Solid-state electrolyte-electrode composite and method of making and use thereof

Abstract

The application provides a solid-state electrolyte-electrode composite and a preparation method and use thereof, the solid-state electrolyte-electrode composite comprises a porous carbon material layer, and solid-state electrolyte layers and electrode layers are arranged on both sides of the porous carbon material layer respectively, and the solid-state electrolyte layers and the electrode layers form interpenetrating structures.The solid-state electrolyte-electrode composite provided by the application can not only increase the contact area between the solid-state electrolyte and the electrode, reduce the current density and inhibit lithium dendrite growth through the synergistic effect between the interpenetrating structures of the solid-state electrolyte layers and the electrode layers and the porous carbon material layer, but also has excellent mechanical strength and can provide sufficient support strength, so that the huge volume change stress in the lithium metal deposition / peeling process can be borne, the problem of insufficient mechanical strength of the solid-state electrolyte film is solved, and the cycle stability and rate performance of the solid-state battery are further improved.

Description

Technical Field

[0001] This invention belongs to the field of battery manufacturing technology, and particularly relates to a solid electrolyte-electrode composite, its preparation method and application. Background Technology

[0002] All-solid-state batteries, possessing both high energy density and high safety, have garnered widespread attention in the battery industry. They typically employ a solid electrolyte and lithium metal as the negative electrode. Commonly used solid electrolytes include sulfide and halide electrolytes, both exhibiting extremely high ionic conductivity and good ductility. These electrolytes are generally deposited using wet or dry film-forming processes, with the electrolyte membrane consisting of a solid electrolyte and a binder. However, to improve the ionic conductivity of the electrolyte membrane, the binder content is often below 3%, resulting in insufficient mechanical strength and flexibility, making the membrane prone to damage during production and leading to low yield rates.

[0003] Meanwhile, the negative electrode in all-solid-state batteries typically uses lithium metal or lithium alloy materials, which face a serious lithium dendrite problem during battery operation, affected by lithium deposition characteristics, interface vacancies, surface defects, and grain boundaries. To suppress lithium dendrite growth, it is necessary to increase the reaction area, reduce the current density, and increase the carrier concentration. This can usually be achieved through external pressure or the use of lithium composite negative electrodes. However, external pressure is less feasible in large-scale battery cells, while lithium composite negative electrodes can affect the battery's energy density.

[0004] CN112736277A discloses a solid electrolyte-lithium anode composite, its preparation method, and an all-solid-state lithium secondary battery. The solid electrolyte-lithium anode composite comprises: a polyphenylene sulfide solid electrolyte layer; a lithium layer vapor-deposited on one surface of the solid electrolyte layer; and optionally, a metal foil attached to the lithium layer as a current collector or tab. While this composite effectively controls the lithium layer thickness by depositing a lithium layer on the surface of the solid electrolyte, the contact area between the solid electrolyte and the lithium layer remains relatively small. Furthermore, it does not solve the problem of insufficient mechanical strength of the solid electrolyte film, which cannot withstand the large volumetric stress during lithium metal deposition / stripping.

[0005] CN110137560A discloses an integrated composite electrode material, its preparation method, and its application. The integrated composite electrode material includes an electrode sheet containing active material and a solid electrolyte layer integrally formed with the surface of the electrode sheet. The solid electrolyte layer includes a solid electrolyte and a lithium salt, wherein the solid electrolyte is a polymer electrolyte and / or an organic / inorganic composite solid electrolyte. However, this integrated composite electrode material still forms the solid electrolyte layer directly on the surface of the electrode sheet, which fails to address the problems of a small contact area between the solid electrolyte and the electrode sheet, and insufficient mechanical strength of the solid electrolyte film.

[0006] CN114171784A discloses an integrated solid-state electrolyte-positive electrode assembly, its preparation method, and its application. The integrated solid-state electrolyte-positive electrode assembly includes a solid electrolyte sheet and a positive electrode sheet stacked together. The solid electrolyte sheet includes a first solid electrolyte and a first plastic-crystalline electrolyte; the positive electrode sheet includes a positive electrode material, a second solid electrolyte, and a second plastic-crystalline electrolyte. Using a plastic-crystalline electrolyte as the interfacial lithium-conducting phase, the positive electrode and electrolyte are bonded together, achieving lithium-ion conduction between the positive electrode material and the solid electrolyte, resulting in high room-temperature ionic conductivity. However, it cannot simultaneously suppress lithium dendrites and provide sufficient mechanical strength.

