Diaphragm-free battery, preparation method thereof and electric equipment

Abstract

The invention discloses a diaphragm-free battery and a preparation method thereof and electric equipment, the diaphragm-free battery comprises a positive pole piece and a negative pole piece which are laminated, large surfaces of the positive pole piece and / or the negative pole piece which are oppositely arranged are provided with isolating layers, side surfaces of the positive pole piece and / or the negative pole piece are provided with protective layers, and the protective layers are arranged on the side surfaces of the positive pole piece and / or the negative pole piece. The protective layer includes an insulating elastomeric material and a two-dimensional inorganic material, and active ions in the diaphragmless battery may pass through the isolation layer. Therefore, the diaphragm-free battery not only has excellent high temperature resistance, but also has relatively high safety performance, rate capability, cycle performance and power performance.

Description

Technical Field

[0001] The invention belongs to the field of batteries, and in particular relates to a diaphragm-free battery and a preparation method and electrical equipment thereof. Background Art

[0002] The diaphragm is an important component of the commercialized lithium-ion battery. It can effectively prevent the direct contact between the positive and negative electrodes, build a path for the transmission of lithium ions between the positive and negative electrodes, and isolate the free shuttle of electrons. However, the diaphragms in lithium-ion batteries are mostly made of polyethylene (PE) or polypropylene (PP) materials with poor mechanical properties and thermal stability, which seriously affects the safety of lithium-ion batteries. Traditional ceramic-coated diaphragms will still experience varying degrees of thermal shrinkage during the heating process, and cannot prevent the battery from catching fire, exploding, and other safety accidents at high temperatures.

[0003] Improving the safety of lithium-ion batteries is one of the important research and development directions in the field of power batteries. In order to fundamentally improve the safety of lithium-ion batteries, a diaphragm-free system is selected to fundamentally avoid safety problems caused by diaphragm shrinkage. However, in actual application, micro-short circuits will occur when the rough surfaces of the positive and negative pole pieces are in direct contact, and burrs, falling materials and other defects will appear on the edges of the pole pieces after cutting. Although protection on the pole piece surface can prevent direct contact between the positive and negative poles, due to the presence of edge burrs, assembling diaphragm-free batteries without using diaphragms is very prone to short circuits, limiting the application of diaphragm-free batteries.

[0004] Therefore, the existing membrane-free batteries need to be improved. Summary of the invention

[0005] The present invention aims to solve at least one of the above technical problems to a certain extent. To this end, one object of the present invention is to provide a diaphragm-free battery and a preparation method and an electrical device thereof, wherein the diaphragm-free battery has not only excellent high temperature resistance but also high safety performance, rate performance, cycle performance and power performance.

[0006] In one aspect of the present invention, the present invention proposes a diaphragm-free battery. According to an embodiment of the present invention, the diaphragm-free battery comprises: a positive electrode sheet and a negative electrode sheet arranged in a stacked manner, a separation layer is provided on the large surface of the positive electrode sheet and / or the negative electrode sheet arranged opposite to each other, a protective layer is provided on the side of the positive electrode sheet and / or the negative electrode sheet, the protective layer comprises an insulating elastomer material and a two-dimensional inorganic material, and active ions in the diaphragm-free battery can pass through the separation layer.

[0007] According to the diaphragmless battery of the embodiment of the present invention, by providing an isolation layer on the large surface of the relatively arranged positive electrode plate and / or negative electrode plate, the active ions in the diaphragmless battery can pass through the isolation layer, without the need to use a traditional isolation membrane, thereby improving the high temperature resistance of the battery; and a protective layer is provided on the side of the positive electrode plate and / or the negative electrode plate, and the protective layer includes an insulating elastomer material and a two-dimensional inorganic material. On the one hand, the protective layer of this composition can not only increase the flatness of the sides of the positive and negative electrode plates, but also cover the burrs on the edges of the electrode plates to prevent micro-short circuits caused by the burrs. On the other hand, the protective layer of this composition can reduce defects such as material falling off at the edges of the electrode plates, reduce the internal resistance of the battery, and improve the cycle performance and power performance of the battery. On the other hand, the protective layer can enhance the peeling force between the current collector and the electrode active material layer, effectively improve the close contact between the current collector and the active material, construct an electron transmission path, and improve the rate performance of the diaphragmless battery. On the other hand, the protective layer adopts a combination of two-dimensional inorganic materials and insulating elastomer materials. The planar and curved ductility of the two-dimensional inorganic materials can further improve the mechanical properties of the protective layer, ensuring that the pole piece improves battery safety during extrusion and deformation. Adding two-dimensional inorganic materials to the insulating elastomer material can simultaneously enhance the coupling force within the protective layer system and the contact interface, improve the mechanical strength and maximum load capacity of the pole piece, thereby reducing deformation when rapid strain occurs and avoiding short circuits.

[0008] In addition, the diaphragm-free battery according to the above embodiment of the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, the mass ratio of the insulating elastomer material to the two-dimensional inorganic material is (80-99): (1-20). Thus, the safety performance, rate performance, cycle performance and power performance of the battery can be improved.

[0010] In some embodiments of the present invention, the two-dimensional inorganic material includes at least one of beryllium oxide and boron nitride, thereby improving the safety performance, rate performance, cycle performance and power performance of the battery.

[0011] In some embodiments of the present invention, the insulating elastomer material includes at least one of polytrifluorochloroethylene, polytetrafluoroethylene, polyvinyl chloride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polyimide, polymethylene isophthalamide, polymethylene terephthalamide, ethylene-vinyl acetate copolymer, polyetheretherketone, polyurethane, polyphenylene sulfide, polyetherimide, polyvinyl chloride thermoplastic elastomer, polyolefin elastomer, polyester elastomer and polyamide thermoplastic elastomer. Thus, the safety performance, rate performance, cycle performance and power performance of the battery can be improved.

[0012] In some embodiments of the present invention, the protective layer includes at least one of beryllium oxide and boron nitride and at least one of poly(m-phenylene terephthalamide), polyetheretherketone, polyurethane and ethylene-vinyl acetate copolymer, thereby improving the safety performance, rate performance, cycle performance and power performance of the battery.

