Lamination unit and battery

Abstract

The invention provides a lamination unit and a battery. The lamination unit comprises n first pole pieces with the same polarity, the n first pole pieces are respectively n-2 composite pole pieces, first foil pole pieces and second foil pole pieces, and the composite pole pieces are arranged between the first foil pole pieces and the second foil pole pieces; each of the first foil pole piece, the second foil pole piece and the composite pole piece comprises a first tab and a second tab, the first tab of the composite pole piece is connected with the first tab of the first foil pole piece, and the second tab of the composite pole piece is connected with the second tab of the second foil pole piece; the first foil pole piece further comprises a first foil tab, and the first tab and the second tab of the first foil pole piece are respectively connected with the first foil tab; the second foil pole piece further comprises a second foil pole lug, and the first pole lug and the second pole lug of the second foil pole piece are respectively connected with the second foil pole lug. According to the lamination unit disclosed by the invention, the use amount of foil tabs of the composite pole piece is reduced, the quality of the battery is reduced, and the energy density of the battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular, to a laminated unit and a battery. Background Art

[0002] In related battery cells, metal foils are used as current collectors. For example, copper foil is used as the negative current collector and aluminum foil is used as the positive current collector. These metal foil current collectors have advantages such as good electrical conductivity, soft texture, and good environmental stability (for example, an oxide film can be formed on the surface of aluminum to prevent further reaction).

[0003] Currently, composite current collectors are gradually emerging in the industry. While improving the safety of batteries, they also have great potential in increasing the energy density of batteries. The composite current collector itself also has the characteristics of low manufacturing cost, high safety, and good compatibility. However, since the polymer-based film of the composite current collector is not conductive and the metal conductive layers on both sides cannot be electrically connected, in practical applications, there is a problem of leading out the tabs of the metal conductive layers. In related technologies, a solution of welding metal foil tabs to the micron-level metal conductive layers on both sides is mostly adopted. However, while increasing the weight of the battery, it also greatly increases the technical requirements for the welding process. Summary of the Invention

[0004] In view of the problem that the metal conductive layers on both sides of the composite current collector are not electrically connected and metal foil tabs need to be welded separately, the present invention provides a laminated unit and a battery.

[0005] On the one hand, the present invention provides a laminated unit, including n first polar plates with the same polarity, where n is a positive integer greater than or equal to 3; the n first polar plates with the same polarity are respectively n - 2 composite polar plates, a first foil tab plate, and a second foil tab plate, and the n - 2 composite polar plates are arranged between the first foil tab plate and the second foil tab plate;

[0006] The first foil tab plate, the second foil tab plate, and the n - 2 composite polar plates all include a first tab and a second tab. The first tabs of the n - 2 composite polar plates are respectively connected to the first tab of the first foil tab plate, and the second tabs of the n - 2 composite polar plates are respectively connected to the second tab of the second foil tab plate; the first foil tab plate further includes a first foil tab, and the first tab and the second tab of the first foil tab plate are respectively connected to the first foil tab; the second foil tab plate further includes a second foil tab, and the first tab and the second tab of the second foil tab plate are respectively connected to the second foil tab.

[0007] Optionally, the first tab and the second tab of each composite polar plate do not overlap along the width direction of the composite polar plate.

[0008] Optionally, the projection of the first tab of each composite electrode tab in the direction of the first foil electrode tab is located within the area where the first tab of the first foil electrode tab is located; the projection of the second tab of each composite electrode tab in the direction of the second foil electrode tab is located within the area where the second tab of the second foil electrode tab is located.

[0009] Optionally, a first spacing is provided between the first tabs of every two adjacent composite electrode tabs, and the width of the first spacing is 10 - 5000 μm; a second spacing is provided between the second tabs of every two adjacent composite electrode tabs, and the width of the second spacing is 10 - 5000 μm.

[0010] Optionally, the width of the n first electrode tabs with the same polarity is w mm, and the widths of the first tabs and second tabs of the first foil electrode tab and the second foil electrode tab are a mm respectively, and 2a ≤ w; the widths of the first tabs and second tabs of n - 2 composite electrode tabs are b mm respectively, and b ≤ a / (n - 2); the widths of the first foil tab and the second foil tab are c mm respectively, and c > w - 2a mm.

[0011] Optionally, 2 mm ≤ b ≤ a / (n - 2) for the first tabs and second tabs of n - 2 composite electrode tabs.

[0012] Optionally, the number n of the first electrode tabs and the width w of the first electrode tabs satisfy the following relationship: n < w / 4 + 2.

[0013] Optionally, the heights of the first tabs of n - 2 composite electrode tabs are the same, and the heights of the second tabs of n - 2 composite electrode tabs are the same;

[0014] The heights of the first tabs of the first foil electrode tab and the second foil electrode tab are greater than or equal to the heights of the first tabs of the composite electrode tabs, and the heights of the second tabs of the first foil electrode tab and the second foil electrode tab are greater than or equal to the heights of the second tabs of the composite electrode tabs.

