Integrated all-solid-state single-layer battery cell unit, preparation method thereof and internal series and internal parallel all-solid-state battery

Abstract

The invention provides an integrated all-solid-state single-layer battery cell unit and a preparation method thereof, and an internal series connection and internal parallel connection all-solid-state battery, the integrated all-solid-state single-layer battery cell unit comprises a gel positive electrode, a solid electrolyte and a gel negative electrode, by using a gel electrode / electrolyte in-situ polymerization technology, electrode-electrolyte integrated construction is completed before solidification, and the internal series connection and internal parallel connection all-solid-state battery cell unit is obtained. And the gel electrolyte in the electrode / electrolyte is homogenized and polymerized in a hot-pressing curing manner. According to the invention, one-step molding preparation of the all-solid-state battery cell from raw materials to the battery cell is realized, and the complexity of a battery process is simplified. The in-situ polymerization method is adopted, solvent volatilization and recovery are not needed, the method has the advantages of being simple in process, environmentally friendly and low in cost, and the requirements for high energy density and high safety of all-solid-state batteries are met.

Description

Technical Field

[0001] The present invention relates to the field of new energy battery technology, and in particular to an integrated all-solid-state single-layer battery cell unit and a preparation method thereof, as well as internally series and internally parallel all-solid-state batteries. Background Art

[0002] Traditional lithium-ion batteries are primarily composed of four key materials: the positive electrode, the negative electrode, the separator, and the electrolyte. The electrolyte, the "blood" of the lithium-ion battery, transports ions between the positive and negative electrodes. These electrolytes are typically organic liquid electrolytes, filling the gaps and pores between the positive and negative electrode active materials and the separator. Liquid electrolytes are volatile and flammable, posing significant safety risks such as explosions and fires. In high-capacity and high-energy-density systems, lithium-ion batteries are at risk of thermal runaway due to bloating, leakage, and internal short circuits.

[0003] All-solid-state batteries are a new type of battery that uses solid electrolytes to replace the liquid electrolytes in traditional lithium-ion batteries. They have the advantages of high safety, high energy density and long cycle stability. Existing solid electrolytes are generally divided into four types: oxides, sulfides, polymers and composite electrolytes. Among them, composite solid electrolytes take into account the safety, stability and high voltage resistance of inorganic solid electrolytes and the easy molding, excellent mechanical properties and high interface compatibility of organic electrolytes, and have received widespread attention in the industry. Different from the solid-liquid contact in liquid lithium-ion batteries, the solid-solid contact in all-solid-state batteries leads to large internal interface resistance, which has become one of the problems limiting the application of all-solid-state batteries. In addition, the molding process of all-solid-state battery cells is difficult to match the existing liquid battery preparation process, and the process design needs to be based on matching different electrolyte systems. For example, the oxide electrolyte membrane needs to be molded under high-temperature calcination conditions. At the same time, the positive and negative electrode plates are difficult to match the high-temperature process and the cell folding assembly process. Sulfide electrolytes require membrane formation and cell pressing under high pressure, which increases the difficulty in application. Compared with the process complexity of all-solid-state batteries with oxide and sulfide electrolyte systems, the preparation and cell forming of polymer and composite electrolytes are easier to achieve.

[0004] The preparation of polymers and composite electrolytes can be achieved through relatively simple processes such as blade coating, casting, and in-situ polymerization to form films. Among them, the in-situ polymerization method can improve the interfacial compatibility between the electrode and the electrolyte, achieve seamless contact at the solid-solid interface, and thus reduce the interfacial resistance. In addition, the in-situ polymerization process is highly compatible with the existing lithium-ion battery manufacturing process, which is conducive to the industrialization and large-scale production of solid-state battery technology. The in-situ polymerization process provides a promising path for the commercialization of solid-state batteries. Summary of the Invention

[0005] The present invention provides an integrated all-solid-state single-layer battery cell unit and a preparation method thereof, as well as an internal series and internal parallel all-solid-state battery, which solves the problems of complex solid-state battery cell preparation process, large solid-solid interface impedance, and poor battery cycle performance in the prior art.

