Solid state structure battery and method of making the same

Abstract

This invention relates to a solid-state battery and its fabrication method, belonging to the field of solid-state battery technology. The solid-state battery comprises, in sequence, a negative electrode current collector, a carbon fiber negative electrode, a solid electrolyte layer, a carbon fiber positive electrode, and a positive electrode current collector, and further includes a three-dimensional continuous porous ceramicized network that at least penetrates and connects the carbon fiber negative electrode, the solid electrolyte layer, and the carbon fiber positive electrode. The three-dimensional continuous porous ceramicized network is formed by heat treatment of an organic-inorganic hybrid resin. The organic-inorganic hybrid resin comprises an organic resin that decomposes at 200-500℃ and inorganic pre-ceramizationable particles that form ceramic bonds at 400-800℃. The inorganic pre-ceramizationable particles include low-melting-point glass powder, nano-oxide powder, and pre-ceramizationable precursors. The solid-state battery of this invention possesses excellent electrochemical and mechanical properties, significantly enhancing the bonding strength of the solid-solid interface and the ion transport efficiency within the solid-state battery.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery technology, and particularly relates to a solid-state structure battery and its preparation method. Background Technology

[0002] Solid-state batteries are considered to be the next generation of high-safety, high-energy-density energy storage devices. If they are combined with the concept of carbon fiber structure batteries to prepare solid-state structure batteries, the use of existing liquid electrolyte systems can be effectively avoided, and the interlayer performance and structural load-bearing capacity of the batteries can be greatly improved. However, one of the core challenges facing its industrialization is the preparation process. Solid electrolytes (especially oxide and sulfide electrolytes) and electrode materials are both rigid solids, and there is a solid-solid point contact between the two, resulting in extremely high interfacial impedance. In order to obtain acceptable ionic conductivity, existing technologies usually adopt: (1) ultra-high pressure cold pressing / hot pressing: the pressure usually needs to reach 300 MPa or even higher. This method has stringent equipment requirements, high energy consumption, and is difficult to prepare large-size, complex-shaped batteries. Moreover, high pressure can easily cause the electrode active material particles to break and the current collector to be damaged, which seriously restricts production efficiency and product qualification rate. (2) high-temperature sintering: for oxide electrolytes, co-sintering at above 1300℃ is often required to achieve densification. This process is not only energy-intensive, but it also triggers side reactions between the electrode and the electrolyte, forming a high-resistivity interface layer, and is completely incompatible with heat-sensitive materials (such as polymers and carbon materials).

[0003] To address the aforementioned technical bottlenecks, it is essential to provide a novel solid-state battery structure and its fabrication method. Summary of the Invention

[0004] To address one or more technical problems existing in the prior art, this invention provides a solid-state battery and its fabrication method. The solid-state battery of this invention contains a three-dimensional continuous porous ceramic network that penetrates and connects the carbon fiber anode, the solid electrolyte layer, and the carbon fiber cathode, forming an integrated mechanical support and ion transport framework, exhibiting excellent electrochemical and mechanical properties. The method of this invention enables the integrated fabrication of the carbon fiber anode and cathode with the solid electrolyte under low pressure (≤10 MPa), significantly enhancing the bonding strength of the solid-solid interface and the ion transport efficiency within the solid-state battery.

[0005] The present invention provides a solid-state battery structure in a first aspect, the solid-state battery structure comprising, sequentially stacked, a negative electrode current collector, a carbon fiber negative electrode, a solid electrolyte layer, a carbon fiber positive electrode, and a positive electrode current collector, the solid-state battery structure further comprising a three-dimensional continuous porous ceramicized network that at least penetrates and connects the carbon fiber negative electrode, the solid electrolyte layer, and the carbon fiber positive electrode; the three-dimensional continuous porous ceramicized network is formed by heat treatment of an organic-inorganic hybrid resin; the organic-inorganic hybrid resin comprises an organic resin that decomposes at 200~500℃ and inorganic pre-ceramizationable particles that form ceramic connections at 400~800℃; the inorganic pre-ceramizationable particles comprise low-melting-point glass powder, nano-oxide powder, and pre-ceramizationable precursor; the pre-ceramizationable precursor is one or more of polycarbosilane, polysiloxane, polysilazane, silicone resin, polysilsesquioxane, borosilicate sol, nano-silica sol, alumina precursor, and zirconium dioxide precursor.

[0006] Preferably, the organic resin is epoxy resin and / or phenolic resin.

[0007] Preferably, the low-melting-point glass powder is borosilicate glass powder and / or phosphate glass powder; and / or the nano-oxide powder is one or more of nano-silica, nano-magnesium oxide, nano-alumina, nano-copper oxide, and nano-boron oxide.

[0008] Preferably, the carbon fiber positive electrode comprises a carbon fiber substrate and a positive electrode active material loaded on the carbon fiber substrate; the carbon fiber negative electrode comprises a carbon fiber substrate and a negative electrode active material loaded on the carbon fiber substrate; and / or the solid electrolyte contained in the solid electrolyte layer is an oxide-based solid electrolyte and / or a sulfide-based solid electrolyte.

[0009] Preferably, the oxide-based solid electrolyte is lithium lanthanum zirconium oxide (LLZO) and / or lithium lanthanum titanium oxide (LLTO); the sulfide-based solid electrolyte is lithium phosphorus sulfide compound (LPS) and / or lithium germanium phosphorus sulfide compound (LGPS); the carbon fiber substrate is carbon fiber cloth; the positive electrode active material is one or more of lithium iron phosphate, lithium cobalt oxide, and nickel manganese cobalt oxide; and / or the negative electrode active material is one or more of graphite, silicon-carbon composite, and metallic lithium.

[0010] Preferably, before heat treatment, the amount of the organic-inorganic hybrid resin accounts for 5 to 20% of the mass of the solid electrolyte contained in the solid electrolyte layer.

[0011] Preferably, the amount of organic resin used accounts for 50-60% of the sum of the mass of organic resin and inorganic pre-ceramizable particles.

[0012] Preferably, the inorganic pre-ceramizationable particles comprise low-melting-point glass powder, nano-oxide powder, and pre-ceramizationable precursor in a mass ratio of (2~3):(1~2):(4~6).

[0013] The present invention provides, in a second aspect, a method for fabricating a solid-state battery according to the first aspect of the present invention, the method comprising the following steps: (1) Preparation of carbon fiber positive electrode and carbon fiber negative electrode; (2) Mix the solid electrolyte with the organic-inorganic hybrid resin to obtain a pre-ceramizable solid electrolyte slurry; (3) The negative electrode current collector, carbon fiber negative electrode, pre-ceramizable solid electrolyte slurry, carbon fiber positive electrode and positive electrode current collector are stacked in sequence to obtain a laminate; (4) The laminate is placed in a mold and molded under a pressure of 1~10MPa and a temperature of 80~150℃ to obtain a battery blank; (5) Under an inert protective atmosphere, heat the battery blank to 400~800℃ for 0.5~4h to obtain a solid structure battery.

[0014] Preferably, in step (1), the preparation of the carbon fiber positive electrode includes: dispersing the positive electrode active material, conductive additive and binder evenly with a dispersant to obtain a positive electrode active material slurry, then adding an organic-inorganic hybrid resin to the positive electrode active material slurry and dispersing it evenly to obtain a pre-ceramizable positive electrode active material slurry, and then coating the pre-ceramizable positive electrode active material slurry onto a carbon fiber substrate to obtain a carbon fiber positive electrode.

[0015] Preferably, in step (1), the preparation of the carbon fiber negative electrode includes: dispersing the negative electrode active material, conductive additive and binder evenly with a dispersant to obtain a negative electrode active material slurry, then adding an organic-inorganic hybrid resin to the negative electrode active material slurry and dispersing it evenly to obtain a pre-ceramizable negative electrode active material slurry, and then coating the pre-ceramizable negative electrode active material slurry onto a carbon fiber substrate to obtain a carbon fiber negative electrode.