[0007] Therefore, there is an urgent need to develop an integrated solid electrolyte-electrode composite material that can effectively increase the contact area between the electrolyte and the electrode, suppress lithium dendrites, and simultaneously take into account ionic conductivity and the mechanical strength of the solid electrolyte membrane. This is crucial for further improving the electrochemical performance of batteries. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a solid electrolyte-electrode composite, its preparation method, and its applications. This composite increases the contact area between the solid electrolyte and the electrode, reduces current density, and suppresses lithium dendrite growth. Furthermore, the solid electrolyte-electrode composite provided by the present invention possesses excellent mechanical strength, capable of withstanding the enormous volume change stress during lithium metal deposition / stripping, thus solving the problem of insufficient mechanical strength of solid electrolyte films and further improving the cycle stability and rate performance of solid-state batteries.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a solid electrolyte-electrode composite, the solid electrolyte-electrode composite comprising a porous carbon material layer, a solid electrolyte layer and an electrode layer respectively disposed on both sides of the porous carbon material layer, the solid electrolyte layer and the electrode layer forming an interpenetrating structure.

[0011] The integrated solid electrolyte-electrode composite of the present invention comprises a porous carbon material layer, with a solid electrolyte layer and an electrode layer respectively constructed on both sides thereon. Due to the presence of the porous structure in the porous carbon material layer, when the solid electrolyte slurry is coated on one side, it is subjected to capillary action, penetration and surface deposition, which can form a unique solid electrolyte coating structure on the surface of the porous carbon material layer, greatly increasing the specific surface area of ​​the solid electrolyte layer, thereby further increasing the reaction area with the electrode layer.

[0012] On the other side of the porous carbon material layer, an electrode layer is bonded by calendering. Due to the excellent ductility of the electrode layer, it penetrates into the pores of the porous carbon material layer during the calendering process, forming a large-area interpenetrating structure with the solid electrolyte. This significantly increases the contact area between the two, effectively reducing the current density, inhibiting lithium dendrite growth, and effectively extending the cycle life of the solid-state battery. Furthermore, the porous carbon material layer possesses high tensile strength, capable of withstanding the enormous volumetric stress during lithium metal deposition / stripping, thereby improving cycle stability and rate performance, and also addressing the issue of insufficient mechanical strength in solid electrolyte membranes.

[0013] The solid electrolyte-electrode composite provided by this invention, through the synergistic effect between the interpenetration structure of the solid electrolyte layer and the electrode layer and the porous carbon material layer, can not only increase the contact area between the solid electrolyte and the electrode, reduce the current density, and suppress lithium dendrite growth, but also has excellent mechanical strength, providing sufficient support strength to withstand the huge volume change stress during lithium metal deposition / stripping. This solves the problem of insufficient mechanical strength of solid electrolyte films, thereby further improving the cycle stability and rate performance of solid batteries.

[0014] As a preferred embodiment of the present invention, the interpenetrating structure is located inside the porous carbon material layer.

[0015] Preferably, the interpenetrating structure is located inside the porous carbon material layer and on both sides of the porous carbon material layer, and there is a gap between the interpenetrating structure and the surface of the solid electrolyte layer away from the porous carbon material layer.

[0016] For the interpenetrating structure in the solid electrolyte-electrode composite, the present invention provides the following two technical solutions: (1) the interpenetrating structure formed by the solid electrolyte layer and the electrode layer is located inside the porous carbon material layer; (2) the interpenetrating structure formed by the solid electrolyte layer and the electrode layer is located inside the porous carbon material layer and on both sides of the porous carbon material layer, and there is a gap between the interpenetrating structure and the side surface of the solid electrolyte layer away from the porous carbon material layer.

[0017] In other words, the present invention must ensure that the interpenetrating structure formed by the solid electrolyte layer and the electrode layer cannot contact the side of the solid electrolyte layer away from the porous carbon material layer. That is, the side of the solid electrolyte layer away from the porous carbon material layer cannot form an interpenetrating structure. This is because during the assembly of the all-solid-state battery, the side of the solid electrolyte layer away from the porous carbon material layer needs to be superimposed and bonded to another electrode in the battery. If the side of the solid electrolyte layer away from the porous carbon material layer in the solid electrolyte-electrode composite also forms an interpenetrating structure, it will cause the battery to short circuit.