[0006] The specific technical solutions are: The method for preparing an integrated all-solid-state single-layer battery cell comprises the following steps: (1) In situ polymerization gel electrolyte solution preparation; The components of the in-situ polymerized gel electrolyte include: polymer monomers, cross-linking agents, additives, lithium salts and initiators, which account for 10%-20%; 1%-5%; 40%-70%; 10%-30%; 0.1%-1% of the total mass, and the total is 100%; The polymerizable monomer comprises at least one of butyl acrylate, methyl methacrylate, trifluoroethyl methacrylate and pentaerythritol triacrylate; The cross-linking agent includes at least one of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polytetrafluoroethylene, and polyvinylidene fluoride-hexafluoropropylene copolymer; The auxiliary agent includes at least one of carbonates, ethers, sulfones, and ionic liquids; The lithium salt includes at least one of lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium difluorooxalatoborate, lithium bis(oxalatoborate) and lithium tetrafluoroborate; The initiator comprises a photoinitiator and a thermal initiator. The photoinitiator comprises at least one of persulfate and 1-hydroxycyclohexyl phenyl ketone. The thermal initiator comprises at least one of diacyl peroxide and azobisisobutyronitrile.

[0007] (2) Preparation of gel electrode slurry; The gel electrode slurry can be in-situ polymerized to obtain a dry composite electrode, which includes: positive and negative electrode active materials; conductive agent; in-situ polymerized gel electrolyte solution. Based on the total mass of the positive electrode slurry, the proportion of each component is: 60-80%; 32%-10%; 10-40%; totaling 100%; The positive electrode active material includes at least one of lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide, and lithium-rich manganese-based materials; The negative electrode active material includes at least one of graphite, silicon carbon, silicon oxide, lithium titanate, and metallic lithium. The conductive agent includes at least one of conductive carbon black, Ketjen black, acetylene black, carbon nanotubes and graphene.

[0008] (3) Preparation of composite solid electrolyte slurry; The composite solid electrolyte includes: solid electrolyte, in-situ polymerized gel electrolyte solution, and coupling agent; the proportions of the total mass are 50-70%, 30-50%, and 1-10%, respectively, totaling 100%; (4) Preparation of prefabricated modules of gel anode-composite electrolyte-gel cathode integrated all-solid-state single-layer battery cell units by extrusion process; The specific process includes: simultaneously extruding the evenly mixed gel electrode slurry and composite solid electrolyte slurry into sheets through a screw, and compounding them in the order of negative electrode-electrolyte-positive electrode, die-cutting them into preset size battery cells, laminating the positive electrode fluid, negative electrode fluid and battery cells, and forming an integrated all-solid-state single-layer battery cell unit prefabricated module through molding.

[0009] (5) In-situ curing and molding of prefabricated modules of integrated all-solid-state single-layer battery cell units.

[0010] The process includes packaging and hot pressing of prefabricated battery modules, wherein the curing pressure is 1-20 MPa, the curing temperature is 40-80° C., and the curing time is 6-24 hours.

[0011] The integrated all-solid-state single-layer battery cell obtained by the present invention is used to prepare an all-solid-state battery. Specifically: An internally connected all-solid-state battery is constructed by stacking integrated all-solid-state single-layer cell units with composite current collectors layer by layer. One side of the composite current collector is a negative electrode current collector, and the other side is a positive electrode current collector. The negative electrode side includes one or more of: copper foil, carbon-coated copper foil, stainless steel foil, and nickel foil; the positive electrode side includes one or more of: aluminum foil, carbon-coated aluminum foil, and stainless steel foil. The negative electrode of the integrated all-solid-state single-layer cell unit is connected to the negative electrode side of the composite current collector, and the positive electrode side of the composite current collector is connected to the positive electrode of another integrated all-solid-state single-layer cell unit. The cells are stacked in sequence to form an internally connected cell prefabricated module.

