WO2023004833A1 - 电池单体、电池、用电装置及制备电池单体的方法和设备 - Google Patents

电池单体、电池、用电装置及制备电池单体的方法和设备 Download PDF

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Publication number
WO2023004833A1
WO2023004833A1 PCT/CN2021/109921 CN2021109921W WO2023004833A1 WO 2023004833 A1 WO2023004833 A1 WO 2023004833A1 CN 2021109921 W CN2021109921 W CN 2021109921W WO 2023004833 A1 WO2023004833 A1 WO 2023004833A1
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WIPO (PCT)
Prior art keywords
electrode assembly
battery cell
support
electrode
pole piece
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PCT/CN2021/109921
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English (en)
French (fr)
Inventor
杨彦超
喻鸿钢
唐代春
杨晴雅
Original Assignee
宁德时代新能源科技股份有限公司
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Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to CN202180071668.3A priority Critical patent/CN116349052A/zh
Priority to PCT/CN2021/109921 priority patent/WO2023004833A1/zh
Publication of WO2023004833A1 publication Critical patent/WO2023004833A1/zh

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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/058Construction or manufacture
    • H01M10/0587Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the embodiments of the present application relate to the field of battery technology, and in particular to a battery cell, a battery, an electrical device, and a method and device for preparing a battery cell.
  • Battery cells are widely used in electronic equipment, such as mobile phones, laptop computers, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.
  • the battery cells may include nickel-cadmium battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, secondary alkaline zinc-manganese battery cells, and the like.
  • the embodiments of the present application provide a battery cell, a battery, an electrical device, and a method and equipment for preparing a battery cell, which can reduce the probability of an internal short circuit of the battery cell and improve the safety performance of the battery cell .
  • a battery cell including: a casing; an electrode assembly arranged in the casing, the electrode assembly includes a positive pole piece and a negative pole piece, and the positive pole
  • the sheet and the negative electrode sheet are stacked and wound to form a winding structure, the electrode assembly includes a straight zone and a bent zone, and the bent zone is located at the end of the straight zone along the first direction; a support member , the support member is arranged in the casing, on the side of the electrode assembly, and the support member is used to reduce the innermost pole piece of the electrode assembly located in the bending area along the electrode assembly.
  • the expansion space in the thickness direction is provided.
  • the expansion space of the innermost pole piece of the electrode assembly located in the bending area along the thickness direction of the electrode assembly can be reduced.
  • it can make the innermost pole piece of the electrode assembly located in the bending area not easy to wrinkle, prevent lithium ions from depositing at the wrinkle, cause lithium precipitation to trigger thermal runaway, and improve the safety of the battery cell .
  • At least part of the support member is located at the junction of the bending zone and the straight zone.
  • the position of the support is set so that at least part of the support is located at the junction of the bending zone and the straight zone, which can reduce the expansion space of the part of the innermost pole piece that is prone to wrinkling along the thickness direction of the electrode assembly, making this part extremely
  • the sheet is not easy to wrinkle, preventing the deposition of lithium ions in the wrinkled place, causing lithium precipitation to trigger thermal runaway.
  • the largest dimension of the support member corresponds to the corner of the innermost pole piece and abuts against the electrode assembly.
  • the largest size of the support is set to correspond to the corner of the innermost pole piece, and the support is against the electrode assembly, which can reduce the expansion space along the thickness direction of the electrode assembly at the corner of the innermost pole piece, so that This part of the pole piece is not easy to wrinkle, which prevents the deposition of lithium ions in the wrinkled place, causing lithium precipitation to trigger thermal runaway.
  • both ends of the support member are flush with ends of the negative electrode sheet along a second direction, and the second direction is perpendicular to the first direction and the thickness direction.
  • the support can be evenly spaced in the second direction.
  • the expansion space of the innermost pole piece of the electrode assembly located in the bending area along the thickness direction of the electrode assembly can be reduced, and the support member can be prevented from protruding from the negative pole piece, which increases the weight of the battery cell and reduces the energy density of the battery cell.
  • the support includes a first support portion, a second support portion and a connecting portion, the first support portion and the second support portion are respectively located at two ends of the support, and the connection part is used to connect the first supporting part and the second supporting part;
  • the bending area includes a first bending area and a second bending area, at least part of the first supporting part and the first bending area The position of the bending area corresponds, and at least part of the second support part corresponds to the position of the second bending area.
  • the expansion space of the innermost pole piece along the thickness direction of the electrode assembly at both ends can be reduced, so that This part of the pole piece is not easy to wrinkle, and the structural strength of the support can be improved by providing the connecting part between the first support part and the second support part.
  • the connecting portion is a hollow structure for providing expansion space for the straight region.
  • connection part As a hollow structure, it is possible to reserve an expansion space for the flat area of the electrode assembly in the thickness direction to prevent lithium precipitation, thereby reducing the impact on the safety of the battery cell.
  • connection part includes a first connection part and a second connection part arranged along the second direction, the hollow structure is formed between the first connection part and the second connection part, the The second direction is perpendicular to the first direction and the thickness direction.
  • the first connecting portion and the second connecting portion arranged along the second direction can improve the structural strength of the supporting member and prevent the supporting frame from falling down.
  • the connecting portion includes a first connecting portion and a second connecting portion disposed along the thickness direction, and the first connecting portion and the second connecting portion are close to the side of the electrode assembly and the The sides of the first support part and the second support part close to the electrode assembly are flush.
  • first connection part and the second connection part By arranging the first connection part and the second connection part along the thickness direction, a hollow structure is formed between the first connection part and the second connection part, which can reserve an expansion space for the flat region of the electrode assembly in the thickness direction, preventing lithium precipitation, Thereby reducing the impact on the safety of the battery cell; the sides of the first connection part and the second connection part close to the electrode assembly are flush with the sides of the first support part and the second support part close to the electrode assembly, so that the entire support is close to the electrode
  • the side of the component is flat, which can reduce the stress concentration at the contact position between the side of the first support part and the second support part and the electrode assembly, thereby reducing the damage of the support part to the electrode assembly in contact with it, and preventing the positive and negative electrodes from overlapping. Reduce the risk of short circuit inside the battery cell.
  • the outer surface of the support member in contact with the electrode assembly is an arc surface.
  • the stress at the contact position between the side edges of the first support part and the second support part and the electrode assembly can be further reduced Concentration, so as to avoid the damage of the support part to the electrode assembly in contact with it, prevent the positive and negative electrodes from overlapping, and reduce the risk of short circuit inside the battery cell.
  • the battery cell includes a plurality of electrode assemblies, and the plurality of electrode assemblies are arranged side by side in the casing along the thickness direction, and in the thickness direction, the support member is disposed on the between the casing and the electrode assembly adjacent to the casing.
  • the battery cell includes a plurality of electrode assemblies, the plurality of electrode assemblies are arranged side by side in the casing along the thickness direction, and the support member is disposed between two adjacent electrode assemblies between.
  • one support can simultaneously make the innermost pole pieces of the two electrode assemblies on both sides of the support in the bending area not easy Wrinkled, thereby achieving the same effect by using fewer supports, reducing battery cell weight.
  • the support is fixed to the side of the electrode assembly by sticking, or the support is fixed to the side of the electrode assembly by a buckle.
  • the support By setting the buckle, the support can be fixed on the side of the electrode assembly, preventing the support from falling down during use, or being displaced relative to the electrode assembly, causing wrinkles on the innermost pole piece of the electrode assembly located in the bending area
  • the suppression effect of the support is reduced, and the fixing method of the buckle improves the structural strength of the support; by pasting and fixing the support on the side of the electrode assembly, it prevents the support from falling down during use, or displacement relative to the electrode assembly, and the pasting
  • the method can reduce the weight of the interlayer unit, and has little impact on the energy density of the battery cell.
  • the support member is provided with a through hole through which the electrolyte passes through in a second direction, and the second direction is perpendicular to the first direction and the thickness direction.
  • the supporting member is provided with a through-hole for the electrolyte to pass through in the second direction, the electrolyte can flow from the bottom of the battery cell to the top through the through-hole, improving the wetting effect of the electrolyte on the electrode assembly and ensuring the battery cell. Charge and discharge performance.
  • the electrode assembly further includes a separator for isolating the positive electrode sheet and the negative electrode sheet
  • the support member is one or more layers of separators located outside the electrode assembly
  • the One or more layers of diaphragms have through holes penetrating along the thickness direction, and the through holes are arranged corresponding to the straight regions.
  • the expansion space of the innermost pole piece of the electrode assembly located in the bending area along the thickness direction of the electrode assembly can be reduced; by using this as a support Through holes are set on part of the diaphragm, which can reserve expansion space for the flat area of the electrode assembly in the thickness direction to prevent lithium deposition, thereby reducing the impact on the safety of the battery cell; in addition, directly using the diaphragm as a support can simplify components, reducing the difficulty of processing and assembly.
  • a battery including the battery cells of the above embodiments.
  • an electric device including the battery cell in the above embodiment, wherein the battery cell is used to provide electric energy.
  • a method for preparing a battery cell including: providing a casing; providing an electrode assembly, the electrode assembly including a positive electrode piece and a negative electrode piece, the positive electrode piece and the negative electrode piece
  • the negative pole pieces are stacked and wound to form a winding structure, the electrode assembly includes a straight area and a bent area, the bent area is located at the end of the straight area along the first direction; a support is provided; disposing the electrode assembly and the support member in the casing, and making the support member located on the side of the electrode assembly, so that the support member can reduce the electrode located in the bending area
  • the expansion space of the innermost pole piece of the assembly along the thickness direction of the electrode assembly including: providing a casing; providing an electrode assembly, the electrode assembly including a positive electrode piece and a negative electrode piece, the positive electrode piece and the negative electrode piece
  • the negative pole pieces are stacked and wound to form a winding structure, the electrode assembly includes a straight area and a bent area, the bent area is located at the end of the straight area along the
  • a device for preparing a battery cell including: a first providing device configured to provide a casing; a second providing device configured to provide an electrode assembly, the electrode The assembly includes a positive pole piece and a negative pole piece, the positive pole piece and the negative pole piece are laminated and wound to form a winding structure, the electrode assembly includes a straight zone and a bent zone, and the bent zone is located at the The end of the straight region along the first direction; the third providing device is configured to provide a support; the assembly device is configured to arrange the electrode assembly and the support in the casing, and make the The support is located on the side of the electrode assembly, so that the support can reduce the expansion space of the innermost pole piece of the electrode assembly located in the bending area along the thickness direction of the electrode assembly.
  • Fig. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Fig. 2 is a schematic explosion diagram of a battery provided by some embodiments of the present application.
  • Fig. 3 is a schematic structural diagram of the battery module in Fig. 2;
  • Fig. 4 is an exploded schematic diagram of a battery cell provided by some embodiments of the present application.
  • Fig. 5 is a schematic structural view of a cross-section of the electrode assembly of Fig. 4 in the XOY plane;
  • Fig. 6 is a schematic diagram of cooperation between the electrode assembly and the support in Fig. 4;
  • Fig. 7 is a schematic diagram of the cooperation of the electrode assembly and the support provided by some embodiments of the present application.
  • Fig. 8 is a schematic structural diagram of a support provided by some embodiments of the present application.
  • Fig. 9 is a schematic diagram of cooperation between the support member and the electrode assembly shown in (a) in Fig. 8;
  • Fig. 10 is a schematic structural view of a support provided by some embodiments of the present application.
  • Fig. 11 is a schematic diagram of cooperation between the support and the electrode assembly shown in (a) in Fig. 10;
  • Fig. 12 is a schematic structural view of a support provided by some embodiments of the present application.
  • Fig. 13 is a schematic diagram of cooperation between the support and the electrode assembly shown in (a) in Fig. 12;
  • Figure 14 is a schematic diagram of the coordination of the electrode assembly and the support in the battery cell provided by some embodiments of the present application.
  • Fig. 15 is a schematic diagram of cooperation between an electrode assembly and a support in a battery cell provided by some embodiments of the present application;
  • Fig. 16 is a schematic diagram of cooperation between an electrode assembly and a support in a battery cell provided by some embodiments of the present application;
  • Fig. 17 is a schematic diagram of the coordination of the electrode assembly and the support in the battery cell provided by some embodiments of the present application.
  • Fig. 18 is a schematic diagram of cooperation between the electrode assembly and the support in the battery cell provided by some embodiments of the present application.
  • Fig. 19 is a schematic diagram of cooperation between an electrode assembly and a support in a battery cell provided by some embodiments of the present application.