[0015] Optionally, the composite electrode tab includes a base film, a conductive layer, and a first active material layer. The conductive layer is disposed on both sides of the base film. The conductive layer includes a first active material region and a first tab region. The first active material layer is disposed on the side of the first active material region away from the base film. The first tab and the second tab of the composite electrode tab are disposed in the first tab region;

[0016] The first foil electrode and the second foil electrode both include a foil current collector and a second active material layer. The foil current collector includes a second active material region and a second tab region. The second active material layer is disposed on the second active material region. The first tab and the second tab of the first foil electrode and the second foil electrode are disposed in the second tab region.

[0017] Optionally, the thickness of the conductive layer is 0.1 - 15 μm, and the thickness of the base film is 0.5 - 30 μm.

[0018] Optionally, the material of the base film includes one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, and polyethylene naphthalate;

[0019] The conductive layer includes one or more of a metal conductive agent, a carbon-based conductive agent, and a polymer conductive agent. The metal conductive agent includes one or more of copper, aluminum, gold, silver, iron, nickel, and zinc; the carbon-based conductive agent includes one or more of graphene, amorphous carbon, carbon nanotubes, and carbon fibers.

[0020] Optionally, the first active material layer and the second active material layer are respectively a positive electrode active material layer. The positive electrode active material layer includes one or more of lithium nickel cobalt manganese oxide, lithium iron manganese phosphate, lithium iron phosphate, lithium manganate, lithium cobaltate, lithium nickelate, lithium-rich manganese-based, lithium nickel manganese oxide, and lithium vanadium phosphate;

[0021] Or, the first active material layer and the second active material layer are respectively a negative electrode active material layer. The negative electrode active material layer includes one or more of a carbon-based active material, a silicon-based active material, a metal oxide, a tin-based active material, and a lithium-based active material.

[0022] Optionally, the carbon-based active material includes one or more of natural graphite, artificial graphite, hard carbon, soft carbon, and mesocarbon microbeads;

[0023] The silicon-based active material includes one or more of single crystal silicon, silicon carbide compounds, and silicon oxide compounds;

[0024] The tin-based active material includes one or more of elemental tin, tin-sulfur alloys, tin-phosphorus alloys, tin-iron alloys, and tin-cobalt alloys;

[0025] The metal oxide includes lithium titanate;

[0026] The lithium-based active material includes a lithium foil or a lithium alloy foil. The lithium alloy foil includes an alloy formed by one or more of gold, silver, tin, indium, magnesium, zinc, chromium, nickel, molybdenum, tungsten, vanadium, titanium, niobium, zirconium, cobalt, manganese, aluminum, copper, sodium, calcium, gallium, boron, silicon, carbon, and phosphorus and metallic lithium.

[0027] On the other hand, the present invention also provides a battery, which includes a separator, an electrolyte, a second electrode sheet, and the laminated unit described in any one of the above. The second electrode sheet has the opposite polarity to the first electrode sheet. The laminated unit, the separator, and the second electrode sheet are laminated, and the tab of the second electrode sheet is arranged on the side opposite to the first tab and the second tab of the laminated unit.

[0028] Optionally, the second electrode sheet is the laminated unit described in any one of the above, and the first foil tab and the second foil tab with the same polarity in the laminated unit are connected in sequence.

[0029] Optionally, the separator includes at least one of polypropylene or polyethylene;

[0030] The electrolyte includes a lithium salt, a solvent, and an additive. The solvent includes one or more of carbonate compounds, ether compounds, and nitrile compounds; the lithium salt includes one or more of LiPF6, LiClO4, LiBF4, LiAsF6, LiCF3SO, LiTFSI, LiFSI, LiTNFSI, LiFNFSI, LiBOB, LiN(CF3SO2)2, and LiC(SO2CF3)3; the additive includes one or more of a film-forming additive, a conductive additive, a flame retardant additive, and an overcharge protection additive.

[0031] Optionally, the carbonate compounds include one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and γ-butyrolactone;

[0032] The ether compounds include one or more of tetrahydrofuran, 2-methyl-tetrahydrofuran, dimethoxydimethyl ether, and 1,2-dimethoxyethane;

[0033] The nitrile compound includes acetonitrile.

[0034] On the other hand, the present invention also provides a battery, which includes a solid electrolyte, a second electrode sheet, and the laminated unit described in any one of the above. The second electrode sheet has the opposite polarity to the first electrode sheet. The laminated unit, the solid electrolyte, and the second electrode sheet are laminated, and the tab of the second electrode sheet is arranged on the side opposite to the first tab and the second tab of the laminated unit.

[0035] Optionally, the second electrode sheet is the laminated unit described in any one of the above, and the first foil tab and the second foil tab with the same polarity in the laminated unit are connected in sequence.

[0036] Optionally, the solid electrolyte includes one of inorganic solid electrolytes, polymer solid electrolytes, and...