[0013] In some embodiments of the present invention, the thickness of the protective layer is 0.2 μm-20 μm, thereby improving the safety performance, rate performance, cycle performance and power performance of the battery.

[0014] In some embodiments of the present invention, the isolation layer includes at least one of an inorganic solid electrolyte, an organic solid electrolyte, a nitride, a metal oxide, a non-metal oxide, montmorillonite and kaolin, thereby improving the high temperature resistance of the battery.

[0015] In some embodiments of the present invention, the inorganic solid electrolyte includes at least one of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a nitride solid electrolyte, a boride solid electrolyte and a hydride solid electrolyte, thereby improving the high temperature resistance of the battery.

[0016] In some embodiments of the present invention, the oxide solid electrolyte includes at least one of lithium lanthanum zirconium oxide, niobium-doped lithium lanthanum zirconium oxide, tantalum-doped lithium lanthanum zirconium oxide, niobium-tantalum dual-doped lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide, lithium aluminum titanium phosphate, lithium yttrium titanium phosphate, lithium aluminum germanium phosphate and lithium aluminum oxide. Thus, the high temperature resistance of the battery can be improved.

[0017] In some embodiments of the present invention, the sulfide solid electrolyte includes at least one of glassy sulfide, Argyrodite-type sulfide, ThioLiSICON-type sulfide and glass-ceramic sulfide, thereby improving the high temperature resistance of the battery.

[0018] In some embodiments of the present invention, the sulfide solid electrolyte includes at least one of lithium germanium phosphorus sulfur, lithium silicon phosphorus sulfur chlorine, lithium phosphorus sulfur bromine, lithium phosphorus sulfur iodine, lithium phosphorus sulfur chlorine, lithium thiophosphate, Li2S P2S5, Li2S SiS2 and Li2S B2S3. Thus, the high temperature resistance of the battery can be improved.

[0019] In some embodiments of the present invention, the nitride solid electrolyte includes at least one of LiPON, Li3N, Li7PN4 and LiSi2N3, thereby improving the high temperature resistance of the battery.

[0020] In some embodiments of the present invention, the halide solid electrolyte includes Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x Brx , at least one of Li2ACl4, Li2X′I4, LiMCl5X″ and Li 3-a Zr a M′ 1-a Cl6, where 0 < x < 1, A includes Cd and / or Mg, X′ includes Cd and / or Zn, M includes at least one of La, Ta and Nb, X″ includes at least one of O, Cl, F and OH, M′ includes at least one of Y, Er, Yb, Ho and Lu, and 0 ≤ a ≤ 1. Thus, the high temperature resistance of the battery can be improved.

[0021] In some embodiments of the present invention, the boride solid electrolyte includes at least one of Li2B4O7, Li2O - B2O3 - P2O5 and Li 6+2y [B 10 S 18 S y , where 1 ≤ y ≤ 3. Thus, the high temperature resistance of the battery can be improved.

[0022] In some embodiments of the present invention, the hydride solid electrolyte includes at least one of Li3AlH6, LiBH4, LiNH2, Li2NH, LiBH4 - LiNH2 and LiBH4 - LiX, where X includes at least one of Cl, Br and I. Thus, the high temperature resistance of the battery can be improved.

[0023] In some embodiments of the present invention, the organic solid electrolyte includes at least one of polyethylene oxide, polyvinylidene fluoride, polyvinylidene fluoride - hexafluoropropylene, polyvinylidene fluoride - chlorotrifluoroethylene, polyacrylonitrile, polymethyl methacrylate, polypropylene carbonate, polyphenylene sulfide, polyethyl cyanoacrylate, poly(ethylene succinate), polyvinyl chloride, poly(vinylidene carbonate), polyimide, polyacrylate, polyurethane, polyamide and polyetherimide. Thus, the high temperature resistance of the battery can be improved.

[0024] In some embodiments of the present invention, the nitride includes at least one of silicon nitride, titanium nitride, aluminum nitride, boron nitride, magnesium nitride and zirconium nitride. Thus, the high temperature resistance of the battery can be improved.

[0025] In some embodiments of the present invention, the metal oxide includes at least one of aluminum oxide, titanium dioxide, zirconium dioxide and magnesium oxide. Thus, the high temperature resistance of the battery can be improved.

[0026] In some embodiments of the present invention, the non - metal oxide includes at least one of silicon dioxide and boron oxide. Thus, the high temperature resistance of the battery can be improved.

[0027] In some embodiments of the present invention, the isolation layer further comprises a lithium salt, and the lithium salt comprises at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide), lithium bis(trifluoromethanesulfonyl imide) and lithium difluorooxalatoborate.

[0028] In some embodiments of the present invention, the thickness of the isolation layer is 1 μm-20 μm, preferably 5 μm-10 μm, thereby improving the high temperature resistance of the battery.

[0029] In some embodiments of the present invention, the porosity of the isolation layer is 10%-70%, preferably 20%-50%, thereby improving ion transport in the battery and improving the power performance of the battery.

[0030] In a second aspect of the present invention, the present invention provides a method for preparing a diaphragm-free battery. According to an embodiment of the present invention, the method comprises:

[0031] Forming an isolation layer on a large surface of the positive electrode sheet and / or the negative electrode sheet, and forming a protective layer on a side surface of the positive electrode sheet and / or the negative electrode sheet;

[0032] The positive electrode sheet and the negative electrode sheet are stacked.

[0033] Therefore, the method can be used to prepare the above-mentioned membrane-free battery with excellent high temperature resistance, safety performance, rate performance, cycle performance and power performance.

[0034] In addition, the method for preparing a diaphragm-free battery according to the above embodiment of the present invention may also have the following additional technical features:

[0035] In some embodiments of the present invention, a spraying method is used to form an isolation layer on the large surface of the positive electrode sheet and / or the negative electrode sheet; and / or a spraying method is used to form a protective layer on the side of the positive electrode sheet and / or the negative electrode sheet.

[0036] In the third aspect of the present application, the present invention provides an electrical device. According to an embodiment of the present invention, the electrical device comprises the diaphragm-free battery described in the first aspect of the present invention or the diaphragm-free battery obtained by the method described in the second aspect of the present invention.

[0037] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0039] Figure 1 It is a front schematic diagram of the positive electrode or negative electrode in a diaphragm-free battery.

