Lamination unit and battery

Abstract

Provided are a lamination unit and a battery. The lamination unit comprises n first electrode sheets having the same polarity, wherein the n first electrode sheets are respectively n-2 composite electrode sheets, a first foil electrode sheet, and a second foil electrode sheet, and the composite electrode sheets are arranged between the first foil electrode sheet and the second foil electrode sheet; the first foil electrode sheet, the second foil electrode sheet, and the composite electrode sheets each comprise a first tab and a second tab, the first tabs of the composite electrode sheets are respectively connected to the first tab of the first foil electrode sheet, and the second tabs of the composite electrode sheets are respectively connected to the second tab of the second foil electrode sheet; the first foil electrode sheet further comprises a first foil tab, and the first tab and the second tab of the first foil electrode sheet are respectively connected to the first foil tab; and the second foil electrode sheet further comprises a second foil tab, and the first tab and the second tab of the second foil electrode sheet are respectively connected to the second foil tab. The lamination unit of the present invention reduces the consumption of the foil tabs of the composite electrode sheets, thereby reducing the mass of the battery, and increasing the energy density of the battery.

Description

A laminate unit and a battery

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to a Chinese patent application filed with the Patent Office of China on December 7, 2023, with application number 202311672106.1 and application name “A laminated unit and battery”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the technical field of batteries, and in particular to a laminate unit and a battery. Background Art

[0004] Related battery cells use metal foil as the current collector, for example, copper foil for the negative electrode current collector and aluminum foil for the positive electrode current collector. These metal foil current collectors have advantages such as good conductivity, soft texture, and good environmental stability (for example, an oxide film can form on the aluminum surface to prevent further reaction).

[0005] Composite current collectors are gradually emerging in the industry. While improving battery safety, they also have great potential in increasing battery energy density. Composite current collectors themselves have the characteristics of low manufacturing cost, high safety, and good compatibility. However, since the polymer base film of composite current collectors is not conductive, the metal conductive layers on both sides cannot be electrically conductive. In practical applications, they face the problem of metal conductive layer tabs. Related technologies often use the solution of welding metal foil tabs on both sides of the micron-level metal conductive layer. However, while adding extra weight to the battery, it also greatly increases the technical requirements for the welding process.

[0006] Summary of the Invention

[0007] To address the problem that the metal conductive layers on both sides of a composite current collector are not conductive and metal foil tabs need to be welded separately, the present invention provides a laminate unit and a battery.

[0008] In one aspect, the present invention provides a laminated unit, comprising 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;

[0009] The first foil electrode piece, the second foil electrode piece and the n-2 composite electrode pieces all include a first electrode tab and a second electrode tab, the first electrode tabs of the n-2 composite electrode pieces are respectively connected to the first electrode tab of the first foil electrode piece, and the second electrode tabs of the n-2 composite electrode pieces are respectively connected to the second electrode tab of the second foil electrode piece; the first foil electrode piece also includes a first foil electrode tab, and the first electrode tab and the second electrode tab of the first foil electrode piece are respectively connected to the first foil electrode tab; the second foil electrode piece also includes a second foil electrode tab, and the first electrode tab and the second electrode tab of the second foil electrode piece are respectively connected to the second foil electrode tab.

[0010] Optionally, the first electrode tab and the second electrode tab of each composite electrode piece do not overlap with each other along the width direction of the composite electrode piece.

[0011] Optionally, the projection of the first pole tab of each composite pole piece in the direction of the first foil pole piece is located in the area where the first pole tab of the first foil pole piece is located; the projection of the second pole tab of each composite pole piece in the direction of the second foil pole piece is located in the area where the second pole tab of the second foil pole piece is located.

[0012] Optionally, a first spacing is set between the first pole tabs of each two adjacent composite pole pieces, and the first spacing width is 10-5000 μm; a second spacing is set between the second pole tabs of each two adjacent composite pole pieces, and the second spacing width is 10-5000 μm.

[0013] Optionally, 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 respectively a mm, 2a≤w; the width of the first pole ear and the second pole ear of the n-2 composite pole pieces are respectively b mm, b≤a / (n-2); the width of the first foil pole ear and the second foil pole ear are respectively c mm, c>w-2a mm.