  • Fig. 20 is an exploded schematic diagram of a battery cell provided by some embodiments of the present application.
  • Fig. 21 is a schematic diagram of the assembly of the buckle and the electrode assembly in Fig. 20;
  • Fig. 22 is a schematic top view of the buckle and the electrode assembly in the XOY plane in Fig. 21;
  • Fig. 23 is a schematic cross-sectional structure diagram of the A-A direction in Fig. 22;
  • Fig. 24 is an exploded schematic diagram of a battery cell provided by some embodiments of the present application.
  • Fig. 25 is an exploded schematic diagram of a battery cell provided by some embodiments of the present application.
  • Fig. 26 is a schematic flowchart of a method for preparing a battery cell provided by some embodiments of the present application.
  • Fig. 27 is a schematic structural diagram of a device for preparing a battery cell provided by some embodiments of the present application.
  • 72-electrode assembly 721-positive pole piece, 722-negative pole piece, 722a-innermost pole piece, 723-diaphragm, 724-through hole, R 1 -straight area, R 2 -bending area, R 21 - the first bending zone, R 22 - the second bending zone;
  • Multiple appearing in this application refers to more than two (including two), similarly, “multiple groups” refers to more than two groups (including two groups), and “multi-piece” refers to more than two (including two pieces), unless expressly and specifically qualified otherwise.
  • the electrode assembly of the battery usually includes a positive electrode sheet, a negative electrode sheet and a separator, and the positive electrode sheet, the negative electrode sheet and the separator are stacked and wound around the winding axis to form a winding structure.
  • the wound electrode assembly includes a straight zone and bending zones located at both ends of the straight zone.
  • the positive pole piece includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector.
  • the material of the positive electrode current collector can be aluminum
  • the positive electrode active material layer includes the positive electrode active material
  • the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the material of the negative electrode current collector may be copper, the negative electrode active material layer includes the negative electrode active material, and the negative electrode active material may be carbon or silicon.
  • the material of the diaphragm can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • lithium ions intercalated into the pole piece will lead to changes in the lattice parameters of the pole piece, causing the pole piece to expand in the thickness direction, and expand and contract with the frequency of charge and discharge.
  • the expansion of the innermost pole piece of the electrode assembly located in the bending area is likely to cause wrinkling of this part of the pole piece, and lithium ions are easy to deposit on the wrinkle, resulting in lithium precipitation.
  • the precipitated lithium dendrites may react with the electrolyte and locally generate A large amount of heat or piercing the separator will cause a short circuit between the positive and negative electrodes, which will cause thermal runaway of the battery cell and cause a safety accident.
  • the present application provides a battery cell, which can reduce the thickness of the innermost pole piece of the electrode assembly located in the bending area along the electrode assembly by arranging a support on the side of the electrode assembly in the casing
  • the expansion space in the direction, during the charge and discharge process of the battery cell can make the innermost pole piece of the electrode assembly located in the bending area not easy to wrinkle, prevent lithium ions from depositing at the wrinkle, and cause lithium precipitation to trigger thermal runaway.
  • the battery cells described in the embodiments of the present application are applicable to batteries and electric devices using batteries.
  • Electric devices can be vehicles, mobile phones, portable devices, notebook computers, ships, spacecraft, electric toys and electric tools, and so on.
  • Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles;
  • spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.;
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric boat toys and electric airplane toys, etc.;
  • electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, electric planers, and more.
  • the embodiments of the present application do not impose special limitations on the above-mentioned electrical devices.
  • the electric device is taken as an example for description.
  • FIG. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • a battery 2 is provided inside a vehicle 1
  • a battery 2 refers to a single physical module including one or more battery cells to provide higher voltage and capacity, for example, the one mentioned in this application
  • the battery 2 may include a battery module or a battery pack or the like.
  • the battery 2 can be arranged at the bottom or the head or the tail of the vehicle 1 .
  • the battery 2 can be used for power supply of the vehicle 1 , for example, the battery 2 can be used as an operating power source of the vehicle 1 .
  • the vehicle 1 may also include a controller 3 and a motor 4 , the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, for the starting, navigation and working power requirements of the vehicle 1 during driving.
  • the battery 2 can not only be used as an operating power source for the vehicle 1 , but can also be used as a driving power source for the vehicle 1 to provide driving power for the vehicle 1 instead of or partially replacing fuel oil or natural gas.
  • FIG. 2 is a schematic explosion diagram of a battery provided in some embodiments of the present application.
  • the battery 2 includes a case body 5 and a battery module 6 , and the battery module 6 is accommodated in the case body 5 .
  • the box body 5 is used to accommodate the battery module 6, and the box body 5 may have various structures.
  • the box body 5 may include a first box body part 51 and a second box body part 52, the first box body part 51 and the second box body part 52 cover each other, the first box body part 51 and the second box body part 51
  • the two box parts 52 jointly define an accommodating space 53 for accommodating the battery module 6 .
  • the second box part 52 can be a hollow structure with an open end, and the first box part 51 can be a plate-shaped structure, and the first box part 51 covers the opening side of the second box part 52 to form an accommodating space.
  • the first casing part 51 and the second casing part 52 also all can be the hollow structure of one side opening, and the opening side of the first casing part 51 covers the opening of the second casing part 52 side to form a box body 5 with an accommodating space 53 .
  • the first box body part 51 and the second box body part 52 can be in various shapes, such as a cylinder, a cuboid, and the like.
  • a sealing member may also be provided between the first box body portion 51 and the second box body portion 52, such as sealant, sealing ring, etc. .
  • the first box part 51 covers the top of the second box part 52
  • the first box part 51 can also be called an upper box cover
  • the second box part 52 can also be called a lower box.
  • the battery 2 there are a plurality of battery cells 7 (not shown in the figure).
  • the plurality of battery cells 7 can be connected in series, in parallel or in parallel.
  • the mixed connection means that the plurality of battery cells 7 are both connected in series and in parallel.
  • a plurality of battery cells 7 can be directly connected in series or in parallel or mixed together, and then the whole composed of a plurality of battery cells 7 is contained in the box body 5; of course, a plurality of battery cells 7 can also be connected in series first
  • the battery modules 6 are formed by connecting in parallel or in series, and a plurality of battery modules 6 are connected in series or in parallel or in series to form a whole, and are accommodated in the box body 5 .
  • FIG. 3 is a schematic structural diagram of the battery module 6 in FIG. 2 .
  • there are multiple battery cells 7 and the multiple battery cells 7 are connected in series, in parallel, or in parallel to form a battery module 6 .
  • a plurality of battery modules 6 are connected in series, in parallel or in parallel to form a whole, and accommodated in the box.
  • the embodiment of the present application provides a battery cell 7 , and the battery cell 7 includes a casing 71 , an electrode assembly 72 and a support member 73 .
  • the electrode assembly 72 is arranged in the housing 71 , and the electrode assembly 72 includes a positive pole piece 721 and a negative pole piece 722 , and the positive pole piece 721 and the negative pole piece 722 are laminated and wound to form a wound structure.
  • the electrode assembly 72 includes a straight region R 1 and a bent region R 2 , and the bent region R 2 is located at an end of the straight region R 1 along the first direction X.
  • the support member 73 is arranged in the casing 71 and is located on the side of the electrode assembly 72. The support member 73 is used to reduce the thickness direction Y of the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2. room for expansion.
  • the battery cells 7 may include lithium-ion secondary battery cells 7, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or Magnesium ion battery cells, etc., are not limited in this embodiment of the present application.
  • the battery cell 7 may be in the shape of a flat body, a rectangular parallelepiped, or other shapes, and the embodiment of the present application is not limited thereto. For the convenience of description, the following embodiments all take a flat body-shaped battery as an example.
  • the battery cells 7 generally include hard-shell battery cells and soft-pack battery cells, which are not limited in this embodiment of the present application.
  • FIG. 4 is a schematic exploded view of a battery cell provided in some embodiments of the present application.
  • the battery cell 7 may include a casing 71 , an electrode assembly 72 , a support 73 , an end cap 74 and an electrolyte (not shown in the figure).
  • the casing 71 may have an opening at one end or at both ends, and the end cap 74 covers the opening of the casing 71 to jointly form an accommodating space for the electrode assembly 72 and the electrolyte with the casing 71 .
  • the shell 71 and the end cap 74 can be made of the same material, for example, the shell 71 and the end cap 74 can be made of aluminum, so that it is easy to weld the shell 71 and the end cap 74, or the shell 71 and the end cover 74 can also be made of different materials, for example, the housing 71 and the end cover 74 can be made of different metals respectively, and other connection methods such as riveting can be used to connect the housing 71 and the end cover 74 .
  • the electrode assembly 72 may include a positive pole piece 721 , a negative pole piece 722 and a separator 723 (see FIG. 6 ).
  • the battery cell 7 mainly relies on the movement of metal ions between the positive pole piece 721 and the negative pole piece 722 to work.
  • the positive pole piece 721 , the negative pole piece 722 and the separator 723 are laminated and wound around the winding axis to form a winding structure.
  • FIG. 5 is a schematic structural diagram of a cross-section of the electrode assembly in FIG. 4 in the XOY plane.
  • the wound electrode assembly 72 includes a straight region R 1 and a bent region R 2 located at the end of the straight region R 1 along the first direction X.
  • the flat region R1 refers to a region with a parallel structure in the winding structure, that is, the positive pole piece 721, the negative pole piece 722, and the separator 723 in the straight region R1 are substantially parallel to each other, that is, the electrode assembly 72 is in a flat state.
  • the surface of each layer of positive electrode sheet 721, negative electrode sheet 722 and separator 723 in the straight region R1 is plane.
  • the bending region R2 refers to the region with a bending structure in the winding structure, that is, the positive pole piece 721, the negative pole piece 722 and the separator 723 in the bending zone R2 are all bent, that is, the electrode assembly 72 is
  • the surface of each layer of positive electrode sheet 721 , negative electrode sheet 722 and separator 723 in the bending region R 2 is a curved surface. As shown in FIG. 5 , both ends of the straight region R 1 along the first direction X have bending regions R 2 .
  • the positive pole piece 721 includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector.
  • the material of the positive electrode current collector can be aluminum
  • the positive electrode active material layer includes the positive electrode active material
  • the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate.
  • the negative electrode sheet 722 includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the material of the negative electrode current collector may be copper
  • the negative electrode active material layer includes the negative electrode active material
  • the negative electrode active material may be carbon or silicon.
  • the material of the diaphragm 723 can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene) or the like.
  • FIG. 6 is a schematic diagram of cooperation between the electrode assembly and the support in FIG. 4 .
  • the support member 73 is located on the side of the electrode assembly 72 , wherein the side of the electrode assembly 72 refers to the surface of the electrode assembly 72 on one side in the thickness direction Y thereof.
  • the shape of the support member 73 may be a prism, a cylinder, an ellipse, etc., which is not limited in this embodiment of the present application.
  • the support member 73 can be made of insulating material to meet the structural strength requirements such as lodging resistance and extrusion resistance, as well as the high temperature resistance requirements for the materials used to prepare the battery. For example, porous polyolefin materials can be selected.
  • electrolyte corrosion and electrochemical corrosion may occur in the battery cell 7 , and the material of the support member 73 must also have corrosion resistance against acid and alkali.
  • the support member 73 By arranging the support member 73 on the side of the electrode assembly 72 in the housing 71, the expansion space of the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2 along the thickness direction Y of the electrode assembly 72 can be reduced, and the battery During the charge and discharge process of the cell 7, the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2 is not easy to wrinkle, preventing lithium ions from depositing at the wrinkle, causing lithium precipitation to trigger thermal runaway, and improving battery performance. Monomer 7 Security.
  • At least part of the support member 73 is located at the junction of the bending region R 2 and the straight region R 1 .
  • the junction of the bent region R2 and the straight region R1 refers to the side of the electrode assembly 72 , the position near the junction of the bent region R2 and the straight region R1, and does not refer to the junction point in the strict sense itself.
  • the position of the support member 73 is set so that at least part of the support member 73 is located in the bending region R 2 and the junction of the flat region R1 can reduce the expansion space of the part of the innermost pole piece 722a that is easy to wrinkle along the thickness direction Y of the electrode assembly 72, so that this part of the pole piece is not easy to wrinkle and prevent lithium ions from being wrinkled. Deposits on the wrinkle, resulting in lithium precipitation and triggering thermal runaway.
  • the largest dimension of the support member 73 corresponds to the corner of the innermost pole piece 722 a and abuts against the electrode assembly 72 .