[0016] Preferably, in step (2): the mass ratio of the solid electrolyte to the organic-inorganic hybrid resin is (4~19):1; and / or the solid content of the pre-ceramizable solid electrolyte slurry is 80~90wt%.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The solid-state battery in this invention is not simply an interface modification layer, but has a three-dimensional continuous porous ceramic network (a porous ceramic network continuously distributed in three-dimensional space) that runs through and connects the carbon fiber negative electrode, the solid electrolyte layer and the carbon fiber positive electrode. Mechanically, the three-dimensional continuous porous ceramic network forms a continuous ceramic skeleton structure in the solid-state battery. Through in-situ fusion of the interface and mechanical interlocking, the integrated connection of each functional layer is realized, which significantly enhances the interlayer bonding force and structural stiffness and effectively solves the technical problem of easy delamination between solid-state battery layers. Electrochemically, the three-dimensional continuous porous ceramic network has high ion conductivity, providing ions with an additional three-dimensional fast transport channel in addition to the solid electrolyte particle body, which significantly reduces the overall interface impedance. The three-dimensional continuous porous ceramic network in the solid-state battery of this invention enables the solid-state battery to have excellent electrochemical performance and mechanical performance at the same time.

[0018] (2) This invention proposes a novel method for preparing solid-state batteries based on a new strategy of “low-pressure molding-ceramic connection”. The method of this invention can achieve the integrated molding and integration of carbon fiber positive and negative electrodes and solid electrolytes at a pressure far lower than that of traditional methods, i.e., at low pressure (≤10MPa), which significantly enhances the bonding strength and ion transport efficiency of the solid-solid interface inside the solid-state battery. Specifically, this invention creatively proposes to first use a low-modulus organic-inorganic hybrid resin to achieve preliminary composite and shaping of each component under low pressure, and then transform the organic-inorganic hybrid resin into a high-modulus ceramic skeleton through heat treatment. This completely avoids the ultra-high pressure of hundreds of megapascals required by traditional solid-state structure batteries, reducing the molding pressure by 1-2 orders of magnitude and solving the core equipment bottleneck in the preparation of solid-state structure batteries. This invention uses a multi-continuous phase organic-inorganic hybrid resin, which can be used as a binder at room temperature, enabling the battery blank to achieve good composite under low pressure. In the subsequent heat treatment, its inorganic pre-ceramicized particles form a three-dimensional continuous porous ceramicized network that runs through the battery body. This three-dimensional continuous porous ceramicized network mechanically acts like "rivets" to strongly connect the functional layers, while the pores left by the removed organic resin can provide additional three-dimensional high-speed channels for ion transport, thus solving the core problems of high-pressure molding difficulty, high interfacial impedance, and weak interlayer structure of solid-state structure batteries in one fell swoop.

[0019] (3) The method of the present invention is simple, has low energy consumption, is compatible with large-scale production, and can effectively protect the thermosensitive electrode material.

[0020] (4) In some preferred technical solutions of the present invention, in view of the fact that carbon fiber and battery active materials are not resistant to high temperature, the present invention achieves effective ceramicized connection at relatively low temperature (400~800℃) by precisely designing the type and ratio of inorganic pre-ceramicized particles in a multi-continuous phase structure. At the same time, by strictly controlling the amount of organic-inorganic hybrid resin added, it is ensured that while forming an effective ceramicized connection network, the main phase content of the solid electrolyte and the performance of the electrochemical active material are not sacrificed, thus successfully achieving a balance between "structure" and "function". Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention and are only used to more clearly illustrate the technical solutions of the embodiments of the present invention, so they should not be regarded as a limitation of the scope. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings of the present invention are provided for illustrative purposes only, and the proportions, sizes, and quantities of the parts in the drawings may not be consistent with the actual product.

[0022] Figure 1 These are schematic diagrams of the solid-state battery structure in some specific embodiments of the present invention; Figure 2 This is a flowchart illustrating the fabrication process of a solid-state battery according to some specific embodiments of the present invention. Figure 3 These are physical images of solid-state battery structures prepared in some specific embodiments of the present invention.

[0023] exist Figure 1 In the diagram, 1: negative electrode current collector; 2: carbon fiber negative electrode; 21: carbon fiber substrate included in the carbon fiber negative electrode; 22: negative electrode active material; 3: solid electrolyte layer; 4: carbon fiber positive electrode; 41: carbon fiber substrate included in the carbon fiber positive electrode; 42: positive electrode active material; 5: positive electrode current collector; 6: three-dimensional continuous porous ceramic network. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments thereof. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0025] In a first aspect, the present invention provides a solid-state battery structure, for example, such as... Figure 1As shown, the solid-state battery includes a negative electrode current collector 1, a carbon fiber negative electrode 2, a solid electrolyte layer 3, a carbon fiber positive electrode 4, and a positive electrode current collector 5 stacked sequentially. The solid-state battery also includes a three-dimensional continuous porous ceramicized network 6 that at least penetrates and connects the carbon fiber negative electrode, the solid electrolyte layer, and the carbon fiber positive electrode. In this invention, the three-dimensional continuous porous ceramicized network at least penetrates and firmly connects the carbon fiber positive and negative electrodes and the solid electrolyte layer, forming an integrated framework for mechanical support and ion transport. The three-dimensional continuous porous ceramicized network is formed by heat treatment of an organic-inorganic hybrid resin. The organic-inorganic hybrid resin includes an organic resin that decomposes at 200-500℃ and a resin that decomposes at 400-800℃, preferably 400-800℃. More preferably, the inorganic pre-ceramization particles with ceramic linkages are formed at 700℃, or 400~650℃. In this invention, the organic-inorganic hybrid resin is a multi-continuous organic-inorganic hybrid resin, that is, after the organic-inorganic hybrid resin is cured, its organic resin phase and inorganic pre-ceramization particle phase each form and maintain a continuous network structure that is mutually interpenetrating in three-dimensional space, thereby constituting a multi-continuous phase. The inorganic pre-ceramization particles include low-melting-point glass powder, nano-oxide powder and pre-ceramization precursor. The pre-ceramization precursor is one or more of polycarbosilane, polysiloxane, polysilazane, silicone resin, polysilsesquioxane (POSS), borosilicate sol, nano-silica sol, alumina precursor, and zirconium dioxide precursor.

[0026] In this invention, the pre-ceramizationable precursor is capable of undergoing a ceramization transformation during heat treatment and generating a porous ceramic framework. In some specific embodiments of this invention, the pre-ceramizationable precursor includes, but is not limited to: organosilicon polymer precursors, such as one or more of polysiloxanes, polysilazanes, silicone resins, polysilsesquioxanes (POSS), polycarbosilanes, polysilazane derivatives, and boron / aluminum / phosphorus modified silicone resins; sol-gel systems and inorganic precursors, such as borosilicate sols, nano-silica sols, and trioxide sols. One or more of aluminum dioxide precursors and zirconium dioxide precursors; one or more of inorganic polymer systems, such as phosphate-based inorganic polymers, aluminum phosphate precursors, magnesium phosphate cement (MPC), geopolymers, metakaolin and alkali activator systems; these pre-ceramization precursors can form ceramic phases or ceramic framework structures with "quasi-ceramization" characteristics at 400~800℃; among them, for systems with higher ceramization temperatures, the addition of fluxes such as low-melting-point glass powder can promote liquid phase formation, thereby reducing the temperature required for ceramization.

[0027] The solid-state battery of this invention is not simply an addition of an interface modification layer, but rather possesses a three-dimensional continuous porous ceramic network (a porous ceramic network continuously distributed in three-dimensional space) that penetrates and connects at least the carbon fiber negative electrode, the solid electrolyte layer, and the carbon fiber positive electrode. Mechanically, this three-dimensional continuous porous ceramic network forms a continuous, interconnected ceramic skeleton structure within the solid-state battery. Through in-situ interface fusion and mechanical interlocking, it achieves integrated connection of each functional layer, significantly enhancing interlayer bonding and structural stiffness, effectively solving the technical problem of easy delamination between layers in solid-state batteries. Electrochemically, this three-dimensional continuous porous ceramic network exhibits highly efficient ion conductivity, providing ions with an additional three-dimensional rapid transport channel besides the solid electrolyte particles themselves, significantly reducing overall interface impedance. The three-dimensional continuous porous ceramic network in the solid-state battery of this invention enables it to possess both excellent electrochemical and mechanical properties, making it a solid-state battery with both excellent mechanical load-bearing capacity and energy storage capabilities. Existing technologies have reported the incorporation of functional layers containing resin and / or ceramics in solid-state batteries. However, such simple layered stacked structures cannot form a three-dimensional integrated connection that spans multiple layers, making it difficult to solve the problems of weak interlayer bonding, easy delamination, and discontinuous ion transport. In contrast, this invention constructs a three-dimensional continuous porous ceramic network that spans the carbon fiber anode, solid electrolyte layer, and carbon fiber cathode through in-situ thermal treatment of organic-inorganic hybrid resin. This three-dimensional continuous porous ceramic network forms a dual continuous structure of mechanical interlocking and ion conduction in space, which not only significantly improves the interlayer bonding and overall mechanical stiffness but also provides an efficient and stable three-dimensional transport channel for lithium ions, significantly reduces interfacial impedance, and achieves synergistic optimization of mechanical load-bearing capacity and electrochemical energy storage.