[0014] Optionally, the width of the first pole tab and the second pole tab of n-2 composite pole pieces is 2mm≤b≤a / (n-2).

[0015] Optionally, 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。

[0016] Optionally, the first tabs of n-2 composite pole pieces have the same height, and the second tabs of n-2 composite pole pieces have the same height;

[0017] The height of the first tabs of the first foil pole piece and the second foil pole piece is greater than or equal to the height of the first tab of the composite pole piece, and the height of the second tabs of the first foil pole piece and the second foil pole piece is greater than or equal to the height of the second tab of the composite pole piece.

[0018] Optionally, the composite electrode sheet includes a base film, a conductive layer and a first active material layer, the conductive layer is arranged 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 arranged on a side of the first active material region away from the base film, and the first tab and the second tab of the composite electrode sheet are arranged in the first tab region;

[0019] The first foil pole piece and the second foil pole piece both include a foil current collector and a second active material layer. The foil current collector includes a second active material area and a second tab area. The second active material layer is arranged in the second active material area. The first tab and the second tab of the first foil pole piece and the second foil pole piece are arranged in the second tab area.

[0020] Optionally, the thickness of the conductive layer is 0.1-15 μm, and the thickness of the base film is 0.5-30 μm.

[0021] Optionally, the material of the base film includes one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide and polyethylene naphthalate;

[0022] The conductive layer includes one or more of a metal conductive agent, a carbon 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 conductive agent includes one or more of graphene, amorphous carbon, carbon nanotubes and carbon fibers.

[0023] Optionally, the first active material layer and the second active material layer are respectively positive electrode active material layers, and the positive electrode active material layers include one or more of lithium nickel cobalt manganese oxide, lithium iron manganese phosphate, lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium rich manganese base, lithium nickel manganese oxide and lithium vanadium oxyphosphate;

[0024] Alternatively, the first active material layer and the second active material layer are negative electrode active material layers respectively, and the negative electrode active material layers include one or more of carbon-based active materials, silicon-based active materials, metal oxides, tin-based active materials and lithium-based active materials.

[0025] Optionally, the carbon active material includes one or more of natural graphite, artificial graphite, hard carbon, soft carbon and mesocarbon microbeads;

[0026] The silicon-based active material includes one or more of single crystal silicon, silicon-carbon compounds and silicon-oxygen compounds;

[0027] The tin-based active material includes one or more of elemental tin, tin-sulfur alloy, tin-phosphorus alloy, tin-iron alloy and tin-cobalt alloy;

[0028] The metal oxide includes lithium titanate;

[0029] The lithium-based active material includes lithium foil or 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.

[0030] On the other hand, the present invention also provides a battery, comprising a diaphragm, an electrolyte, a second pole piece and a laminate unit as described above, wherein the second pole piece has an opposite polarity to the first pole piece, the laminate unit, the diaphragm and the second pole piece are stacked, and the pole tab of the second pole piece is arranged on the opposite side of the first pole tab and the second pole tab of the laminate unit.

[0031] Optionally, the second pole piece is a laminated unit as described above, and a first foil tab and a second foil tab of the same polarity in the laminated unit are connected in sequence.

[0032] Optionally, the diaphragm comprises at least one of polypropylene or polyethylene;

[0033] The electrolyte includes a lithium salt, a solvent and an additive, wherein the solvent includes one or more of a carbonate compound, an ether compound and a nitrile compound; 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.

[0034] Optionally, the carbonate compound includes one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate and γ-butyrolactone;

[0035] The ether compound includes one or more of tetrahydrofuran, 2-methyltetrahydrofuran, dimethoxydimethyl ether and 1,2-dimethoxyethane;

[0036] The nitrile compound includes acetonitrile.

[0037] On the other hand, the present invention also provides a battery, comprising a solid electrolyte, a second pole piece and a laminate unit as described above, wherein the second pole piece has an opposite polarity to the first pole piece, the laminate unit, the solid electrolyte and the second pole piece are stacked, and the pole tab of the second pole piece is arranged on the opposite side of the first pole tab and the second pole tab of the laminate unit.

