A basic solid-state electrolyte, an all-solid-state battery, its preparation method and application

Abstract

This invention discloses a basic solid-state electrolyte, an all-solid-state battery, its preparation method, and its applications, belonging to the field of lithium battery technology. The battery includes a positive electrode layer, an electrolyte layer, a negative electrode layer, and a T-shaped quaternary powder insulating and leveling sealing layer. The electrolyte uses a golden ratio of 65wt% quaternary inorganic powder (80-200 mesh), 7wt% PVDF, 18wt% LiTFSI, and 10wt% composite conductive agent, compatible with all types of positive electrodes (NCM / LFP / LiFePC) and all types of negative electrodes (graphite / silicon-carbon / hard carbon), serving as a universal basic solid-state electrolyte for solid-state batteries. The same quaternary powder is added to both the positive and negative electrodes, achieving electrode universality and interchangeability. The silicon-carbon negative electrode increases the quaternary powder content to 5-7%, constructing an elastic buffer framework to physically suppress volume expansion and particle pulverization, achieving an initial coulombic efficiency of over 90%.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a basic solid-state electrolyte, an all-solid-state battery, and its preparation method and application that is dry-processed, solvent-free, and has universal electrodes and electrolytes. Background Technology

[0002] Current solid-state batteries are mainly classified into four categories: sulfide, oxide, polymer, and halide. They generally suffer from the following bottlenecks: 1) Incompatible electrolytes: Different systems (NCM / LFP / graphite / silicon-carbon) require specific electrolytes, making formulations non-interchangeable, resulting in high costs and long development cycles. 2) High interfacial impedance: Poor electrode / electrolyte contact necessitates high temperature / high pressure / solvent assistance, leading to high energy consumption and a tendency for side reactions. 3) Incompatible positive and negative electrodes: The formulations of positive electrodes (NCM / LFP / lithium iron manganese) and negative electrodes (graphite / silicon-carbon / hard carbon) differ significantly, making them non-interchangeable and resulting in poor production line flexibility. 4) Limited molding: Most are square sheets; irregular shapes and cylinders are difficult to mold in one piece, and uneven powder settling and height differences in dry processes can easily cause edge short circuits. 5) Poor safety and cycle performance: Solvent residue and high-temperature processing can easily cause interfacial cracking and lithium dendrite growth; powder bridging in dry processes can easily cause micro-short circuits. 6) Significant pain points of silicon-carbon anodes: The volume expansion of silicon-carbon anodes due to lithium intercalation is as high as 250% or more, making them prone to pulverization and with a high content of dead lithium. The initial coulombic efficiency is only 80%-85%, and the capacity decays rapidly during cycling. Existing wet processes rely on chemical modification and pre-lithiation treatment, which are complex and costly, and cannot fundamentally solve the problem. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a solid electrolyte and a solid battery for all-solid-state batteries. The same quaternary powder is added to the electrode system of the solid battery to achieve universal positive electrode, universal negative electrode and interchangeability between electrodes. At the same time, it solves the industry pain points of silicon-carbon negative electrode expansion and pulverization and low coulombic efficiency.

[0004] In a first aspect, the technical solution adopted by the present invention to solve the above-mentioned technical problem is as follows: a basic solid electrolyte for all-solid-state batteries, comprising, by mass percentage: 65wt% quaternary inorganic powder, 7wt% polyvinylidene fluoride micro powder, 18wt% lithium bis(trifluoromethanesulfonyl)imide, and 10wt% composite conductive agent; the total mass percentage of each component is 100%; the quaternary inorganic powder is composed of 55% microcrystalline cellulose, 28% hydroxypropyl methylcellulose, 12% fumed silica, and 5% magnesium stearate, and the overall mesh size of the quaternary inorganic powder is 80~200 mesh, and the particle size D50 is 75~180μm.

[0005] In the above technical solution, the raw materials for the basic solid electrolyte of the all-solid-state battery are as follows:

[0006] (1) Quaternary inorganic powder: The quaternary inorganic powder is composed of 55% microcrystalline cellulose, 28% hydroxypropyl methylcellulose, 12% fumed silica, and 5% magnesium stearate. The overall mesh size of the quaternary inorganic powder is 80~200 mesh, and the particle size D50 is 75~180μm. The raw material requirements for the quaternary inorganic powder are as follows: the mesh size of the microcrystalline cellulose is 120~200 mesh, and the particle size D50 is 75~125μm; the mesh size of the hydroxypropyl methylcellulose (HPMC) is 100~180 mesh, and the particle size D50 is 83~150μm; the particle size D50 of the fumed silica is 10~50nm, and the specific surface area is ≥150m² / g; the mesh size of the magnesium stearate is 80~150 mesh, and the particle size D50 is 100~180μm.