  • the size of the support member 73 refers to the size of the support member 73 along the thickness direction Y in the XOY plane. "Corresponding" means that in the cross-section shown in FIG. 6 , the projection of the support member 73 at its largest size in the first direction X coincides or substantially coincides with the projection of the corner of the innermost pole piece 722a in the first direction X.
  • the corner of the innermost pole piece 722a refers to the point where the pole pieces on both sides are bent toward the center of the electrode assembly 72 , such as points P1 and P2 shown in FIG. 6 .
  • the abutment of the support member 73 against the electrode assembly 72 means that the support member 73 is in contact with the electrode assembly 72 , and the support member 73 and the electrode assembly 72 may be an interference fit, and at this time there is a force between the two.
  • the support member 73 and the electrode assembly 72 may also be clearance fit, and at this time there is no force between the two.
  • the largest size of the support member 73 is set to correspond to the corner of the innermost pole piece 722a, and the support The part 73 is against the electrode assembly 72, which can reduce the expansion space along the thickness direction Y of the electrode assembly 72 at the corner of the innermost pole piece 722a, so that this part of the pole piece is not easy to wrinkle, and prevents lithium ions from being wrinkled. deposition, leading to lithium precipitation and triggering thermal runaway.
  • the support member 73 is a cuboid (square prism) among Fig. 6, and the support member 73 is placed in its length direction or width direction consistent with the thickness direction Y, and the support member 73 is in the XOY plane along the thickness direction Y.
  • the size is consistent everywhere, and any position of the support member 73 along its length direction or width direction corresponds to the corner of the innermost pole piece 722 a and abuts against the electrode assembly 72 .
  • FIG. 7 is a schematic diagram of cooperation between an electrode assembly and a support provided in some embodiments of the present application.
  • the support member 73 is a cylinder, and the largest dimension of the support member 73 along the thickness direction Y in the XOY plane is P 3 , and the P 3 position of the support member 73 corresponds to the corner of the innermost pole piece 722a, and is against Lean against the electrode assembly 72 .
  • both ends of the support member 73 are flush with the ends of the negative electrode sheet 722 , and the second direction Z is perpendicular to the first direction X and the thickness direction Y.
  • the end of the negative pole piece 722 exceeds the end of the positive pole piece 721 .
  • both the support member 73 can reduce the expansion space of the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2 along the thickness direction Y of the electrode assembly 72 in the second direction Z, and can also Prevent the support member 73 from protruding from the negative pole piece 722 , increase the weight of the battery cell 7 , and reduce the energy density of the battery cell 7 .
  • the support member 73 its thickness (dimension in the thickness direction Y) can be calculated according to the degree of thickness of the electrode assembly.
  • the group margin refers to the ratio of the maximum dimension of the electrode assembly 72 to the maximum dimension of the case 71 in the thickness direction Y.
  • the thickness of the support the thickness of the inner cavity of the shell - (the number of electrode assemblies * the thickness of the electrode assembly) / the thickness of the inner cavity of the shell)
  • the actual degree of separation at the corner of the innermost pole piece 722a of the electrode assembly can meet or substantially meet 100%.
  • FIG. 8-FIG. 9 is a support and an electrode shown in (a) of FIG. 8 Schematic diagram of the fit of the components.
  • the support member 73 includes a first support portion 731, a second support portion 732 and a connecting portion 733, the first support portion 731 and the second support portion 732 are respectively located at two ends of the support member 73, and the connecting portion 733 is used to connect the first support portion 731 and the second supporting part 732.
  • the bending region R 2 includes a first bending region R 21 and a second bending region R 22 , at least part of the first support portion 731 corresponds to the position of the first bending region R 21 , and at least part of the second support portion 732 corresponds to the position of the second bending region R 21 .
  • the positions of the two bending regions R 22 correspond to each other.
  • "Corresponding" means that at least part of the first support part 731 and the projection of the first bending region R21 in the first direction X have overlapping parts, and at least part of the second support part 732 and the second bending region have a projection in the first direction The projection of X has overlapping parts.
  • the innermost pole piece 722a can be reduced along the electrode assembly 72 at both ends.
  • the expansion space in the thickness direction Y makes this part of the pole piece not easy to wrinkle, and the structural strength of the support member 73 can be improved by providing the connection part 733 between the first support part 731 and the second support part 732 .
  • the connecting portion 733 is a hollow structure, and is used to provide an expansion space for the straight region R 1 .
  • the hollow structure means that a part of the connecting portion 733 is hollow, especially the portion corresponding to the middle portion of the connecting portion 733 (such as the flat region R 1 ) of the electrode assembly is a hollow structure.
  • connection portion 733 As a hollow structure, an expansion space can be reserved for the flat region R 1 of the electrode assembly 72 in the thickness direction Y, preventing lithium deposition, thereby reducing the impact on the safety of the battery cell 7 .
  • the connecting portion 733 includes a first connecting portion 733a and a second connecting portion 733b arranged along the thickness direction Y, and the first connecting portion 733a and the second connecting portion 733b are close to the electrode assembly.
  • 72 is flush with the side surfaces of the first support portion 731 and the second support portion 732 close to the electrode assembly 72 .
  • the support member 73 is disposed between the two electrode assemblies 72, the first connecting portion 733a and the second connecting portion 733b respectively abut against the electrode assemblies 72 on both sides, and the first connecting portion 733a is close to the electrode assembly below.
  • both the first connecting portion 733a and the second connecting portion 733b are plate-shaped structures.
  • the sides of the first connecting portion 733a and the second connecting portion 733b close to the electrode assembly 72 are flush with the sides of the first supporting portion 731 and the second supporting portion 732 close to the electrode assembly 72, so that the side of the entire support 73 close to the electrode assembly 72 is plane, which can reduce the stress concentration at the contact position between the side of the first support part 731 and the second support part 732 and the electrode assembly 72, thereby reducing the damage of the support part to the electrode assembly 72 in contact with it, and preventing the positive and negative electrodes from overlapping.
  • the risk of internal short circuit of the battery cell 7 is reduced.
  • FIG. 8 A hollow structure is formed between the parts 733b, and the second direction Z is perpendicular to the first direction X and the thickness direction Y two by two.
  • the first connecting portion 733a and the second connecting portion 733b shown in (b) of FIG. 8 are X-shaped brackets, and the first connecting portion 733a and the second connecting portion 733b shown in (c) of FIG. 8 are thin plate-shaped supports.
  • the first connecting portion 733a and the second connecting portion 733b may also have other shapes, which are not limited in the present invention.
  • the first connecting portion 733a and the second connecting portion 733b arranged along the second direction Z can improve the structural strength of the supporting member 73 and prevent the supporting frame from falling down.
  • the shapes of the first support part 731 and the second support part 732 may be a prism, a cylinder, an ellipse, etc., which are not limited in this embodiment of the present application.
  • the first supporting portion 731 and the second supporting portion 732 shown in FIG. 8 are cuboid structures, and the cross-sectional shape of the first supporting portion 731 and the second supporting portion 732 in the XOY plane is rectangular (square or rectangular).
  • the first support portion 731 and the second support portion 732 of the cuboid structure are easy to process, and when there is an interaction force between the electrode assembly 72 and the support member 73, the first support portion 731 and the second support portion 732 of the cuboid structure have Sufficient strength is used to abut against the electrode assembly 72, reduce the expansion probability of the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2 along the thickness direction Y of the electrode assembly 72 , and reduce the The risk of wrinkling of the innermost pole piece 722a of the electrode assembly 72.
  • FIG. 10 is a schematic structural diagram of a support provided in some embodiments of the present application
  • FIG. 11 is a support and an electrode shown in (a) of FIG. 10 Schematic diagram of the fit of the components.
  • the structure of the first supporting part 731 and the second supporting part 732 in Fig. 10 is different from that in Fig. 8, it is a combination of two triangular prisms, and the cross-sectional shape of the first supporting part 731 and the second supporting part 732 in the XOY plane is two A combination of three triangles, two triangles are set opposite each other, with their apexes connected and their bases parallel.
  • the combined structure of two triangular prisms can reduce the material and weight of the support member 73 and increase the energy density of the battery cell 7 compared with the rectangular parallelepiped structure with the same cross-sectional side length.
  • the outer surface of the support member 73 in contact with the electrode assembly 72 is an arc surface.
  • FIG. 12-FIG. 13 wherein FIG. 12 is a schematic structural diagram of a support provided by some embodiments of the present application, and FIG. 13 is a schematic diagram of cooperation between the support and the electrode assembly shown in (a) of FIG. 12 .
  • the structure of the first support part 731 and the second support part 732 in Fig. 12 is different from that in Fig. 8 and Fig. 10, which is a cylinder, and the cross-sectional shape of the first support part 731 and the second support part 732 in the XOY plane is circular .
  • the first supporting part 731 and the second supporting part 732 of the cylinder make the outer surface of the supporting part 73 in contact with the electrode assembly 72 an arc surface, and compared with the supporting part 73 with angular sides, the first supporting part 731 and the second supporting part 732 can be further reduced.
  • the stress concentration at the contact position between the side of the second support portion 732 and the electrode assembly 72 avoids damage to the electrode assembly 72 in contact with the support portion, prevents positive and negative electrodes from overlapping, and reduces the risk of internal short circuit of the battery cell 7 .
  • the connecting part 733 (including the first connecting part 733a and the second connecting part 733b) can be integrally formed with the first supporting part 731 and the second supporting part 732, or these parts can be processed separately
  • the first support part 731 , the second support part 732 and the connecting part 733 are fixed together by welding, screwing, gluing, etc., to obtain the support 73 .
  • the number of electrode assemblies 72 in the battery cell 7 is one, and the number of support members 73 is also one.
  • the support member 73 is set between the casing 71 and the electrode assembly 72 .
  • FIG. 14 is a schematic diagram of cooperation between the electrode assembly and the support in the battery cell provided by some embodiments of the present application.
  • There is one electrode assembly 72 in the battery cell 7 and there are two sets of support members 73 , each set of support members includes two support members.
  • two sets of support members 73 are respectively disposed on both sides of the electrode assembly 72 and located between the casing 71 and the electrode assembly 72 .
  • the thickness of a single support member 73 may be half of the thickness of the support member 73 in FIG. 6 .
  • the battery cell 7 includes a plurality of electrode assemblies 72, and the plurality of electrode assemblies 72 are arranged side by side in the casing 71 along the thickness direction Y, and in the thickness direction Y, the support member 73 is disposed on the casing 71 and between the electrode assembly 72 adjacent to the casing 71 .
  • FIG. 15 is a schematic diagram of cooperation between an electrode assembly and a support member in a battery cell provided by some embodiments of the present application.
  • the battery cell 7 includes two electrode assemblies 72, and the two electrode assemblies 72 are arranged side by side in the casing 71 along the thickness direction Y. In the thickness direction Y, the support member 73 is arranged on the casing 71 and adjacent to the casing 71. between the electrode assemblies 72 .
  • FIG. 16 is a schematic diagram of cooperation between an electrode assembly and a support member in a battery cell provided by some embodiments of the present application.
  • the battery cell 7 includes four electrode assemblies 72, and the four electrode assemblies 72 are arranged side by side in the casing 71 along the thickness direction Y. In the thickness direction Y, the support member 73 is arranged on the casing 71 and adjacent to the casing 71. between the electrode assemblies 72 .
  • the battery cell 7 includes a plurality of electrode assemblies 72, and the plurality of electrode assemblies 72 are arranged side by side in the casing 71 along the thickness direction Y, and the support member 73 is arranged on two adjacent electrode assemblies 72 between.
  • FIG. 17 is a schematic diagram of cooperation between an electrode assembly and a support member in a battery cell provided by some embodiments of the present application.
  • the battery cell 7 includes two electrode assemblies 72 , and the two electrode assemblies 72 are arranged side by side in the casing 71 along the thickness direction Y. In the thickness direction Y, the support member 73 is disposed between two adjacent electrode assemblies 72 .
  • FIG. 18 is a schematic diagram of cooperation between an electrode assembly and a support in a battery cell according to some embodiments of the present application.
  • the battery cell 7 includes four electrode assemblies 72 , and the four electrode assemblies 72 are arranged side by side in the casing 71 along the thickness direction Y. In the thickness direction Y, the support member 73 is disposed between adjacent electrode assemblies 72 .
  • FIG. 19 is a schematic diagram of cooperation between an electrode assembly and a support member in a battery cell provided by some embodiments of the present application.