[0037] The inorganic solid electrolyte includes one or more of an oxide solid electrolyte, a sulfide solid electrolyte, and a halide solid electrolyte;

[0038] The polymer solid electrolyte includes a polymer matrix and a lithium salt;

[0039] The composite solid electrolyte includes a polymer matrix and inorganic fillers.

[0040] Optionally, the oxide solid electrolyte includes one or more of a NASICON-type electrolyte, a perovskite-type electrolyte, and a Garnet garnet-type electrolyte;

[0041] The sulfide solid electrolyte includes one or more of Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-MS2-P2S5, and Li6PS5X, where X is selected from at least one of F, Cl, Br, and I, and M is selected from at least one of Si, Ge, Sn, and Al;

[0042] The halide solid electrolyte includes one or more of Li2MnCl4, Li2ZnCl4, LiYbF4, LiAlF4, Li3YCl6, Li3BrCl6, and Li6CoCl8;

[0043] The polymer matrix includes one or more of polyethylene oxide, polycarbonate, polytrimethylene carbonate, polymethyl methacrylate, polyacrylonitrile, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoroethylene copolymer, and lithium polyacrylate;

[0044] The lithium salt includes one or more of LiAsF6, LiPF6, LiClO4, LiTFSI, LiFSI, and LiBF4;

[0045] The inorganic fillers include one or more of LATP, LLZO, Al2O3, and metal-organic frameworks.

[0046] In the present invention, on the one hand, by providing a first tab and a second tab on the first electrode sheet, connecting the first tab of the composite electrode sheet to the first tab of the first foil electrode sheet, and connecting the second tab of the composite electrode sheet to the second tab of the second foil electrode sheet, the composite electrode sheet located between the first foil electrode sheet and the second foil electrode sheet does not require additional welding of metal foil tabs, which can significantly reduce the usage amount of metal foil tabs, thereby improving the energy density of the battery and avoiding the problem of incomplete ultrasonic welding of the first tab and the second tab of the composite electrode sheet and the need for multi-layer transfer welding. On the other hand, the structure of the stacked sheet unit of the present invention facilitates the battery to be flexibly designed according to the cell capacity requirement by multiple core stacked sheet units and corresponding second electrode sheets of opposite polarities. Description of the Drawings

[0047] Figure 1 It is a top view of a laminated unit provided by an embodiment of the present invention;

[0048] Figure 2 It is a front view of a laminated unit provided by an embodiment of the present invention;

[0049] Figure 3 It is a rear view of a laminated unit provided by an embodiment of the present invention;

[0050] Figure 4 It is a top view of the first foil electrode and the second foil electrode of a laminated unit provided by an embodiment of the present invention;

[0051] Figure 5 It is a front view of the first foil electrode and the second foil electrode of a laminated unit provided by an embodiment of the present invention;

[0052] Figure 6 It is a top view of four composite electrodes of a laminated unit provided by an embodiment of the present invention;

[0053] Figure 7 It is a front view of the composite electrode of a laminated unit provided by an embodiment of the present invention.

[0054] The reference numerals in the accompanying drawings of the specification are as follows:

[0055] 1. Composite electrode; 11. Base film; 12. Conductive layer; 13. First active material layer;

[0056] 2. First foil electrode; 21. Foil current collector; 22. Second active material layer;

[0057] 3. Second foil electrode;

[0058] 41. First tab; 42. Second tab; 43. First foil tab. Detailed implementation manners

[0059] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0060] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0061] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0062] In order to illustrate the technical solution of the present invention, the following will be described by means of specific embodiments.

[0063] As Figures 1-7 shown, a lamination unit according to an embodiment of the present invention includes n first pole pieces of the same polarity, where n is a positive integer greater than or equal to 3. The n first pole pieces of the same polarity are respectively n - 2 composite pole pieces 1, a first foil pole piece 2 and a second foil pole piece 3, and the n - 2 composite pole pieces 1 are arranged between the first foil pole piece 2 and the second foil pole piece 3.

[0064] The first foil electrode 2, the second foil electrode 3, and n - 2 of the composite electrodes 1 each include a first tab 41 and a second tab 42. Specifically, the first tab 41 and the second tab 42 are located on the same side. The first tabs 41 of the n - 2 composite electrodes 1 are respectively connected to the first tab 41 of the first foil electrode 2, and the second tabs 42 of the n - 2 composite electrodes 1 are respectively connected to the second tab 42 of the second foil electrode 3. Specifically, the first tab 41 of the composite electrode 1 and the first tab 41 of the first foil electrode 2 are connected by welding, and the second tab 42 of the composite electrode 1 and the second tab 42 of the second foil electrode 3 are connected by welding. The first foil electrode 2 further includes a first foil tab 43, and the first tab 41 and the second tab 42 of the first foil electrode 2 are respectively connected to the first foil tab 43. The second foil electrode 3 further includes a second foil tab (not shown in the figure), and the first tab 41 and the second tab 42 of the second foil electrode 3 are respectively connected to the second foil tab. The first foil tab 43 and the second foil tab are used to lead out current.