[0028] According to some preferred embodiments, the organic resin is epoxy resin and / or phenolic resin; the present invention does not specifically limit the type of epoxy resin and phenolic resin, and those skilled in the art can conventionally select epoxy resin and / or phenolic resin that can be decomposed and removed at 200~500℃; in some specific embodiments, the organic-inorganic hybrid resin also contains a curing agent and / or an accelerator, the present invention does not specifically limit the selection of the curing agent, as long as it is compatible with the selected organic resin, and those skilled in the art can conventionally select it; in the present invention, the mass ratio of the organic resin to the curing agent can be, for example, 10:(1~14), and the mass ratio of the organic resin to the accelerator can be, for example, 10:(0.5~1).

[0029] According to some preferred embodiments, the low-melting-point glass powder is borosilicate glass powder and / or phosphate glass powder. This invention does not particularly limit the type of borosilicate glass powder and / or phosphate glass powder, but preferably uses borosilicate glass powder and / or phosphate glass powder with a softening point of 400~750℃, more preferably 400~650℃. In some specific embodiments, the borosilicate glass powder can be, for example, borosilicate glass powder B-3033 or D245; and / or the nano-oxide powder is nano-silica (SiO2), nano-magnesium oxide (… The nano-oxide powder is selected from one or more of MgO, nano-alumina (Al2O3), nano-copper oxide (CuO), and nano-boron oxide (B2O3); preferably, the nano-oxide powder is a mixture of nano-silicon dioxide, nano-magnesium oxide, and nano-alumina, which can undergo a solid-state reaction to generate magnesium aluminum spinel during heat treatment; in this invention, the nano-copper oxide and nano-boron oxide can also be used as sintering aids, which is beneficial to reducing the overall sintering temperature; in this invention, the particle size of the nano-oxide powder can be, for example, 20~50 nm.

[0030] According to some preferred embodiments, the carbon fiber positive electrode 4 includes a carbon fiber substrate and a positive electrode active material 42 loaded on the carbon fiber substrate; the carbon fiber negative electrode 2 includes a carbon fiber substrate and a negative electrode active material 22 loaded on the carbon fiber substrate; and / or the solid electrolyte contained in the solid electrolyte layer is an oxide-based solid electrolyte and / or a sulfide-based solid electrolyte.

[0031] This invention does not impose specific limitations on the materials and thicknesses used for the positive electrode current collector, negative electrode current collector, carbon fiber substrate, positive electrode active material, negative electrode active material, and solid electrolyte; those skilled in the art can make conventional choices.

[0032] According to some preferred embodiments, the positive current collector and / or the negative current collector is a stainless steel mesh with a thickness of 6~30μm; in this invention, when the negative current collector and / or the positive current collector is a metal mesh (e.g., stainless steel mesh), the three-dimensional continuous porous ceramic network can also be formed in the positive current collector and / or the negative current collector; this invention does not specifically limit the metal mesh, and those skilled in the art can choose conventionally.

[0033] According to some preferred embodiments, the oxide-based solid electrolyte is lithium lanthanum zirconium oxide (LLZO) and / or lithium lanthanum titanium oxide (LLTO); the sulfide-based solid electrolyte is lithium phosphorus sulfide compound (LPS) and / or lithium germanium phosphorus sulfide compound (LGPS); in this invention, the thickness of the solid electrolyte layer can be, for example, 20~200 μm; the carbon fiber substrate is carbon fiber cloth, with a thickness of, for example, 100~500 μm; the carbon fiber cloth can be, for example, carbon fiber woven fabric or carbon fiber nonwoven fabric; in this invention, the carbon fiber substrate can simultaneously provide electronic conductivity paths and mechanical reinforcement; the positive electrode active material is one or more of lithium iron phosphate, lithium cobalt oxide, and lithium nickel manganese cobalt oxide, and the loading thickness of the positive electrode active material can be, for example, 50~200 μm; and / or the negative electrode active material is one or more of graphite, silicon-carbon composite, and metallic lithium, and the loading thickness of the negative electrode active material can be, for example, 50~200 μm.

[0034] According to some preferred embodiments, before heat treatment, the amount of the organic-inorganic hybrid resin accounts for 5-20% (e.g., 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%) of the mass of the solid electrolyte contained in the solid electrolyte layer, preferably 15-20%. In this invention, it is preferable to control the amount of organic-inorganic hybrid resin added. This 5-20% ratio ensures sufficient adhesion during the molding stage, while avoiding excessive insulating phases from affecting electrochemical performance. That is, it ensures that while forming an effective connection network, the main phase content of the solid electrolyte and the performance of the electrochemically active material are not sacrificed, thus successfully achieving a balance between "structure" and "function".

[0035] According to some preferred embodiments, the amount of organic resin is 50-60% of the sum of the mass of the organic resin and the inorganic pre-ceramization particles. In this invention, it is preferred that the amount of organic resin is 50-60% of the sum of the mass of the organic resin and the inorganic pre-ceramization particles. At this ratio, the amount of gas generated by the decomposition of organic resin during heat treatment at 200-500°C is moderate, which can form a uniform and interconnected three-dimensional porous framework structure and provide an ideal template space for the ceramicization connection of inorganic pre-ceramization particles. This invention has found that if the organic resin content is too low, it is difficult to form a three-dimensional continuous network with sufficient porosity, which will hinder ion transport. If the organic resin content is too high, it will lead to excessively large pores in the functional layers of the solid-state battery, structural collapse, etc., and will also reduce the ionic conductivity of the solid electrolyte layer, damaging the battery interface stability.

[0036] According to some preferred embodiments, the inorganic pre-ceramizationable particles comprise low-melting-point glass powder, nano-oxide powder, and pre-ceramizationable precursor in a mass ratio of (2~3):(1~2):(4~6). In this invention, the inorganic pre-ceramization particles preferably comprise low-melting-point glass powder, nano-oxide powder, and pre-ceramization precursor in a mass ratio of (2~3):(1~2):(4~6). Under this ratio, the pre-ceramization precursor serves as the main source of ceramic phase formation, pyrolyzing into a ceramic skeleton during heat treatment at 400~800℃, forming the main body of the three-dimensional continuous network. The low-melting-point glass powder acts as a flux, melting first during heat treatment to form a liquid phase, bridging and filling the ceramic skeleton with the nano-oxide powder, promoting network densification. The nano-oxide powder acts as a reinforcing phase, dispersing in the ceramic network to suppress excessive shrinkage and improve mechanical strength. The three work synergistically to form a dense but appropriately porous three-dimensional continuous ceramicized network. This network penetrates and connects the carbon fiber anode, the solid electrolyte layer, and the carbon fiber cathode, ensuring both unobstructed ion / electron transport channels and providing sufficient structural support strength. This invention reveals that if there is too much low-melting-point glass powder, the excessive glass phase will cause the network to soften excessively and collapse during heat treatment, blocking ion transport channels and potentially causing cracking due to thermal expansion coefficient mismatch. If there is too much nano-oxide powder, the excessive nano-powder is prone to agglomeration, hindering the uniform flow of the glass phase, resulting in discontinuous ceramic connections and reducing the overall integrity of the network and ionic conductivity. If there is too little pre-ceramization precursor, the ceramic framework will be insufficient, making it impossible to form an effective and continuous three-dimensional network structure, leading to a decrease in interfacial bonding strength and affecting the structural stability of the battery. If there is too much pre-ceramization precursor, the decomposition of the precursor will produce excessive volume shrinkage, causing stress concentration inside the ceramic network, generating cracks, and destroying the structural integrity of carbon fibers and active materials. Furthermore, if there is too little low-melting-point glass powder and nano-oxide powder, it will also lead to insufficient ceramic connection strength, failing to effectively support the electrode-electrolyte interface, making the solid-state battery prone to structural failure during cycling.