  • the battery cell 7 includes four electrode assemblies 72 , and the four electrode assemblies 72 are arranged side by side in the casing 71 along the thickness direction Y. In the thickness direction Y, the support member 73 is disposed between adjacent electrode assemblies 72 .
  • one support member 73 can simultaneously make the two electrode assemblies 73 on both sides of the support member 73 located in the bending region R2
  • the innermost pole piece 722a is not easy to wrinkle, so that the same effect can be achieved by using less support members 73, and the weight of the battery cell 7 can be reduced.
  • FIG. 20 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application.
  • FIG. 21 is a schematic diagram of the assembly of the buckle and the electrode assembly in FIG. 20.
  • FIG. 22 is a schematic top view of the buckle and the electrode assembly in FIG. 21 on the XOY plane, and
  • FIG. 23 is a schematic cross-sectional view of the AA direction in FIG. 22 .
  • the support member 73 is fixed on the side of the electrode assembly 72 through the buckle 734 .
  • the support 73 can be fixed on the side of the electrode assembly 72, preventing the support 73 from falling down during use, or from being displaced relative to the electrode assembly 72, causing the electrode assembly 72 located in the bending region R2
  • the effect of suppressing the wrinkling of the innermost pole piece 722a is reduced. If the support member 73 falls or is displaced relative to the electrode assembly 72, the position of the support frame will not correspond to the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2, so that the reduction in the electrode assembly 72 located in the bending region R2 cannot be achieved. 2 , the effect of the expansion space of the innermost pole piece 722a of the electrode assembly 72 along the thickness direction Y of the electrode assembly 72. Moreover, the fixing method of the buckle 734 improves the structural strength of the support 73 .
  • the buckle 734 includes a clamping plate arranged at the top of the support 73, which overlaps the top of the electrode assembly 72; and a clamping plate arranged at the bottom of the support 73, which overlaps At the bottom of the electrode assembly 72 .
  • the buckle 734 can only be overlapped on the electrode assembly 72, and the position of the support 73 can be limited by the positional cooperation between the electrode assembly 72, the support 73 and the buckle 734, so that the support 73 can be fixed on the electrode. side of assembly 72.
  • the buckle 734 can also be fixed on the electrode assembly 72 through a fixing member, so that the fixing between the support member 73 and the electrode assembly 72 is more stable.
  • the battery cell 7 shown in the figure includes two electrode assemblies 72 , and the support member 73 is disposed between the electrode assemblies 72 , so the buckle member 734 overlaps the electrode assemblies 72 on both sides of the support member 73 .
  • the battery cell 7 includes only one electrode assembly 72, and the support member 73 is disposed between the electrode assembly 72 and the casing 71, or although the battery cell 7 includes a plurality of electrode assemblies 72, the support member 73 is also It is also arranged between the electrode assembly 72 and the casing 71 , and at this time, the buckle 734 can only overlap the electrode assembly 72 on one side of the support 73 .
  • the buckle 734 can only be provided at one end of the support 73.
  • the buckle 734 includes a clamping plate arranged at the top of the support 73, which overlaps the electrode assembly. 72, the support 73 is limited by the positional cooperation between the electrode assembly 72, the support 73 and the buckle 734, so that the support 73 is fixed on the side of the electrode assembly 72. Only one end of the supporting member 73 is engaged with the buckle 734 , which facilitates assembly, reduces the weight of the battery cell 7 , and improves the energy density of the battery cell 7 .
  • the buckle 734 may be an independent component, or integrally formed with the support 73 .
  • FIG. 24 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application.
  • the support 73 is fixed on the side of the electrode assembly 72 by pasting, and S is the support. on the paste surface.
  • S is the support. on the paste surface.
  • the supporting member 73 is prevented from falling down or being displaced relative to the electrode assembly 72 during use. If the support member 73 falls or is displaced relative to the electrode assembly 72, the position of the support frame will not correspond to the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2, so that the reduction in the electrode assembly 72 located in the bending region R2 cannot be achieved.
  • the pasting method can reduce the weight of the interlayer unit, and has little influence on the energy density of the battery cell 7 .
  • the surface of the support member 73 may have appropriate viscosity, so that the support member 73 can be better pasted and fixed on the side of the electrode assembly 72 .
  • the sticky support 73 can be selected, or the non-adhesive support 73 can be selected, and an adhesive or back glue is coated on the surface of the side against the electrode assembly 72, or An adhesive or adhesive is coated on the surface where the electrode assembly 72 abuts against the support member 73 to facilitate the sticking of the support member 73 .
  • the support member 73 in the second direction Z, is provided with a through hole 724 (not shown in the drawings) for the electrolyte to pass through, and the second direction Z is compatible with the first direction X and the thickness direction Y. Two by two vertical.
  • the form of the through hole 724 is not limited, the support member 73 can be made by opening the through hole 724 on the support member 73, or by selecting a material with the through hole 724 itself, such as a porous polyolefin material with a certain surface porosity.
  • the support member 73 is provided with a through hole 724 for the electrolyte to pass through in the second direction Z, the electrolyte can flow from the bottom to the top of the battery cell 7 through the through hole 724, thereby improving the infiltration effect of the electrolyte on the electrode assembly 72 , to ensure the charging and discharging performance of the battery cell 7 .
  • FIG. 25 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application.
  • the component is one or more layers of separators 723 located outside the electrode assembly 72.
  • the one or more layers of separators 723 have a through hole 724 penetrating along the thickness direction Y, and the through hole 724 is arranged corresponding to the flat region R1.
  • One or more layers of separators 723 are wound on the outside of the electrode assembly 72 as a support to reduce the expansion of the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2 along the thickness direction Y of the electrode assembly 72 space.
  • an expansion space can be reserved for the flat region R1 of the electrode assembly 72 in the thickness direction Y to prevent lithium precipitation, thereby reducing the safety of the battery cell 7 Impact.
  • directly using the diaphragm as a support can simplify the components and reduce the difficulty of processing and assembly.
  • the number of layers of the separator 723 as the support member 73 can be calculated according to the degree of thickness of the electrode assembly 72 . For example, if the degree of grouping at the corner of the innermost pole piece 722a is 90%, then:
  • Diaphragm layers ((housing cavity thickness * (1-90%)) / single-layer diaphragm thickness)
  • the actual degree of separation at the corner of the innermost pole piece 722 a of the electrode assembly 72 satisfies or substantially satisfies 100%. If the grouping degree exceeds 100%, it exceeds the thickness that the casing 71 can accommodate the electrode assembly 72, and the electrode assembly 72 cannot be loaded into the casing 71, or the electrode assembly 72 will be damaged if the electrode assembly 72 is forcibly loaded into the casing 71. . If the grouping degree is less than 100%, one or more layers of separators 723 as support members 73 located outside the electrode assembly 72 cannot reduce the edge of the innermost pole piece 722a of the electrode assembly 72 located in the bending region R2. The effect of the expansion space in the thickness direction Y of the electrode assembly 72 .
  • the size of the through hole 724 of the separator 723 serving as the support member 73 is determined according to the overall size of the electrode assembly 72 and the size of the bending region R 2 .
  • the width of the electrode assembly 72 is X1 (the dimension on the first direction X)
  • the height is Y1 (the dimension on the second square Z)
  • the width of the corner of the bending region R2 is X2
  • the size of the through hole 724 is :
  • Through hole height Y1-2k, where k is determined according to processing requirements, and k refers to the distance between the through hole 724 and the edge of the diaphragm 723 in the second direction Z.
  • FIG. 26 is a schematic flow chart of a method for preparing a battery cell provided by some embodiments of the present application.
  • the method for preparing a battery cell includes the following contents:
  • Step 261 providing a casing.
  • Step 262 provide an electrode assembly, the electrode assembly includes a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet are laminated and wound to form a wound structure, the electrode assembly includes a straight area and a bent area, and the bent area is located on the flat surface. The end of the straight zone along the first direction.
  • Step 263 providing a support.
  • Step 264 disposing the electrode assembly and the support member in the casing, and placing the support member on the side of the electrode assembly, so that the support member can reduce the innermost pole piece of the electrode assembly located in the bending area along the thickness direction of the electrode assembly space for expansion.
  • FIG. 27 is a schematic structural diagram of a device for preparing a battery cell provided by some embodiments of the present application.
  • the device 8 for preparing a battery cell includes: a first providing device 81, a second providing device 82, a third Means 83 and assembly means 84 are provided.
  • the first providing device 81 is configured to provide the casing.
  • the second providing device 82 is configured to provide an electrode assembly, the electrode assembly includes a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet are laminated and wound to form a coiled structure, and the electrode assembly includes a straight area and a bent area , the bending zone is located at the end of the straight zone along the first direction.
  • the third providing device 83 is configured to provide supports.
  • the assembly device 84 is configured to arrange the electrode assembly and the support in the housing, and make the support located on the side of the electrode assembly, so that the support can reduce the innermost pole piece of the electrode assembly located in the bending area along the electrode. Expansion space in the thickness direction of the component.