[0065] In this embodiment, by providing the first tab 41 and the second tab 42 on the first electrode, connecting the first tab 41 of the composite electrode 1 to the first tab 41 of the first foil electrode 2, and connecting the second tab 42 of the composite electrode 1 to the second tab 42 of the second foil electrode 3, it is possible to avoid the need for additional welding of metal foil tabs for the composite electrode 1 located between the first foil electrode 2 and the second foil electrode 3, significantly reducing the amount of tabs used, thereby improving the energy density of the battery. At the same time, it avoids the problem that the ultrasonic welding of the first tab 41 and the second tab 42 of the composite electrode 1 is not thorough and requires multi-layer transfer welding.

[0066] As Figure 6 shown, in some embodiments of the present invention, the first tab 41 and the second tab 42 of each composite electrode 1 do not overlap along the width direction of the composite electrode 1, avoiding problems such as increased heat generation caused by excessive local current density in the tabs of traditional electrodes. The non-overlap of the first tab 41 and the second tab 42 of each composite electrode 1 in the width direction means that the positions of the first tab 41 and the second tab 42 of each layer of the composite electrode 1 are different. In addition to using traditional mechanical processing methods (such as die cutting) to cut the tabs, laser cutting can be used, resulting in more accurate dimensions of the first tab 41 and the second tab 42 and less likely to cause damage.

[0067] As Figure 2 、 Figure 4 and Figure 6 shown, in a specific embodiment, the stacking unit is composed of six first electrodes of the same polarity. The first electrode of the first layer and the first electrode of the sixth layer are the first foil electrode 2 and the second foil electrode 3, and the first electrodes of the second to fifth layers are the composite electrodes 1. Among themFigure 4 -a and Figure 4 -b are the first foil electrode tab 2 of the first layer and the second foil electrode tab 3 of the sixth layer, Figure 6 -a, Figure 6 -b, Figure 6 -c, Figure 6 -d are the composite electrode tabs 1 of the second to fifth layers.

[0068] As Figure 1 shown, in some embodiments of the present invention, the projection of the first tab 41 of each composite electrode tab 1 in the direction of the first foil electrode tab 2 is located within the area where the first tab 41 of the first foil electrode tab 2 is located. The projection of the second tab 42 of each composite electrode tab 1 in the direction of the second foil electrode tab 3 is located within the area where the second tab 42 of the second foil electrode tab 3 is located, which is convenient for increasing the welding area between the first tab 41 and the second tab 42 of each composite electrode tab 1 and the first tab 41 and the second tab 42 of the first foil electrode tab 2, and increasing the connection reliability.

[0069] In some embodiments of the present invention, a first spacing is provided between the first tabs 41 of every two adjacent composite electrode tabs 1, and the width of the first spacing is 10 - 5000 μm. A second spacing is provided between the second tabs 42 of every two adjacent composite electrode tabs 1, and the width of the second spacing is 10 - 5000 μm. By providing the first spacing and the second spacing, local overcurrent density between the first tabs 41 and the second tabs 42 of adjacent composite electrode tabs 1 is avoided, and the first tab 41 spacing and the second tab 42 spacing may not be the same.

[0070] In some embodiments of the present invention, the width of n first electrode tabs of the same polarity is w mm, and the widths of the first tabs 41 and the second tabs 42 of the first foil electrode tab 2 and the second foil electrode tab 3 are a mm respectively, and 2a ≤ w. Specifically, the widths of the first tabs 41 and the second tabs 42 of the first foil electrode tab 2 and the second foil electrode tab 3 may not be exactly the same. The widths of the first tabs 41 and the second tabs 42 of n - 2 composite electrode tabs 1 are b mm respectively, and b ≤ a / (n - 2). Specifically, the widths of the first tabs 41 and the second tabs 42 of the composite electrode tab 1 may not be exactly the same. The widths of the first foil tab 43 and the second foil tab are c mm respectively, and c > w - 2a mm, which is convenient for welding with the first tabs 41 and the second tabs 42 of the first foil electrode tab 2 and the second foil electrode tab 3.

[0071] In some embodiments of the present invention, considering the welding quality of the first tab 41 and the second tab 42, 2 mm ≤ b ≤ a / (n - 2) for the widths of the first tabs 41 and the second tabs 42 of n - 2 composite electrode tabs 1.

[0072] In some embodiments of the present invention, the upper limit of the number n of the first pole pieces of the laminated unit can be determined by the width m of the first pole piece. The number n of the first pole pieces and the width w of the first pole piece satisfy the following relationship: n < w / 4 + 2.

[0073] As Figure 6 shown, in some embodiments of the present invention, the heights of the first pole ears 41 of n - 2 of the composite pole pieces 1 are the same, and the heights of the second pole ears 42 of n - 2 of the composite pole pieces 1 are the same.