[0012] An internally parallel all-solid-state battery is constructed by stacking integrated all-solid-state single-layer battery cells with positive and negative current collectors layer by layer. The negative current collector comprises one or more of copper foil, double-sided carbon-coated copper foil, stainless steel foil, and nickel foil; the positive current collector comprises one or more of aluminum foil, double-sided carbon-coated aluminum foil, and stainless steel foil. The negative electrode of the integrated all-solid-state single-layer battery cell is connected to one side of the negative current collector, and the other side of the negative current collector is connected to the negative electrode of another integrated all-solid-state single-layer battery cell. The positive electrode side of the other integrated all-solid-state single-layer battery cell is connected to the positive current collector, and the cells are stacked in sequence to form an internally parallel battery cell prefabricated module.

[0013] The present invention provides an integrated all-solid-state single-layer battery cell unit and a preparation method thereof. First, an integrated module is constructed before in-situ polymerization, and then an electrode / electrolyte integrated battery cell structure is constructed by in-situ thermal curing. The battery cell module structure includes a gel positive electrode, a solid electrolyte, and a gel negative electrode. A uniform gel electrolyte is present inside the battery cell to support ion conduction during the battery cycle, thereby reducing the influence of the large interface impedance between the electrode / electrolyte in the all-solid-state battery and increasing the stability of the battery. The preparation of the integrated battery cell module utilizes the technology of in-situ polymerization of the gel electrode / electrolyte to complete the electrode-electrolyte integration before curing, and the gel electrolyte in the electrode / electrolyte is homogenized and polymerized by hot pressing curing, thereby achieving the purpose of reducing the interface impedance and curing the electrode / electrolyte.

[0014] This method enables the one-step preparation of all-solid-state battery cells, from raw materials to cell formation, simplifying the complexity of the battery process (electrode preparation, electrolyte membrane preparation, and cell assembly). Because this application utilizes an in-situ polymerization method, eliminating the need for solvent volatilization and recovery, the all-solid-state battery integrated cell prepared by this invention features a simple process, environmental friendliness, and low cost, while also meeting the high energy density and high safety requirements of all-solid-state batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart for preparing the integrated all-solid-state single-layer battery cell of the present invention; Figure 2 This is a structural diagram of the integrated all-solid-state single-layer battery cell of the present invention; Figure 3 This is a SEM image of the integrated all-solid-state single-layer battery cell of the present invention; Figure 4 This is the EIS test diagram of the integrated all-solid-state single-layer battery cell unit and the stacked battery cell of the present invention; Figure 5 This is a structural diagram of the all-solid-state battery cell connected in series according to the present invention; Figure 6 This is a structural diagram of the internally parallel all-solid-state battery cells of the present invention; Figure 7 Diagram of the process equipment for continuous production of integrated all-solid-state single-layer battery cell units provided for this application. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0017] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various implementations, and the operational steps involved in each embodiment may be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the specification and drawings are only for the purpose of clearly describing a particular embodiment and do not imply a required composition and / or sequence.

[0018] Component numbers used herein, such as "first" and "second," are used solely to distinguish the components being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0019] The following is an explanation of some of the terms used in this application. It should be noted that these explanations are for the purpose of facilitating understanding by those skilled in the art and do not limit the scope of protection claimed in this application.

[0020] The present application provides an integrated all-solid-state single-layer battery cell unit structure and preparation method, which realizes the preparation of all-solid-state batteries by extruding integrated battery cell stacking-prefabricated module curing-battery cell series / parallel connection, and realizes the preparation of all-solid-state battery modules by in-situ polymerization process, which has the advantages of good interface compatibility and low internal resistance. In addition, the process is simple, easy to operate, low-cost, fast and efficient, and has great potential for large-scale production.