Abstract

本申请实施例涉及电池技术领域,提供了一种电池单体、电池、用电装置及制备电池单体的方法和设备。该电池单体包括:壳体;电极组件,布置于壳体内,电极组件包括正极极片和负极极片,正极极片和负极极片层叠并卷绕形成卷绕结构,电极组件包括平直区和弯折区,弯折区位于平直区沿第一方向的端部;支撑件,支撑件设置于壳体内,位于电极组件的侧面,支撑件用于减小位于弯折区的电极组件的最内层极片沿电极组件的厚度方向的膨胀空间。通过上述方式,能够使位于弯折区的电极组件的最内层极片不容易起皱,防止锂离子在起皱处沉积,导致析锂触发热失控,提高电池单体的安全性。

Description

电池单体、电池、用电装置及制备电池单体的方法和设备 技术领域
本申请实施例涉及电池技术领域,具体涉及一种电池单体、电池、用电装置及制备电池单体的方法和设备。
背景技术
电池单体被广泛应用于电子设备,例如手机、笔记本电脑、电瓶车、电动汽车、电动飞机、电动轮船、电动玩具汽车、电动玩具轮船、电动玩具飞机和电动工具等等。电池单体可以包括镉镍电池单体、氢镍电池单体、锂离子电池单体和二次碱性锌锰电池单体等。
在电池技术的发展中,安全问题是一个不可忽视的问题,尤其当电池单体的内部发生短路时,容易引起严重的安全事故。因此,如何降低电池单体发生内部短路的概率以提高电池单体的安全性能,是该领域中一直备受关注的一个问题。
发明内容
鉴于上述问题,本申请实施例提供了一种电池单体、电池、用电装置及制备电池单体的方法和设备,其能降低电池单体发生内部短路的概率,提高电池单体的安全性能。
根据本申请实施例的第一方面,提供了一种电池单体,包括:壳体;电极组件,布置于所述壳体内,所述电极组件包括正极极片和负极极片,所述正极极片和所述负极极片层叠并卷绕形成卷绕结构,所述电极组件包括平直区和弯折区,所述弯折区位于所述平直区沿第一方向的端部;支撑件,所述支撑件设置于所述壳体内,位于所述电极组件的侧面,所述支撑件用于减小位于所述弯折区的所述电极组件的最内层极片沿所述电极组件的厚度方向的膨胀空间。
本申请实施例的电池单体中,通过在壳体内电极组件的侧面设置支撑件,能够减小位于弯折区的电极组件的最内层极片沿电极组件的厚度方向的膨胀空间,在电池单体充放电过程中,能够使位于弯折区的电极组件的最内层极片不容易起皱,防止锂离子在起皱处沉积,导致析锂触发热失控,提高电池单体的安全性。
在一些实施例中,至少部分所述支撑件位于所述弯折区与所述平直区的交界处。
将支撑件的位置设置为至少部分支撑件位于弯折区与平直区的交界处,能够减小最内层极片容易起皱的部分沿电极组件的厚度方向的膨胀空间,使该部分极片不容易起皱,防止锂离子在起皱处沉积,导致析锂触发热失控。
在一些实施例中,沿所述厚度方向,所述支撑件的尺寸最大处与所述最内层极片的拐角对应,并抵靠于所述电极组件。
将支撑件的尺寸最大处设置为与最内层极片的拐角对应,且支撑件抵靠于电极组件,可以减小最内层极片的拐角处沿电极组件的厚度方向的膨胀空间,使该部分极片不容易起皱,防止锂离子在起皱处沉积,导致析锂触发热失控。
在一些实施例中,沿第二方向,所述支撑件的两端与所述负极极片的端部平齐,所述第二方向与所述第一方向和所述厚度方向两两垂直。
由于支撑件的两端与负极极片的端部平齐,也即,支撑件高度与负极极片的高度相同且在第二方向的位置也相同,既能使支撑件在第二方向上均能减小位于弯折区的电极组件的最内层极片沿电极组件的厚度方向的膨胀空间,又能避免支撑件突出负极极片,增加电池单体重量,降低电池单体能量密度。
在一些实施例中,所述支撑件包括第一支撑部、第二支撑部和连接部,所述第一支撑部和所述第二支撑部分别位于所述支撑件的两端,所述连接部用于连接所述第一支撑部和所述第二支撑部;所述弯折区包括第一弯折区和第二弯折区,至少部分所述第一支撑部与所述第一弯折区的位置对应,至少部分所述第二支撑部与所述第二弯折区的位置对应。
通过设置与第一弯折区和第二弯折区分别对应的第一支撑部和第二支撑部,能够减小最内层极片在两端部位沿电极组件的厚度方向的膨胀空间,使该部分极片不容易起皱,并通过设置第一支撑部和第二支撑部之间的连接部,可以提高支撑件的结构强度。
在一些实施例中,所述连接部为中空结构,用于为所述平直区提供膨胀空间。
若平直区的极片在厚度方向的膨胀被抑制,将导致电极组件中的电解液被挤出,影响锂离子在正负极间的传递,出现大面积析锂,引发热失控从而影响电池单体的安全性,通过将连接部设置为中空结构,能够为电极组件的 平直区在厚度方向预留膨胀空间,防止析锂,从而降低对电池单体的安全性的影响。
在一些实施例中,所述连接部包括沿第二方向设置的第一连接部和第二连接部,所述第一连接部和所述第二连接部之间形成所述中空结构,所述第二方向与所述第一方向和所述厚度方向两两垂直。
沿第二方向设置的第一连接部和第二连接部可以提高支撑件的结构强度,避免支撑架倒伏。
在一些实施例中,所述连接部包括沿所述厚度方向设置的第一连接部和第二连接部,所述第一连接部和所述第二连接部靠近所述电极组件的侧面与所述第一支撑部和所述第二支撑部靠近所述电极组件的侧面平齐。
通过沿厚度方向设置第一连接部和第二连接部,第一连接部和第二连接部之间形成中空结构,能够为电极组件的平直区在厚度方向预留膨胀空间,防止析锂,从而降低对电池单体的安全性的影响;第一连接部和第二连接部靠近电极组件的侧面与第一支撑部和第二支撑部靠近电极组件的侧面平齐,使整个支撑件靠近电极组件的侧面呈平面,可以降低第一支撑部和第二支撑部的侧边与电极组件接触位置的应力集中,从而减少支撑部对与其接触的电极组件的损伤,防止正负极片搭接,降低电池单体内部短路风险。
在一些实施例中,所述支撑件与所述电极组件接触的外表面为弧面。
通过将支撑件与所述电极组件接触的外表面设置为弧面,相比侧边具有棱角的支撑件,可以进一步降低第一支撑部和第二支撑部的侧边与电极组件接触位置的应力集中,从而避免支撑部对与其接触的电极组件的损伤,防止正负极片搭接,降低电池单体内部短路风险。
在一些实施例中,所述电池单体包括多个电极组件,所述多个电极组件沿所述厚度方向并排布置于所述壳体内,在所述厚度方向,所述支撑件设置于所述壳体和与所述壳体相邻的所述电极组件之间。
在一些实施例中,所述电池单体包括多个电极组件,所述多个电极组件沿所述厚度方向并排布置于所述壳体内,所述支撑件设置于相邻的两个电极组件之间。
通过将支撑件设置于多个电极组件中相邻的两个电极组件之间,使得一个支撑件能够同时使位于其两侧的两个电极组件的位于弯折区的最内层极片不容易起皱,从而通过使用较少的支撑件达到相同的效果,减少电池单体重 量。
在一些实施例中,所述支撑件通过粘贴固定于所述电极组件的侧面,或者,所述支撑件通过卡扣件固定于所述电极组件的侧面。
通过设置卡扣件,可以将支撑件固定于电极组件的侧面,防止在使用过程中支撑件倒伏,或相对电极组件产生位移,导致对位于弯折区的电极组件的最内层极片起皱的抑制效果降低,卡扣件的固定方式提高了支撑件的结构强度;通过将支撑件粘贴固定于电极组件的侧面,防止在使用过程中支撑件倒伏,或相对电极组件产生位移,而且,粘贴的方式可以减轻夹层单元的重量,对电池单体的能量密度影响较小。
在一些实施例中,在第二方向上所述支撑件设有供电解液通过的贯通孔,所述第二方向与所述第一方向和所述厚度方向两两垂直。
由于在第二方向上支撑件设有供电解液通过的贯通孔,电解液可以通过该贯通孔从电池单体的底部流动到顶端,提高电解液对电极组件的浸润效果,保证电池单体的充放电性能。
在一些实施例中,所述电极组件还包括用于隔离所述正极极片和所述负极极片的隔膜,所述支撑件为位于所述电极组件外侧的一层或多层隔膜,所述一层或多层隔膜具有沿所述厚度方向贯通的通孔,所述通孔对应所述平直区设置。
通过在电极组件外侧卷绕一层或多层隔膜作为支撑件,可以减小位于弯折区的电极组件的最内层极片沿电极组件的厚度方向的膨胀空间;通过在作为支撑件的这部分隔膜上开设通孔,能够为电极组件的平直区在厚度方向预留膨胀空间,防止析锂,从而降低对电池单体的安全性的影响;此外,直接采用隔膜作为支撑件,可以简化部件,降低加工和装配难度。
根据本申请实施例的第二方面,提供了一种电池,包括上述实施例的电池单体。
根据本申请实施例的第三方面,提供了一种用电装置,包括上述实施例的电池单体,其中所述电池单体用于提供电能。
根据本申请实施例的第四方面,提供了一种制备电池单体的方法,包括:提供壳体;提供电极组件,所述电极组件包括正极极片和负极极片,所述正极极片和所述负极极片层叠并卷绕形成卷绕结构,所述电极组件包括平直区和弯折区,所述弯折区位于所述平直区沿第一方向的端部;提供支撑件;将 所述电极组件和所述支撑件设置于所述壳体内,并使所述支撑件位于所述电极组件的侧面,以使所述支撑件能够减小位于所述弯折区的所述电极组件的最内层极片沿所述电极组件的厚度方向的膨胀空间。
根据本申请实施例的第五方面,提供了一种制备电池单体的设备,包括:第一提供装置,被配置为提供壳体;第二提供装置,被配置为提供电极组件,所述电极组件包括正极极片和负极极片,所述正极极片和所述负极极片层叠并卷绕形成卷绕结构,所述电极组件包括平直区和弯折区,所述弯折区位于所述平直区沿第一方向的端部;第三提供装置,被配置为提供支撑件;组装装置,被配置为将所述电极组件和所述支撑件设置于所述壳体内,并使所述支撑件位于所述电极组件的侧面,以使所述支撑件能够减小位于所述弯折区的所述电极组件的最内层极片沿所述电极组件的厚度方向的膨胀空间。
上述说明仅是本申请技术方案的概述,为了能够更清楚了解本申请的技术手段,而可依照说明书的内容予以实施,并且为了让本申请的上述和其它目的、特征和优点能够更明显易懂,以下特举本申请的具体实施方式。
附图说明
下面将参考附图来描述本申请示例性实施例的特征、优点和技术效果。
图1是本申请一些实施例提供的车辆的结构示意图;
图2是本申请一些实施例提供的电池的爆炸示意图;
图3是图2中的电池模块的结构示意图;
图4是本申请一些实施例提供的电池单体的爆炸示意图;
图5是图4的电极组件在XOY平面内的横截面的结构示意图;
图6是图4中电极组件和支撑件的配合示意图;
图7是本申请一些实施例提供的电极组件和支撑件的配合示意图;
图8是本申请一些实施例提供的支撑件的结构示意图;
图9是图8中(a)所示的支撑件与电极组件的配合示意图;
图10是本申请一些实施例提供的支撑件的结构示意图;
图11是图10中(a)所示的支撑件与电极组件的配合示意图;
图12是本申请一些实施例提供的支撑件的结构示意图;
图13是图12中(a)所示的支撑件与电极组件的配合示意图;
图14是本申请一些实施例提供的电池单体中电极组件和支撑件的配合 示意图;
图15是本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图;
图16是本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图;
图17是本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图;
图18是本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图;
图19是本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图;
图20是本申请一些实施例提供的电池单体的爆炸示意图;
图21是图20中卡扣件与电极组件的装配示意图;
图22是图21中卡扣件与电极组件在XOY平面内的俯视示意图;
图23是图22中A-A方向的截面结构示意图;
图24是本申请一些实施例提供的电池单体的爆炸示意图;
图25是本申请一些实施例提供的电池单体的爆炸示意图;
图26是本申请一些实施例提供的一种制备电池单体的方法的流程示意图;
图27是本申请一些实施例提供的一种制备电池单体的设备的结构示意图。
在附图中,附图未必按照实际的比例绘制。
附图标记:
1-车辆、2-电池、3-控制器、4-马达、5-箱体、6-电池模块;
51-第一箱体部、52-第二箱体部、53-容纳空间;
7-电池单体;
71-壳体;
72-电极组件、721-正极极片、722-负极极片、722a-最内层极片、723-隔膜、724-通孔、R 1-平直区、R 2-弯折区、R 21-第一弯折区、R 22-第二弯折区;
73-支撑件、731-第一支撑部、732-第二支撑部、733-连接部、733a-第一连接部、733b-第二连接部、734-卡扣件;
74-端盖;
8-制备电池单体的设备、81-第一提供装置、82-第二提供装置、83-第三提供装置、84-组装装置;
P 1,P 2-最内层极片的拐角、P 3-支撑件的尺寸最大处;
S-支撑件上的粘贴面;
X-第一方向、Y-电极组件的厚度方向、Z-第二方向。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚,下面将结合本申请实施例中的附图,对本申请实施例中的技术方案进行清楚地描述,显然,所描述的实施例是本申请一部分实施例,而不是全部的实施例。基于本申请中的实施例,本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例,都属于本申请保护的范围。