[0074] The heights of the first pole ears 41 of the first foil pole piece 2 and the second foil pole piece 3 are greater than or equal to the heights of the first pole ears 41 of the composite pole piece 1, and the heights of the second pole ears 42 of the first foil pole piece 2 and the second foil pole piece 3 are greater than or equal to the heights of the second pole ears 42 of the composite pole piece 1, so as to avoid the situation where the first pole ears 41 and the second pole ears 42 of the composite pole piece 1 are exposed after the first pole ears 41 and the second pole ears 42 are welded.

[0075] As Figure 6 and Figure 7 shown, in some embodiments of the present invention, the composite pole piece 1 includes a base film 11, a conductive layer 12, and a first active material layer 13. The conductive layer 12 is disposed on both sides of the base film 11. The conductive layer 12 includes a first active material region and a first pole ear 41 region. The first active material layer 13 is disposed on the side of the first active material region facing away from the base film 11. The first pole ear 41 and the second pole ear 42 of the composite pole piece 1 are disposed in the first pole ear 41 region.

[0076] Both the first foil pole piece 2 and the second foil pole piece 3 include a foil current collector 21 and a second active material layer 22. The foil current collector 21 includes a second active material region and a second pole ear 42 region. The second active material layer 22 is disposed in the second active material region. The first pole ear 41 and the second pole ear 42 of the first foil pole piece 2 and the second foil pole piece 3 are disposed in the second pole ear 42 region.

[0077] In some embodiments of the present invention, the thickness of the conductive layer 12 is 0.1 - 15 μm, and the thickness of the base film 11 is 0.5 - 30 μm.

[0078] In some embodiments of the present invention, the material of the base film 11 includes one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, and polyethylene naphthalate.

[0079] The conductive layer 12 includes one or more of a metal conductive agent, a carbon-based conductive agent, and a polymer conductive agent. The metal conductive agent includes one or more of copper, aluminum, gold, silver, iron, nickel, and zinc. The carbon-based conductive agent includes one or more of graphene, amorphous carbon, carbon nanotubes, and carbon fibers. Specifically, the conductive layer 12 can be prepared on the base film 11 by physical vapor deposition (PVD), chemical vapor deposition (CVD), or electroplating. When the polarity of the laminated unit is negative, the negative copper conductive layer 12 can be prepared on the base film 11 by a one-step method, a two-step method, or a three-step method. Among them, the one-step method includes chemical deposition, vacuum magnetron sputtering, and vacuum evaporation. Chemical deposition deposits a copper layer through a chemical reaction. Vacuum magnetron sputtering deposits a copper layer by repeatedly magnetron sputtering. Vacuum evaporation deposits a copper layer by repeatedly evaporating. The two-step method is to use magnetron sputtering as a primer and then use electroplating to thicken the copper layer. The three-step method is to use magnetron sputtering as a primer, then use vacuum evaporation, and finally use electroplating to thicken the copper layer. When the polarity of the laminated unit is positive, the positive aluminum conductive layer 12 can be prepared on the base film 11 by a one-step evaporation method.

[0080] In some embodiments of the present invention, the first active material layer 13 and the second active material layer 22 are respectively positive electrode active material layers. The positive electrode active material layer includes lithium nickel cobalt manganate (LiNi x M y C z , x + y + z = 1), lithium iron manganese phosphate (LiFe x’ Mn y’ PO4, x'+y' = 1), lithium iron phosphate, lithium manganate, lithium cobaltate, lithium nickelate, lithium-rich manganese-based, lithium nickel manganate, and lithium vanadium phosphate (Li3V2(PO4)3, LiVOPO4), or one or more of them.

[0081] Or, the first active material layer 13 and the second active material layer 22 are respectively negative electrode active material layers. The negative electrode active material layer includes one or more of a carbon-based active material, a silicon-based active material, a metal oxide, a tin-based active material, and a lithium-based active material.

[0082] In some embodiments of the present invention, the carbon-based active material includes one or more of natural graphite, artificial graphite, hard carbon, soft carbon, and mesophase carbon microspheres.

[0083] The silicon-based active material includes one or more of single-crystalline silicon, silicon carbide compounds, and silicon oxide compounds.

[0084] The tin-based active material includes one or more of elemental tin, tin-sulfur alloys, tin-phosphorus alloys, tin-iron alloys, and tin-cobalt alloys.

[0085] The metal oxide includes lithium titanate.

[0086] The lithium-based active material includes a lithium foil or a lithium alloy foil, and the lithium alloy foil includes an alloy formed by one or more of gold, silver, tin, indium, magnesium, zinc, chromium, nickel, molybdenum, tungsten, vanadium, titanium, niobium, zirconium, cobalt, manganese, aluminum, copper, sodium, calcium, gallium, boron, silicon, carbon, and phosphorus and metallic lithium.