[0021] Specifically, the integrated all-solid-state single-layer battery cell preparation method is: (1) In situ polymerization gel electrolyte solution preparation; Furthermore, the in-situ polymerized gel electrolyte solution is configured as follows: the polymerization monomer, cross-linking agent, auxiliary agent, lithium salt and initiator are mixed evenly in proportion to obtain the in-situ polymerized gel electrolyte solution, and the in-situ polymerized gel electrolyte solution is used as a solvent to be mixed with the positive and negative electrode materials, conductive agent and solid fast ion conductor for polymerization, thereby avoiding the process of solvent volatilization and not requiring solvent recovery, which can reduce the preparation cost.

[0022] Furthermore, the polymerizable monomer, cross-linking agent, auxiliary agent, lithium salt and initiator account for 10%-20%; 1%-5%; 40%-70%; 10%-30%; 0.1%-1% of the total mass, respectively.

[0023] Methods for uniformly mixing the above-mentioned monomers, cross-linking agent, auxiliary agent, lithium salt, and initiator in proportion include, but are not limited to, magnetic stirring and ultrasonic stirring. For example, when using magnetic stirring, the temperature can be set at 20-30° C., the stirring speed can be set at 300-600 rpm, and the stirring time can be set at 1-6 hours to obtain an in-situ polymerized gel electrolyte solution with uniform composition. Those skilled in the art can select the mixing method as needed.

[0024] Furthermore, the polymerization monomer is one or more polyhydroxyl and ester monomers such as BA (butyl acrylate), PEGDA (polyethylene glycol diacrylate), MMA (methyl methacrylate), TFEMA (trifluoroethyl methacrylate), and PETA (pentaerythritol triacrylate); the initiator is one or more of benzophenone, thioxanthone, camphor quinone, and bisimidazole; the coupling agent is one or more of vinyltriethoxysilane, propenyltriethoxysilane, and propenyltrimethoxysilane; the auxiliary agent is one or more of carbonates, ethers, sulfones, amides, and ionic liquids; and the lithium salt is one or more of LiFSI (lithium bis(fluorosulfonyl)imide), LiTFSI (lithium bis(trifluoromethylsulfonyl)imide), LiBF4 (lithium tetrafluoroborate), and LiPF6 (lithium hexafluoroarsenate).

[0025] (2) Preparation of gel mixed positive and negative electrode slurry; Furthermore, the preparation of the gel mixed positive and negative electrode slurry and the organic-inorganic composite electrolyte slurry is to mix the positive and negative electrode materials, the conductive agent, and the in-situ polymerized gel electrolyte in a certain proportion, and then uniformly slurry them through an internal mixer to prepare the electrode slurry; Furthermore, the positive electrode material is one or more of NCM, LFP, LCO, and lithium-rich manganese-based, the negative electrode material is one or more of Gr, silicon carbon, silicon oxide, LTO, and lithium metal, the conductive agent is one or more of super P, Ketjen black, carbon nanotubes, and graphene, and the solid fast ion conductor is one or more of perovskite-type, NASICON-type, LISICON-type, and garnet-type solid electrolytes.

[0026] (3) Preparation of organic-inorganic composite electrolyte slurry; The solid fast ion conductor, the in-situ polymerized gel electrolyte and the coupling agent are mixed in a certain proportion and then uniformly slurried by an internal mixer to prepare an organic-inorganic composite electrolyte slurry.

[0027] (4) Extruding the negative electrode slurry, composite electrolyte slurry, and positive electrode slurry in sequence through an extrusion process to prepare a negative electrode-electrolyte-positive electrode integrated battery cell prefabricated module; The positive and negative electrode precursor slurries and the organic-inorganic composite electrolyte slurry are extruded into sheets, and an integrated battery prefabricated module is prepared according to the structure of negative electrode-electrolyte-positive electrode.

[0028] Specifically, extrusion is performed using a twin-screw extruder, and then rolling is performed using a twin-roll press. The twin-screw extruder includes a feed barrel, a temperature control zone, and a sheet extruder head. The configured positive and negative electrode precursor slurries and the organic-inorganic composite electrolyte slurry are respectively placed in the feed barrel of the twin-screw extruder, and are further mixed and extruded into a sheet structure through the twin-screw extruder. The sheet precursor of the negative electrode-electrolyte-positive electrode is then pressed into an integrated prefabricated module through the twin-roll press to obtain an unpolymerized integrated battery cell prefabricated module precursor.