[0018] As a preferred embodiment of the present invention, the thickness of the porous carbon material layer is 50 to 100 μm, for example, it can be 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm or 100 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0019] This invention limits the thickness of the porous carbon material layer to 50–100 μm. The purpose of setting the thickness of the porous carbon material layer is to enable it to simultaneously possess high surface area and high mechanical strength: when the thickness is less than 50 μm, the interface area between the electrolyte layer and the electrode layer increases, but its mechanical strength cannot withstand the volume expansion during operation, which is not conducive to improving the working stability of the cell; when the thickness is greater than 100 μm, the electrolyte cannot be evenly distributed inside the porous carbon layer by relying on the permeation effect of the electrolyte dispersion, which will instead lead to a reduction in the contact area between the electrolyte and the electrode, an increase in cell impedance, and rapid performance degradation.

[0020] Preferably, the thickness of the solid electrolyte layer is 10 to 20 μm, for example, it can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0021] This invention limits the thickness of the solid electrolyte layer to 10–20 μm. The thickness of the solid electrolyte layer is set with consideration for both lithium-ion transport and mechanical strength: when the electrolyte layer thickness is too low, due to the large volume expansion effect of the lithium metal anode during charging, the electrolyte layer is easily punctured by the burrs on the surface of the porous carbon material layer, resulting in a short circuit in the cell; while when the thickness exceeds 20 μm, the transport path of lithium ions in the electrolyte is greatly extended, and the rate performance decreases.

[0022] Preferably, the thickness of the electrode layer is 10 to 48 μm, for example, it can be 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 23 μm, 25 μm, 28 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm or 48 μm, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0023] This invention limits the thickness of the electrode layer to 10–48 μm. The setting of the electrode layer thickness mainly considers the N / P ratio of the battery cell and production feasibility: when the thickness is <10 μm, the lithium metal anode will be continuously consumed during the battery cell cycle, and too little lithium anode cannot support the battery cell to cycle stably for a long time; when the thickness exceeds 48 μm, rolled lithium metal is prone to wrinkles, sticking to the rollers and other phenomena, which are not conducive to improving product uniformity.

[0024] Preferably, the compaction density of the solid electrolyte layer is 2.0–2.5 g / cm³. 3 For example, it could be 2.0 g / cm³. 3 2.1g / cm 3 2.2g / cm 3 2.3g / cm 3 2.4g / cm 3 Or 2.5g / cm 3 However, it is not limited to the listed values; other unlisted values ​​within this range also apply. A further preferred value is 2.2–2.3 g / cm³. 3 .

[0025] This invention specifies that the compaction density of the solid electrolyte layer is 2.0–2.5 g / cm³. 3 This is because, as the compaction density increases, although the ionic conductivity of the solid electrolyte layer increases, the mechanical strength of the porous carbon material layer gradually decreases; therefore, this invention controls the compaction density of the solid electrolyte layer to 2.0–2.5 g / cm³. 3 Within this range, the ionic conductivity of the solid electrolyte layer and the mechanical strength of the porous carbon material layer can be balanced.

[0026] Preferably, the porosity of the porous carbon material layer is 30-60%, for example, it can be 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 53%, 55%, 58% or 60%, but is not limited to the listed values, other unlisted values ​​within this range are also applicable; more preferably, it is 40-50%.

[0027] This invention limits the porosity of the porous material layer to 30-60%. When the porosity is below 30%, it will lead to a decrease in battery rate performance and cycle stability. This is because the electrolyte cannot form a continuous permeation network in the porous carbon material layer, the contact area with the electrode is reduced, and the internal resistance polarization increases. When the porosity is above 60%, it will lead to a short circuit in the cell and a decrease in cycle stability. This is because the presence of a large number of voids will reduce the mechanical strength of the porous carbon material layer, making it unable to maintain a good pore structure during cycling.