[0040] Figure 2 It is a side view of the positive electrode or negative electrode in a diaphragmless battery. DETAILED DESCRIPTION

[0041] The embodiments of the present invention are described in detail below, which are intended to explain the present invention but should not be construed as limiting the present invention.

[0042] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0043] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] In one aspect of the present invention, the present invention proposes a diaphragm-free battery. According to an embodiment of the present invention, the diaphragm-free battery comprises: a positive electrode sheet and a negative electrode sheet arranged in a stacked manner, a separation layer is provided on the large surface of the positive electrode sheet and / or the negative electrode sheet arranged opposite to each other, a protective layer is provided on the side of the positive electrode sheet and / or the negative electrode sheet, the protective layer comprises an insulating elastomer material and a two-dimensional inorganic material, and active ions in the diaphragm-free battery can pass through the separation layer.

[0045] The inventors discovered that by providing an isolation layer on the large surfaces of the relatively arranged positive electrode plates and / or negative electrode plates, the active ions in the diaphragm-free battery can pass through the isolation layer, without the need to use a traditional isolation membrane, thereby improving the high temperature resistance of the battery; and a protective layer is provided on the side of the positive electrode plates and / or the negative electrode plates, and the protective layer includes an insulating elastomer material and a two-dimensional inorganic material. On the one hand, the protective layer of this composition can not only increase the flatness of the sides of the positive and negative electrode plates, but also cover the burrs on the edges of the plates to prevent micro-short circuits caused by the burrs. On the other hand, the protective layer of this composition can reduce defects such as material falling off at the edges of the plates, reduce the internal resistance of the battery, and improve the cycle performance of the battery. On the other hand, the protective layer can enhance the peeling force between the current collector and the electrode active material layer, effectively improve the close contact between the current collector and the active material, construct an electron transmission pathway, and improve the rate performance of the diaphragm-free battery. On the other hand, the protective layer adopts a combination of two-dimensional inorganic materials and insulating elastomer materials. The planar and curved ductility of the two-dimensional inorganic materials can further improve the mechanical properties of the protective layer, ensuring that the pole piece improves battery safety during extrusion and deformation. Adding two-dimensional inorganic materials to the insulating elastomer material can simultaneously enhance the coupling force within the protective layer system and the contact interface, improve the mechanical strength and maximum load capacity of the pole piece, thereby reducing deformation when rapid strain occurs and avoiding short circuits.

[0046] It should be noted that the reference Figure 1-2 In the present invention, "the large surface of the positive electrode sheet and / or the negative electrode sheet" refers to the two surfaces opposite to each other along the thickness direction of the positive electrode sheet and / or the negative electrode sheet; "the side surface of the positive electrode sheet and / or the negative electrode sheet" refers to the surface of the remaining part of the positive electrode sheet and / or the negative electrode sheet except the large surface, and the side surface of the positive electrode sheet and / or the negative electrode sheet includes the side surface of the positive electrode sheet and / or the negative electrode sheet on the ear side.

[0047] According to an embodiment of the present invention, the isolation layer on the large surface of the positive electrode sheet and / or the negative electrode sheet may extend to the edge of the large surface, thereby improving the transmission channel of lithium ions and improving the rate performance of the battery. According to one embodiment of the present invention, the protective layer on the side of the positive electrode sheet and / or the negative electrode sheet may extend to the large surface of the positive electrode sheet and / or the negative electrode sheet, that is, the protective layer may cover a small part of the large surface of the positive electrode sheet and / or the negative electrode sheet. According to another embodiment of the present invention, the isolation layer on the large surface of the positive electrode sheet and / or the negative electrode sheet may extend to the side of the positive electrode sheet and / or the negative electrode sheet, that is, the isolation layer may cover a small part of the side of the positive electrode sheet and / or the negative electrode sheet.

[0048] According to an embodiment of the present invention, the mass ratio of the insulating elastomer material to the two-dimensional inorganic material is (80-99)(1-20), for example, (80-99)(2-18), (80-99)(5-15), (80-99)(7-15), (80-99)(10-12), (82-97)(1-20), (85-95)(1-20), (87-92)(1-20), (87-90)(1-20), etc. Therefore, the present invention controls the insulating elastomer material and the two-dimensional inorganic material in the protective layer to be mixed according to the above-mentioned proportion. On the one hand, it can not only increase the flatness of the sides of the positive and negative electrode sheets, but also cover the burrs on the edges of the electrode sheets to prevent micro short circuits caused by the burrs. On the other hand, it can reduce defects such as material falling off at the edges of the electrode sheets, reduce the internal resistance of the battery, and improve the cycle performance and power performance of the battery. On the other hand, it can enhance the peeling force between the current collector and the electrode active material layer, effectively improve the close contact between the current collector and the active material, construct an electron transmission path, and improve the rate performance of the membrane-free battery.

[0049] As an example, the two-dimensional inorganic material includes at least one of beryllium oxide and boron nitride. Compared with other two-dimensional inorganic materials, beryllium oxide and boron nitride ceramics have better thermal stability and mechanical properties, and low thermal expansion coefficient, which can improve the stability of the battery structure at high temperature and prevent thermal runaway. The insulating elastomer material includes polytrifluorochloroethylene, polytetrafluoroethylene, polyvinyl chloride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-trifluorochloroethylene copolymer, polyimide, polyisophthalamide, polyphenylene terephthalamide, ethylene-vinyl acetate copolymer, polyetheretherketone, polyurethane, polyphenylene sulfide, polyetherimide, polyvinyl chloride thermoplastic elastomer, polyolefin elastomer, vinyl chloride, polyester elastomer and polyamide thermoplastic elastomer, wherein the polyurethane may include thermoplastic polyurethane. Specifically, the combination of the insulating elastomer material and the two-dimensional inorganic material used above can not only improve the thermal stability and insulation of the protective layer, but also effectively improve the thermal stability and wrapping of the edge spray material, prevent thermal shrinkage, and improve the safety performance of the membrane-free battery.