[0029] Furthermore, the temperature inside the cavity of the twin-screw extruder during extrusion molding is 20-30°C, such as 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C or 30°C according to needs; the head thickness of the twin-screw extruder is 20-200μm.

[0030] Furthermore, the compaction density of the unpolymerized integrated battery prefabricated module precursor is greater than 2 g / cm 3 The compaction density can be achieved by adjusting the roller spacing of the double-roller press.

[0031] It should be noted that the model of the twin-screw extruder is not specifically limited, and those skilled in the art can select a suitable model according to the specific material weight.

[0032] At the same time, the head specifications of the twin-screw extruder are not specifically limited, and those skilled in the art can select according to the size of the electrolyte to be prepared, for example, a rectangular head with a length of 50 and a width (thickness) of 0.5 mm.

[0033] (5) The prepared all-solid-state battery cell prefabricated module is in-situ cured and formed.

[0034] Furthermore, the integrated battery prefabricated module precursor is sealed and hot-pressed to solidify. In order to ensure that there is no gap inside the battery, the integrated battery prefabricated module needs to be sealed, and the gel electrolyte inside the battery is polymerized in situ by hot-pressing and curing. The hot-pressing pressure is 0.1-10 MPa. At this time, a flat press is selected to perform hot-pressing on the integrated battery prefabricated module. The pressure is selected according to needs, such as 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa. MPa, 5MPa, 6MPa, 7MPa, 8MPa, 9MPa or 10MPa, etc.; the curing temperature is 40-80°C, and the time is 6-24h. Specifically, the temperature of the oven and the time of high-temperature polymerization are selected as needed, such as the temperature is 40°C, 50°C, 60°C, 70°C or 80°C, and the time is 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h or 24h, etc., and the problem of monomer volatilization can be avoided by complete high-temperature polymerization, so that the monomer is completely polymerized.

[0035] Furthermore, the integrated all-solid-state single-layer battery cell unit is combined with a composite current collector, and internal series and parallel all-solid-state batteries are constructed by stacking them layer by layer.

[0036] Furthermore, the composite current collector of the series structure has a negative electrode current collector on one side and a positive electrode current collector on the other side. The negative electrode current collector includes one or more of copper foil, carbon-coated copper foil, stainless steel foil, nickel foil, etc.; the positive electrode current collector includes one or more of aluminum foil, carbon-coated aluminum foil, stainless steel foil, etc.

[0037] Furthermore, the composite current collector of the parallel structure is a pure negative electrode current collector and a positive electrode current collector, the negative electrode current collector includes: one or more of copper foil, carbon-coated copper foil, stainless steel foil, nickel foil, etc.; the positive electrode current collector includes: one or more of aluminum foil, carbon-coated aluminum foil, stainless steel foil, etc.

[0038] The integrated all-solid-state single-layer battery cell unit prepared in this application is mainly used in all-solid-state batteries, which can effectively reduce the interface resistance between the electrode and the electrolyte of the all-solid-state battery, and improve its battery performance, safety and service life.

[0039] Example 1

[0040] This embodiment provides a method for preparing an integrated all-solid-state single-layer battery cell. Figure 1 The process steps shown are as follows: first, an in-situ polymerized gel electrolyte solution is prepared in a certain proportion, wherein the components include a polymer monomer, a cross-linking agent, an initiator, an auxiliary agent and a lithium salt. The polymer monomer is MMA (methyl methacrylate), the cross-linking agent is PEGDMA (polyethylene dimethacrylate), and the auxiliary agent is a mixed solution of one or more EC, EMC, DEC, FEC, VEC, VC, etc. The monomer, initiator and auxiliary agent are mixed in a mass ratio of 1:1:1, and then the initiator AIBN (azobisisobutyronitrile) is added to account for 0.5wt% of the polymer monomer, and the lithium salt LPF6 is added at a concentration of 1M. The polymer monomer, cross-linking agent, initiator, auxiliary agent and lithium salt are stirred at room temperature until they are in a uniform solution state to obtain the in-situ polymerized gel electrolyte solution.