为使本申请实施例的目的、技术方案和优点更加清楚,下面将结合本申请实施例中的附图,对本申请实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例是本申请一部分实施例,而不是全部的实施例。基于本申请中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本申请保护的范围。
需要注意的是,除非另有说明,本申请实施例使用的技术术语或者科学术语应当为本申请实施例所属领域技术人员所理解的通常意义。
在本申请实施例的描述中,技术术语“中心”“纵向”“横向”“长度”“宽度”“厚度”“上”“下”“前”“后”“左”“右”“竖直”“水平”“顶”“底”“内”“外”“顺时针”“逆时针”“轴向”“径向”“周向”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实施例和简化描述,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,因此不能理解为对本申请实施例的限制。
此外,技术术语“第一”“第二”等仅用于描述目的,而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量,亦非用于描述特定顺序或主次关系。
本文中术语“和/或”,仅仅是一种描述关联对象的关联关系,表示可以存在三种关系。例如,“A和/或B”可以表示:单独存在A,同时存在A和B,单独存在B这三种情况。另外,本文中字符“/”,一般表示前后关联对象是一 种“或”的关系。
本申请中出现的“多个”指的是两个以上(包括两个),同理,“多组”指的是两组以上(包括两组),“多片”指的是两片以上(包括两片),除非另有明确具体的限定。
在本申请实施例的描述中,除非另有明确的规定和限定,技术术语“安装”“相连”“连接”“固定”等术语应做广义理解,例如,可以是固定连接,也可以是可拆卸连接,或成一体;也可以是机械连接,也可以是电连接;可以是直接相连,也可以通过中间媒介间接相连,可以是两个元件内部的连通或两个元件的相互作用关系。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在本申请实施例中的具体含义。
在本文中提及“实施例”意味着,结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例,也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员能够理解本文所描述的实施例可以与其它实施例相结合。
电池的电极组件通常包括正极极片、负极极片和隔膜,正极极片、负极极片和隔膜层叠后绕卷绕轴线卷绕形成卷绕结构。卷绕后的电极组件包括平直区和位于该平直区两端的弯折区。正极极片包括正极集流体和正极活性物质层,正极活性物质层涂覆于正极集流体的表面。以锂离子电池为例,正极集流体的材料可以为铝,正极活性物质层包括正极活性物质,正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片包括负极集流体和负极活性物质层,负极活性物质层涂覆于负极集流体的表面。负极集流体的材料可以为铜,负极活性物质层包括负极活性物质,负极活性物质可以为碳或硅等。隔膜的材质可以为PP(polypropylene,聚丙烯)或PE(polyethylene,聚乙烯)等。
电池单体在充放电过程中,锂离子嵌入极片将导致极片晶格参数变化,引起极片在厚度方向膨胀,并伴随充放电的频率进行膨胀和收缩。现有的电池单体结构中,电极组件与壳体之间在电极组件的厚度方向一般存在间隙。该间隙导致电极组件在其厚度方向得不到有效束缚,使电极组件在其厚度方向存在膨胀空间。位于弯折区的电极组件的最内层极片膨胀容易引起该部分极片起皱,锂离子容易在起皱处沉积,导致析锂,析出的锂枝晶可能通过与 电解液反应,局部产生大量热或刺穿隔膜导致正负极短路,从而造成电池单体发生热失控,引起安全事故。
鉴于此,本申请提供了一种电池单体,该电池单体通过在壳体内电极组件的侧面设置支撑件,能够减小位于弯折区的电极组件的最内层极片沿电极组件的厚度方向的膨胀空间,在电池单体充放电过程中,能够使位于弯折区的电极组件的最内层极片不容易起皱,防止锂离子在起皱处沉积,导致析锂触发热失控,提高电池单体的安全性。
本申请实施例描述的电池单体适用于电池以及使用电池的用电装置。
用电装置可以是车辆、手机、便携式设备、笔记本电脑、轮船、航天器、电动玩具和电动工具等等。车辆可以是燃油汽车、燃气汽车或新能源汽车,新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等;航天器包括飞机、火箭、航天飞机和宇宙飞船等等;电动玩具包括固定式或移动式的电动玩具,例如,游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等;电动工具包括金属切削电动工具、研磨电动工具、装配电动工具和铁道用电动工具,例如,电钻、电动砂轮机、电动扳手、电动螺丝刀、电锤、冲击电钻、混凝土振动器和电刨等等。本申请实施例对上述用电装置不做特殊限制。
以下实施例为了方便说明,以用电装置为车辆为例进行说明。
请参阅图1,图1为本申请一些实施例提供的车辆的结构示意图。如图1所示,车辆1的内部设置有电池2,电池2是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块,例如,本申请中所提到的电池2可以包括电池模块或电池包等。电池2可以设置在车辆1的底部或头部或尾部。电池2可以用于车辆1的供电,例如,电池2可以作为车辆1的操作电源。车辆1还可以包括控制器3和马达4,控制器3用来控制电池2为马达4供电,例如,用于车辆1的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中,电池2不仅仅可以作为车辆1的操作电源,还可以作为车辆1的驱动电源,代替或部分地代替燃油或天然气为车辆1提供驱动动力。
请参阅图2,图2为本申请一些实施例提供的电池的爆炸示意图。
如图2所示,电池2包括箱体5和电池模块6,电池模块6容纳于箱体5内。
箱体5用于容纳电池模块6,箱体5可以是多种结构。在一些实施例中, 箱体5可以包括第一箱体部51和第二箱体部52,第一箱体部51与第二箱体部52相互盖合,第一箱体部51和第二箱体部52共同限定出用于容纳电池模块6的容纳空间53。第二箱体部52可以是一端开口的空心结构,第一箱体部51可以为板状结构,第一箱体部51盖合于第二箱体部52的开口侧,以形成具有容纳空间53的箱体5;第一箱体部51和第二箱体部52也均可以是一侧开口的空心结构,第一箱体部51的开口侧盖合于第二箱体部52的开口侧,以形成具有容纳空间53的箱体5。当然,第一箱体部51和第二箱体部52可以是多种形状,比如,圆柱体、长方体等。
为提高第一箱体部51与第二箱体部52连接后的密封性,第一箱体部51与第二箱体部52之间也可以设置密封件,比如,密封胶、密封圈等。
假设第一箱体部51盖合于第二箱体部52的顶部,第一箱体部51亦可称之为上箱盖,第二箱体部52亦可称之为下箱体。
在电池2中,电池单体7(图中未示出)为多个。多个电池单体7之间可串联或并联或混联,混联是指多个电池单体7中既有串联又有并联。多个电池单体7之间可直接串联或并联或混联在一起,再将多个电池单体7构成的整体容纳于箱体5内;当然,也可以是多个电池单体7先串联或并联或混联组成电池模块6,多个电池模块6再串联或并联或混联形成一个整体,并容纳于箱体5内。
图3为图2中的电池模块6的结构示意图。如图3所示,在一些实施例中,电池单体7为多个,多个电池单体7先串联或并联或混联组成电池模块6。多个电池模块6再串联或并联或混联形成一个整体,并容纳于箱体内。
请参阅图4至图6,本申请实施例提供了一种电池单体7,该电池单体7包括壳体71、电极组件72和支撑件73。电极组件72布置于壳体71内,电极组件72包括正极极片721和负极极片722,正极极片721和负极极片722层叠并卷绕形成卷绕结构。电极组件72包括平直区R 1和弯折区R 2,弯折区R 2位于平直区R 1沿第一方向X的端部。支撑件73设置于壳体71内,位于电极组件72的侧面,支撑件73用于减小位于弯折区R 2的电极组件72的最内层极片722a沿电极组件72的厚度方向Y的膨胀空间。
在本申请的一些实施例中,电池单体7可以包括锂离子二次电池单体7、锂离子一次电池单体、锂硫电池单体、钠锂离子电池单体、钠离子电池单体或镁离子电池单体等,本申请实施例对此并不限定。电池单体7可呈扁平体、 长方体或其它形状等,本申请实施例对此也不限定,为便于说明,在下述实施例中均以扁平体形状的电池为示例。电池单体7一般有硬壳电池单体和软包电池单体,本申请实施例对此也不限定。
在本申请的一些实施例中,请参见图4,图4为本申请一些实施例提供的电池单体的爆炸示意图。电池单体7可以包括壳体71、电极组件72、支撑件73、端盖74和电解液(图中未示出)。
壳体71可以为一端具有开口,也可以在两端具有开口,端盖74盖合于壳体71的开口处,以与壳体71共同形成容纳电极组件72和电解液的容纳空间。可选地,壳体71和端盖74可以为同一种材料制成,例如壳体71和端盖74可以均为铝制,这样,可以便于焊接壳体71和端盖74,或者,壳体71和端盖74也可以为不同的材料制成,例如,壳体71和端盖74可以分别采用不同金属制成,并且,可以使用铆接等其他的连接方法连接壳体71和端盖74。
电极组件72可以包括正极极片721、负极极片722和隔膜723(请参见图6)。电池单体7主要依靠金属离子在正极极片721和负极极片722之间移动来工作。正极极片721、负极极片722和隔膜723层叠后绕卷绕轴线卷绕形成卷绕结构。
请参见图5,图5为图4的电极组件在XOY平面内的横截面的结构示意图。卷绕后的电极组件72包括平直区R 1和位于该平直区R 1沿第一方向X的端部的弯折区R 2。平直区R 1是指该卷绕结构中具有平行结构的区域,即在该平直区R 1内的正极极片721、负极极片722和隔膜723相互基本平行,即电极组件72在平直区R 1的每层正极极片721、负极极片722和隔膜723的表面均为平面。弯折区R 2是指该卷绕结构中具有弯折结构的区域,即在该弯折区R 2内的正极极片721、负极极片722和隔膜723均弯折,即电极组件72在弯折区R 2的每层正极极片721、负极极片722和隔膜723的表面均为曲面。如图5中所示,平直区R 1沿第一方向X的两端均具有弯折区R 2
正极极片721包括正极集流体和正极活性物质层,正极活性物质层涂覆于正极集流体的表面。以锂离子电池为例,正极集流体的材料可以为铝,正极活性物质层包括正极活性物质,正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片722包括负极集流体和负极活性物质层,负极活性物质层涂覆于负极集流体的表面。负极集流体的材料可以为铜,负极活性物质层包括负极活性物质,负极活性物质可以为碳或硅等。隔膜723的材 质可以为PP(polypropylene,聚丙烯)或PE(polyethylene,聚乙烯)等。
请参见图6,图6为图4中电极组件和支撑件的配合示意图。支撑件73位于电极组件72的侧面,其中电极组件72的侧面是指电极组件72在其厚度方向Y上一侧的面。支撑件73的形状可以为棱柱体、圆柱体、椭圆柱体等,本申请实施例对此不限定。支撑件73可以由绝缘材料制成,满足抗倒伏、抗挤压等结构强度要求,以及满足对制备电池的材料的耐高温要求,例如可选用多孔聚烯烃材料。此外,电池单体7内可能发生电解液腐蚀、电化学腐蚀,支撑件73的材料还需具备耐酸耐碱的抗腐蚀性能。
通过在壳体71内电极组件72的侧面设置支撑件73,能够减小位于弯折区R 2的电极组件72的最内层极片722a沿电极组件72的厚度方向Y的膨胀空间,在电池单体7充放电过程中,能够使位于弯折区R 2的电极组件72的最内层极片722a不容易起皱,防止锂离子在起皱处沉积,导致析锂触发热失控,提高电池单体7的安全性。
在本申请的一些实施例中,请继续参见图6,至少部分支撑件73位于弯折区R 2与平直区R 1的交界处。弯折区R 2与平直区R 1的交界处是指在电极组件72的侧面,弯折区R 2与平直区R 1的交界点附近的位置,并不是指严格意义上的交界点本身。由于电极组件72的最内层极片722a容易起皱的部分在电极组件72的侧面内的投影位于该交界处附近,因此将支撑件73的位置设置为至少部分支撑件73位于弯折区R 2与平直区R 1的交界处,能够减小最内层极片722a容易起皱的部分沿电极组件72的厚度方向Y的膨胀空间,使该部分极片不容易起皱,防止锂离子在起皱处沉积,导致析锂触发热失控。