[0050] According to an embodiment of the present invention, the protective layer includes at least one of beryllium oxide and boron nitride and at least one of poly(m-phenylene terephthalamide), polyetheretherketone, polyurethane and ethylene-vinyl acetate copolymer. Therefore, the protective layer uses the insulating elastomer material and the two-dimensional inorganic material of this composition, which can not only further increase the flatness of the sides of the positive and negative electrode sheets, but also cover the burrs on the edges of the electrode sheets to prevent micro-short circuits caused by the burrs. On the other hand, it can further reduce defects such as material dropout at the edges of the electrode sheets, reduce the internal resistance of the battery, and further improve the cycle performance and power performance of the battery.

[0051] According to an embodiment of the present invention, the thickness of the protective layer is 0.2μm-20μm, for example, 0.2μm, 0.5μm, 0.7μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 10μm, 15μm, 20μm, etc. Therefore, the present invention forms a protective layer of this thickness on the side of the positive electrode sheet and / or the negative electrode sheet, which can not only further increase the flatness of the side of the positive and negative electrode sheets, but also cover the burrs on the edge of the electrode sheet to prevent micro short circuits caused by the burrs. On the other hand, it can further reduce defects such as material drop at the edge of the electrode sheet, reduce the internal resistance of the battery, and improve the cycle performance and power performance of the battery. On the other hand, it can further enhance the peeling force between the current collector and the electrode active material layer, effectively improve the close contact between the current collector and the active material, construct an electron transmission path, and improve the rate performance of the membrane-free battery.

[0052] According to an embodiment of the present invention, the isolation layer includes at least one of an inorganic solid electrolyte, an organic solid electrolyte, a nitride, a metal oxide, a non-metal oxide, montmorillonite and kaolin. Specifically, the isolation layer of this composition has excellent high temperature resistance and insulation. The present invention arranges the isolation layer of this composition on the large surface of the positive electrode sheet and / or the negative electrode sheet, and the active ions in the membrane-free battery can pass through the isolation layer, without the need to use a traditional isolation membrane, thereby improving the high temperature resistance of the battery.

[0053] According to a specific embodiment of the present invention, the inorganic solid electrolyte includes but is not limited to at least one of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a nitride solid electrolyte, a boride solid electrolyte and a hydride solid electrolyte. As an example, the oxide solid electrolyte includes but is not limited to at least one of lithium lanthanum zirconium oxide, niobium-doped lithium lanthanum zirconium oxide, tantalum-doped lithium lanthanum zirconium oxide, niobium-tantalum dual-doped lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide, lithium aluminum titanium phosphate, lithium yttrium titanium phosphate, lithium aluminum germanium phosphate and lithium aluminum oxide; the sulfide solid electrolyte includes but is not limited to at least one of glassy sulfide, Argyrodite-type sulfide, ThioLiSICON-type sulfide and glass-ceramic sulfide; further, the sulfide solid electrolyte includes but is not limited to at least one of lithium germanium phosphorus sulfur, lithium silicon phosphorus sulfur chlorine, lithium phosphorus sulfur bromine, lithium phosphorus sulfur iodine, lithium phosphorus sulfur chlorine, lithium thiophosphate, Li2S P2S5, Li2SSiS2 and Li2S B2S3; the nitride solid electrolyte includes but is not limited to at least one of LiPON, Li3N, Li7PN4 and LiSi2N3; the halide solid electrolyte includes but is not limited to Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x Br x, Li2ACl4, Li2X′I4, LiMCl5X″ and Li 3-a Zr a M′ 1-a at least one of Cl6, where 0 < x < 1, A includes Cd and / or Mg, X′ includes Cd and / or Zn, M includes at least one of La, Ta, and Nb, X″ includes at least one of O, Cl, F, and OH, M′ includes at least one of Y, Er, Yb, Ho, and Lu, 0 ≤ a ≤ 1; the boride solid electrolyte includes but is not limited to Li2B4O7, Li2O - B2O3 - P2O5, and Li 6+2y [B 10 S 18 S y at least one of them, where 1 ≤ y ≤ 3; the hydride solid electrolyte includes at least one of Li3AlH6, LiBH4, LiNH2, Li2NH, LiBH4 - LiNH2, and LiBH4 - LiX, where X includes at least one of Cl, Br, and I.

[0054] According to specific embodiments of the present invention, the organic solid electrolyte includes but is not limited to at least one of polyethylene oxide, polyvinylidene fluoride, polyvinylidene fluoride - hexafluoropropylene, polyvinylidene fluoride - chlorotrifluoroethylene, polyacrylonitrile, polymethyl methacrylate, polypropylene carbonate, polypropylene carbonate, polyphenylene sulfide, polyethyl cyanoacrylate, poly(ethylene succinate), polyvinyl chloride, poly(vinylidene carbonate), polyimide, polyacrylate, polyurethane, polyamide, and polyetherimide; the nitride includes but is not limited to at least one of silicon nitride, titanium nitride, aluminum nitride, boron nitride, magnesium nitride, and zirconium nitride; the metal oxide includes but is not limited to at least one of aluminum oxide, titanium dioxide, zirconium dioxide, and magnesium oxide; the non - metal oxide includes but is not limited to at least one of silicon dioxide and boron oxide. Thus, the high - temperature resistance of the battery can be improved.

[0055] According to an embodiment of the present invention, the separator layer further includes a lithium salt, and the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, and lithium difluoro(oxalato)borate. The addition of the lithium salt effectively increases the ionic conductivity of the separator layer, ensures the ionic conduction in the non - crystalline region of the polymer, and reduces the internal resistance of the battery. Further, based on the total mass of the separator layer, the mass ratio of the lithium salt is between 5% and 30%, such as 5%, 10%, 15%, 20%, 25%, 30%, etc.

[0056] According to an embodiment of the present invention, the thickness of the isolation layer is 1μm-20μm, for example, 1μm, 3μm, 5μm, 7μm, 10μm, 12μm, 15μm, 17μm, 20μm, etc. Therefore, by providing an isolation layer of this thickness on the large surface of the positive electrode sheet and / or the negative electrode sheet, its high temperature resistance can be further improved, and compared with traditional batteries, no isolation film is required, thereby improving the high temperature resistance of the battery. According to a specific embodiment of the present invention, the thickness of the isolation layer is 5μm-10μm. Thus, the high temperature resistance of the battery can be improved.