[0037] According to some preferred embodiments, the inorganic pre-ceramizationable particles comprise low-melting-point glass powder, nano-oxide powder, and a pre-ceramizationable precursor in a mass ratio of (2~3):(1~2):(4~6). The low-melting-point glass powder is borosilicate glass powder, the nano-oxide powder is composed of nano-silica, nano-magnesium oxide, and nano-alumina in a mass ratio of 1:(1~1.5):(2~2.5), and the pre-ceramizationable precursor is polysilazane. In this invention, it is more preferable that the inorganic pre-ceramizationable particles are designed using this formulation, which can achieve… Currently, a highly dense and strong three-dimensional ceramic network is formed under low-temperature heat treatment (400~800℃). Among them, borosilicate glass powder, as a flux, softens and melts first during the heat treatment process, forming a liquid phase environment, reducing the pyrolysis and ceramization temperature of polysilazane, and promoting its full transformation into the ceramic phase at low temperature. At the same time, the molten glass phase fills the interparticle gaps, accelerating the densification process. Nano-silica, nano-magnesium oxide, and nano-alumina react during the heat treatment process, for example, to partially generate magnesium aluminum spinel phase, and at the same time, they act as reinforcing fillers to effectively improve the mechanical strength of the ceramic skeleton.

[0038] The present invention provides, in a second aspect, a method for fabricating a solid-state battery according to the first aspect of the present invention, the method comprising the following steps: (1) Preparation of carbon fiber positive electrode and carbon fiber negative electrode; (2) The solid electrolyte is mixed uniformly with the organic-inorganic hybrid resin to obtain a pre-ceramizable solid electrolyte slurry; in this invention, for example, the solid electrolyte powder and the organic-inorganic hybrid resin can be mixed uniformly in a solvent at a certain ratio to prepare a uniform pre-ceramizable solid electrolyte slurry; or the organic-inorganic hybrid resin can also be added in the form of an organic-inorganic hybrid resin slurry with a solid content of 40~60wt%, and the organic-inorganic hybrid resin slurry can be, for example, N-methyl-2-pyridine N-methyl-2-pyrrolidone (NMP) solvent is used as a dispersant. For example, solid electrolyte powder is mixed with organic-inorganic hybrid resin slurry, and N-methyl-2-pyrrolidone is added to adjust the flowability to obtain a solid electrolyte / resin slurry with a solid content of 40-60 wt%. The slurry is stirred at 300-600 rpm for 20-40 min using a high-speed disperser to make the slurry uniform. Then, some NMP is evaporated and the mixture is adjusted into a paste to obtain a pre-ceramizable solid electrolyte slurry with a solid content controlled at 80-90 wt%. (3) The negative electrode current collector, carbon fiber negative electrode, pre-ceramicable solid electrolyte slurry, carbon fiber positive electrode and positive electrode current collector are stacked in sequence to obtain a laminate; in this invention, the layup thickness of the pre-ceramicable solid electrolyte slurry can be, for example, 50~150μm; (4) The laminate is placed in a mold and molded and cured under pressure of 1~10MPa and temperature of 80~150℃ to obtain a battery blank; In this step (4), under low pressure of 1~10MPa, the slurry can flow fully and wet the carbon fiber negative electrode, solid electrolyte and carbon fiber positive electrode, to achieve preliminary mechanical fixation and interface contact, and form a liquid organic-inorganic dual continuous network, while heating at 80~150℃ can make the organic resin crosslink and cure; In this invention, the molding and curing time can be, for example, 0.5~2h; (5) Under an inert protective atmosphere (e.g., argon atmosphere), the battery blank is heated to 400~800℃ (preferably 400~700℃, more preferably 400~650℃) for 0.5~4h to obtain a solid-state structure battery; in this invention, the heating rate can be, for example, 0.5~5℃ / min (e.g., 0.5, 1, 2, 3, 4 or 5℃ / min); in this step (5), the organic resin will be thermally decomposed, generating small molecule gas products that escape; the inorganic pre-ceramicized particles soften, melt and connect with each other, reacting and sintering with the surrounding carbon fibers, solid electrolyte particles and carbon fiber positive and negative electrodes to form a strong, porous, three-dimensional continuous inorganic ceramic network, i.e., a three-dimensional continuous porous ceramicized network. This three-dimensional continuous porous ceramicized network can be understood as a steel skeleton similar to "reinforced concrete", tightly riveting the solid electrolyte particles and carbon fiber positive and negative electrodes into one piece; in this invention, the temperature of the heat treatment is The temperature is 400~800℃, and the maximum heat treatment temperature is lower than the thermal damage temperature of carbon fiber and the structural phase transition temperature of the positive and negative electrode active materials, which can ensure that the mechanical properties of carbon fiber and the electrochemical properties of active materials are not damaged. In this invention, the molding and curing pressure is 1~10MPa and the temperature is 80~150℃. Under this low-pressure condition, when the positive and negative current collectors are metal meshes, the pre-ceramicized solid electrolyte slurry and the pre-ceramicized positive and negative electrode active material slurry have suitable fluidity, which can fully wet the interface between the carbon fiber positive and negative electrodes and the solid electrolyte layer, and partially penetrate into the mesh of the metal mesh current collector, thereby forming the three-dimensional continuous porous ceramicized network in the positive and negative current collectors. In this invention, the mesh size of the metal mesh current collector can be, for example, 50~500μm, the low-pressure molding pressure is 1~10MPa, the time is 0.5~2h, and the penetration depth of the slurry will not exceed 50~80% of the thickness of the current collector.

[0039] This invention presents a revolutionary method for preparing solid-state batteries based on a novel strategy of "low-pressure molding-ceramic bonding". This method can achieve integrated molding and integration of carbon fiber positive and negative electrodes and solid electrolytes at a pressure far lower than that of traditional methods, i.e., at low pressure (≤10MPa), which significantly enhances the bonding strength and ion transport efficiency of the solid-solid interface inside the solid-state battery. Specifically, this invention creatively proposes to first use a low-modulus organic-inorganic hybrid resin to achieve preliminary composite and shaping of the components under low pressure, and then transform the organic-inorganic hybrid resin into a high-modulus ceramic framework through heat treatment. This completely avoids the ultra-high pressure of hundreds of megapascals required by traditional solid-state batteries, reducing the molding pressure by 1-2 orders of magnitude and solving the core equipment bottleneck in solid-state battery fabrication. This invention uses a multi-continuous phase organic-inorganic hybrid resin, which can act as a binder at room temperature, enabling the battery blank to achieve good composite under low pressure. In the subsequent heat treatment, its inorganic pre-ceramicized particles form a three-dimensional continuous porous ceramicized network that runs through the battery body. This three-dimensional continuous porous ceramicized network mechanically acts like "rivets" to strongly connect the functional layers, while the pores left by the removed organic resin provide additional three-dimensional high-speed channels for ion transport, thus solving the core problems of high-pressure molding difficulty, high interfacial impedance, and weak interlayer structure in solid-state batteries. The method of this invention is simple, energy-efficient, and compatible with large-scale production, and can effectively protect the thermosensitive electrode material.

[0040] According to some preferred embodiments, in step (1), the preparation of the carbon fiber positive electrode includes: dispersing the positive electrode active material, conductive additive and binder evenly with a dispersant to obtain a positive electrode active material slurry, then adding an organic-inorganic hybrid resin to the positive electrode active material slurry and dispersing it evenly to obtain a pre-ceramizable positive electrode active material slurry, and then coating the pre-ceramizable positive electrode active material slurry onto a carbon fiber substrate to obtain a carbon fiber positive electrode.

[0041] According to some preferred embodiments, in step (1), the preparation of the carbon fiber negative electrode includes: dispersing the negative electrode active material, conductive additive, and binder uniformly with a dispersant to obtain a negative electrode active material slurry; then adding an organic-inorganic hybrid resin to the negative electrode active material slurry and dispersing it uniformly to obtain a pre-ceramizable negative electrode active material slurry; then coating the pre-ceramizable negative electrode active material slurry onto a carbon fiber substrate to obtain a carbon fiber negative electrode; in this invention, when preparing the pre-ceramizable positive electrode active material slurry and / or the pre-ceramizable negative electrode active material slurry, it is preferred that the organic-inorganic hybrid resin is added in the form of an organic-inorganic hybrid resin slurry with a solid content of 40~60wt%; in this invention, the loading of the positive electrode active material and / or the negative electrode active material can be, for example, 8~12mg / cm³. 2This invention does not impose specific limitations on the types and amounts of dispersants, positive electrode active materials, negative electrode active materials, conductive additives, binders, etc., involved, and those skilled in the art can make conventional selections; the conductive additives can be, for example, conductive carbon black and / or carbon nanotube dispersions. This invention does not impose specific limitations on the source of carbon nanotube dispersions, and commercially available products or products synthesized by existing methods can be used.

