所述隔板具有以下特征中的至少一个：
    (a)所述隔板的第一水汽透过率M1满足M1≤10 -3g/(day·m 2)；
    (b)所述密封层的厚度为H，H的范围为14μm至304μm；所述阻隔层的厚度为h，h的范围为5nm至2000nm；
    (c)所述密封层包含离子阻隔片，所述离子阻隔片包括片状石墨烯、水滑石纳米片、勃姆石片中的至少一种；
    (d)所述密封层还包括流平层，所述流平层连接于所述阻隔层，所述流平层相对于所述阻隔层的表面具有低粗糙度，所述流平层包括环氧树脂、聚丙烯树脂、聚丙烯酸酯等聚合物材料中的一种或多种；
    (e)所述隔板还包括位于所述密封层或阻隔层表面的加强层，所述加强层设置于所述阻隔层和/或所述密封层的表面，所述加强层包括聚合物层、玻璃纤维层、碳材料层、弹性聚合物层、氧化物层的至少一种。
  8. 一种电化学装置，其特征在于，包括：
    如上述权利要求1-7中任一项所述的隔板；
    外包装，所述隔板设于所述外包装内，且所述隔板连接于所述外包装，以将所述外包装的内部空间分隔出多个第一腔室；
    电解液，设于各所述第一腔室；及
    多个电极组件，对应设于各所述第一腔室与所述电解液相接触。
  9. 根据权利要求8所述的电化学装置，其特征在于，所述外包装包括连接层，所述连接层与所述隔板的边缘部分相连接，所述连接层包括聚合物；
    所述聚合物包括：聚丙烯、聚乙烯、聚酯塑料、γ-邻苯二甲酰亚氨基-α-羟基丁酸、酸酐改性聚丙烯、乙烯及其共聚物、流延聚丙烯、聚酰亚胺、聚四氟乙烯、聚偏二氟乙烯及其衍生物中的至少一种。
  10. 一种用电设备，其特征在于，包括：
    如上述权利要求8或9中所述的电化学装置。
PCT/CN2022/078428 2022-02-28 2022-02-28 用于电化学装置的隔板、电化学装置及用电设备 WO2023159610A1 (zh)

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Publication number Priority date Publication date Assignee Title
CN104143652A (zh) * 2013-05-09 2014-11-12 神华集团有限责任公司 双极性电池及其封装方法
CN105009353A (zh) * 2013-03-05 2015-10-28 神华集团有限责任公司 双极性电池及其制备方法和车辆
JP2020161290A (ja) * 2019-03-26 2020-10-01 三菱ケミカル株式会社 仕切り部材及び組電池
CN113471631A (zh) * 2021-07-05 2021-10-01 宁德新能源科技有限公司 电化学装置及包含该电化学装置的电子装置

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CN105009353A (zh) * 2013-03-05 2015-10-28 神华集团有限责任公司 双极性电池及其制备方法和车辆
CN104143652A (zh) * 2013-05-09 2014-11-12 神华集团有限责任公司 双极性电池及其封装方法
JP2020161290A (ja) * 2019-03-26 2020-10-01 三菱ケミカル株式会社 仕切り部材及び組電池
CN113471631A (zh) * 2021-07-05 2021-10-01 宁德新能源科技有限公司 电化学装置及包含该电化学装置的电子装置

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