[0007] (2) Polyvinylidene fluoride micro powder (binder matrix): mesh size is 150~250 mesh, particle size D50: 60~100μm.

[0008] (3) The lithium salt of lithium bis(trifluoromethanesulfonylimide) has a mesh size of 100~200 mesh and a particle size D50 of 75~150 μm.

[0009] (4) Composite conductive agent: The composite conductive agent is selected from acetylene black and carbon nanotubes; the particle size D50 of the composite conductive agent is 20~100nm. In some embodiments, the mass ratio of acetylene black and carbon nanotubes in the composite conductive agent is 7:3.

[0010] In the above technical solution, the quaternary inorganic powder accounts for 65 wt% of the basic solid electrolyte, which can form a continuous ion conduction network, while providing rigid support and micro-elasticity to inhibit interface cracking. If the proportion is less than 60%, the ion network will be discontinuous and the impedance will increase significantly; if it is more than 70%, the powder will become brittle and cannot be properly compressed into tablets. The quaternary powder is limited to 80-200 mesh to ensure the self-leveling properties and reasonable porosity of the powder, reserve buffer space for the volume expansion of the silicon-carbon anode, and avoid local stress concentration caused by coarse particles.

[0011] The PVDF addition amount is 7wt%, which ensures bonding performance without hindering ion conduction.

[0012] The addition of LiTFSI at 18wt% ensures the lithium concentration and lithium-ion transference number of the system. The addition of the composite conductive agent at 10wt% establishes a stable electronic pathway and reduces electrode polarization.

[0013] The raw material ratio and powder particle size and mesh parameters of the basic solid electrolyte described in this invention are designed to balance high ionic conductivity (≥10). -4The optimal range for low interfacial impedance, dry compression molding, and compatibility with all electrode systems (S / cm), low interfacial impedance, dry compression molding, and compatibility with all electrode systems.

[0014] In a second aspect, the present invention provides a doped solid electrolyte, which is obtained by doping the above-mentioned basic solid electrolyte with a doping component; the doping component is any one of sulfide, oxide, polymer, halide, silicon-based substrate, and zirconium-based substrate; the mass percentage of the doping component is 7% to 11% based on the total mass of 100%, and the total mass percentage of the basic solid electrolyte and the doping component is 100%.

[0015] Furthermore, different types of doping components correspond to different ranges of doping mass percentages, specifically:

[0016] When the doping component is a sulfide, the doped solid electrolyte comprises 92 wt% of the base solid electrolyte and 8 wt% of the sulfide substrate; wherein the sulfide substrate is Li6PS5Cl and the particle size D50 is 1~5 μm;

[0017] When the doping component is an oxide, the doped solid electrolyte comprises 90 wt% of the base solid electrolyte and 10 wt% of the oxide substrate; wherein the oxide substrate is LLZO yttrium-doped garnet, and the particle size D50 is 0.5~3 μm;

[0018] When the doping component is a polymer, the doped solid electrolyte comprises 93 wt% of the base solid electrolyte and 7 wt% of the polymer substrate; wherein the polymer substrate is a PEO-LiTFSI composite and the particle size D50 is 5~20 μm;

[0019] When the doping component is a halide, the doped solid electrolyte comprises 91 wt% of the base solid electrolyte and 9 wt% of the halide substrate; wherein the halide substrate is Li3Ycl6 or Li2ZrCl6, and the particle size D50 is 1~5 μm;

[0020] When the doping component is a silicon-based substrate, the doped solid electrolyte comprises 89 wt% of the basic solid electrolyte and 11 wt% of silicon-based electrolyte powder; wherein the particle size D50 of the silicon-based electrolyte powder is 0.5~3 μm;

[0021] When the doping component is a zirconium-based substrate, the doped solid electrolyte comprises 90.5 wt% of the basic solid electrolyte and 9.5 wt% of zirconium-based ceramic electrolyte powder; wherein the particle size D50 of the zirconium-based ceramic electrolyte powder is 0.5~3 μm.