[0087] On the other hand, an embodiment of the present invention further provides a battery, including a separator, an electrolyte, a second electrode sheet, and the laminated unit described in any one of the above. The second electrode sheet has a polarity opposite to that of the first electrode sheet. The laminated unit, the separator, and the second electrode sheet are stacked. The tab of the second electrode sheet is disposed on the opposite side of the first tab 41 and the second tab 42 of the laminated unit. The structure of the laminated unit facilitates the battery to be flexibly designed according to the need of the cell capacity by a plurality of core laminated units and corresponding second electrode sheets with opposite polarities.

[0088] In some embodiments of the present invention, the second electrode sheet is the laminated unit described in any one of the above, and the first foil tab 43 and the second foil tab with the same polarity in the laminated unit are connected in sequence.

[0089] It should be noted here that the second electrode sheet can also be a conventional foil electrode sheet.

[0090] In some embodiments of the present invention, the separator includes at least one of polypropylene or polyethylene.

[0091] The electrolyte includes a lithium salt, a solvent, and an additive. The solvent includes one or more of carbonate compounds, ether compounds, and nitrile compounds. The lithium salt includes one or more of LiPF6, LiClO4, LiBF4, LiAsF6, LiCF3SO, LiTFSI, LiFSI, LiTNFSI, LiFNFSI, LiBOB, LiN(CF3SO2)2, and LiC(SO2CF3)3. The additive includes one or more of a film-forming additive, a conductive additive, a flame retardant additive, and an overcharge protection additive.

[0092] It should be noted here that the additive further includes an additive for controlling the water and HF content in the electrolyte, a general-purpose additive for improving low-temperature performance, and an additive for improving the interface stability between the electrode sheet and the electrolyte. The additive for improving the interface stability between the electrode sheet and the electrolyte includes, but is not limited to, fluoroethylene carbonate.

[0093] In some embodiments of the present invention, the carbonate compound includes one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and γ-butyrolactone.

[0094] The ether compounds include one or more of tetrahydrofuran, 2-methyl-tetrahydrofuran, dimethoxydimethane, and 1,2-dimethoxyethane.

[0095] The nitrile compound includes acetonitrile.

[0096] On the other hand, an embodiment of the present invention further provides a battery, including a solid electrolyte, a second electrode sheet, and the laminated unit described in any one of the above. The second electrode sheet has a polarity opposite to that of the first electrode sheet. The laminated unit, the solid electrolyte, and the second electrode sheet are stacked. The tab of the second electrode sheet is disposed on the opposite side of the first tab 41 and the second tab 42 of the laminated unit.

[0097] In some embodiments of the present invention, the second electrode sheet is the laminated unit described in any one of the above, and the first foil tab 43 and the second foil tab of the same polarity in the laminated unit are sequentially connected.

[0098] In some embodiments of the present invention, the solid electrolyte includes one of an inorganic solid electrolyte, a polymer solid electrolyte, and a composite solid electrolyte. Specifically, the composite solid electrolyte is an electrolyte based on a polymer matrix and inorganic fillers.

[0099] The inorganic solid electrolyte includes one or more of an oxide solid electrolyte, a sulfide solid electrolyte, and a halide solid electrolyte.

[0100] The polymer solid electrolyte includes a polymer matrix and a lithium salt;

[0101] The composite solid electrolyte includes a polymer matrix and inorganic fillers. Specifically, the composite manner of the polymer matrix and the inorganic fillers includes, but is not limited to, dispersion and mixing, or the inorganic fillers are filled in the gaps of the polymer matrix.

[0102] In some embodiments of the present invention, the oxide solid electrolyte includes one or more of NASICON-type electrolytes, perovskite-type electrolytes, and Garnet garnet-type electrolytes. Specifically, the NASICON-type electrolyte includes LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3), LAGP (Li 1.5 Al 0.5 Ge 1.5 P3O 12 ). The Garnet garnet-type electrolyte includes lithium lanthanum zirconium oxide LLZO, with a high conductivity of 10- 3 S / cm and good stability to lithium metal.

[0103] The sulfide solid electrolyte includes binary compounds and ternary compounds. The binary compounds include Li2S-SiS2, Li2S-P2S5, Li2S-GeS2. The ternary compounds include one or more of Li2S-MS2-P2S5 and Li6PS5X, where X is selected from at least one of F, Cl, Br, and I, and M is selected from at least one of Si, Ge, Sn, and Al.

[0104] The halide solid electrolyte includes Li a MX4 type, Li a MX6 type, and Li a MX8 type, where M is a divalent metal ion, a trivalent or other-valent metal ion, and X is a halogen. Specifically, the halide solid electrolyte includes one or more of Li2MnCl4, Li2ZnCl4, LiYbF4, LiAlF4, Li3YCl6, Li3BrCl6, and Li6CoCl8.

[0105] The polymer matrix includes one or more of polyethylene oxide, polycarbonate, poly(trimethylene carbonate), polymethyl methacrylate, polyacrylonitrile, polyvinylidene fluoride, poly(vinylidene fluoride - hexafluoroethylene) copolymer, and lithium polyacrylate.