[0028] Preferably, the pore size of the porous carbon material layer is 2 to 5 μm, for example, it can be 2 μm, 2.2 μm, 2.5 μm, 2.8 μm, 3 μm, 3.2 μm, 3.5 μm, 3.8 μm, 4 μm, 4.2 μm, 4.5 μm, 4.8 μm or 5 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable; more preferably, it is 3 to 4 μm.

[0029] This invention limits the pore size to 2-5 μm. When the pore size is less than 2 μm, blockage is likely to occur, which prevents the electrolyte from penetrating into the electrode to form a uniform interface layer. When the pore size is greater than 5 μm, the electrolyte will directly penetrate the porous carbon material layer and will not be able to form a uniform electrolyte layer on the surface of the porous carbon material layer. This is because when the pore size is too large, the surface tension cannot support the distribution of the electrolyte in the pores, and it will continue to penetrate until it flows out of the porous carbon material layer.

[0030] As a preferred embodiment of the present invention, the porous carbon material layer includes a carbon fiber layer.

[0031] The carbon fiber membrane used in this invention has excellent mechanical strength and can effectively withstand the volume change stress of the electrolyte during the operation of the battery cell, thereby improving cycle stability and rate performance.

[0032] Preferably, the carbon fiber layer comprises carbon paper or carbon cloth, and more preferably carbon paper.

[0033] In this invention, carbon cloth has extremely high mechanical strength, but due to its large surface roughness, it is not very effective in forming a stable and uniform interface; while carbon paper has relatively low mechanical strength, but its surface is smoother, which is more conducive to the uniform deposition of the electrode layer.

[0034] Preferably, the solid electrolyte layer is made of a sulfide electrolyte or a halide electrolyte.

[0035] Preferably, the sulfide electrolyte comprises any one or a combination of at least two of lithium phosphorus-sulfur-chloride, lithium germanium-phosphorus-sulfide, lithium phosphorus-sulfur-chloride derivatives, or lithium germanium-phosphorus-sulfur derivatives, and more preferably lithium phosphorus-sulfur-chloride.

[0036] Preferably, the halide electrolyte comprises any one or a combination of at least two of lithium indium chloride, lithium yttrium chloride, lithium zirconium chloride, lithium indium chloride derivatives, lithium yttrium chloride derivatives, or lithium zirconium chloride derivatives, and more preferably lithium indium chloride.

[0037] Preferably, the electrode layer comprises a lithium metal layer or a lithium alloy layer.

[0038] In this invention, the lithium metal layer and lithium alloy layer have excellent ductility. During the rolling process, the lithium metal or lithium alloy will penetrate into the pores of the porous carbon material layer, forming a large-area interpenetration structure with the solid electrolyte. The contact area between the two is greatly increased, which effectively reduces the current density.

[0039] Furthermore, the lithium alloy layer in this invention includes any one of lithium-magnesium alloy, lithium-carbon alloy, lithium-tin alloy, lithium-selenium alloy, or lithium-aluminum alloy.

[0040] In a second aspect, the present invention provides a method for preparing the solid electrolyte-electrode composite described in the first aspect, the method comprising:

[0041] A solid electrolyte slurry is coated on one side of a porous carbon material layer to form a solid electrolyte layer. An electrode is rolled to the other side of the porous carbon material layer to form an electrode layer. The solid electrolyte layer and the electrode layer form an interpenetrating structure during the rolling process.

[0042] This invention first employs a wet coating process to apply a solid electrolyte slurry to one side of a porous carbon material layer. Under the influence of capillary action, permeation, and surface deposition, the solid electrolyte slurry forms a unique coating structure on the surface of the porous carbon material layer, significantly increasing the specific surface area of ​​the solid electrolyte layer. On the other side, when the electrode layer is calendered and bonded, due to the excellent ductility of the electrode layer, it permeates into the pores of the porous carbon material layer during the calendering process, forming a large-area interpenetrating structure with the solid electrolyte. The resulting integrated solid electrolyte-electrode composite exhibits an extremely high reaction area and an extremely low current density, while also providing sufficient support strength.

[0043] As a preferred embodiment of the present invention, the porous carbon material layer is dried before being coated with the solid electrolyte slurry.

[0044] Preferably, the drying temperature of the porous carbon material layer is 60 to 100°C, for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] Preferably, the drying process of the porous carbon material layer is carried out under vacuum conditions.