[0022] As a third aspect of the present invention, the present invention provides an all-solid-state battery, comprising a positive electrode layer, an electrolyte layer, and a negative electrode layer;

[0023] The positive electrode layer is formed by positive electrode layer powder; the positive electrode layer powder, by mass percentage, comprises: 92-93% positive electrode active material, 3% composite conductive agent, 3% quaternary inorganic powder, and 1-2% polyvinylidene fluoride micro powder; the positive electrode active material is selected from any one of NCM811, LFP, and lithium iron manganese, and the particle size D50 is 3-15μm.

[0024] The electrolyte layer is formed from electrolyte layer powder, which is either the basic solid electrolyte or the doped solid electrolyte.

[0025] The negative electrode layer is formed from negative electrode layer powder; the negative electrode layer powder, by mass percentage, comprises: 87-93% negative electrode active material, 3-4% composite conductive agent, 3-7% quaternary inorganic powder, and 1-2% polyvinylidene fluoride micro powder; the negative electrode active material is selected from any one of artificial graphite, silicon carbide, and hard carbon, and the particle size D50 is 5-20 μm.

[0026] The quaternary inorganic powder is composed of 55% microcrystalline cellulose, 28% hydroxypropyl methylcellulose, 12% fumed silica, and 5% magnesium stearate. The overall mesh size of the quaternary inorganic powder is 80~200 mesh, and the particle size D50 is 75~180μm.

[0027] In the above-mentioned all-solid-state battery technology solution, when the negative electrode active material is silicon-carbon, the quaternary inorganic powder in the negative electrode layer accounts for 5-7% of the total weight of the negative electrode layer powder.

[0028] In the above technical solution, the raw materials of the positive electrode system are required to be: the positive electrode active material is arbitrarily selected from NCM811, LFP, and lithium iron manganese, and the particle size D50 of the positive electrode active material is 3~15μm; the composite conductive agent is a combination of acetylene black and carbon nanotubes, and the particle size D50 of the composite conductive agent is 20~100nm; the quaternary powder has a mesh size of 80~200 mesh and a D50 of 75~180μm; the PVDF micro powder has a mesh size of 150~250 mesh and a D50 of 60~100μm. In some embodiments, the mass ratio of acetylene black to carbon nanotubes in the composite conductive agent is 7:3.

[0029] The principle behind the universality of the raw materials in the cathode system is as follows: 3% quaternary powder is added inside the cathode to form a homogeneous interface with the electrolyte, ensuring continuous ion channel connectivity and effectively reducing interface impedance; all types of cathodes can share a single formulation system, and product switching can be completed simply by changing the active material.

[0030] In the above technical solution, the raw materials of the negative electrode system are required to be: the negative electrode active material is selected from any one of artificial graphite, silicon carbide, and hard carbon, and the particle size D50 of the negative electrode active material is 5~20μm. Further, when the negative electrode active material is silicon carbide, the silicon particle D50 in the silicon carbide is 1~5μm. The composite conductive agent is a combination of acetylene black and carbon nanotubes, and the particle size D50 of the composite conductive agent is 20~100nm. The quaternary powder has a mesh size of 80~200 mesh and a D50 of 75~180μm. The PVDF micro powder has a mesh size of 150~250 mesh and a D50 of 60~100μm.

[0031] The raw materials for the described anode system share a universal principle: adding 3-7% quaternary powder to the anode ensures homogeneity with the electrolyte, inhibits lithium dendrite growth, and optimizes lithium deposition. In the silicon-carbon anode system, the quaternary powder content is increased to 5-7%, constructing an elastic buffer framework to encapsulate silicon-carbon particles, absorb volume expansion during lithium intercalation, reduce particle pulverization and dead lithium formation, and improve initial coulombic efficiency and cycle stability. All types of anodes can use a single formulation system; silicon-carbon anodes must be used with quaternary powder, while graphite anodes can use the same formulation.

[0032] As a fourth aspect of the present invention, the present invention also provides a method for preparing an all-solid-state battery, comprising the following steps:

[0033] (1) All raw materials are dried to a moisture content of <50ppm, and the quaternary inorganic powder is sieved to 80~200 mesh with a particle size D50 controlled at 75~180μm;

[0034] (2) The positive electrode powder, electrolyte powder and negative electrode powder are mixed independently at high speed without solvent throughout the process; when the negative electrode active material is silicon carbon, the mixing time of silicon carbon negative electrode is extended to 12~18min to ensure that the quaternary inorganic powder uniformly coats the silicon particles.