[0038] Optionally, the second pole piece is a laminated unit as described above, and a first foil tab and a second foil tab of the same polarity in the laminated unit are connected in sequence.

[0039] Optionally, the solid electrolyte includes one of an inorganic solid electrolyte, a polymer solid electrolyte, and;

[0040] The inorganic solid electrolyte includes one or more of an oxide solid electrolyte, a sulfide solid electrolyte and a halide solid electrolyte;

[0041] The polymer solid electrolyte includes a polymer matrix and a lithium salt;

[0042] The composite solid electrolyte includes a polymer matrix and an inorganic filler.

[0043] Optionally, the oxide solid electrolyte includes one or more of a NASICON electrolyte, a perovskite electrolyte, and a Garnet garnet electrolyte;

[0044] The sulfide solid electrolyte includes one or more of Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-MS2-P2S5 and Li6PS5X, wherein 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;

[0045] The halide solid electrolyte includes one or more of Li2MnCl4, Li2ZnCl4, LiYbF4, LiAlF4, Li3YCl6, Li3BrCl6 and Li6CoCl8;

[0046] 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;

[0047] The lithium salt includes one or more of LiAsF6, LiPF6, LiClO4, LiTFSI, LiFSI and LiBF4;

[0048] The inorganic filler includes one or more of LATP, LLZO, Al2O3 and metal organic framework.

[0049] In the present invention, on the one hand, by providing a first pole tab and a second pole tab on the first pole piece, and connecting the first pole tab of the composite pole piece to the first pole tab of the first foil pole piece, and connecting the second pole tab of the composite pole piece to the second pole tab of the second foil pole piece, the composite pole piece located between the first foil pole piece and the second foil pole piece does not need to be additionally welded with a metal foil pole tab, which can significantly reduce the amount of metal foil pole tabs used, thereby improving the energy density of the battery, while avoiding the problem of ultrasonic welding of the first pole tab and the second pole tab of the composite pole piece not being able to penetrate through, and requiring multi-layer transfer welding. On the other hand, the structure of the laminated unit of the present invention facilitates the flexible design of the battery by multiple core laminated units and corresponding second pole pieces of opposite polarity according to the capacity requirements of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1 is a top view of a lamination unit provided in one embodiment of the present invention;

[0051] FIG2 is a front view of a lamination unit provided in one embodiment of the present invention;

[0052] FIG3 is a rear view of a lamination unit provided in one embodiment of the present invention;

[0053] FIG4A is a top view of a first foil electrode of a laminate unit provided by one embodiment of the present invention;

[0054] FIG4B is a top view of a second foil electrode of a laminate unit provided by one embodiment of the present invention;

[0055] FIG5 is a front view of a first foil electrode piece and a second foil electrode piece of a laminate unit provided by one embodiment of the present invention;

[0056] 6A to 6D are top views of four composite pole pieces of a laminated unit provided in one embodiment of the present invention;

[0057] FIG7 is a front view of a composite pole piece of a laminate unit provided in one embodiment of the present invention.

[0058] The reference numerals in the drawings of the specification are as follows:

[0059] 1. Composite electrode; 11. Base film; 12. Conductive layer; 13. First active material layer;

[0060] 2. First foil electrode; 21. Foil current collector; 22. Second active material layer;

[0061] 3. Second foil electrode;

[0062] 41. First electrode tab; 42. Second electrode tab; 43. First foil electrode tab. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, 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 intended to limit the present invention.

[0064] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0065] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0066] In order to illustrate the technical solution of the present invention, specific embodiments are provided below.

[0067] As shown in Figures 1 to 7, a laminated unit according to an embodiment of the present invention includes n first electrode pieces of the same polarity, where n is a positive integer greater than or equal to 3. The n first electrode pieces of the same polarity are respectively n-2 composite electrode pieces 1, first foil electrode pieces 2, and second foil electrode pieces 3, and the n-2 composite electrode pieces 1 are arranged between the first foil electrode pieces 2 and the second foil electrode pieces 3.