[0106] The lithium salts include one or more of LiAsF6, LiPF6, LiClO4, LiTFSI, LiFSI, and LiBF4.

[0107] The inorganic fillers include one or more of LATP, LLZO, Al2O3, and metal-organic frameworks.

[0108] It should be noted here that the solid electrolyte in the battery can also be replaced with a gel electrolyte, and the gel electrolyte includes at least one of the solid electrolytes in the above embodiments and at least one of the electrolytes in the above embodiments.

[0109] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A laminated unit, characterized in that, It comprises n first pole pieces of the same polarity, where n is a positive integer greater than or equal to 3; the n first pole pieces of the same polarity are respectively n-2 composite pole pieces, a first foil pole piece and a second foil pole piece, and the n-2 composite pole pieces are arranged between the first foil pole piece and the second foil pole piece; The first foil pole piece, the second foil pole piece and the n-2 composite pole pieces all include a first pole ear and a second pole ear, the first pole ears of the n-2 composite pole pieces are respectively connected to the first pole ears of the first foil pole piece, and the second pole ears of the n-2 composite pole pieces are respectively connected to the second pole ears of the second foil pole piece; the first foil pole piece also includes a first foil pole ear, and the first pole ear and the second pole ear of the first foil pole piece are respectively connected to the first foil pole ear; the second foil pole piece also includes a second foil pole ear, and the first pole ear and the second pole ear of the second foil pole piece are respectively connected to the second foil pole ear.

2. The laminated unit according to claim 1, characterized in that, The first pole tab and the second pole tab of each composite pole piece do not overlap each other along the width direction of the composite pole piece.

3. The laminated unit according to claim 2, characterized in that, The projection of the first pole ear of each composite pole piece in the direction of the first foil pole piece is located in the area where the first pole ear of the first foil pole piece is located; the projection of the second pole ear of each composite pole piece in the direction of the second foil pole piece is located in the area where the second pole ear of the second foil pole piece is located.

4. The laminated unit according to claim 2, characterized in that, A first spacing is provided between the first pole ears of each two adjacent composite pole pieces, and the width of the first spacing is 10-5000 μm; a second spacing is provided between the second pole ears of each two adjacent composite pole pieces, and the width of the second spacing is 10-5000 μm.

5. The laminated unit according to claim 1, characterized in that, The width of the n first pole pieces of the same polarity is w mm, the width of the first pole ear and the second pole ear of the first foil pole piece and the second foil pole piece are a mm respectively, 2a≤w; the width of the first pole ear and the second pole ear of the n-2 composite pole pieces are b mm respectively, b≤a / (n-2); the width of the first foil pole ear and the second foil pole ear are c mm respectively, c>w-2a mm.

6. The laminated unit according to claim 5, characterized in that, The width of the first pole tab and the second pole tab of n-2 composite pole pieces is 2mm≤b≤a / (n-2).

7. The laminated unit according to claim 5, characterized in that, The number n of the first pole pieces and the width w of the first pole pieces satisfy the following relationship: n≤w / 4+2.

8. The laminated unit according to claim 1, characterized in that, The first pole tabs of n-2 composite pole pieces have the same height, and the second pole tabs of n-2 composite pole pieces have the same height; The height of the first pole lug of the first foil pole piece and the second foil pole piece is greater than or equal to the height of the first pole lug of the composite pole piece, and the height of the second pole lug of the first foil pole piece and the second foil pole piece is greater than or equal to the height of the second pole lug of the composite pole piece.

9. The laminated unit according to claim 1, characterized in that, The composite pole piece comprises a base film, a conductive layer and a first active material layer, wherein the conductive layer is arranged on both sides of the base film, the conductive layer comprises a first active material region and a first pole lug region, the first active material layer is arranged on a side of the first active material region away from the base film, and the first pole lug and the second pole lug of the composite pole piece are arranged in the first pole lug region; The first foil electrode and the second foil electrode both include a foil current collector and a second active material layer. The foil current collector includes a second active material region and a second tab region. The second active material layer is disposed on the second active material region. The first tab and the second tab of the first foil electrode and the second foil electrode are disposed in the second tab region.

10. The laminated unit according to claim 9, characterized in that, The thickness of the conductive layer is 0.1 - 15 μm, and the thickness of the base film is 0.5 - 30 μm.

11. The laminated unit according to claim 9, characterized in that, The material of the base film includes one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, and polyethylene naphthalate; The conductive layer includes one or more of a metal conductive agent, a carbon-based conductive agent, and a polymer conductive agent. The metal conductive agent includes one or more of copper, aluminum, gold, silver, iron, nickel, and zinc; the carbon-based conductive agent includes one or more of graphene, amorphous carbon, carbon nanotubes, and carbon fibers.