[0057] According to an embodiment of the present invention, the porosity of the isolation layer is 10%-70%, for example, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, etc. Thus, by providing an isolation layer with such porosity on the large surface of the positive electrode sheet and / or the negative electrode sheet, the ion transport in the battery can be further improved, and the power performance of the battery can be improved. According to a specific embodiment of the present invention, the porosity of the isolation layer is 20%-50%.

[0058] In a second aspect of the present invention, the present invention provides a method for preparing a diaphragm-free battery. According to an embodiment of the present invention, the method comprises:

[0059] Forming an isolation layer on a large surface of the positive electrode sheet and / or the negative electrode sheet, and forming a protective layer on a side surface of the positive electrode sheet and / or the negative electrode sheet;

[0060] The positive electrode sheet and the negative electrode sheet are stacked.

[0061] Therefore, the method can be used to prepare the above-mentioned membrane-free battery with excellent high temperature resistance, safety performance, rate performance, cycle performance and power performance.

[0062] According to an embodiment of the present invention, a spraying method can be used to form an isolation layer on the large surface of the positive electrode sheet and / or the negative electrode sheet; and / or a spraying method can be used to form a protective layer on the side of the positive electrode sheet and / or the negative electrode sheet.

[0063] Specifically, the use of the spraying method can construct a stable isolation layer on the surface of the positive and negative electrode sheets, reduce the surface roughness of the positive and negative electrode sheets, effectively prevent the positive electrode sheets and the negative electrode sheets from directly contacting each other to cause a short circuit, and achieve the effect of not needing to use a traditional diaphragm. At the same time, the protective layer can be efficiently and evenly introduced on the sides of the positive and negative electrode sheets to improve the flatness of the sides of the positive and negative electrode sheets and avoid the influence of micro-short circuits caused by burrs; in addition, the thickness of the isolation layer and the protective layer formed by the spraying method is controllable, which can achieve ultra-thin introduction, and the width of the isolation film and the protective layer on the surface of the positive and negative electrode sheets can be controlled, that is, the protective layer can be introduced only at the interface of each side of the positive and negative electrode sheets, which will not reduce the contact area of ​​the positive and negative active materials on the positive and negative electrode sheets, and prevent the capacity loss caused by the wrapping of the surface of the positive electrode sheet by technical solutions such as gluing, so as to achieve lossless introduction and improve the energy density of the diaphragm-free battery; and the insulating elastomer material and the two-dimensional inorganic material forming the protective layer are introduced by slurry spraying, which can reduce the agglomeration of the two-dimensional inorganic material, improve the thermal stability and uniform distribution of the composite system, and the spraying method can achieve the densification of the protective layer on the side of the electrode sheet, further improving the safety performance of the battery.

[0064] It should be noted that the present invention can first spray the large surface of the positive electrode sheet and / or the negative electrode sheet to form an isolation layer, and then spray the side of the positive electrode sheet and / or the negative electrode sheet to form a protective layer; it can also first spray the side of the positive electrode sheet and / or the negative electrode sheet to form a protective layer, and then spray the large surface of the positive electrode sheet and / or the negative electrode sheet to form an isolation layer. According to a specific embodiment of the present invention, the protective layer is first sprayed on the side of the positive electrode sheet and / or the negative electrode sheet, and then the isolation layer is sprayed on the large surface of the positive electrode sheet and / or the negative electrode sheet. Specifically, a protective layer is first formed by spraying on the side of the positive electrode sheet and / or the negative electrode sheet, which can enhance the peeling force between the current collector and the electrode active material layer, effectively improve the close contact between the current collector and the active material layer, construct an electron transmission path, and improve the rate performance of the diaphragm-free battery; then an isolation layer is formed by spraying on the large surface of the positive electrode sheet and / or the negative electrode sheet, which effectively prevents the positive electrode sheet and the negative electrode sheet from directly contacting each other and causing a short circuit, thereby achieving the effect of not needing to use a traditional diaphragm. If an isolation layer is first formed by spraying on the large surface of the positive electrode sheet and / or the negative electrode sheet, and then a protective layer is formed by spraying on the side of the positive electrode sheet and / or the negative electrode sheet, the protective layer will cover part of the isolation layer, thereby affecting the ion path of the diaphragm-free battery.

[0065] According to an embodiment of the present invention, the isolation layer is formed by spraying a large surface of the positive electrode sheet and / or the negative electrode sheet by spraying a slurry containing the isolation layer material, and the spraying pressure is 0.5MPa-5MPa, for example, 0.5MPa, 1MPa, 1.5MPa, 2MPa, 2.5MPa, 3MPa, 3.5MPa, 4MPa, 4.5MPa, 5MPa, etc. The spraying pressure is conducive to forming a dense isolation layer on the surface of the electrode sheet and reducing the occurrence of process problems such as pores. Air-sensitive solid electrolytes are easily oxidized during the preparation of the electrode sheet. Desolvated electrode preparation can be achieved by spraying and pressurizing to prevent oxidation and failure of the isolation layer material.

[0066] According to an embodiment of the present invention, the isolation layer also includes a lithium salt, and the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide), lithium bis(trifluoromethanesulfonyl imide) and lithium difluoroborate oxalate. The addition of lithium salt effectively increases the ionic conductivity of the isolation layer, ensures ionic conduction in the non-crystalline region of the polymer, and reduces the internal resistance of the battery. Furthermore, based on the total mass of the isolation layer, the mass proportion of the lithium salt is between 5% and 30%, for example, 5%, 10%, 15%, 20%, 25%, 30%, etc.

[0067] Further, the slurry containing the isolation layer material includes a solvent, and the solvent used for homogenization may include at least one of N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide, butyrate, toluene, xylene, tetralin, decalin, anisole, carbon tetrachloride, tetrahydrofuran, carbon disulfide, diphenyl ether, diphenyl sulfide, hexane, heptane, dibromomethane, dichloroethane, aromatic hydrocarbons, chlorinated hydrocarbons, halogenated hydrocarbons, ethanol, acetonitrile, pyridine, ether, ethyl acetate, dioxane, cyclohexanone, acetone, phenol, m-cresol, chlorophenol, nitrobenzene, trichloroacetic acid, m-cresol, tetrachloroethylene, phenylenediamine, dimethylformamide, dimethylacetamide, dimethyl sulfoxide and ethylene glycol ether.