[0068] The first foil pole piece 2, the second foil pole piece 3 and the n-2 composite pole pieces 1 all include a first pole lug 41 and a second pole lug 42. Specifically, the first pole lug 41 and the second pole lug 42 are located on the same side. The first pole lugs 41 of the n-2 composite pole pieces 1 are respectively connected to the first pole lug 41 of the first foil pole piece 2, and the second pole lugs 42 of the n-2 composite pole pieces 1 are respectively connected to the second pole lug 42 of the second foil pole piece 3. Specifically, the first pole lug 41 of the composite pole piece 1 is connected to the first pole lug 41 of the first foil pole piece 2 by welding, and the second pole lug 42 of the composite pole piece 1 is connected to the second pole lug 42 of the second foil pole piece 3 by welding. The first foil pole piece 2 also includes a first foil pole lug 43, and the first pole lug 41 and the second pole lug 42 of the first foil pole piece 2 are respectively connected to the first foil pole lug 43. The second foil electrode piece 3 further includes a second foil tab (not shown), to which the first tab 41 and the second tab 42 of the second foil electrode piece 3 are connected respectively. The first foil tab 43 and the second foil tab are used to draw current.

[0069] In this embodiment, by arranging the first pole ear 41 and the second pole ear 42 on the first pole piece, and connecting the first pole ear 41 of the composite pole piece 1 with the first pole ear 41 of the first foil pole piece 2, and connecting the second pole ear 42 of the composite pole piece 1 with the second pole ear 42 of the second foil pole piece 3, the composite pole piece 1 located between the first foil pole piece 2 and the second foil pole piece 3 does not need to be additionally welded with metal foil pole ears, which can significantly reduce the amount of pole ears used, thereby improving the energy density of the battery, and at the same time avoids the problem that the first pole ear 41 and the second pole ear 42 of the composite pole piece 1 cannot be ultrasonically welded through, and multi-layer transfer welding is required.

[0070] As shown in Figures 6A to 6D, in some embodiments of the present invention, the first pole tab 41 and the second pole tab 42 of each composite pole piece 1 do not overlap along the width direction of the composite pole piece 1, thereby avoiding problems such as increased heat generation caused by excessive local overcurrent density in the pole tabs of traditional pole pieces. The first pole tab 41 and the second pole tab 42 of each composite pole piece 1 do not overlap in the width direction, that is, the first pole tab 41 and the second pole tab 42 of each layer of composite pole pieces 1 are positioned differently. In addition to using traditional mechanical processing methods (such as die cutting) to cut the pole tabs, laser cutting can be used. The resulting first pole tab 41 and the second pole tab 42 are more precisely sized and less prone to damage.

[0071] As shown in Figures 2, 4A to 4B, and 6A to 6D, in a specific embodiment, the laminated unit is composed of six first electrode pieces of the same polarity. The first electrode piece of the first layer and the first electrode piece of the sixth layer are the first foil electrode piece 2 and the second foil electrode piece 3, and the first electrode pieces of the second to fifth layers are composite electrode pieces 1. Figures 4A and 4B show the first foil electrode piece 2 of the first layer and the second foil electrode piece 3 of the sixth layer, and Figures 6A, 6B, 6C, and 6D show the composite electrode pieces 1 of the second to fifth layers.

[0072] As shown in FIG1 , in some embodiments of the present invention, the projection of the first pole tab 41 of each composite pole piece 1 in the direction of the first foil pole piece 2 is located within the region where the first pole tab 41 of the first foil pole piece 2 is located. The projection of the second pole tab 42 of each composite pole piece 1 in the direction of the second foil pole piece 3 is located within the region where the second pole tab 42 of the second foil pole piece 3 is located, thereby increasing the welding area between the first pole tab 41 and the second pole tab 42 of each composite pole piece 1 and the first pole tab 41 and the second pole tab 42 of the first foil pole piece 2, thereby increasing the connection reliability.

[0073] In some embodiments of the present invention, a first spacing is provided between the first pole tabs 41 of each adjacent two composite pole pieces 1, and the first spacing width is 10-5000 μm. A second spacing is provided between the second pole tabs 42 of each adjacent two composite pole pieces 1, and the second spacing width is 10-5000 μm. By setting the first spacing and the second spacing, excessive local overcurrent density between the first pole tabs 41 and the second pole tabs 42 of adjacent composite pole pieces 1 is avoided. The spacing between the first pole tabs 41 and the second pole tabs 42 may be different.