[0035] (3) The material is laid or filled in the order of positive electrode → electrolyte → negative electrode, which is suitable for cylindrical, conventional square and side-mounted square box structures.

[0036] (4) Gently vibrate the mold to allow the powder to settle naturally. Use 80-200 mesh quaternary inorganic powder to fill the depressions and seal the top surface to form a T-shaped insulating leveling and sealing layer.

[0037] (5) Room temperature low pressure molding, pressure 5~20MPa, temperature 25~60℃, holding pressure 1~5min; silicon carbide anode cell molding pressure is controlled at 8~15MPa;

[0038] (6) Packaging to obtain the finished all-solid-state battery.

[0039] Furthermore, in step (4), the preparation steps of the T-shaped insulating leveling seal layer are as follows: the first step is to fill the low-lying voids with quaternary inorganic powder; the second step is to spread a thin layer of quaternary inorganic powder on the top surface of the entire area, and to spread a slightly thicker layer in the electrolyte area and overlap it with the positive and negative electrode edges to form a T-shaped coating layer with a layer thickness of 0.2mm to 0.5mm.

[0040] In the above technical solution, this process can produce battery cells of any shape, such as square, irregular, or cylindrical, and the mold can directly press them into shape without adjusting the formula and process parameters.

[0041] In the above technical solution, when an electrolyte combination doped with a solid electrolyte is used, the basic solid electrolyte is doped with a golden ratio of sulfides, oxides, polymers, halides, silicon-based and zirconium-based substrates to form an electrolyte for an all-solid-state battery. This is compatible with all solid-state technology routes in the industry and is also compatible with both traditional wet preparation processes and the all-dry preparation process of this invention. The positive and negative electrode systems do not need to be modified.

[0042] In the above technical solution, the electrolyte is compatible with all types of positive and negative electrodes, realizing electrolyte universality; the positive and negative electrodes are interchangeable and compatible, realizing electrode universality.

[0043] In a further technical solution, when the negative electrode active material is silicon-carbon negative electrode, the silicon-carbon negative electrode relies on the quaternary powder elastic skeleton to physically suppress expansion and pulverization, and the coulombic efficiency is improved to over 90% for the first time.

[0044] As a fourth aspect of the present invention, the present invention also provides an application of the aforementioned all-solid-state battery, which is used in consumer electronics, power batteries, grid energy storage, and special power sources.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] (1) Electrolyte universality: A single type of electrolyte can be adapted to all types of positive electrodes, negative electrodes and various solid systems, creating a universal solid electrolyte for solid batteries; completely solving the industry fragmentation problem of "one system, one electrolyte" in traditional technology, and significantly reducing the overall cost of R&D, production and storage.

[0047] (2) Universalization of positive and negative electrodes: NCM / LFP / LiFeMn positive electrodes share a common positive electrode powder formula, and graphite / silicon-carbon / hard carbon negative electrodes share a common negative electrode powder formula. That is, the basic solid electrolyte of this invention is compatible with all positive electrodes (NCM / LFP / LiFeMn) and all negative electrodes (graphite / silicon-carbon / hard carbon). The universal positive and negative electrode formula of this invention adds the same quaternary powder to the electrode system, realizing universality of positive and negative electrodes and interchangeability between electrodes.

[0048] (3) Silicon-carbon anodes rely on the elastic framework of quaternary powder to physically suppress volume expansion and particle pulverization. Electrodes are interchangeable and compatible, production lines are highly flexible, and product switching does not require equipment replacement or formula adjustment.

[0049] (4) The entire dry process is safe and environmentally friendly: there is no solvent or high-temperature drying process, zero VOC emissions, no material residue and side reactions; it effectively inhibits solvent decomposition, interface cracking and lithium dendrite growth, and significantly improves the overall safety of the battery.

[0050] (5) Wide range of form adaptability: It can be directly pressed into square, irregular and cylindrical cells, covering all application scenarios such as consumer electronics, power batteries and energy storage, breaking the limitation that traditional solid-state batteries can only be made into square sheets.