[0041] In the preparation of the mixed positive electrode, the positive electrode active material NCM811, the conductive agent Super P, and the in-situ polymerization solution were mixed in a mass ratio of 75:4:21 to obtain a uniform mixed positive electrode material.

[0042] Preparation of composite electrolyte: solid electrolyte LLZTO and in-situ polymerization solution are mixed in a mass ratio of 70:30 to obtain a uniform composite electrolyte material.

[0043] In the preparation of the mixed negative electrode, the negative electrode material graphite, the conductive agent Super P, and the in-situ polymerization solution were mixed in a mass ratio of 65:4:31 to obtain a uniform mixed negative electrode material.

[0044] Preparation of integrated all-solid-state single-layer battery cell Figure 2 , respectively, extrude the positive electrode sheet 11, the composite electrolyte sheet 13, and the negative electrode sheet 14 through an extruder, insulate both sides of the positive electrode sheet 12, and stack and assemble in the order of positive electrode-electrolyte-negative electrode, and finally place the stacked integrated prefabricated battery cell in a hot press at 60°C and 0.3Mpa for hot pressing and curing for 12 hours to obtain a single-layer all-solid-state integrated battery cell prefabricated module 100. Figure 3 This is a SEM image of a single-layer all-solid-state integrated battery cell. The integrated structure can effectively improve the interface contact between the electrode / electrolyte and reduce the interface impedance of the battery cell. Figure 4 As shown in the figure, the interface impedance of the integrated structure battery cell is 80.32Ω, which is much smaller than the interface impedance of the stacked battery cell (432.3Ω).

[0045] Example 2 This embodiment provides a method for preparing an integrated battery cell with an all-solid-state internal series structure, based on an integrated all-solid-state single-layer battery cell unit structure, combined with a composite current collector with aluminum foil on one side and copper foil on the other side, to form an all-solid-state battery cell structure with an internal series structure by lamination, such as Figure 5 As shown, the positive electrode side of the integrated all-solid-state single-layer battery cell unit 100 is laminated to the aluminum foil side of the composite current collector 21, and the copper foil of the composite current collector 21 is laminated to the negative electrode side of another integrated all-solid-state single-layer battery cell unit 100. The integrated all-solid-state single-layer battery cell units and the composite current collector are stacked in sequence and finally hot-pressed and cured to obtain a battery cell 200 with an internal series structure.

[0046] Example 3 This embodiment provides a method for preparing an integrated battery cell with an all-solid-state internal parallel structure, based on an integrated all-solid-state single-layer battery cell structure, combined with aluminum foil and copper foil current collectors, to form an all-solid-state battery cell structure with an internal parallel structure by lamination, such as Figure 6 As shown. The negative electrode side of the integrated all-solid-state single-layer battery cell unit 100 is bonded to the copper foil current collector 31, and the other side of the copper foil current collector 31 is bonded to the negative electrode side of another integrated all-solid-state single-layer battery cell unit 100. The positive electrode side of the integrated all-solid-state single-layer battery cell unit is bonded to the aluminum foil current collector 32, and the other side of the aluminum foil current collector is bonded to the positive electrode side of another integrated all-solid-state single-layer battery cell unit 100. The integrated all-solid-state single-layer battery cell units and the current collectors are stacked in sequence and finally hot-pressed and cured to obtain a battery cell 300 with an internal series structure.

[0047] Example 4 This embodiment provides a method for preparing an integrated all-solid-state single-layer battery cell unit. Different from the first embodiment, silicon-carbon material is selected as the negative electrode material, and other materials, processes, and proportions remain unchanged.