[0074] In some embodiments of the present invention, the width of the n first pole pieces of the same polarity is w mm, the width of the first pole piece 41 and the second pole piece 42 of the first foil pole piece 2 and the second foil pole piece 3 are respectively a mm, 2a≤w. Specifically, the widths of the first pole piece 41 and the second pole piece 42 of the first foil pole piece 2 and the second foil pole piece 3 may not be exactly the same. The widths of the first pole piece 41 and the second pole piece 42 of the n-2 composite pole pieces 1 are respectively b mm, b≤a / (n-2). Specifically, the widths of the first pole piece 41 and the second pole piece 42 of the composite pole piece 1 may not be exactly the same. The widths of the first foil pole piece 43 and the second foil pole piece are respectively c mm, c>w-2a mm, which facilitates welding with the first pole piece 41 and the second pole piece 42 of the first foil pole piece 2 and the second foil pole piece 3.

[0075] In some embodiments of the present invention, considering the welding quality of the first electrode tab 41 and the second electrode tab 42 , the width of the first electrode tab 41 and the second electrode tab 42 of the n-2 composite electrode sheets 1 is 2mm≤b≤a / (n-2).

[0076] 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, and the number n of the first pole pieces and the width w of the first pole piece satisfy the following relationship: <w / 4+2。

[0077] As shown in FIG. 6A to FIG. 6D , in some embodiments of the present invention, the first pole tabs 41 of n-2 composite pole pieces 1 have the same height, and the second pole tabs 42 of n-2 composite pole pieces 1 have the same height.

[0078] The height of the first pole tab 41 of the first foil pole piece 2 and the second foil pole piece 3 is greater than or equal to the height of the first pole tab 41 of the composite pole piece 1, and the height of the second pole tab 42 of the first foil pole piece 2 and the second foil pole piece 3 is greater than or equal to the height of the second pole tab 42 of the composite pole piece 1, so as to avoid the situation where the first pole tab 41 and the second pole tab 42 of the composite pole piece 1 are exposed after the first pole tab 41 and the second pole tab 42 are welded.

[0079] As shown in Figures 6A to 6D and Figure 7, in some embodiments of the present invention, the composite electrode 1 includes a base film 11, a conductive layer 12 and a first active material layer 13, the conductive layer 12 is arranged on both sides of the base film 11, the conductive layer 12 includes a first active material area and a first pole ear 41 area, the first active material layer 13 is arranged on the side of the first active material area away from the base film 11, and the first pole ear 41 and the second pole ear 42 of the composite electrode 1 are arranged in the first pole ear 41 area.

[0080] The first foil pole piece 2 and the second foil pole piece 3 both include a foil current collector 21 and a second active material layer 22. The foil current collector 21 includes a second active material area and a second pole tab 42 area. The second active material layer 22 is arranged in the second active material area. The first pole tab 41 and the second pole tab 42 of the first foil pole piece 2 and the second foil pole piece 3 are arranged in the second pole tab 42 area.

[0081] 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.

[0082] 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.

[0083] The conductive layer 12 includes one or more of a metal conductive agent, a carbon 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 conductive agent includes one or more of graphene, amorphous carbon, carbon nanotubes, and carbon fibers. Specifically, the conductive layer 12 can be formed on the base film 11 using physical vapor deposition (PVD), chemical vapor deposition (CVD), or water electroplating. When the polarity of the laminated unit is negative, the negative copper conductive layer 12 can be formed on the base film 11 using a one-step method, a two-step method, or a three-step method. 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 through repeated magnetron sputtering, and vacuum evaporation deposits a copper layer through repeated evaporation. The two-step method uses magnetron sputtering as a primer, followed by water electroplating to thicken the copper layer. The three-step method uses magnetron sputtering as a primer, followed by vacuum evaporation, and finally, water 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.