[0051] (6) Solve the core defects of dry molding: Relying on the self-leveling properties of quaternary powder, solve the problems of uneven powder settling and material surface height difference in dry molding; T-type insulating seal layer blocks powder bridging and short circuit, replacing the local diaphragm function; quaternary powder has buffer toughness, which can adapt to silicon-carbon anode deformation and improve cycle stability.

[0052] (7) Excellent overall performance: the ionic conductivity of the system is ≥10 -4 S / cm, interface impedance reduced by more than 50%; silicon-carbon anode coulombic efficiency increased to more than 90% for the first time, capacity retention ≥85% after 1000 cycles at room temperature; energy density increased by 20% to 30% compared with traditional liquid batteries. Detailed Implementation

[0053] To better understand the content of this invention, further description is provided below with reference to specific embodiments and accompanying drawings. It should be understood that these embodiments are only for further illustration of the invention and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art may make some non-essential modifications or adjustments to the invention, which still fall within the protection scope of this invention.

[0054] Example 1: Preparation of Basic Solid Electrolytes

[0055] Preparation of quaternary powder: Weigh 55g of 120-200 mesh microcrystalline cellulose, 28g of 100-180 mesh hydroxypropyl methylcellulose, 12g of fumed silica with a particle size of 10-50nm, and 5g of 80-150 mesh magnesium stearate. Mix and stir for 10 minutes, and sieve to obtain 80-200 mesh mixed quaternary powder (D50: 75-180μm).

[0056] The following ingredients were prepared by mass ratio: 65g quaternary powder, 7g 150-250 mesh PVDF micro powder, 18g 100-200 mesh LiTFSI, and 10g composite conductive agent with a particle size of 20-100nm. The mixture was high-speed mixed for 15 minutes, and the moisture content was found to be <50ppm, thus obtaining the basic solid electrolyte powder.

[0057] Example 2: Preparation of a general positive electrode

[0058] Weigh 92g of NCM811 active material with a D50 of 3~15μm, 3g of composite conductive agent, 3g of 80~200 mesh quaternary powder, and 2g of 150~250 mesh PVDF; dry mix for 10min to obtain general-purpose positive electrode powder. The preparation of quaternary powder is the same as in Example 1.

[0059] Example 3: Preparation of a universal negative electrode

[0060] Weigh out 87g of silicon-carbon active material with a D50 of 5~20μm (silicon particle D50: 1~5μm), 4g of composite conductive agent, 7g of 80~200 mesh quaternary powder, and 2g of 150~250 mesh PVDF; dry mix for 15min to ensure that the quaternary powder uniformly coats the silicon particles, thus obtaining silicon-carbon anode powder. The preparation of the quaternary powder is the same as in Example 1.

[0061] Example 4: Preparation of a side-mounted prismatic battery

[0062] 1) Two insulating plates are added to a square mold to divide it into three independent chambers: the positive electrode chamber, the electrolyte chamber, and the negative electrode chamber; 2) Positive electrode powder, electrolyte powder, and silicon-carbon negative electrode powder are filled in separately, and the side walls of the mold are closed; 3) The mold is gently shaken for 1 minute to allow the powder to settle naturally; 4) 80-200 mesh pure quaternary powder is used to fill the low-lying areas where there is insufficient material to ensure that the material surface is flat; 5) Quaternary powder with a thickness of 0.3 mm is laid on the top surface of the entire area, and the material is laid slightly thicker in the electrolyte area. The powder overlaps to the edges on both sides to form a T-shaped coating layer; 6) The insulating plates are removed, and the material is compacted and shaped at room temperature under 10 MPa pressure; 7) The copper current collectors on both sides are used to press the material and lead out the leads. The mold is locked and sealed to obtain a 200g side-mounted square box battery.

[0063] Example 5: Fabrication of 18650 cylindrical solar cells (silicon-carbon anode system)

[0064] Using a φ18mm mandrel, positive electrode dry powder, electrolyte dry powder, and silicon-carbon negative electrode dry powder are sequentially filled from bottom to top; the mold is gently shaken for 30 seconds, and 80~200 mesh quaternary powder is used to fill the end face gaps to form an insulating seal; the pressure is set at 12MPa and held at room temperature for 3 minutes. After demolding, it is encapsulated with a steel shell to obtain an 18650 cylindrical battery.