[0046] Preferably, after the drying treatment, the moisture content of the porous carbon material layer is ≤200ppm, for example, it can be 200ppm, 190ppm, 180ppm, 170ppm, 160ppm, 150ppm or 140ppm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0047] In this invention, during the drying process of the porous carbon material layer, its moisture content can be tested every 6 hours until the moisture content of the porous carbon material layer is ≤200ppm. The porous carbon material layer that meets the moisture test standard is then vacuum-sealed for later use. If the moisture content of the porous carbon material layer is too high, it may lead to the decomposition of the solid electrolyte and side reactions between the electrode layer and moisture.

[0048] As a preferred technical solution of the present invention, the preparation process of the solid electrolyte slurry includes: mixing and dispersing solid electrolyte powder with solvent to obtain the solid electrolyte slurry.

[0049] In the preparation process of the solid electrolyte slurry of the present invention, no binder is required, which reduces problems such as the decrease in ionic conductivity caused by the introduction of binder.

[0050] Preferably, the solid electrolyte powder is dried and then mixed and dispersed with the solvent.

[0051] Preferably, the drying temperature of the solid electrolyte powder is 60 to 100°C, for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0052] Preferably, the drying process of the solid electrolyte powder is carried out under vacuum conditions.

[0053] Preferably, after the drying process, the moisture content of the solid electrolyte powder is ≤200ppm.

[0054] In this invention, during the drying process of the solid electrolyte powder, its moisture content can be tested every 6 hours until the moisture content of the solid electrolyte powder is ≤200ppm. The solid electrolyte powder that meets the moisture test standard is then vacuum-sealed for later use. If the moisture content of the solid electrolyte powder is too high, it may lead to decomposition of the solid electrolyte and side reactions between the electrode layer and moisture. Furthermore, in this invention, the porous carbon material layer and the solid electrolyte powder can be dried and their moisture content tested together.

[0055] Preferably, the solvent is a nonpolar solvent.

[0056] Preferably, the solvent includes any one or a combination of at least two of p-xylene, toluene, n-heptane, p-xylene derivatives, toluene derivatives, or n-heptane derivatives, and more preferably p-xylene and / or n-heptane.

[0057] Preferably, the dispersion process includes: after the solid electrolyte powder is mixed with the solvent, it is then subjected to ultrasonic dispersion and stirring dispersion in sequence.

[0058] Preferably, the stirring and dispersing speed is 1000 to 1500 rpm, for example, it can be 1000 rpm, 1000 rpm, 1000 rpm, 1000 rpm, 1000 rpm, or 1000 rpm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0059] Preferably, the stirring and dispersion time is 1 to 3 hours, for example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours or 3 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0060] Preferably, the solid electrolyte slurry has a solid content of 20 to 60 wt%, for example, it can be 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, or 60 wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0061] As a preferred technical solution of the present invention, the coating method of the solid electrolyte slurry includes casting coating.

[0062] This invention employs a casting machine to coat a solid electrolyte slurry. A porous carbon material layer is mounted on the casting machine as a casting substrate, and the solid electrolyte slurry serves as the casting layer. The front squeegee has a thickness of 200 μm, and the rear squeegee has a thickness of 150 μm. The solid electrolyte slurry is uniformly coated onto the surface of the porous carbon material layer. During the casting process, the solid electrolyte slurry gradually penetrates into the interior of the porous carbon material layer, forming a uniform coating layer on its surface. It should be noted that the coating method for the solid electrolyte slurry in this invention is not limited to casting coating; other coating methods capable of uniformly coating the solid electrolyte slurry onto the surface of the porous carbon material layer are also applicable to this invention.

[0063] Preferably, the casting speed of the casting coating is 0.05 to 0.4 m / min, for example, it can be 0.05 m / min, 0.1 m / min, 0.15 m / min, 0.2 m / min, 0.25 m / min, 0.3 m / min, 0.35 m / min or 0.4 m / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0064] This invention limits the casting speed of the casting coating to the range of 0.05 to 0.4 m / min. When the casting speed is too low, the solid electrolyte slurry is prone to accumulate, forming a wavy solid electrolyte layer on the surface of the porous carbon material layer; when the casting speed is too high, scratches are easily generated. Therefore, adjusting the casting speed to the range of 0.05 to 0.4 m / min is beneficial to uniformly coat the solid electrolyte slurry on the surface of the porous carbon material layer and helps to control the thickness of the solid electrolyte layer.