[0084] In some embodiments of the present invention, the first active material layer 13 and the second active material layer 22 are positive electrode active material layers, respectively. The positive electrode active material layer includes lithium nickel cobalt manganese oxide (N x M y C z , x+y+z=1), lithium manganese iron phosphate (LiFe x’ Mn y’ PO4, x'+y'=1), one or more of lithium iron phosphate, lithium manganate, lithium cobaltate, lithium nickelate, lithium-rich manganese-based, lithium nickel manganate and lithium vanadium phosphate (Li3V2(PO4)3, LiVOPO4).

[0085] Alternatively, the first active material layer 13 and the second active material layer 22 are negative electrode active material layers respectively, and the negative electrode active material layers include one or more of carbon-based active materials, silicon-based active materials, metal oxides, tin-based active materials and lithium-based active materials.

[0086] 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 mesocarbon microbeads.

[0087] The silicon-based active material includes one or more of single crystal silicon, silicon-carbon compounds and silicon-oxygen compounds.

[0088] The tin-based active material includes one or more of elemental tin, tin-sulfur alloy, tin-phosphorus alloy, tin-iron alloy and tin-cobalt alloy.

[0089] The metal oxide includes lithium titanate.

[0090] The lithium-based active material includes lithium foil or 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.

[0091] On the other hand, an embodiment of the present invention further provides a battery comprising a separator, an electrolyte, a second pole piece, and a laminate unit as described above, wherein the second pole piece has an opposite polarity to the first pole piece, the laminate unit, the separator, and the second pole piece are stacked, and the tabs of the second pole piece are located on opposite sides of the first tab 41 and the second tab 42 of the laminate unit. The structure of the laminate unit facilitates flexible design of the battery, comprising multiple core laminate units and corresponding second pole pieces of opposite polarity, depending on the cell capacity requirements.

[0092] In some embodiments of the present invention, the second pole piece is a laminated unit as described above, and the first foil tab 43 and the second foil tab of the same polarity in the laminated unit are connected in sequence.

[0093] It should be noted here that the second electrode piece may also be a traditional foil electrode piece.

[0094] In some embodiments of the present invention, the membrane comprises at least one of polypropylene or polyethylene.

[0095] The electrolyte includes a lithium salt, a solvent, and an additive. The solvent includes one or more of a carbonate compound, an ether compound, and a nitrile compound. 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.

[0096] It should be noted here that additives also include additives for controlling the water and HF content in the electrolyte, general additives for improving low-temperature performance, and additives for improving the interface stability between the electrode and the electrolyte. Additives for improving the interface stability between the electrode and the electrolyte include but are not limited to fluoroethylene carbonate.

[0097] 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.

[0098] The ether compound includes one or more of tetrahydrofuran, 2-methyltetrahydrofuran, dimethoxydimethyl ether and 1,2-dimethoxyethane.

[0099] The nitrile compound includes acetonitrile.

[0100] On the other hand, an embodiment of the present invention also provides a battery, comprising a solid electrolyte, a second pole piece and a laminate unit as described above, wherein the second pole piece has an opposite polarity to the first pole piece, the laminate unit, the solid electrolyte and the second pole piece are stacked, and the pole tab of the second pole piece is arranged on the opposite side of the first pole tab 41 and the second pole tab 42 of the laminate unit.

[0101] In some embodiments of the present invention, the second pole piece is a laminated unit as described above, and the first foil tab 43 and the second foil tab of the same polarity in the laminated unit are connected in sequence.

[0102] In some embodiments of the present invention, the solid electrolyte comprises 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 an inorganic filler.

[0103] The inorganic solid electrolyte includes one or more of an oxide solid electrolyte, a sulfide solid electrolyte and a halide solid electrolyte.

[0104] The polymer solid electrolyte includes a polymer matrix and a lithium salt;

[0105] The composite solid electrolyte comprises a polymer matrix and an inorganic filler. Specifically, the composite method of the polymer matrix and the inorganic filler includes but is not limited to dispersion and mixing, or filling the inorganic filler in the gaps of the polymer matrix.

[0106] In some embodiments of the present invention, the oxide solid electrolyte includes one or more of a NASICON electrolyte, a perovskite electrolyte, and a Garnet garnet electrolyte. Specifically, the NASICON 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 Garnet garnet electrolyte includes lithium lanthanum zirconium oxide LLZO, with a high conductivity of 10- 3 S / cm, and has good stability to lithium metal.