[0042] In this invention, in addition to adding the organic-inorganic hybrid resin to the pre-ceramicable solid electrolyte slurry in step (2), it is also preferred to add the organic-inorganic hybrid resin to the positive and negative electrode active material slurry. The inventors have found that, compared with adding the organic-inorganic hybrid resin only to the solid electrolyte layer, this preferred solution is more conducive to achieving uniform penetration of the three-dimensional continuous porous ceramic network throughout the electrode-electrolyte interface and deep integration with the positive and negative electrode active materials, thereby better constructing continuous ion conduction channels, inhibiting the shedding of active material particles, and obtaining better mechanical and electrochemical properties.

[0043] In this invention, when the organic-inorganic hybrid resin is added to the positive and negative electrode active material slurry, the total amount (mass amount) of the organic-inorganic hybrid resin is controlled to be 5-20% of the mass of the solid electrolyte.

[0044] This invention introduces an organic-inorganic hybrid resin into a solid electrolyte (preferably also used in the positive and negative electrode active materials), which has significant advantages over using organic resin alone or inorganic pre-ceramized particles. This invention reveals that if only organic resin is introduced, it will generate a large number of pores during pyrolysis, destroying the intrinsic activity of the material, and lacking the support of the inorganic ceramic phase, it is difficult to form a continuous ion transport network. On the other hand, using only inorganic pre-ceramized particles, due to the lack of the binding and / or dispersing effect of organic resin, results in poor contact between the inorganic particles and the positive and negative electrode materials, causing serious interfacial impedance problems, making it difficult to form a three-dimensional continuous porous ceramicized network. However, the organic-inorganic hybrid resin used in this invention, through low-temperature in-situ ceramicization, avoids the influence of organic resin components on the positive and negative electrode materials. The resulting three-dimensional continuous porous ceramicized network provides excellent ion conduction channels. Simultaneously, this three-dimensional continuous porous ceramicized network forms a tight mechanical interlocking structure with the active material and solid electrolyte, not only not affecting the chemical performance of the solid-state battery, but also simultaneously improving the interfacial ion transport efficiency and structural stability, thus enhancing the mechanical and electrochemical performance of the solid-state battery.

[0045] According to some preferred embodiments, in step (2): the mass ratio of the solid electrolyte to the organic-inorganic hybrid resin is (4~19):1 (e.g., 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1 or 19:1), that is, the mass ratio is 80:20 to 95:5 (e.g., 80:20, 85:15, 90:10 or 95:5). Preferably, the mass ratio of the solid electrolyte to the organic-inorganic hybrid resin is (4~6):1; and / or the solid content of the pre-ceramizable solid electrolyte slurry is 80~90wt%.

[0046] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments. The present invention may have many other embodiments, and those skilled in the art can make various corresponding changes and modifications based on the present invention without departing from its spirit and essence. However, all such corresponding changes and modifications should fall within the scope of protection of the appended claims. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials, reagents, etc., used in the following embodiments can be obtained commercially or by existing methods.

[0047] Example 1 (1) Preparation of carbon fiber cathode: Lithium iron phosphate (LiFePO4) powder (D50 = 1-3 μm, electrochemical specific capacity 120-160 mAh / g), conductive carbon black (SUPER) C65), polyvinylidene fluoride (PVDF), and a 0.2 wt% aqueous dispersion of single-walled carbon nanotubes were dispersed in N-methyl-2-pyrrolidone (NMP) and stirred thoroughly for 6 hours to obtain a positive electrode active material slurry with a solid content of 50 wt%. The mass ratio of lithium iron phosphate (LiFePO4) powder to conductive carbon black was 90:2.8, and the mass ratio of LiFePO4 powder to the single-walled carbon nanotubes contained in the aqueous dispersion was 100:0.5. The positive electrode active material slurry contained 2 wt% PVDF, and the sum of the mass percentages of LiFePO4 powder, conductive carbon black, PVDF, and single-walled carbon nanotubes (i.e., the solid content) was 50 wt%. Then, the positive electrode active material slurry was uniformly coated with a 200 μm thick carbon fiber cloth (T300-1K woven fabric, surface density 100 g / m²) using a coating machine. 2 One surface of the electrode is coated with a 60 μm thick layer of LiFePO4 positive electrode active material with a loading of 10 mg / cm³. 2 Then, it is dried in a 60℃ oven for later use to obtain carbon fiber cathode.

[0048] (2) Preparation of carbon fiber anode: Artificial graphite (SRWY-1B, particle size D50=10μm), conductive carbon black (SUPERC65) and polyvinylidene fluoride (PVDF) were dispersed in N-methyl-2-pyrrolidone (NMP) and stirred thoroughly for 6 hours to obtain a negative electrode active material slurry with a solid content of 50wt%, wherein the mass ratio of artificial graphite, conductive carbon black and PVDF was 95:2:3; then, the negative electrode active material slurry was uniformly coated with a carbon fiber cloth (T300-1K woven cloth, surface density 100g / m²) with a thickness of 200μm using a coating machine. 2 One surface of the coating is coated with a thickness of 60 μm and an artificial graphite loading of 10 mg / cm³. 2 Then, the carbon fiber anode is dried in a 60℃ oven for later use.

[0049] (3) Preparation of organic-inorganic hybrid resin slurry: o-cresol epoxy resin (Nanya NPCN-704), nano silica, borosilicate glass powder (D245), organopolysilazane (IOTA 9108), methyl hexahydrophthalic anhydride and BDMA accelerator (N,N-dimethylbenzylamine) were uniformly dispersed in N-methyl-2-pyrrolidone (NMP) to obtain an organic-inorganic hybrid resin slurry with a solid content of 50wt%; wherein, the mass ratio of o-cresol epoxy resin, nano silica, borosilicate glass powder, organopolysilazane, methyl hexahydrophthalic anhydride and BDMA accelerator was 10:2.5:1.5:5:8:0.8.

[0050] (4) Preparation of pre-ceramizable solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder is mixed with the organic-inorganic hybrid resin slurry obtained in step (3), and N-methyl-2-pyrrolidone (NMP) is added to adjust the fluidity to obtain a solid electrolyte / resin slurry with a solid content of 50 wt%. The slurry is stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some N-methyl-2-pyrrolidone is volatilized and the mixture is adjusted into a paste to obtain a pre-ceramizable solid electrolyte slurry with a solid content of 85 wt%. The mass ratio of the LLZO powder to the organic-inorganic hybrid resin contained in the organic-inorganic hybrid resin slurry is 80:20.

[0051] (5) Lamination and low-pressure molding: Cut carbon fiber positive and negative electrodes to size (using 40mm×40mm specification), and sequentially laminate stainless steel mesh (negative electrode current collector, thickness of 10μm, mesh size of 100μm), carbon fiber negative electrode, pre-ceramicizable solid electrolyte slurry (thickness of 80μm), carbon fiber positive electrode, and stainless steel mesh (positive electrode current collector, thickness of 10μm, mesh size of 100μm) to obtain a laminate; then, place the laminate in a mold and mold it for 1 hour under a pressure of 5MPa and a temperature of 120℃ to obtain a battery blank; the stainless steel mesh as the negative electrode current collector is bonded to one surface of the carbon fiber negative electrode without negative electrode active material slurry, and the stainless steel mesh as the positive electrode current collector is bonded to one surface of the carbon fiber positive electrode without positive electrode active material slurry.

[0052] (6) Under an inert protective atmosphere (argon atmosphere), the battery blank is heated to 600℃ for 2h at a heating rate of 2℃ / min to complete the ceramicization reaction, and then naturally cooled to room temperature to obtain a solid structure battery.

[0053] Example 2 Example 2 is basically the same as Example 1, except that: (4) Preparation of pre-ceramizable solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder is mixed with the organic-inorganic hybrid resin slurry obtained in step (3), and N-methyl-2-pyrrolidone (NMP) is added to adjust the fluidity to obtain a solid electrolyte / resin slurry with a solid content of 50 wt%. The slurry is stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some N-methyl-2-pyrrolidone is volatilized and the mixture is adjusted into a paste to obtain a pre-ceramizable solid electrolyte slurry with a solid content of 85 wt%. The mass ratio of the LLZO powder to the organic-inorganic hybrid resin contained in the organic-inorganic hybrid resin slurry is 95:5.

[0054] Example 3 Example 3 is basically the same as Example 1, except that: (4) Preparation of pre-ceramizable solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder is mixed with the organic-inorganic hybrid resin slurry obtained in step (3), and N-methyl-2-pyrrolidone (NMP) is added to adjust the fluidity to obtain a solid electrolyte / resin slurry with a solid content of 50 wt%. The slurry is stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some N-methyl-2-pyrrolidone is volatilized and the mixture is adjusted into a paste to obtain a pre-ceramizable solid electrolyte slurry with a solid content of 85 wt%. The mass ratio of the LLZO powder to the organic-inorganic hybrid resin contained in the organic-inorganic hybrid resin slurry is 85:15.