在本申请的一些实施例中,沿厚度方向Y,支撑件73的尺寸最大处与最内层极片722a的拐角对应,并抵靠于电极组件72。支撑件73的尺寸是指支撑件73在XOY平面内的沿厚度方向Y的尺寸。“对应”是指在图6所示截面内,支撑件73的尺寸最大处在第一方向X的投影与最内层极片722a的拐角在第一方向X的投影重合或基本重合。最内层极片722a的拐角是指在其两侧极片均朝向电极组件72的中心弯折的点,如图6所示的P 1和P 2点。支撑件73抵靠于电极组件72是指支撑件73与电极组件72接触,支撑件73与电极组件72之间可以为过盈配合,此时二者之间存在作用力。支撑件73与电极组件72之间还可以为间隙配合,此时二者之间不存在作用力。由于电极组件72的最内层极片722a容易起皱的部分为最内层极片722a的拐角,因 此将支撑件73的尺寸最大处设置为与最内层极片722a的拐角对应,且支撑件73抵靠于电极组件72,可以减小最内层极片722a的拐角处沿电极组件72的厚度方向Y的膨胀空间,使该部分极片不容易起皱,防止锂离子在起皱处沉积,导致析锂触发热失控。
请继续参见图6,图6中支撑件73为长方体(四棱柱),支撑件73被放置为其长度方向或宽度方向与厚度方向Y一致,支撑件73在XOY平面内的沿厚度方向Y的尺寸各处均一致,支撑件73沿其长度方向或宽度方向的任一位置与最内层极片722a的拐角对应,并抵靠于电极组件72。
请参见图7,图7为本申请一些实施例提供的电极组件和支撑件的配合示意图。图7中支撑件73为圆柱体,支撑件73在XOY平面内的沿厚度方向Y的尺寸最大处为P 3,支撑件73的P 3处与最内层极片722a的拐角对应,并抵靠于电极组件72。
在本申请的一些实施例中,沿第二方向Z,支撑件73的两端与负极极片722的端部平齐,第二方向Z与第一方向X和厚度方向Y两两垂直。在电极组件72中,沿第二方向Z的两端,负极极片722的端部均超出正极极片721的端部。由于支撑件73的两端与负极极片722的端部平齐,也即,支撑件73高度(在第二方向Z的尺寸)与负极极片722的高度相同且在第二方向Z的位置也相同,既能使支撑件73在第二方向Z上均能减小位于弯折区R 2的电极组件72的最内层极片722a沿电极组件72的厚度方向Y的膨胀空间,又能避免支撑件73突出负极极片722,增加电池单体7重量,降低电池单体7能量密度。
此外,关于支撑件73的其他尺寸,其厚度(厚度方向Y上的尺寸)可以根据电极组件厚度的群域度计算。群裕度是指在厚度方向Y,电极组件72的最大尺寸与壳体71的最大尺寸之比。
支撑件厚度=壳体内腔厚度-(电极组件数量*电极组件厚度)/壳体内腔厚度)
将电极组件72和支撑件73装入壳体71后,电极组件最内层极片722a的拐角处实际群域度可满足或基本满足100%。
在本申请的一些实施例中,请参见图8-图9,其中图8为本申请一些实施例提供的支撑件的结构示意图,图9为图8中(a)所示的支撑件与电极组件的配合示意图。支撑件73包括第一支撑部731、第二支撑部732和连 接部733,第一支撑部731和第二支撑部732分别位于支撑件73的两端,连接部733用于连接第一支撑部731和第二支撑部732。弯折区R 2包括第一弯折区R 21和第二弯折区R 22,至少部分第一支撑部731与第一弯折区R 21的位置对应,至少部分第二支撑部732与第二弯折区R 22的位置对应。“对应”是指至少部分第一支撑部731与第一弯折区R 21在第一方向X的投影具有重合的部分,以及至少部分第二支撑部732与第二弯折区在第一方向X的投影具有重合的部分。通过设置与第一弯折区R 21和第二弯折区R 22分别对应的第一支撑部731和第二支撑部732,能够减小最内层极片722a在两端部位沿电极组件72的厚度方向Y的膨胀空间,使该部分极片不容易起皱,并通过设置第一支撑部731和第二支撑部732之间的连接部733,可以提高支撑件73的结构强度。
在本申请的一些实施例中,请继续参见图8和图9,连接部733为中空结构,用于为平直区R 1提供膨胀空间。中空结构是指连接部733的一部分为空心结构,特别是在连接部733与电极组件的中间部位(例如平直区R 1)对应的部位,为空心结构。电池单体7在充放电过程中,锂离子嵌入极片将导致极片晶格参数变化,引起极片在厚度方向Y膨胀,并伴随充放电的频率进行膨胀和收缩。若平直区R 1的极片在厚度方向Y的膨胀被抑制,将导致电极组件72中的电解液被挤出,影响锂离子在正负极间的传递,出现大面积析锂,引发热失控从而影响电池单体7的安全性。通过将连接部733设置为中空结构,能够为电极组件72的平直区R 1在厚度方向Y预留膨胀空间,防止析锂,从而降低对电池单体7的安全性的影响。
请继续参见图8和图9。图8中(a)所示的支撑件73中,连接部733包括沿厚度方向Y设置的第一连接部733a和第二连接部733b,第一连接部733a和第二连接部733b靠近电极组件72的侧面与第一支撑部731和第二支撑部732靠近电极组件72的侧面平齐。如图9所示,支撑件73设置于两个电极组件72之间,第一连接部733a和第二连接部733b分别抵靠两侧的电极组件72,第一连接部733a靠近下方的电极组件72的侧面与第一支撑部731靠近下方的电极组件72的侧面平齐,第二连接部733b靠近上方的电极组件72的侧面与第二支撑部732靠近上方的电极组件72的侧面平齐。其中,第一连接部733a和第二连接部733b均为板状结构。通过沿厚度方向Y设置第一连接部733a和第二连接部733b,第一连接部733a和 第二连接部733b之间形成中空结构,能够为电极组件72的平直区R 1在厚度方向Y预留膨胀空间,防止析锂,从而降低对电池单体7的安全性的影响。第一连接部733a和第二连接部733b靠近电极组件72的侧面与第一支撑部731和第二支撑部732靠近电极组件72的侧面平齐,使整个支撑件73靠近电极组件72的侧面呈平面,可以降低第一支撑部731和第二支撑部732的侧边与电极组件72接触位置的应力集中,从而减少支撑部对与其接触的电极组件72的损伤,防止正负极片搭接,降低电池单体7内部短路风险。
请继续参见图8。图8中(b)和(c)所示的支撑件73中,连接部733包括沿第二方向Z设置的第一连接部733a和第二连接部733b,第一连接部733a和第二连接部733b之间形成中空结构,第二方向Z与第一方向X和厚度方向Y两两垂直。图8中(b)所示的第一连接部733a和第二连接部733b为X型支架,图8中(c)所示的第一连接部733a和第二连接部733b为薄板状支架,本领域技术人员应当理解,第一连接部733a和第二连接部733b还可以为其他形状,本发明对此不做限制。沿第二方向Z设置的第一连接部733a和第二连接部733b可以提高支撑件73的结构强度,避免支撑架倒伏。
第一支撑部731和第二支撑部732的形状可以为棱柱体、圆柱体、椭圆柱体等,本申请实施例对此不限定。图8中所示的第一支撑部731和第二支撑部732为长方体结构,第一支撑部731和第二支撑部732在XOY平面内的截面形状为矩形(正方形或长方形)。长方体结构的第一支撑部731和第二支撑部732容易加工,而且,当电极组件72与支撑件73之间存在相互作用力时,长方体结构的第一支撑部731和第二支撑部732具备足够的强度用于抵靠电极组件72,降低位于弯折区R 2的电极组件72的最内层极片722a沿电极组件72的厚度方向Y的膨胀概率,减小位于弯折区R 2的电极组件72的最内层极片722a起皱的风险。
在本申请的一些实施例中,请参见图10-图11,其中图10为本申请一些实施例提供的支撑件的结构示意图,图11为图10中(a)所示的支撑件与电极组件的配合示意图。图10中第一支撑部731和第二支撑部732的结构与图8中不同,为两个三棱柱的组合,第一支撑部731和第二支撑部732在XOY平面内的截面形状为两个三角形的组合,两个三角形相对设置,顶点相接,底边平行。图10中连接部733的结构与图8中相同或者基本相同。 两个三棱柱的组合结构相比截面边长相同的长方体结构,可以减少支撑件73的用料,减轻支撑件73的重量,提高电池单体7能量密度。
在本申请的一些实施例中,支撑件73与电极组件72接触的外表面为弧面。请参见图12-图13,其中图12为本申请一些实施例提供的支撑件的结构示意图,图13为图12中(a)所示的支撑件与电极组件的配合示意图。图12中第一支撑部731和第二支撑部732的结构与图8以及图10中不同,为圆柱体,第一支撑部731和第二支撑部732在XOY平面内的截面形状为圆形。图12中连接部733的结构与图8中相同或者基本相同。圆柱体的第一支撑部731和第二支撑部732使得支撑件73与电极组件72接触的外表面为弧面,相比侧边具有棱角的支撑件73,可以进一步降低第一支撑部731和第二支撑部732的侧边与电极组件72接触位置的应力集中,从而避免支撑部对与其接触的电极组件72的损伤,防止正负极片搭接,降低电池单体7内部短路风险。
如上所述的一些实施例中,连接部733(包括第一连接部733a和第二连接部733b)可以和第一支撑部731、第二支撑部732一体成型,也可以分别加工后将这些部件组装成支撑件73,例如通过焊接、螺接、胶粘等方式将支第一支撑部731、第二支撑部732和连接部733固定在一起,得到支撑件73。
在本申请的一些实施例中,请继续参见图4和图6,其中电池单体7中电极组件72的数量为一个,支撑件73的数量也为一个,在厚度方向Y,支撑件73设置于壳体71和电极组件72之间。
在本申请的一些实施例中,请参见图14,图14为本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图。电池单体7中电极组件72的数量为一个,支撑件73的数量为两组,每组支撑件包括两个支撑件。在厚度方向Y,两组支撑件73分别设置于电极组件72的两侧,位于壳体71和电极组件72之间。其中单个支撑件73的厚度可以为图6中支撑件73厚度的一半。
在本申请的一些实施例中,电池单体7包括多个电极组件72,多个电极组件72沿厚度方向Y并排布置于壳体71内,在厚度方向Y,支撑件73设置于壳体71和与壳体71相邻的电极组件72之间。请参见图15,图15为本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图。其中电池单体7包括两个电极组件72,两个电极组件72沿厚度方向Y并排 布置于壳体71内,在厚度方向Y,支撑件73设置于壳体71和与壳体71相邻的电极组件72之间。
请参见图16,图16为本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图。其中电池单体7包括四个电极组件72,四个电极组件72沿厚度方向Y并排布置于壳体71内,在厚度方向Y,支撑件73设置于壳体71和与壳体71相邻的电极组件72之间。在本申请的一些实施例中,电池单体7包括多个电极组件72,多个电极组件72沿厚度方向Y并排布置于壳体71内,支撑件73设置于相邻的两个电极组件72之间。
请参见图17,图17为本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图。其中电池单体7包括两个电极组件72,两个电极组件72沿厚度方向Y并排布置于壳体71内,在厚度方向Y,支撑件73设置于相邻的两个电极组件72之间。
请参见图18,图18为本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图。其中电池单体7包括四个电极组件72,四个电极组件72沿厚度方向Y并排布置于壳体71内,在厚度方向Y,支撑件73设置于相邻的电极组件72之间。
请参见19,图19为本申请一些实施例提供的电池单体中电极组件和支撑件的配合示意图。其中电池单体7包括四个电极组件72,四个电极组件72沿厚度方向Y并排布置于壳体71内,在厚度方向Y,支撑件73设置于相邻的电极组件72之间。
通过将支撑件73设置于多个电极组件72中相邻的两个电极组件72之间,使得一个支撑件73能够同时使位于其两侧的两个电极组件73的位于弯折区R 2的最内层极片722a不容易起皱,从而通过使用较少的支撑件73达到相同的效果,减少电池单体7重量。
在本申请的一些实施例中,请参见图20-图23,图20为本申请一些实施例提供的电池单体的爆炸示意图,图21为图20中卡扣件与电极组件的装配示意图,图22为图21中卡扣件与电极组件在XOY平面的俯视示意图,图23为图22中A-A方向的截面结构示意图。图中,支撑件73通过卡扣件734固定于电极组件72的侧面。通过设置卡扣件734,可以将支撑件73固定于电极组件72的侧面,防止在使用过程中支撑件73倒伏,或相对电极组件72产生位移,导致对位于弯折区R 2的电极组件72的最内层极片722a起 皱的抑制效果降低。若支撑件73倒伏或者相对电极组件72产生位移,将使支撑架的位置不与位于弯折区R 2的电极组件72的最内层极片722a对应,从而不能实现减小位于弯折区R 2的电极组件72的最内层极片722a沿电极组件72的厚度方向Y的膨胀空间的效果。而且,卡扣件734的固定方式提高了支撑件73的结构强度。
图20-图23所示实施例中,卡扣件734包括设置于支撑件73顶端的卡板,其搭接于电极组件72的顶端;以及设置于支撑件73底端的卡板,其搭接于电极组件72底端。卡扣件734可以仅搭接于电极组件72上,通过电极组件72、支撑件73和卡扣件734三者之间的位置配合对支撑件73进行限位,从而将支撑件73固定于电极组件72的侧面。本领域技术人员应当理解,在其他实施例中,卡扣件734还可以通过固定件固定于电极组件72上,使支撑件73和电极组件72之间的固定更稳固。图中所示的电池单体7包括两个电极组件72,支撑件73设置于电极组件72之间,因此卡扣件734搭接于支撑件73两侧的电极组件72上。在一些实施例中,电池单体7仅包括一个电极组件72,支撑件73设置于电极组件72和壳体71之间,或者虽然电池单体7包括多个电极组件72,但是支撑件73同样也设置于电极组件72和壳体71之间,此时卡扣件734可以仅搭接于支撑件73一侧的电极组件72上。