[0107] The sulfide solid electrolyte includes binary compounds and ternary compounds. The binary compounds include Li2S-SiS2, Li2S-P2S5, and Li2S-GeS2. The ternary compounds include one or more of Li2S-MS2-P2S5 and Li6PS5X, wherein 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.

[0108] The halide solid electrolyte includes Li a MX4 class, Li a MX6 class and Li a MX8 type, M is a divalent metal ion, a trivalent metal ion or other valence 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.

[0109] 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.

[0110] The lithium salt includes one or more of LiAsF6, LiPF6, LiClO4, LiTFSI, LiFSI and LiBF4.

[0111] The inorganic filler includes one or more of LATP, LLZO, Al2O3 and metal organic framework.

[0112] It should be noted that the solid electrolyte in the battery may also be replaced with a gel electrolyte, which includes at least one solid electrolyte in the above embodiments and at least one electrolyte in the above embodiments.

[0113] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. However, such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention and are intended to be included within the scope of protection of the present invention.

Claims

1. A lamination 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 lamination 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 lamination 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 lamination 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 lamination 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 lamination 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 lamination 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 lamination 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 lamination 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 pole piece and the second foil pole piece 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 pole lug region, the second active material layer is arranged in the second active material region, and the first pole lug and the second pole lug of the first foil pole piece and the second foil pole piece are arranged in the second pole lug region.

10. The lamination 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 lamination 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 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 conductive agent includes one or more of graphene, amorphous carbon, carbon nanotubes and carbon fibers.

12. The lamination unit according to claim 9, characterized in that The first active material layer and the second active material layer are positive electrode active material layers, respectively, and the positive electrode active material layer includes one or more of lithium nickel cobalt manganese oxide, lithium iron manganese phosphate, lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium rich manganese base, lithium nickel manganese oxide and lithium vanadium phosphate; Alternatively, the first active material layer and the second active material layer are negative electrode active material layers respectively, and the negative electrode active material layers include one or more of carbon-based active materials, silicon-based active materials, metal oxides, tin-based active materials and lithium-based active materials.

13. The lamination unit according to claim 12, characterized in that The carbon 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-carbon compounds and silicon-oxygen compounds; The tin-based active material includes one or more of elemental tin, tin-sulfur alloy, tin-phosphorus alloy, tin-iron alloy and tin-cobalt alloy; the metal oxide includes lithium titanate; The lithium-based active material includes lithium foil or 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.

14. A battery, characterized in that: It includes a diaphragm, an electrolyte, a second pole piece and a laminate unit as described in any one of claims 1 to 13, wherein the second pole piece has an opposite polarity to the first pole piece, the laminate unit, the diaphragm and the second pole piece are stacked, and the pole ear of the second pole piece is arranged on the opposite side of the first pole ear and the second pole ear of the laminate unit.

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

16. The battery according to claim 14, characterized in that The diaphragm includes at least one of polypropylene or polyethylene; the electrolyte includes a lithium salt, a solvent and an additive, and the solvent includes one or more of a carbonate compound, an ether compound and a nitrile compound; 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, characterized in that 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, dimethoxydimethyl ether and 1,2-dimethoxyethane; and the nitrile compounds include acetonitrile.

18. A battery, characterized in that: It comprises a solid electrolyte, a second pole piece and a lamination unit as claimed in any one of claims 1 to 13, wherein the second pole piece has opposite polarity to the first pole piece, the lamination unit, the solid electrolyte and the second pole piece are stacked, and the pole ear of the second pole piece is arranged on the opposite side of the first pole ear and the second pole ear of the lamination unit.

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

20. The battery according to claim 18, characterized in that 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 comprises a polymer matrix and an inorganic filler.

21. The battery according to claim 20, characterized in that The oxide solid electrolyte includes one or more of a NASICON electrolyte, a perovskite electrolyte and a Garnet garnet electrolyte; The sulfide solid electrolyte includes one or more of Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-MS2-P2S5 and Li6PS5X, wherein 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 framework; The lithium salt includes one or more of LiAsF6, LiPF6, LiClO4, LiTFSI, LiFSI and LiBF4.

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