[0068] According to an embodiment of the present invention, the protective layer formed by spraying on the side of the positive electrode sheet and / or the negative electrode sheet is achieved by spraying a slurry containing an insulating elastomer material and a two-dimensional inorganic material, and the spraying pressure is 0.1MPa-2MPa, for example, 0.1MPa, 0.5MPa, 1MPa, 1.5MPa, 2MPa, etc. The spraying pressure is conducive to forming a smooth protective layer on the side of the electrode sheet to avoid short circuit of the diaphragm-free battery due to process defects.

[0069] According to an embodiment of the present invention, the positive electrode plate and the negative electrode plate in the membrane-free battery of the present invention can both adopt the plates conventionally used in the field of lithium batteries, for example, the positive electrode plate includes a positive current collector and a positive active material layer disposed on one side of the positive current collector, wherein the positive active material in the positive active material layer includes but is not limited to lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, etc. The negative electrode plate includes a negative current collector and a negative active material layer disposed on one side of the negative current collector, wherein the negative active material in the negative active material layer includes but is not limited to soft carbon, hard carbon, silicon-based materials, tin-based materials, etc. The silicon-based material may include at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may include at least one of elemental tin, tin oxide compounds, and tin alloys.

[0070] In the third aspect of the present application, the present invention provides an electrical device. According to an embodiment of the present invention, the electrical device comprises the diaphragm-free battery described in the first aspect of the present invention or the diaphragm-free battery obtained by the method described in the second aspect of the present invention. The electrical device has the same advantages as the above-mentioned diaphragm-free battery over the prior art, which will not be repeated here.

[0071] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0072] Example 1

[0073] The method for preparing a positive electrode sheet comprises:

[0074] Preparation of positive electrode:

[0075] 1) Preparation of positive electrode sheet:

[0076] The positive electrode active material lithium iron phosphate (LiFePO4), conductive carbon black (SP), and adhesive polyvinylidene fluoride (PVDF) are dispersed in the solvent N-methylpyrrolidone (NMP) and mixed evenly to obtain a positive electrode slurry, wherein the mass ratio of lithium iron phosphate, PVDF and conductive carbon black is 96:2:2. The positive electrode slurry is coated on the double-side surfaces of the positive electrode current collector aluminum foil, and after drying, cold pressing, slitting and cutting, the positive electrode sheet is obtained.

[0077] 2) Preparation of negative electrode sheet:

[0078] The negative electrode active material artificial graphite, the conductive agent carbon black (Super P), the binder styrene-butadiene rubber, and the thickener sodium carboxymethyl cellulose are fully stirred and mixed in a solvent deionized water in a mass ratio of 96:1:1:2 to form a uniform negative electrode slurry, and then the negative electrode slurry is evenly coated on the double-side surfaces of the negative electrode current collector copper foil. After drying and cold pressing, the negative electrode sheet is obtained.

[0079] 3) Preparation of diaphragm-free batteries:

[0080] S1: Add the two-dimensional inorganic material beryllium oxide and the insulating elastomer material polyamide into N-methylpyrrolidone (NMP) solvent in a mass ratio of 10:90 to obtain a protective layer slurry, and then spray the protective layer slurry on the side of the positive electrode sheet at a spraying pressure of 1 MPa. After drying, a protective layer is formed on the side of the positive electrode sheet. The thickness of the protective layer is 2 μm.

[0081] S2: adding the isolation layer material lithium lanthanum zirconium oxide to dimethylformamide (DMF) to obtain an isolation layer slurry, and then spraying the isolation layer slurry on the large surfaces of both sides of the positive electrode plate at a spraying pressure of 3MPa. After drying, an isolation layer is formed on the large surface of the positive electrode plate, and the thickness of the isolation layer is 10μm;

[0082] S3: The positive electrode sheet with the isolation layer and the protective layer obtained in S2 is stacked and rolled to produce a separator-free battery.

[0083] The method for preparing the membrane-free battery in Examples 2-13 is the same as that in Example 1, and the differences are shown in Table 1.

[0084] Table 1

[0085]

[0086]

[0087] Embodiment 14

[0088] The method for preparing a positive electrode sheet comprises:

[0089] Preparation of positive electrode:

[0090] 1) Preparation of positive electrode sheet:

[0091] The positive electrode active material lithium iron phosphate (LiFePO4), conductive carbon black (SP), and adhesive polyvinylidene fluoride (PVDF) are dispersed in the solvent N-methylpyrrolidone (NMP) and mixed evenly to obtain a positive electrode slurry, wherein the mass ratio of lithium iron phosphate, PVDF and conductive carbon black is 96:2:2. The positive electrode slurry is coated on the double-side surfaces of the positive electrode current collector aluminum foil, and after drying, cold pressing, slitting and cutting, the positive electrode sheet is obtained.

[0092] 2) Preparation of negative electrode sheet:

[0093] The negative electrode active material artificial graphite, the conductive agent carbon black (Super P), the binder styrene-butadiene rubber, and the thickener sodium carboxymethyl cellulose are fully stirred and mixed in a solvent deionized water in a mass ratio of 96:1:1:2 to form a uniform negative electrode slurry, and then the negative electrode slurry is evenly coated on the double-side surfaces of the negative electrode current collector copper foil. After drying and cold pressing, the negative electrode sheet is obtained.