本领域技术人员应当理解,可以仅在支撑件73的一端设置卡扣件734,例如,在一些实施例中,卡扣件734包括设置于支撑件73顶端的卡板,其搭接于电极组件72的顶端,通过电极组件72、支撑件73和卡扣件734三者之间的位置配合对支撑件73进行限位,从而将支撑件73固定于电极组件72的侧面。仅在支撑件73的一端卡扣件734,便于装配,也降低电池单体7的重量,提高电池单体7能量密度。
上述实施例中,卡扣件734可以为独立的部件,也可以和支撑件73一体成型。
在本申请的一些实施例中,请参见图24,图24为本申请一些实施例提供的电池单体的爆炸示意图,图中支撑件73通过粘贴固定于电极组件72的侧面,S为支撑件上的粘贴面。通过将支撑件73粘贴固定于电极组件72的侧面,防止在使用过程中支撑件73倒伏,或相对电极组件72产生位移。若支撑件73倒伏或者相对电极组件72产生位移,将使支撑架的位置不与 位于弯折区R 2的电极组件72的最内层极片722a对应,从而不能实现减小位于弯折区R 2的电极组件72的最内层极片722a沿电极组件72的厚度方向Y的膨胀空间的效果。而且,粘贴的方式可以减轻夹层单元的重量,对电池单体7的能量密度影响较小。
支撑件73的表面可以具有适当的粘性,从而可以使支撑件73可以较好地粘贴固定于电极组件72的侧面。本领域技术人员应当理解,可以选用带有粘性的支撑件73,也可以选用不带粘性的支撑件73,并在其抵靠电极组件72的一侧表面涂覆粘结剂或背胶,或者在电极组件72与支撑件73抵靠的表面涂覆粘结剂或背胶,便于支撑件73的粘贴。
在本申请的一些实施例中,在第二方向Z上支撑件73设有供电解液通过的贯通孔724(附图中未示出),第二方向Z与第一方向X和厚度方向Y两两垂直。贯通孔724的形成形式不限,可以通过在支撑件73上开设贯通孔724,也可以通过选择自身具备贯通孔724的材料制作支撑件73,例如具有一定表面孔隙率的多孔聚烯烃材料。由于在第二方向Z上支撑件73设有供电解液通过的贯通孔724,电解液可以通过该贯通孔724从电池单体7的底部流动到顶端,提高电解液对电极组件72的浸润效果,保证电池单体7的充放电性能。
在本申请的一些实施例中,请参见图25,图25为本申请一些实施例提供的电池单体的爆炸示意图,电极组件72还包括用于隔离正极极片和负极极片的隔膜,支撑件为位于电极组件72外侧的一层或多层隔膜723,一层或多层隔膜723具有沿厚度方向Y贯通的通孔724,通孔724对应平直区R 1设置。在电极组件72外侧卷绕一层或多层隔膜723,作为支撑件,用于减小位于弯折区R 2的电极组件72的最内层极片722a沿电极组件72的厚度方向Y的膨胀空间。此外,电池单体7在充放电过程中,锂离子嵌入极片将导致极片晶格参数变化,引起极片在厚度方向Y膨胀,并伴随充放电的频率进行膨胀和收缩。若平直区R 1的极片在厚度方向Y的膨胀被抑制,将导致电极组件72中的电解液被挤出,影响锂离子在正负极间的传递,出现大面积析锂,引发热失控从而影响电池单体7的安全性。通过在作为支撑件的这部分隔膜723上开设通孔724,能够为电极组件72的平直区R 1在厚度方向Y预留膨胀空间,防止析锂,从而降低对电池单体7的安全性的影响。此外,直接采用隔膜作为支撑件,可以简化部件,降低加工和装配难度。
作为支撑件73的隔膜723的层数可以根据电极组件72厚度的群域度计算。例如,最内层极片722a的拐角处群域度为90%,则:
隔膜层数=((壳体内腔厚度*(1-90%))/单层隔膜厚度)
将卷绕好的电极组件72装入壳体71后,电极组件72最内层极片722a的拐角处实际群域度满足或基本满足100%。若群域度超过100%,则超出了壳体71可以容纳电极组件72的厚度,电极组件72无法装入壳体71内,或者强行将电极组件72装入壳体71内将损伤电极组件72。若群域度不足100%,则位于电极组件72外侧的一层或多层作为支撑件73的隔膜723不能起到减小位于弯折区R 2的电极组件72的最内层极片722a沿电极组件72的厚度方向Y的膨胀空间的效果。
作为支撑件73的隔膜723的通孔724的尺寸根据电极组件72的整体尺寸以及弯折区R 2的尺寸确定。例如,电极组件72的宽度为X1(第一方向X上的尺寸),高度为Y1(第二方形Z上的尺寸),弯折区R 2拐角位置的宽度为X2,则通孔724尺寸为:
通孔宽度=X1-X2*2
通孔高度=Y1-2k,其中k根据加工要求确定,k是指在第二方向Z上通孔724与隔膜723边缘的距离。
请参见图26,图26为本申请一些实施例提供的一种制备电池单体的方法的流程示意图,制备电池单体的方法包括如下内容:
步骤261,提供壳体。
步骤262,提供电极组件,电极组件包括正极极片和负极极片,正极极片和负极极片层叠并卷绕形成卷绕结构,电极组件包括平直区和弯折区,弯折区位于平直区沿第一方向的端部。
步骤263,提供支撑件。
步骤264,将电极组件和支撑件设置于壳体内,并使支撑件位于电极组件的侧面,以使支撑件能够减小位于弯折区的电极组件的最内层极片沿电极组件的厚度方向的膨胀空间。
通过本实施例制备方法制造出的电池单体的相关结构,可以参考前述图1-25对应的实施例描述的电池单体7的相关内容,在此不再赘述。
请参见图27,图27为本申请一些实施例提供的一种制备电池单体的设备的结构示意图,制备电池单体的设备8包括:第一提供装置81、第二提供 装置82、第三提供装置83和组装装置84。
第一提供装置81,被配置为提供壳体。
第二提供装置82,被配置为提供电极组件,电极组件包括正极极片和负极极片,正极极片和负极极片层叠并卷绕形成卷绕结构,电极组件包括平直区和弯折区,弯折区位于平直区沿第一方向的端部。
第三提供装置83,被配置为提供支撑件。
组装装置84,被配置为将电极组件和支撑件设置于壳体内,并使支撑件位于电极组件的侧面,以使支撑件能够减小位于弯折区的电极组件的最内层极片沿电极组件的厚度方向的膨胀空间。
通过本实施例制备设备制造出的电池单体的相关结构,可以参考前述图1-25对应的实施例描述的电池单体7的相关内容,在此不再赘述。
最后应说明的是:以上各实施例仅用以说明本申请的技术方案,而非对其限制;尽管参照前述各实施例对本申请进行了详细的说明,本领域的普通技术人员应当理解:其依然可以对前述各实施例所记载的技术方案进行修改,或者对其中部分或者全部技术特征进行等同替换;而这些修改或者替换,并不使相应技术方案的本质脱离本申请各实施例技术方案的范围,其均应涵盖在本申请的权利要求和说明书的范围当中。尤其是,只要不存在结构冲突,各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例,而是包括落入权利要求的范围内的所有技术方案。

Claims (18)

  1. 一种电池单体,其中,包括:
    壳体(71);
    电极组件(72),布置于所述壳体(71)内,所述电极组件(72)包括正极极片(721)和负极极片(722),所述正极极片(721)和所述负极极片(722)层叠并卷绕形成卷绕结构,所述电极组件(72)包括平直区(R 1)和弯折区(R 2),所述弯折区(R 2)位于所述平直区(R 1)沿第一方向(X)的端部;
    支撑件(73),所述支撑件(73)设置于所述壳体(71)内,位于所述电极组件(72)的侧面,所述支撑件(73)用于减小位于所述弯折区(R 2)的所述电极组件(72)的最内层极片(722a)沿所述电极组件(72)的厚度方向(Y)的膨胀空间。
  2. 如权利要求1所述的电池单体,其中,至少部分所述支撑件(73)位于所述弯折区(R 2)与所述平直区(R 1)的交界处。
  3. 如权利要求1或2所述的电池单体,其中,沿所述厚度方向(Y),所述支撑件(73)的尺寸最大处(P 3)与所述最内层极片(722a)的拐角(P 1,P 2)对应,并抵靠于所述电极组件(72)。
  4. 如权利要求1-3中任一项所述的电池单体,其中,沿第二方向(Z),所述支撑件(73)的两端与所述负极极片(722)的端部平齐,所述第二方向(Z)与所述第一方向(X)和所述厚度方向(Y)两两垂直。
  5. 如权利要求1-4中任一项所述的电池单体,其中,所述支撑件(73)包括第一支撑部(731)、第二支撑部(732)和连接部(733),所述第一支撑部(731)和所述第二支撑部(732)分别位于所述支撑件(73)的两端,所述连接部(733)用于连接所述第一支撑部(731)和所述第二支撑部(732);
    所述弯折区(R 2)包括第一弯折区(R 21)和第二弯折区(R 22),至少 部分所述第一支撑部(731)与所述第一弯折区(R 21)的位置对应,至少部分所述第二支撑部(732)与所述第二弯折区(R 22)的位置对应。
  6. 如权利要求5所述的电池单体,其中,所述连接部(733)为中空结构,用于为所述平直区(R 1)提供膨胀空间。
  7. 如权利要求6所述的电池单体,其中,所述连接部(733)包括沿第二方向(Z)设置的第一连接部(733a)和第二连接部(733b),所述第一连接部(733a)和所述第二连接部(733b)之间形成所述中空结构,所述第二方向(Z)与所述第一方向(X)和所述厚度方向(Y)两两垂直。
  8. 如权利要求6所述的电池单体,其中,所述连接部(733)包括沿所述厚度方向(Y)设置的第一连接部(733a)和第二连接部(733b),所述第一连接部(733a)和所述第二连接部(733b)靠近所述电极组件(72)的侧面与所述第一支撑部(731)和所述第二支撑部(732)靠近所述电极组件(72)的侧面平齐。
  9. 如权利要求1-8中任一项所述的电池单体,其中,所述支撑件(73)与所述电极组件(72)接触的外表面为弧面。
  10. 如权利要求1-8中任一项所述的电池单体,其中,所述电池单体(7)包括多个电极组件(72),所述多个电极组件(72)沿所述厚度方向(Y)并排布置于所述壳体(71)内,在所述厚度方向(Y),所述支撑件(73)设置于所述壳体(71)和与所述壳体(71)相邻的所述电极组件(72)之间。
  11. 如权利要求1-8中任一项所述的电池单体,其中,所述电池单体(7)包括多个电极组件(72),所述多个电极组件(72)沿所述厚度方向(Y)并排布置于所述壳体(71)内,所述支撑件(73)设置于相邻的两个电极组件(72)之间。
  12. 如权利要求1-8中任一项所述的电池单体,其中,所述支撑件(73)通过粘贴固定于所述电极组件(72)的侧面,或者,所述支撑件(73)通过卡扣件(734)固定于所述电极组件(72)的侧面。
  13. 如权利要求1-8中任一项所述的电池单体,其中,在第二方向(Z) 上所述支撑件(73)设有供电解液通过的贯通孔(724),所述第二方向(Z)与所述第一方向(X)和所述厚度方向(Y)两两垂直。
  14. 如权利要求1-3中任一项所述的电池单体,其中,所述电极组件(72)还包括用于隔离所述正极极片(721)和所述负极极片(722)的隔膜(723),所述支撑件(73)为位于所述电极组件(72)外侧的一层或多层隔膜(723),所述一层或多层隔膜(723)具有沿所述厚度方向(Y)贯通的通孔(724),所述通孔(724)对应所述平直区(R 1)设置。
  15. 一种电池,其中,包括:如权利要求1-14中任一项所述的电池单体(7)。
  16. 一种用电装置,其中,所述用电装置包括如权利要求1-14中任一项所述的电池单体(7),所述电池单体(7)用于提供电能。
  17. 一种制备电池单体的方法,其中,包括:
    (261)提供壳体;
    (262)提供电极组件,所述电极组件包括正极极片和负极极片,所述正极极片和所述负极极片层叠并卷绕形成卷绕结构,所述电极组件包括平直区和弯折区,所述弯折区位于所述平直区沿第一方向的端部;
    (263)提供支撑件;
    (264)将所述电极组件和所述支撑件设置于所述壳体内,并使所述支撑件位于所述电极组件的侧面,以使所述支撑件能够减小位于所述弯折区的所述电极组件的最内层极片沿所述电极组件的厚度方向的膨胀空间。
  18. 一种制备电池单体的设备,其中,包括:
    第一提供装置(81),被配置为提供壳体;
    第二提供装置(82),被配置为提供电极组件,所述电极组件包括正极极片和负极极片,所述正极极片和所述负极极片层叠并卷绕形成卷绕结构,所述电极组件包括平直区和弯折区,所述弯折区位于所述平直区沿第一方向 的端部;
    第三提供装置(83),被配置为提供支撑件;
    组装装置(84),被配置为将所述电极组件和所述支撑件设置于所述壳体内,并使所述支撑件位于所述电极组件的侧面,以使所述支撑件能够减小位于所述弯折区的所述电极组件的最内层极片沿所述电极组件的厚度方向的膨胀空间。
PCT/CN2021/109921 2021-07-30 2021-07-30 电池单体、电池、用电装置及制备电池单体的方法和设备 WO2023004833A1 (zh)

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