[0065] Example 6: Comprehensive Performance Test Results

[0066] Example 5 uses a silicon-carbon anode, and the overall performance was measured. The ionic conductivity was 1.2 × 10⁻⁶. -4 S / cm; Interface impedance: 32Ω; Edge short circuit rate: 0%; First coulombic efficiency of silicon-carbon anode: 91.2%; Dead lithium content: 4.1%; Volume expansion rate: 135%; Energy density: 260Wh / kg; Capacity retention rate of 88.3% after 1000 cycles at 0.5C; Safety test: No fire after needle penetration, no leakage after extrusion.

[0067] Example 7: Dual-Compatible Dry and Wet Process Example of Sulfide System

[0068] The total mass of the doped electrolyte is 100wt%: 92wt% of the basic solid electrolyte and 8wt% of the sulfide substrate (Li6PS5Cl, D50 1~5μm).

[0069] Dry process: After the materials are blended, the dry mixing, spreading, T-shaped leveling and compaction process of this invention is adopted, without the need for solvents and high-temperature sintering; Wet process: It can be directly adapted to the traditional wet coating, solvent dispersion and high-temperature curing process of sulfide batteries, and is compatible with existing mass production lines.

[0070] Adaptation effect: The positive and negative electrode systems are fully compatible, solving the defects of sulfides being afraid of water and having poor interfacial contact, and realizing mass production with the same formula and dual processes.

[0071] Example 8: Dry and Wet Compatibility Example of Oxide System

[0072] Total mass of doped electrolyte 100wt%: 90wt% basic solid electrolyte, 10wt% oxide substrate (LLZO yttrium doped garnet, D50 0.5~3μm).

[0073] Dry process: The room temperature and low pressure dry process is combined with T-shaped leveling and sealing to make up for the defects of oxides being brittle and prone to cracking; Wet process: It is compatible with traditional oxide high temperature sintering and wet coating processes.

[0074] Adaptation effect: Combining the high stability of oxides, no adjustment is required for the positive and negative electrodes, realizing integrated dry and wet mass production.

[0075] Example 9: Dry and Wet Compatibility Example of Polymer System

[0076] The total mass of the doped electrolyte is 100wt%: 93wt% of the basic solid electrolyte and 7wt% of the polymer substrate (PEO-LiTFSI composite, D50 5~20μm).

[0077] Dry process: low-temperature molding, no high-temperature melting required, combined with T-shaped edge sealing to prevent powder drift and short circuit; Wet process: suitable for polymer solution casting and coating curing processes.

[0078] Adaptation effect: It retains the flexibility of polymers and solves the problems of high-temperature operation and molding limitations.

[0079] Example 10: Dry and Wet Compatibility Example of Halogen Systems

[0080] The total mass of the doped electrolyte is 100wt%: 91wt% of the basic solid electrolyte and 9wt% of the halide substrate (Li3YCl6 / Li2ZrCl6, D50 1~5μm).

[0081] Dry process: Powder blending and compaction, no high temperature required, no toxic gas release, retains the insulation advantages of T-type edge sealing; Wet process: Adaptable to halide wet dispersion, coating drying, low temperature curing mass production processes.

[0082] Adaptation effect: It leverages the advantages of high-voltage stability and good air stability of halides, while avoiding the problems of easy reaction at the negative electrode interface and difficulty in thick forming.

[0083] Example 11: Dry and Wet Compatibility Example of Silicon-Based Electrolyte System

[0084] The total mass of the doped electrolyte is 100wt%: 89wt% basic solid electrolyte and 11wt% silicon-based electrolyte powder (D50 0.5~3μm).

[0085] Dry process: Based on the all-dry process and T-shaped leveling process, it solves the problems of expansion and unevenness in the molding of silicon-based materials; Wet process: It is adapted to the wet coating and compaction process of silicon-based batteries.

[0086] Compatibility: Combining the advantages of silicon-based high ionic conductivity, it can be directly adapted to all types of positive and negative electrodes.

[0087] Example 12: Dry and Wet Compatibility Example of Zirconium-based Ceramic Electrolyte System

[0088] The total mass of the doped electrolyte is 100wt%: 90.5wt% of the basic solid electrolyte and 9.5wt% of the zirconium-based ceramic electrolyte powder (D50 0.5~3μm).