[0094] 3) Preparation of diaphragm-free batteries:

[0095] S1: Adding the isolation layer material lithium lanthanum zirconium oxide into DMF solvent to obtain isolation layer slurry, and then spraying the isolation layer slurry on the large surfaces of both sides of the positive electrode plate at a spraying pressure of 3MPa. After drying, an isolation layer is formed on the large surface of the positive electrode plate. The thickness of the isolation layer is 10μm;

[0096] S2: adding the two-dimensional inorganic material beryllium oxide and the insulating elastomer material polyamide into the NMP solvent at a mass ratio of 10:90 to obtain a protective layer slurry, and then spraying the protective layer slurry on the side of the negative electrode plate at a spraying pressure of 1 MPa. After drying, a protective layer is formed on the side of the negative electrode plate, and the thickness of the protective layer is 2 μm;

[0097] S3: The negative electrode sheet with the isolation layer and the protective layer obtained in S2 is stacked and rolled with the positive electrode sheet to produce a separator-free battery

[0098] Embodiment 15

[0099] The method for preparing a positive electrode sheet comprises:

[0100] Preparation of positive electrode:

[0101] 1) Preparation of positive electrode sheet:

[0102] The positive electrode active material lithium iron phosphate (LiFePO4), conductive carbon black (SP), and adhesive polyvinylidene fluoride (PVDF) are dispersed in a solvent N-methylpyrrolidone (NMP) and mixed evenly to obtain a positive electrode slurry, wherein the mass ratio of lithium iron phosphate, PVDF and conductive carbon black is 96:2:2. The positive electrode slurry is coated on the double-side surface 0 of the positive electrode current collector aluminum foil, and after drying, cold pressing, slitting and cutting, the positive electrode sheet is obtained.

[0103] 2) Preparation of negative electrode sheet:

[0104] The negative electrode active material artificial graphite, the conductive agent carbon black (Super P), the binder styrene-butadiene rubber, and the thickener sodium carboxymethyl cellulose are fully stirred and mixed in a solvent deionized water in a mass ratio of 96:1:1:2 to form a uniform negative electrode slurry, and then the negative electrode slurry is evenly coated on the double-side surfaces of the negative electrode current collector copper foil. After drying and cold pressing, the negative electrode sheet is obtained.

[0105] 3) Preparation of diaphragm-free batteries:

[0106] S1: adding the two-dimensional inorganic material beryllium oxide and the insulating elastomer material polyamide into the NMP solvent at a mass ratio of 10:90 to obtain a protective layer slurry, and then spraying the protective layer slurry on the side of the negative electrode plate at a spraying pressure of 1 MPa. After drying, a protective layer is formed on the side of the negative electrode plate, and the thickness of the protective layer is 2 μm;

[0107] S2: adding the isolation layer material lithium lanthanum zirconium oxide into DMF solvent to obtain isolation layer slurry, and then spraying the isolation layer slurry on the large surfaces of both sides of the positive electrode plate at a spraying pressure of 3MPa. After drying, an isolation layer is formed on the large surface of the positive electrode plate, and the thickness of the isolation layer is 10μm;

[0108] S3: The negative electrode sheet with the isolation layer and the protective layer obtained in S2 is stacked and rolled with the positive electrode sheet to produce a separator-free battery.

[0109] Comparative Example 1

[0110] The method for preparing a membrane-free battery is the same as that in Example 1, except that the two-dimensional inorganic material in the protective layer slurry is replaced by silicon nitride.

[0111] Comparative Example 2

[0112] The method for preparing a membrane-free battery is the same as that in Example 1, except that the two-dimensional inorganic material in the protective layer slurry is replaced by alumina.

[0113] Comparative Example 3

[0114] The method for preparing a membrane-free battery is the same as that in Example 1, except that no two-dimensional inorganic material is added to the protective layer slurry.

[0115] Comparative Example 4

[0116] The method for preparing a diaphragm-free battery is the same as that in Example 1, except that no insulating elastomer material is added to the protective layer slurry.

[0117] Comparative Example 5

[0118] The method for preparing a diaphragm-free battery is the same as that in Example 1, except that the protective layer slurry is not sprayed on the side of the positive electrode plate.

[0119] Comparative Example 6

[0120] The method for preparing a diaphragm-free battery is the same as that in Example 1, except that the isolation layer slurry is not sprayed on the large surface of the positive electrode plate.

[0121] The cycle performance, internal resistance and safety performance of the batteries of Examples 1-15 and Comparative Examples 1-6 were tested. The test results are shown in Table 2.

[0122] Battery cycle performance test: At 25°C, charge the battery to 4.2V at a constant current rate of 1C, then discharge it to 2.8V at a rate of 1C, record the first charge and discharge capacity C1, then repeat the above charge and discharge cycle for 500 times, and record the discharge capacity C1 of the 500th battery. 500 , battery capacity retention rate = (C 500 / C1)×100%.

[0123] Battery internal resistance test: charge to a cut-off voltage of 4.2V under 0.5C charge and discharge conditions, let stand for 30 minutes, record the battery voltage before discharge termination and the battery voltage after the battery voltage stabilizes, calculate the voltage drop, and calculate the battery internal resistance (R) = voltage drop (ΔU) / current (I).

[0124] Battery safety performance test: After the battery cell is charged to 4.2V at 0.5C constant current and constant voltage, it is left to stand for 12 hours, and the target temperature is set. The heating starts at 25°C, and the hot box temperature is increased at a rate of 5°C per minute. It is heated to 160°C and maintained at this temperature for 0.5 hours, and then the test is terminated. The test results are shown in Table 1. If the battery cell does not catch fire, burn, or explode within 0.5 hours at 160°C, it passes the hot box test.

[0125] Table 2

[0126]

[0127]

[0128] Conclusion: As shown in Table 1, the batteries of Examples 1-15 have higher cycle performance and lower internal resistance, and the cells do not catch fire, burn or explode within 0.5 hours in the hot box test at 160°C, while the batteries of Comparative Examples 3-6 short-circuit during the cycle performance and internal resistance test, and the batteries of Comparative Examples 1-6 do not pass the hot box test. This shows that by providing an isolation layer on the large surface of the positive electrode sheet and / or the negative electrode sheet, and providing a protective layer including an edge elastomer material and a two-dimensional inorganic material on the side of the positive electrode sheet and / or the negative electrode sheet, the high temperature resistance, safety performance, rate performance, cycle performance and power performance of the battery can be improved.

[0129] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0130] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A diaphragm-free battery, characterized in that: It includes a stacked positive electrode sheet and a negative electrode sheet, wherein the large surfaces of the positive electrode sheet and / or the negative electrode sheet arranged opposite to each other are provided with an isolation layer, and the sides of the positive electrode sheet and / or the negative electrode sheet are provided with a protective layer, wherein the protective layer includes an insulating elastomer material and a two-dimensional inorganic material, and the active ions in the diaphragm-free battery can pass through the isolation layer.