[0055] Example 4 Example 4 is basically the same as Example 1, except that: (4) Preparation of pre-ceramizable solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder is mixed with the organic-inorganic hybrid resin slurry obtained in step (3), and N-methyl-2-pyrrolidone (NMP) is added to adjust the fluidity to obtain a solid electrolyte / resin slurry with a solid content of 50 wt%. The slurry is stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some N-methyl-2-pyrrolidone is volatilized and the mixture is adjusted into a paste to obtain a pre-ceramizable solid electrolyte slurry with a solid content of 85 wt%. The mass ratio of the LLZO powder to the organic-inorganic hybrid resin contained in the organic-inorganic hybrid resin slurry is 98:2.

[0056] Example 5 Example 5 is basically the same as Example 1, except that: (4) Preparation of pre-ceramizable solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder is mixed with the organic-inorganic hybrid resin slurry obtained in step (3), and N-methyl-2-pyrrolidone (NMP) is added to adjust the fluidity to obtain a solid electrolyte / resin slurry with a solid content of 50 wt%. The slurry is stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some N-methyl-2-pyrrolidone is volatilized and the mixture is adjusted into a paste to obtain a pre-ceramizable solid electrolyte slurry with a solid content of 85 wt%. The mass ratio of the LLZO powder to the organic-inorganic hybrid resin contained in the organic-inorganic hybrid resin slurry is 70:30.

[0057] Example 6 (1) Preparation of organic-inorganic hybrid resin slurry: o-cresol epoxy resin (Nanya NPCN-704), nano silica, borosilicate glass powder (D245), organopolysilazane (IOTA 9108), methyl hexahydrophthalic anhydride and BDMA accelerator (N,N-dimethylbenzylamine) were uniformly dispersed in N-methyl-2-pyrrolidone (NMP) to obtain an organic-inorganic hybrid resin slurry with a solid content of 50wt%; wherein, the mass ratio of o-cresol epoxy resin, nano silica, borosilicate glass powder, organopolysilazane, methyl hexahydrophthalic anhydride and BDMA accelerator was 10:2.5:1.5:5:8:0.8.

[0058] (2) Preparation of carbon fiber cathode: Lithium iron phosphate (LiFePO4) powder (D50=1-3μm, electrochemical specific capacity 120-160mAh / g), conductive carbon black (SUPER C65), polyvinylidene fluoride (PVDF), and a 0.2wt% aqueous dispersion of single-walled carbon nanotubes were dispersed in N-methyl-2-pyrrolidone (NMP) and stirred thoroughly for 6 hours to obtain a cathode active material slurry with a solid content of 50wt%. The mass ratio of lithium iron phosphate (LiFePO4) powder to conductive carbon black was 90:2.8, the mass ratio of lithium iron phosphate (LiFePO4) powder to the single-walled carbon nanotubes contained in the aqueous dispersion was 100:0.5, and the PVDF content in the cathode active material slurry was 2wt%. The positive electrode active material slurry contains a total mass percentage (i.e., solid content) of 50 wt% for LiFePO4 powder, conductive carbon black, PVDF, and single-walled carbon nanotubes. Then, an organic-inorganic hybrid resin slurry is added to the positive electrode active material slurry and dispersed evenly to obtain a pre-ceramizable positive electrode active material slurry. The amount of lithium iron phosphate LiFePO4 powder used is the same as in Example 1. Then, the pre-ceramizable positive electrode active material slurry is uniformly coated with a 200 μm thick carbon fiber cloth (T300-1K woven cloth, surface density 100 g / m²) using a coating machine. 2 One surface of the electrode is coated with a 60 μm thick layer of LiFePO4 positive electrode active material with a loading of 10 mg / cm³. 2 Then, it is dried in a 60℃ oven for later use to obtain carbon fiber cathode.

[0059] (3) Preparation of carbon fiber anode: Artificial graphite (SRWY-1B, particle size D50=10μm), conductive carbon black (SUPERC65) and polyvinylidene fluoride (PVDF) were dispersed in N-methyl-2-pyrrolidone (NMP) and stirred thoroughly for 6 hours to obtain a negative electrode active material slurry with a solid content of 50wt%, wherein the mass ratio of artificial graphite, conductive carbon black and PVDF was 95:2:3; then, an organic-inorganic mixed resin slurry was added to the negative electrode active material slurry and dispersed evenly to obtain a pre-ceramizationable negative electrode active material slurry, wherein the amount of artificial graphite was the same as in Example 1; the pre-ceramizationable negative electrode active material slurry was uniformly coated with a carbon fiber cloth (T300-1K woven cloth, surface density 100g / m²) with a thickness of 200μm using a coating machine. 2 One surface of the coating is coated with a thickness of 60 μm and an artificial graphite loading of 10 mg / cm³. 2 Then, the carbon fiber anode is dried in a 60℃ oven for later use.

[0060] (4) Preparation of pre-ceramizable solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder was mixed with the organic-inorganic hybrid resin slurry obtained in step (3), and N-methyl-2-pyrrolidone (NMP) was added to adjust the flowability to obtain a solid electrolyte / resin slurry with a solid content of 50 wt%. The slurry was stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some of the N-methyl-2-pyrrolidone was volatilized and the mixture was adjusted into a paste to obtain a pre-ceramizable solid electrolyte with a solid content of 85 wt%. The mass ratio of the LLZO powder to the organic-inorganic mixed resin in the organic-inorganic mixed resin slurry added in step (4) is 80:10. The amount of lithium lanthanum zirconium oxide LLZO powder used in this embodiment is the same as in Example 1. The total amount of organic-inorganic mixed resin slurry used in this embodiment is the same as in Example 1, and it is divided into three parts with a mass ratio of 2:1:1. The part with the larger proportion is used in step (4), and the other two parts are used to prepare carbon fiber positive electrode and carbon fiber negative electrode, respectively.

[0061] (5) Lamination and low-pressure molding: Cut carbon fiber positive and negative electrodes to size (using 40mm×40mm specification), and sequentially laminate stainless steel mesh (negative electrode current collector, thickness of 10μm, mesh size of 100μm), carbon fiber negative electrode, pre-ceramicable solid electrolyte slurry (thickness of 80μm), carbon fiber positive electrode, and stainless steel mesh (positive electrode current collector, thickness of 10μm, mesh size of 100μm) to obtain a laminate; then, place the laminate in a mold and mold it for 1 hour under a pressure of 5MPa and a temperature of 120℃ to obtain a battery blank; the stainless steel mesh as the negative electrode current collector is bonded to one surface of the carbon fiber negative electrode without the pre-ceramicable negative electrode active material slurry, and the stainless steel mesh as the positive electrode current collector is bonded to one surface of the carbon fiber positive electrode without the pre-ceramicable positive electrode active material slurry.

[0062] (6) Under an inert protective atmosphere (argon atmosphere), the battery blank is heated to 600℃ for 2h at a heating rate of 2℃ / min to complete the ceramicization reaction, and then naturally cooled to room temperature to obtain a solid structure battery.

[0063] Example 7 Example 7 is basically the same as Example 3, except that: (3) Preparation of organic-inorganic hybrid resin slurry: o-cresol epoxy resin (Nanya NPCN-704), nano oxide powder, borosilicate glass powder (D245), organopolysilazane (IOTA 9108), methyl hexahydrophthalic anhydride and BDMA accelerator (N,N-dimethylbenzylamine) were uniformly dispersed in N-methyl-2-pyrrolidone (NMP) to obtain an organic-inorganic hybrid resin slurry with a solid content of 50wt%; wherein, the mass ratio of o-cresol epoxy resin, nano oxide powder, borosilicate glass powder, organopolysilazane, methyl hexahydrophthalic anhydride and BDMA accelerator was 10:2.5:1.5:5:8:0.8, and the nano oxide powder was composed of nano silica, nano magnesium oxide and nano aluminum oxide in a mass ratio of 1:1:2.5.

[0064] Example 8 Example 8 is basically the same as Example 1, except that: (3) Preparation of organic-inorganic hybrid resin slurry: o-cresol epoxy resin (Nanya NPCN-704), nano silica, borosilicate glass powder (D245), organopolysilazane (IOTA 9108), methyl hexahydrophthalic anhydride and BDMA accelerator (N,N-dimethylbenzylamine) were uniformly dispersed in N-methyl-2-pyrrolidone (NMP) to obtain an organic-inorganic hybrid resin slurry with a solid content of 50wt%; wherein, the mass ratio of o-cresol epoxy resin, nano silica, borosilicate glass powder, organopolysilazane, methyl hexahydrophthalic anhydride and BDMA accelerator was 6:2.5:1.5:5:4.8:0.48.