[0065] Preferably, the casting coating is performed under dry conditions.

[0066] Preferably, the dew point temperature of the drying conditions is -50 to -40°C, for example, it can be -50°C, -49°C, -48°C, -47°C, -46°C, -45°C, -44°C, -43°C, -42°C, -41°C or -40°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0067] This invention limits the dew point temperature to -50 to -40°C. This is because solid electrolytes are more sensitive to moisture. When the dew point is higher than -40°C, the electrolyte is prone to hydrolysis during the drying process. When the dew point is lower than -50°C, the manufacturing cost is too high.

[0068] Preferably, after the solid electrolyte slurry is coated onto one side of the porous carbon material layer, it is dried and cold-pressed in sequence to form the solid electrolyte layer.

[0069] Preferably, the drying temperature is 60 to 100°C, for example, it can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0070] When coating and drying using a casting machine, the casting machine has four drying tunnels, and the casting temperature is controlled at 60℃, 80℃, 80℃ and 80℃ respectively, so as to dry the solid electrolyte slurry in stages.

[0071] Preferably, the drying time is 10 to 80 minutes, for example, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes or 80 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0072] Preferably, the compaction density of the solid electrolyte layer is 2.0–2.5 g / cm³. 3 For example, it could be 2.0 g / cm³. 3 2.1g / cm 3 2.2g / cm 3 2.3g / cm 3 2.4g / cm 3 Or 2.5g / cm 3 However, it is not limited to the listed values; other unlisted values ​​within this range also apply. A further preferred value is 2.2–2.3 g / cm³. 3 .

[0073] Preferably, the electrode with a thickness of 15 to 50 μm is rolled onto the side of the porous carbon material layer away from the solid electrolyte layer to form an electrode layer.

[0074] Preferably, the rolling pressure is 1 to 3 MPa, for example, it can be 1 MPa, 1.2 MPa, 1.4 MPa, 1.6 MPa, 1.8 MPa, 2 MPa, 2.2 MPa, 2.4 MPa, 2.6 MPa, 2.8 MPa or 3 MPa, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0075] The present invention limits the calendering pressure to 1-3 MPa. When the pressure is too high, it is easy to cause the interpenetrating structure to contact the surface of the solid electrolyte away from the porous carbon material layer, that is, to form an interpenetrating structure on the surface of the solid electrolyte away from the porous carbon material layer. When the pressure is too low, the interpenetrating structure formed by the solid electrolyte layer and the electrode layer is not obvious, or even cannot form an interpenetrating structure.

[0076] Preferably, the electrode layer comprises a lithium metal and a lithium alloy layer.

[0077] As a preferred embodiment of the present invention, the preparation method includes:

[0078] S1: The porous carbon material layer with a porosity of 30-60%, a pore size of 2-5 μm, and a thickness of 50-100 μm is subjected to vacuum drying at 60-100°C until the moisture content of the porous carbon material layer is ≤200ppm.

[0079] S2: The solid electrolyte powder is vacuum dried at 60-100℃ until the moisture content of the solid electrolyte powder is ≤200ppm. Then the solid electrolyte powder is mixed with a solvent and ultrasonically dispersed and stirred in sequence to obtain a solid electrolyte slurry with a solid content of 20-60wt%. The stirring speed is 1000-1500rpm and the time is 1-3h.

[0080] S3: Under drying conditions with a dew point temperature of -50 to -40°C, the solid electrolyte slurry is coated onto one side of the porous carbon material layer. After drying at 60 to 100°C for 10 to 80 minutes, cold pressing is performed to form a compaction density of 2.0 to 2.5 g / cm³ on one side of the porous carbon material layer. 3 A solid electrolyte layer with a thickness of 10–20 μm;

[0081] S4: Under a pressure of 1 to 3 MPa, an electrode with a thickness of 15 to 50 μm is rolled onto the side of the porous carbon material layer away from the solid electrolyte layer to form an electrode layer with a thickness of 10 to 48 μm. The solid electrolyte layer and the electrode layer form an interpenetrating structure during the rolling process to obtain the solid electrolyte-electrode composite.