[0089] Dry process: room temperature and low pressure molding, hard zirconium-based powder and flexible quaternary powder complement each other to prevent cracking and powder shedding, and T-shaped edge sealing improves insulation in extreme environments; Wet process: adapted to wet sintering and coating processes of zirconium-based batteries.

[0090] Adaptability: It combines the high and low temperature resistance and long cycle characteristics of zirconium-based materials, making it suitable for extreme working conditions in power and energy storage.

[0091] Example 13: Specific Example of Optimizing the Coulombic Efficiency of Silicon-Carbon Anodes

[0092] Formula: 87% silicon-carbon active material (D50 5~20μm), 4% composite conductive agent, 7% 80~200 mesh quaternary powder, 2% PVDF. Process: Dry mixing for 15min → spreading → vibration compaction and settling → quaternary powder leveling and edge sealing → 10MPa room temperature pressing molding.

[0093] Performance comparison:

[0094]

[0095] Mechanism Explanation: The quaternary powder forms a porous elastic network that encapsulates silicon-carbon particles, buffering volume expansion and preventing hard particle contact and stress concentration. Uniform pores provide controllable space for silicon expansion, preventing structural collapse. The polar groups on the quaternary powder surface form a dense interface layer, inhibiting repeated SEI film growth and reducing lithium source consumption. This also reduces particle pulverization and dead lithium formation, improving reversible lithium insertion / extraction capabilities. This solution addresses the two core pain points of silicon-carbon anodes at the physical level, eliminating the need for additional processes such as chemical modification and pre-lithiation.

[0096] All the above examples of electrolyte doping do not alter the core formulation, universal electrode system, all-dry process flow, or T-shaped leveling and sealing process of this invention. By simply doping the corresponding substrate material in the base electrolyte, it is compatible with solid-state technologies across the entire industry, including sulfide, oxide, polymer, halide, silicon-based, and zirconium-based technologies. All systems are simultaneously adaptable to both traditional wet processes and the all-dry process of this invention. The positive and negative electrode formulations do not require separate adaptation, truly achieving universality across all materials, processes, forms, and scenarios, and completely solving the problem of industry technology fragmentation.

[0097] The foregoing description is not intended to limit the invention, nor is the invention limited to the examples given. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the invention should also be considered within the protection scope of the invention.

Claims

1. A basic solid-state electrolyte for all-solid-state batteries, characterized in that, The raw material components, by mass percentage, include: 65wt% quaternary inorganic powder, 7wt% polyvinylidene fluoride micro powder, 18wt% lithium bis(trifluoromethanesulfonyl)imide, and 10wt% composite conductive agent; the total mass percentage of each component is 100%; the quaternary inorganic powder is composed of 55% microcrystalline cellulose, 28% hydroxypropyl methylcellulose, 12% fumed silica, and 5% magnesium stearate, and the overall mesh size of the quaternary inorganic powder is 80~200 mesh, and the particle size D50 is 75~180μm.

2. A doped solid electrolyte, characterized in that, It includes the basic solid electrolyte for all-solid-state batteries as described in claim 1 and the doping component; the doping component is any one of sulfide, oxide, polymer, halide, silicon-based substrate, and zirconium-based substrate; the mass percentage of the doping component is 7% to 11% based on the total mass of 100%.

3. The doped solid electrolyte according to claim 2, characterized in that, When the doping component is a sulfide, the doped solid electrolyte comprises 92 wt% of the basic solid electrolyte as described in claim 1 and 8 wt% of the sulfide substrate; wherein the sulfide substrate is Li6PS5Cl and the particle size D50 is 1~5 μm; When the doping component is an oxide, the doped solid electrolyte comprises 90 wt% of the basic solid electrolyte as described in claim 1 and 10 wt% of the oxide substrate; wherein the oxide substrate is LLZO yttrium-doped garnet, and the particle size D50 is 0.5~3 μm; When the doping component is a polymer, the doped solid electrolyte comprises 93 wt% of the basic solid electrolyte as described in claim 1 and 7 wt% of the polymer substrate; wherein the polymer substrate is a PEO-LiTFSI composite and the particle size D50 is 5~20 μm; When the doping component is a halide, the doped solid electrolyte comprises 91 wt% of the basic solid electrolyte as described in claim 1 and 9 wt% of the halide substrate; wherein the halide substrate is Li3Ycl6 or Li2ZrCl6, and the particle size D50 is 1~5 μm; When the doping component is a silicon-based substrate, the doped solid electrolyte comprises 89 wt% of the basic solid electrolyte as described in claim 1 and 11 wt% of silicon-based electrolyte powder; wherein the particle size D50 of the silicon-based electrolyte powder is 0.5~3 μm; When the doping component is a zirconium-based substrate, the doped solid electrolyte comprises 90.5 wt% of the basic solid electrolyte as described in claim 1 and 9.5 wt% of zirconium-based ceramic electrolyte powder; wherein the particle size D50 of the zirconium-based ceramic electrolyte powder is 0.5~3 μm.