[0048] Example 5

[0049] This embodiment provides a method for preparing an integrated all-solid-state single-layer battery cell unit. Different from Example 1, LFP is selected as the positive electrode material, LTO is selected as the negative electrode material, the in-situ polymerized electrolyte remains unchanged, the mass ratio of the active material, the conductive agent, and the in-situ polymerized electrolyte solution in the mixed positive electrode is 60:4:36, and the mass ratio of the active material, the conductive agent, and the in-situ polymerized electrolyte solution in the mixed negative electrode is 62:4:34. Other materials, processes, and proportions remain unchanged.

[0050] Example 6

[0051] This embodiment provides a method for preparing an integrated all-solid-state single-layer battery cell unit. Different from the first embodiment, LCO is selected as the positive electrode material, and other materials, processes, and proportions remain unchanged.

[0052] Example 7

[0053] This embodiment provides a method for preparing an integrated all-solid-state single-layer battery cell unit. Different from the fifth embodiment, LFP is selected as the positive electrode material, LATP is selected as the solid electrolyte, and LTO is selected as the negative electrode. Other materials, processes, and proportions remain unchanged.

[0054] Example 8

[0055] This embodiment provides a continuous production process design for an integrated all-solid-state single-layer battery cell. The entire equipment process is as follows: Figure 7 As shown, the overall equipment mainly includes a screw extruder, an insulation treatment device, and a die-cutting device. The mixed positive electrode, composite electrolyte, and mixed negative electrode materials are placed in the positive electrode extruders 41, 43, and 44 respectively. The mixed positive electrode is extruded into a sheet by the extruder 41. The positive electrode sheet is then conveyed to the insulation treatment device 42 by a conveyor belt driven by rollers 47 for edge insulation treatment. The positive electrode sheet is then conveyed to the electrolyte extruder by a conveyor belt. At the same time, the electrolyte extruder 43 extrudes the composite electrolyte into a sheet. The positive electrode sheet and the composite electrolyte sheet are pre-pressed and composited by the pre-roller 48. The sheet is then conveyed to the negative electrode extruder. At the same time, the negative electrode extruder 44 extrudes the negative electrode sheet. The positive electrode sheet, composite electrolyte sheet, and negative electrode sheet are pre-pressed and composited by the pre-roller 45. Finally, the sheet is conveyed to the die-cutting device 46 by a conveyor belt for die-cutting of the battery cell to obtain an integrated all-solid-state single-layer battery cell unit of a certain specification.

[0056] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A method for preparing an integrated all-solid-state single-layer battery cell, characterized in that: The following steps are involved: (1) In situ polymerization gel electrolyte solution preparation; The components of the in-situ polymerized gel electrolyte include: polymer monomers, cross-linking agents, additives, lithium salts and initiators, which account for 10%-20%; 1%-5%; 40%-70%; 10%-30%; 0.1%-1% of the total mass, and the total is 100%; (2) Preparation of gel electrode slurry; The gel electrode slurry can be in-situ polymerized to obtain a dry composite electrode, which includes: positive and negative electrode active materials; conductive agent; in-situ polymerized gel electrolyte solution, with the proportion of each component being: 60-80%; 32%-10%; 10-40%; totaling 100%; (3) Preparation of composite solid electrolyte slurry; The composite solid electrolyte includes: solid electrolyte, in-situ polymerized gel electrolyte solution, and coupling agent; the proportions of the total mass are 50-70%, 30-50%, and 1-10%, respectively, totaling 100%; (4) Preparation of prefabricated modules of gel anode-composite electrolyte-gel cathode integrated all-solid-state single-layer battery cell units by extrusion process; (5) In-situ curing and molding of the integrated all-solid-state single-layer battery cell prefabricated module.