12. The laminated unit according to claim 9, characterized in that, The first active material layer and the second active material layer are respectively a positive electrode active material layer. The positive electrode active material layer includes one or more of lithium nickel cobalt manganese oxide, lithium iron manganese phosphate, lithium iron phosphate, lithium manganate, lithium cobaltate, lithium nickelate, lithium-rich manganese-based, lithium nickel manganese oxide, and lithium vanadium phosphate. Or, the first active material layer and the second active material layer are respectively a negative electrode active material layer. The negative electrode active material layer includes one or more of a carbon-based active material, a silicon-based active material, a metal oxide, a tin-based active material, and a lithium-based active material.

13. The laminated unit according to claim 12, characterized in that, The carbon-based active material includes one or more of natural graphite, artificial graphite, hard carbon, soft carbon, and mesophase carbon microspheres; The silicon-based active material includes one or more of single crystal silicon, silicon carbide compounds, and silicon oxide compounds; The tin-based active material includes one or more of elemental tin, tin-sulfur alloys, tin-phosphorus alloys, tin-iron alloys, and tin-cobalt alloys; the metal oxide includes lithium titanate; The lithium-based active material includes a lithium foil or a lithium alloy foil. The lithium alloy foil includes an alloy formed by one or more of gold, silver, tin, indium, magnesium, zinc, chromium, nickel, molybdenum, tungsten, vanadium, titanium, niobium, zirconium, cobalt, manganese, aluminum, copper, sodium, calcium, gallium, boron, silicon, carbon, and phosphorus and metallic lithium.

14. A battery, characterized in that, It includes a separator, an electrolyte, a second electrode, and the laminated unit according to any one of claims 1 - 13. The second electrode has a polarity opposite to that of the first electrode. The laminated unit, the separator, and the second electrode are stacked. The tab of the second electrode is disposed on the side opposite to the first tab and the second tab of the laminated unit.

15. The battery according to claim 14, characterized in that, The second electrode is the laminated unit according to any one of claims 1 - 12. The first foil tabs and the second foil tabs of the same polarity in the laminated unit are connected in sequence.

16. The battery according to claim 14, characterized in that, The separator includes at least one of polypropylene and polyethylene; the electrolyte includes a lithium salt, a solvent, and an additive, the solvent includes one or more of carbonate compounds, ether compounds, and nitrile compounds; the lithium salt includes one or more of LiPF6, LiClO4, LiBF4, LiAsF6, LiCF3SO, LiTFSI, LiFSI, LiTNFSI, LiFNFSI, LiBOB, LiN(CF3SO2)2, and LiC(SO2CF3)3; the additive includes one or more of a film-forming additive, a conductive additive, a flame-retardant additive, and an overcharge protection additive.

17. The battery according to claim 16, wherein, The carbonate compounds include one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and γ-butyrolactone; the ether compounds include one or more of tetrahydrofuran, 2-methyl-tetrahydrofuran, dimethoxydimethane, and 1,2-dimethoxyethane; the nitrile compound includes acetonitrile.

18. A battery, wherein, It includes a solid electrolyte, a second electrode sheet, and the laminated unit according to any one of claims 1-13, the second electrode sheet has the opposite polarity to the first electrode sheet, the laminated unit, the solid electrolyte, and the second electrode sheet are laminated, and the tab of the second electrode sheet is arranged on the opposite side of the first tab and the second tab of the laminated unit.

19. The battery according to claim 18, wherein, The second electrode sheet is the laminated unit according to any one of claims 1-12, and the first foil tab and the second foil tab of the same polarity in the laminated unit are connected in sequence.

20. The battery according to claim 18, wherein, The solid electrolyte includes one of an inorganic solid electrolyte, a polymer solid electrolyte, and a composite solid electrolyte; The inorganic solid electrolyte includes one or more of an oxide solid electrolyte, a sulfide solid electrolyte, and a halide solid electrolyte; The polymer solid electrolyte includes a polymer matrix and a lithium salt; The composite solid electrolyte includes a polymer matrix and an inorganic filler.

21. The battery according to claim 20, wherein, The oxide solid electrolyte includes one or more of NASICON-type electrolytes, perovskite-type electrolytes, and Garnet garnet-type electrolytes; The sulfide solid electrolyte includes one or more of Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-MS2-P2S5, and Li6PS5X, where X is selected from at least one of F, Cl, Br, and I, and M is selected from at least one of Si, Ge, Sn, and Al; The halide solid electrolyte includes one or more of Li2MnCl4, Li2ZnCl4, LiYbF4, LiAlF4, Li3YCl6, Li3BrCl6, and Li6CoCl8; The polymer matrix includes one or more of polyethylene oxide, polycarbonate, polytrimethylene carbonate, polymethyl methacrylate, polyacrylonitrile, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoroethylene copolymer, and lithium polyacrylate; The inorganic filler includes one or more of LATP, LLZO, Al2O3, and metal-organic frameworks; The lithium salt includes one or more of LiAsF6, LiPF6, LiClO4, LiTFSI, LiFSI, and LiBF4.

Images