4. An all-solid-state battery, characterized in that, It includes a positive electrode layer, an electrolyte layer, and a negative electrode layer; The positive electrode layer is formed by positive electrode layer powder; the positive electrode layer powder, by mass percentage, comprises: 92-93% positive electrode active material, 3% composite conductive agent, 3% quaternary inorganic powder, and 1-2% polyvinylidene fluoride micro powder; the positive electrode active material is selected from any one of NCM811, LFP, and lithium iron manganese, and the particle size D50 is 3-15μm. The electrolyte layer is formed from electrolyte layer powder, which is the basic solid electrolyte as described in claim 1 or the doped solid electrolyte as described in claim 3; The negative electrode layer is formed from negative electrode layer powder; the negative electrode layer powder, by mass percentage, comprises: 87-93% negative electrode active material, 3-4% composite conductive agent, 3-7% quaternary inorganic powder, and 1-2% polyvinylidene fluoride micro powder; the negative electrode active material is selected from any one of artificial graphite, silicon carbide, and hard carbon, and the particle size D50 is 5-20 μm. The quaternary inorganic powder is composed of 55% microcrystalline cellulose, 28% hydroxypropyl methylcellulose, 12% fumed silica, and 5% magnesium stearate. The overall mesh size of the quaternary inorganic powder is 80~200 mesh, and the particle size D50 is 75~180μm.

5. A solid-state battery according to claim 4, characterized in that, When the negative electrode active material is silicon-carbon, the quaternary inorganic powder in the negative electrode layer accounts for 5-7% of the total weight of the negative electrode layer powder.

6. A method for preparing an all-solid-state battery as described in claim 4 or 5, characterized in that, Includes the following steps: (1) All raw materials are dried to a moisture content of <50ppm, and the quaternary inorganic powder is sieved to 80~200 mesh with a particle size D50 controlled at 75~180μm; (2) The positive electrode powder, electrolyte powder and negative electrode powder are mixed independently at high speed without solvent throughout the process; when the negative electrode active material is silicon carbon, the mixing time of silicon carbon negative electrode is extended to 12~18min to ensure that the quaternary inorganic powder uniformly coats the silicon particles. (3) The material is laid or filled in the order of positive electrode → electrolyte → negative electrode, which is suitable for cylindrical, conventional square and side-mounted square box structures. (4) Gently vibrate the mold to allow the powder to settle naturally. Use 80-200 mesh quaternary inorganic powder to fill the depressions and seal the top surface to form a T-shaped insulating leveling and sealing layer. (5) Room temperature low pressure molding, pressure 5~20MPa, temperature 25~60℃, holding pressure 1~5min; silicon carbide anode cell molding pressure is controlled at 8~15MPa; (6) Packaging to obtain the finished all-solid-state battery.

7. The method for preparing an all-solid-state battery as described in claim 6, characterized in that, In step (4), the preparation steps of the T-shaped insulating leveling seal layer are as follows: the first step is to fill the low-lying voids with quaternary inorganic powder; the second step is to spread a thin layer of quaternary inorganic powder on the top surface of the entire area, and spread a slightly thicker layer in the electrolyte area and overlap it with the positive and negative electrode edges to form a T-shaped coating layer with a layer thickness of 0.2mm to 0.5mm.

8. The method for preparing an all-solid-state battery according to claim 7, characterized in that, When silicon-carbon anodes are used as the active material, the silicon-carbon anode relies on the quaternary powder elastic framework to physically suppress expansion and pulverization, and the initial coulombic efficiency is increased to over 90%.

9. The application of an all-solid-state battery according to claim 4 or 5, characterized in that, This battery is used in consumer electronics, power batteries, grid energy storage, and special power sources.

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