2. The diaphragm-free battery according to claim 1, characterized in that: The mass ratio of the insulating elastomer material to the two-dimensional inorganic material is (80-99): (1-20).

3. The diaphragm-free battery according to claim 1 or 2, characterized in that: The two-dimensional inorganic material includes at least one of beryllium oxide and boron nitride.

4. The diaphragm-less battery according to claim 1 or 2, characterized in that: The insulating elastomer material includes at least one of polytrifluorochloroethylene, polytetrafluoroethylene, polyvinyl chloride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polyimide, poly(m-phenylene isophthalamide), poly(m-phenylene terephthalamide), ethylene-vinyl acetate copolymer, polyetheretherketone, polyurethane, polyphenylene sulfide, polyetherimide, polyvinyl chloride thermoplastic elastomer, polyolefin elastomer, polyester elastomer and polyamide thermoplastic elastomer.

5. The diaphragmless battery according to claim 1, characterized in that: The protective layer includes at least one of beryllium oxide and boron nitride and at least one of poly(m-phenylene terephthalamide), polyetheretherketone, polyurethane and ethylene-vinyl acetate copolymer.

6. The diaphragm-less battery according to claim 1, characterized in that: The thickness of the protective layer is 0.2 μm-20 μm.

7. The diaphragm-less battery according to claim 1, characterized in that: The isolation layer includes at least one of an inorganic solid electrolyte, an organic solid electrolyte, a nitride, a metal oxide, a non-metal oxide, montmorillonite and kaolin.

8. The diaphragm-less battery according to claim 7, characterized in that: The inorganic solid electrolyte includes at least one of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a nitride solid electrolyte, a boride solid electrolyte and a hydride solid electrolyte.

9. The diaphragm-less battery according to claim 8, characterized in that: The oxide solid electrolyte includes at least one of lithium lanthanum zirconium oxide, niobium-doped lithium lanthanum zirconium oxide, tantalum-doped lithium lanthanum zirconium oxide, niobium-tantalum dual-doped lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide, lithium aluminum titanium phosphate, lithium yttrium titanium phosphate, lithium aluminum germanium phosphate and lithium aluminum oxide.

10. The diaphragm-less battery according to claim 8, characterized in that: The sulfide solid electrolyte includes at least one of glassy sulfide, Argyrodite-type sulfide, Thio LiSICON-type sulfide and glass-ceramic sulfide.

11. The diaphragm-less battery according to claim 8 or 10, characterized in that: The sulfide solid electrolyte includes at least one of lithium germanium phosphosulfur, lithium silicon phosphosulfuryl chlorine, lithium phosphosulfuryl bromine, lithium phosphosulfuryl iodine, lithium phosphosulfuryl chlorine, lithium thiophosphate, Li2S P2S5, Li2S SiS2 and Li2SB2S3.

12. The diaphragmless battery according to claim 8, characterized in that: The nitride solid electrolyte includes at least one of LiPON, Li3N, Li7PN4 and LiSi2N3.

13. The diaphragmless battery according to claim 8, characterized in that: The halide solid electrolyte includes Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x Br x , Li2ACl4, Li2X′I4, LiMCl5X″ and Li 3-a Zr a M′ 1-a Cl6, where 0 < x < 1, A includes Cd and / or Mg, X′ includes Cd and / or Zn, M includes at least one of La, Ta, and Nb, X″ includes at least one of O, Cl, F, and OH, M′ includes at least one of Y, Er, Yb, Ho, and Lu, and 0 ≤ a ≤ 1.

14. The diaphragmless battery according to claim 8, characterized in that: The boride solid electrolyte includes Li2B4O7, Li2O-B2O3-P2O5 and Li 6+2y [B 10 S 18 ]S y At least one of , where 1≤y≤3.

15. The diaphragmless battery according to claim 8, characterized in that: The hydride solid electrolyte includes at least one of Li3AlH6, LiBH4, LiNH2, Li2NH, LiBH4-LiNH2 and LiBH4-LiX, wherein X includes at least one of Cl, Br and I.

16. The diaphragmless battery according to claim 7, characterized in that: The organic solid electrolyte includes at least one of polyethylene oxide, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-chlorotrifluoroethylene, polyacrylonitrile, polymethyl methacrylate, polypropylene carbonate, polyphenylene sulfide, polyethyl cyanoacrylate, polypentylene succinate, polyvinyl chloride, polyvinylene carbonate, polyimide, polyacrylate, polyurethane, polyamide and polyetherimide.

17. The diaphragmless battery according to claim 7, characterized in that: The nitride includes at least one of silicon nitride, titanium nitride, aluminum nitride, boron nitride, magnesium nitride and zirconium nitride.

18. The diaphragmless battery according to claim 7, characterized in that: The metal oxide includes at least one of aluminum oxide, titanium dioxide, zirconium dioxide and magnesium oxide.

19. The diaphragmless battery according to claim 7, characterized in that: The non-metal oxide includes at least one of silicon dioxide and boron oxide.

20. The diaphragmless battery according to claim 1, characterized in that: The isolation layer further includes a lithium salt, and the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide), lithium bis(trifluoromethanesulfonyl imide) and lithium difluorooxalatoborate.

21. The diaphragmless battery according to claim 7, characterized in that: The thickness of the isolation layer is 1 μm-20 μm, preferably 5 μm-10 μm.

22. The diaphragmless battery according to claim 7, characterized in that: The porosity of the isolation layer is 10%-70%, preferably 20%-50%.

23. A method for preparing a diaphragm-free battery according to any one of claims 1 to 22, characterized in that: include: Forming an isolation layer on a large surface of the positive electrode sheet and / or the negative electrode sheet, and forming a protective layer on a side surface of the positive electrode sheet and / or the negative electrode sheet; The positive electrode sheet and the negative electrode sheet are stacked.

24. The method according to claim 23, characterized in that Using a spraying method to form an isolation layer on the large surface of the positive electrode sheet and / or the negative electrode sheet; and / or A protective layer is formed on the side of the positive electrode sheet and / or the negative electrode sheet by spraying.

25. An electrical device, characterized in that: A diaphragm-free battery comprising any one of claims 1 to 22 or a diaphragm-free battery obtained by the method of claim 23 or 24.

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