[0065] Example 9 Example 9 is basically the same as Example 1, except that: (3) Preparation of organic-inorganic hybrid resin slurry: o-cresol epoxy resin (Nanya NPCN-704), nano silica, borosilicate glass powder (D245), organopolysilazane (IOTA 9108), methyl hexahydrophthalic anhydride and BDMA accelerator (N,N-dimethylbenzylamine) were uniformly dispersed in N-methyl-2-pyrrolidone (NMP) to obtain an organic-inorganic hybrid resin slurry with a solid content of 50wt%; wherein, the mass ratio of o-cresol epoxy resin, nano silica, borosilicate glass powder, organopolysilazane, methyl hexahydrophthalic anhydride and BDMA accelerator was 15:2.5:1.5:5:12:1.2.

[0066] Comparative Example 1 (1) Same as step (1) in Example 1.

[0067] (2) is the same as step (2) in Example 1.

[0068] (3) Preparation of solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder was added to N-methyl-2-pyrrolidone (NMP) for flowability adjustment to obtain a solid electrolyte slurry with a solid content of 50 wt%. The slurry was stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some of the N-methyl-2-pyrrolidone was volatilized and the mixture was adjusted into a paste to obtain a solid electrolyte slurry with a solid content of 85 wt%.

[0069] (4) Lamination and high-pressure molding: Cut carbon fiber positive and negative electrodes to size (using 40mm×40mm specification), and sequentially laminate stainless steel mesh (negative electrode current collector, thickness of 10μm, mesh aperture of 100μm), carbon fiber negative electrode, solid electrolyte slurry (thickness of 80μm), carbon fiber positive electrode, and stainless steel mesh (positive electrode current collector, thickness of 10μm, mesh aperture of 100μm) to obtain a laminate; then, place the laminate in a mold and mold it for 1 hour under a pressure of 300MPa and a temperature of 120℃ to obtain a battery blank; the stainless steel mesh as negative electrode current collector is bonded to one surface of the carbon fiber negative electrode without negative electrode active material slurry, and the stainless steel mesh as positive electrode current collector is bonded to one surface of the carbon fiber positive electrode without positive electrode active material slurry.

[0070] (5) Under an inert protective atmosphere (argon atmosphere), the battery blank is heated to 600℃ for 2h at a heating rate of 2℃ / min, and then naturally cooled to room temperature to obtain a solid structure battery.

[0071] Comparative Example 2 (1) Same as step (1) in Example 1.

[0072] (2) is the same as step (2) in Example 1.

[0073] (3) Preparation of organic resin slurry: o-cresol epoxy resin (Nanya NPCN-704), methyl hexahydrophthalic anhydride and BDMA accelerator (N,N-dimethylbenzylamine) were uniformly dispersed in N-methyl-2-pyrrolidone (NMP) to obtain an organic resin slurry with a solid content of 50wt%; wherein, the mass ratio of o-cresol epoxy resin, methyl hexahydrophthalic anhydride and BDMA accelerator was 10:8:0.8.

[0074] (4) Preparation of solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder is mixed with the organic resin slurry obtained in step (3), and N-methyl-2-pyrrolidone (NMP) is added to adjust the fluidity to obtain a solid electrolyte / resin slurry with a solid content of 50 wt%. The slurry is stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some of the N-methyl-2-pyrrolidone is volatilized and the mixture is adjusted into a paste to obtain a solid electrolyte slurry with a solid content of 85 wt%. The mass ratio of the LLZO powder to the organic resin contained in the organic resin slurry is 85:15.

[0075] (5) Lamination and low-pressure molding: Cut carbon fiber positive and negative electrodes to size (using 40mm×40mm specification), and sequentially laminate stainless steel mesh (negative electrode current collector, thickness of 10μm, mesh size of 100μm), carbon fiber negative electrode, solid electrolyte slurry (thickness of 80μm), carbon fiber positive electrode, and stainless steel mesh (positive electrode current collector, thickness of 10μm, mesh size of 100μm) to obtain a laminate; then, place the laminate in a mold and mold it for 1 hour under a pressure of 5MPa and a temperature of 120℃ to obtain a battery blank; the stainless steel mesh as the negative electrode current collector is bonded to one surface of the carbon fiber negative electrode without negative electrode active material slurry, and the stainless steel mesh as the positive electrode current collector is bonded to one surface of the carbon fiber positive electrode without positive electrode active material slurry.

[0076] (5) Under an inert protective atmosphere (argon atmosphere), the battery blank is heated to 600℃ for 2h at a heating rate of 2℃ / min, and then naturally cooled to room temperature to obtain a solid structure battery.

[0077] Comparative Example 3 (1) Same as step (1) in Example 1.

[0078] (2) Same as step (1) in Example 1.

[0079] (3) Preparation of inorganic pre-ceramization particle slurry: Nano silica, borosilicate glass powder (D245) and organopolysilazane (IOTA 9108) are uniformly dispersed in N-methyl-2-pyrrolidone (NMP) to obtain an inorganic pre-ceramization particle slurry with a solid content of 50wt%; wherein, the mass ratio of nano silica, borosilicate glass powder and organopolysilazane is 2.5:1.5:5.

[0080] (4) Preparation of solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder is mixed with the inorganic pre-ceramization particle slurry obtained in step (3), and N-methyl-2-pyrrolidone (NMP) is added to adjust the fluidity to obtain a solid electrolyte slurry with a solid content of 50 wt%. The slurry is stirred at 400 rpm for 30 min using a high-speed disperser to make the slurry uniform. Then, some N-methyl-2-pyrrolidone is volatilized and the mixture is adjusted into a paste to obtain a solid electrolyte slurry with a solid content of 85 wt%. The mass ratio of the LLZO powder to the inorganic pre-ceramization particles contained in the inorganic pre-ceramization particle slurry is 85:15.

[0081] (5) Lamination and low-pressure molding: Cut carbon fiber positive and negative electrodes to size (using 40mm×40mm specification), and sequentially laminate stainless steel mesh (negative electrode current collector, thickness of 10μm, mesh size of 100μm), carbon fiber negative electrode, solid electrolyte slurry (thickness of 80μm), carbon fiber positive electrode, and stainless steel mesh (positive electrode current collector, thickness of 10μm, mesh size of 100μm) to obtain a laminate; then, place the laminate in a mold and mold it for 1 hour under a pressure of 5MPa and a temperature of 120℃ to obtain a battery blank; the stainless steel mesh as the negative electrode current collector is bonded to one surface of the carbon fiber negative electrode without negative electrode active material slurry, and the stainless steel mesh as the positive electrode current collector is bonded to one surface of the carbon fiber positive electrode without positive electrode active material slurry.

[0082] (6) Under an inert protective atmosphere (argon atmosphere), the battery blank is heated to 600°C for 2 hours at a heating rate of 2°C / min, and then naturally cooled to room temperature to obtain a solid structure battery.

[0083] Comparative Example 4 (1) Same as step (1) in Example 1.

[0084] (2) is the same as step (2) in Example 1.

[0085] (3) is the same as step (3) in Example 1.

[0086] (4) A layer of organic-inorganic hybrid resin slurry with a thickness of 20 μm is uniformly coated on one side of the carbon fiber positive electrode loaded with positive electrode active material using a coating machine to obtain a carbon fiber positive electrode coated with organic-inorganic hybrid resin slurry; a layer of organic-inorganic hybrid resin slurry with a thickness of 20 μm is uniformly coated on one side of the carbon fiber negative electrode loaded with negative electrode active material using a coating machine to obtain a carbon fiber negative electrode coated with organic-inorganic hybrid resin slurry.

[0087] (5) Preparation of solid electrolyte slurry: Lithium lanthanum zirconium oxide (LLZO) powder was added to N-methyl-2-pyrrolidone (NMP) for flowability adjustment to obtain a solid electrolyte slurry with a solid content of 50 wt%. The slurry was stirred at 400 rpm for 30 min using a high-speed disperser to make it uniform. Then, some of the N-methyl-2-pyrrolidone was volatilized and the mixture was adjusted into a paste to obtain a solid electrolyte slurry with a solid content of 85 wt%.