2. The method for preparing an integrated all-solid-state single-layer battery cell according to claim 1, characterized in that: In step (1), the polymerizable monomer includes at least one of butyl acrylate, methyl methacrylate, trifluoroethyl methacrylate and pentaerythritol triacrylate; The cross-linking agent includes at least one of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polytetrafluoroethylene, and polyvinylidene fluoride-hexafluoropropylene copolymer; The auxiliary agent includes at least one of carbonates, ethers, sulfones, and ionic liquids; The lithium salt includes at least one of lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium difluorooxalatoborate, lithium bis(oxalatoborate) and lithium tetrafluoroborate; The initiator comprises a photoinitiator and a thermal initiator. The photoinitiator comprises at least one of persulfate and 1-hydroxycyclohexyl phenyl ketone. The thermal initiator comprises at least one of diacyl peroxide and azobisisobutyronitrile.

3. The method for preparing an integrated all-solid-state single-layer battery cell according to claim 1, characterized in that: In step (2), the positive electrode active material includes at least one of lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide, and lithium-rich manganese-based materials; The negative electrode active material includes at least one of graphite, silicon carbon, silicon oxide, lithium titanate, and metallic lithium. The conductive agent includes at least one of conductive carbon black, Ketjen black, acetylene black, carbon nanotubes and graphene.

4. The method for preparing an integrated all-solid-state single-layer battery cell according to claim 1, characterized in that: The specific process of step (4) includes: simultaneously extruding the uniformly mixed gel electrode slurry and composite solid electrolyte slurry into sheets through a screw, and compounding them in the order of negative electrode-electrolyte-positive electrode, die-cutting them into preset size battery cells, laminating the positive electrode fluid, negative electrode fluid and battery cells, and forming an integrated all-solid-state single-layer battery cell unit prefabricated module through molding.

5. The method for preparing an integrated all-solid-state single-layer battery cell according to claim 1, characterized in that: The in-situ curing and molding of the integrated all-solid-state single-layer battery cell unit prefabricated module in step (5) includes: packaging and hot pressing curing of the battery cell prefabricated module, wherein the curing pressure is 1-20 MPa, the curing temperature is 40-80° C., and the curing time is 6-24 h.

6. An integrated all-solid-state single-layer battery cell unit obtained by the method for preparing an integrated all-solid-state single-layer battery cell unit according to any one of claims 1 to 5.

7. An all-solid-state battery connected in series, characterized in that: The integrated all-solid-state single-layer battery cell according to claim 6 is stacked layer by layer in combination with a composite current collector to construct an internal series all-solid-state battery.

8. The all-solid-state battery connected in series according to claim 7, characterized in that: One side of the composite current collector is a negative electrode current collector, and the other side is a positive electrode current collector. The negative electrode side includes: copper foil, carbon-coated copper foil, stainless steel foil, nickel foil or one or more; the positive electrode side includes: aluminum foil, carbon-coated aluminum foil, stainless steel foil or one or more; The negative electrode of the integrated all-solid-state single-layer battery cell unit is connected to the negative electrode side of the composite current collector, and the positive electrode side of the composite current collector is connected to the positive electrode of another integrated all-solid-state single-layer battery cell unit, which are stacked in sequence to construct an internal series battery cell prefabricated module.

9. An internally parallel all-solid-state battery, characterized in that: The invention comprises the integrated all-solid-state single-layer battery cell unit as described in claim 6, which is combined with the positive electrode current collector and the negative electrode current collector to be stacked layer by layer to construct an internal series all-solid-state battery.

10. The internally parallel all-solid-state battery according to claim 9, characterized in that: The negative electrode current collector includes: copper foil, double-sided carbon-coated copper foil, stainless steel foil, nickel foil or one or more; the positive electrode current collector includes: aluminum foil, double-sided carbon-coated aluminum foil, stainless steel foil or one or more; The negative electrode of the integrated all-solid-state single-layer battery cell unit is connected to one side of the negative electrode current collector, the other side of the negative electrode current collector is connected to the negative electrode of another integrated all-solid-state single-layer battery cell unit, and the positive electrode side of the other integrated all-solid-state single-layer battery cell unit is connected to the positive electrode current collector, and the internal parallel battery cell prefabricated modules are stacked in sequence.

Images