[0088] (6) Lamination and low-pressure molding: Cut carbon fiber positive and negative electrodes to size (using 40mm×40mm specification), and sequentially laminate stainless steel mesh (negative electrode current collector, thickness of 10μm, mesh size of 100μm), carbon fiber negative electrode coated with organic-inorganic hybrid resin slurry, solid electrolyte slurry (thickness of 80μm), carbon fiber positive electrode coated with organic-inorganic hybrid resin slurry, and stainless steel mesh (positive electrode current collector, thickness of 10μm, mesh size of 100μm) to obtain a laminate; then, place the laminate in a mold and mold it for 1 hour under a pressure of 5MPa and a temperature of 120℃ to obtain a battery blank; the stainless steel mesh as negative electrode current collector is bonded to the surface of the carbon fiber negative electrode that is not coated with organic-inorganic hybrid resin slurry, and the stainless steel mesh as positive electrode current collector is bonded to the surface of the carbon fiber positive electrode that is not coated with organic-inorganic hybrid resin slurry.

[0089] (7) Under an inert protective atmosphere (argon atmosphere), the battery blank is heated to 600°C for 2 hours at a heating rate of 2°C / min, and then naturally cooled to room temperature to obtain a solid structure battery.

[0090] The performance of solid-state structure batteries prepared in each embodiment and comparative example was tested, and the test results are shown in Table 1 below.

[0091] Table 1 This invention quantitatively measures interfacial impedance using electrochemical impedance spectroscopy (EIS). As shown in Table 1, the solid-state battery structure in the preferred embodiments of this invention (such as Examples 1, 3, 6, and 7) significantly improves the interfacial contact between the electrode and the electrolyte due to the formation of a three-dimensional continuous porous ceramic network, achieving structural integration, and the interfacial impedance value is as low as 29~48 Ω·cm. 2The interlaminar shear strength is significantly lower than that of the comparative examples. In this invention, the interlaminar shear strength is obtained by testing the entire solid-state battery sample using a universal testing machine, reflecting the bonding strength at the weakest point of the interfacial bonding between layers. The preferred embodiment of this invention achieves an interlaminar shear strength of 25-35 MPa and a compressive strength of 152-220 MPa, with the overall structural strength significantly higher than that of the comparative examples, indicating that the three-dimensional continuous porous ceramic network of this invention effectively enhances the interlaminar bonding force and structural stiffness. The three-dimensional continuous porous ceramic network constructed by this invention using organic-inorganic hybrid resin significantly improves the lithium-ion conductivity, with some preferred embodiments (such as Examples 1, 3, 6, and 7) achieving a lithium-ion conductivity as high as 3.5 × 10⁻⁶. -4 ~5.2×10 -4 The S / cm ratio is significantly higher than that of the comparative examples. Charge-discharge test results show that the solid-state battery of the preferred embodiment retains a capacity of 90%–95% after 200 cycles at 0.1C, while the capacity retention of the comparative examples is less than 80% after 200 cycles under the same conditions. This fully demonstrates that the three-dimensional continuous porous ceramic network constructed in this invention ensures efficient and stable lithium-ion transport between the carbon fiber positive and negative electrodes and the solid electrolyte, thereby achieving long cycle life and high capacity retention. These data in Table 1 collectively prove that this invention, using an organic-inorganic hybrid resin system, successfully prepared a solid-state battery with low interfacial impedance, high mechanical strength, and excellent electrochemical cycle stability through low-pressure molding and in-situ ceramicization.

[0092] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solid-state battery, comprising a negative electrode current collector, a carbon fiber negative electrode, a solid electrolyte layer, a carbon fiber positive electrode, and a positive electrode current collector stacked sequentially, characterized in that: The solid-state battery also includes a three-dimensional continuous porous ceramic network that penetrates and connects at least the carbon fiber negative electrode, the solid electrolyte layer, and the carbon fiber positive electrode; The three-dimensional continuous porous ceramicized network is formed by heat treatment of an organic-inorganic hybrid resin. The organic-inorganic hybrid resin comprises an organic resin that decomposes at 200-500°C and inorganic pre-ceramizable particles that form ceramic bonds at 400-800°C. The inorganic pre-ceramizationable particles include low-melting-point glass powder, nano-oxide powder, and pre-ceramizationable precursors. The pre-ceramizable precursor is one or more of the following: polycarbosilane, polysiloxane, polysilazane, silicone resin, polysilsesquioxane, borosilicate sol, nano-silica sol, aluminum oxide precursor, and zirconium dioxide precursor.

2. The solid-state battery according to claim 1, characterized in that: The organic resin is epoxy resin and / or phenolic resin.

3. The solid-state battery according to claim 1, characterized in that: The low-melting-point glass powder is borosilicate glass powder and / or phosphate glass powder; and / or The nano-oxide powder is one or more of nano-silicon dioxide, nano-magnesium oxide, nano-aluminum oxide, nano-copper oxide, and nano-boron oxide.

4. The solid-state battery according to claim 1, characterized in that: The carbon fiber cathode includes a carbon fiber substrate and a cathode active material loaded on the carbon fiber substrate; The carbon fiber negative electrode comprises a carbon fiber substrate and a negative electrode active material loaded on the carbon fiber substrate; and / or The solid electrolyte layer contains an oxide-based solid electrolyte and / or a sulfide-based solid electrolyte.

5. The solid-state battery according to claim 4, characterized in that: The oxide-based solid electrolyte is lithium lanthanum zirconium oxide (LLZO) and / or lithium lanthanum titanium oxide (LLTO). The sulfide-based solid electrolyte is lithium phosphorus sulfide compound LPS and / or lithium germanium phosphorus sulfide compound LGPS. The carbon fiber substrate is carbon fiber cloth; The positive electrode active material is one or more of lithium iron phosphate, lithium cobalt oxide, and lithium nickel manganese cobalt oxide; and / or The negative electrode active material is one or more of graphite, silicon-carbon composite, and metallic lithium.

6. The solid-state battery according to claim 1, characterized in that: Before heat treatment, the amount of the organic-inorganic hybrid resin accounts for 5 to 20% of the mass of the solid electrolyte contained in the solid electrolyte layer.

7. The solid-state battery according to claim 1, characterized in that: The amount of the organic resin used accounts for 50-60% of the sum of the mass of the organic resin and the inorganic pre-ceramicized particles.

8. The solid-state battery according to claim 1, characterized in that: The inorganic pre-ceramizationable particles comprise low-melting-point glass powder, nano-oxide powder, and pre-ceramizationable precursor in a mass ratio of (2~3):(1~2):(4~6).

9. The method for preparing a solid-state battery according to any one of claims 1 to 8, characterized in that, The preparation method includes the following steps: (1) Preparation of carbon fiber positive electrode and carbon fiber negative electrode; (2) Mix the solid electrolyte with the organic-inorganic hybrid resin to obtain a pre-ceramizable solid electrolyte slurry; (3) The negative electrode current collector, carbon fiber negative electrode, pre-ceramizable solid electrolyte slurry, carbon fiber positive electrode and positive electrode current collector are stacked in sequence to obtain a laminate; (4) The laminate is placed in a mold and molded under a pressure of 1~10MPa and a temperature of 80~150℃ to obtain a battery blank; (5) Under an inert protective atmosphere, heat the battery blank to 400~800℃ for 0.5~4h to obtain a solid structure battery.

10. The preparation method according to claim 9, characterized in that: In step (1), the preparation of the carbon fiber positive electrode includes: dispersing the positive electrode active material, conductive additive and binder evenly with a dispersant to obtain a positive electrode active material slurry, then adding an organic-inorganic hybrid resin to the positive electrode active material slurry and dispersing it evenly to obtain a pre-ceramizable positive electrode active material slurry, and then coating the pre-ceramizable positive electrode active material slurry onto a carbon fiber substrate to obtain a carbon fiber positive electrode.

11. The preparation method according to claim 9, characterized in that: In step (1), the preparation of the carbon fiber negative electrode includes: dispersing the negative electrode active material, conductive additive and binder evenly with a dispersant to obtain a negative electrode active material slurry, then adding an organic-inorganic hybrid resin to the negative electrode active material slurry and dispersing it evenly to obtain a pre-ceramizable negative electrode active material slurry, and then coating the pre-ceramizable negative electrode active material slurry onto a carbon fiber substrate to obtain a carbon fiber negative electrode.

12. The preparation method according to claim 9, characterized in that, In step (2): The mass ratio of the solid electrolyte to the organic-inorganic hybrid resin is (4~19):1; and / or The solid content of the pre-ceramizable solid electrolyte slurry is 80~90wt%.

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