[0082] Thirdly, the present invention provides an all-solid-state battery, the all-solid-state battery comprising the solid electrolyte-electrode composite described in the first aspect.

[0083] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0084] The solid electrolyte-electrode composite provided by this invention, through the synergistic effect between the interpenetration structure of the solid electrolyte layer and the electrode layer and the porous carbon material layer, can not only increase the contact area between the solid electrolyte and the electrode, reduce the current density, and suppress lithium dendrite growth, but also has excellent mechanical strength, providing sufficient support strength to withstand the huge volume change stress during lithium metal deposition / stripping. This solves the problem of insufficient mechanical strength of solid electrolyte films, thereby further improving the cycle stability and rate performance of solid batteries. Detailed Implementation

[0085] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0086] Example 1

[0087] This embodiment provides a method for preparing a solid electrolyte-electrode composite, the method comprising:

[0088] S1: The carbon paper with a porosity of 45%, a pore size of 3.5 μm, and a thickness of 80 μm is vacuum dried at 80°C until the moisture content of the carbon paper is ≤200 ppm.

[0089] S2: The lithium phosphorus sulfur chlorine powder was vacuum dried at 80°C until the moisture content of the lithium phosphorus sulfur chlorine powder was ≤200ppm. Then the lithium phosphorus sulfur chlorine powder was mixed with p-xylene and ultrasonically dispersed and stirred in sequence to obtain a solid electrolyte slurry with a solid content of 40wt%. The stirring speed was 1200rpm and the time was 2h.

[0090] S3: Under drying conditions with a dew point temperature of -45℃, a solid electrolyte slurry is coated onto one side of carbon paper at a casting speed of 0.1 m / min. After drying at 60℃, 80℃, 80℃, and 80℃ for 10 min respectively, cold pressing is performed to form a compaction density of 2.3 g / cm³ on one side of the carbon paper. 3 A solid electrolyte layer with a thickness of 15 μm;

[0091] S4: Under a pressure of 2MPa, lithium metal with a thickness of 30μm is rolled onto the side of carbon paper away from the solid electrolyte layer to form an electrode layer with a thickness of 26μm. During the rolling process, the solid electrolyte layer and the electrode layer form an interpenetrating structure to obtain a solid electrolyte-electrode composite.

[0092] Example 2

[0093] This embodiment provides a method for preparing a solid electrolyte-electrode composite, the method comprising:

[0094] S1: The carbon paper with a porosity of 40%, a pore size of 4μm, and a thickness of 50μm is vacuum dried at 60℃ until the moisture content of the carbon paper is ≤200ppm.

[0095] S2: The lithium indium chloride powder was vacuum dried at 60°C until the moisture content of the lithium indium chloride powder was ≤200ppm. Then, the lithium indium chloride powder was mixed with n-heptane and ultrasonically dispersed and stirred in sequence to obtain a solid electrolyte slurry with a solid content of 20wt%. The stirring speed was 1000rpm and the time was 3h.

[0096] S3: Under drying conditions with a dew point temperature of -50℃, a solid electrolyte slurry is coated onto one side of carbon paper at a casting speed of 0.4 m / min. After drying at 60℃, 80℃, 80℃, and 100℃ for 10 min respectively, cold pressing is performed to form a compaction density of 2.2 g / cm³ on one side of the carbon paper. 3 A solid electrolyte layer with a thickness of 10 μm;

[0097] S4: Under a pressure of 1 MPa, lithium metal with a thickness of 50 μm is rolled onto the side of carbon paper away from the solid electrolyte layer to form an electrode layer with a thickness of 48 μm. During the rolling process, the solid electrolyte layer and the electrode layer form an interpenetrating structure to obtain a solid electrolyte-electrode composite.

[0098] Example 3

[0099] This embodiment provides a method for preparing a solid electrolyte-electrode composite, the method comprising:

[0100] S1: The carbon paper with a porosity of 50%, a pore size of 3μm, and a thickness of 100μm is vacuum dried at 100℃ until the moisture content of the carbon paper is ≤200ppm.

[0101] S2: The lithium phosphorus sulfur chlorine powder is vacuum dried at 100°C until the moisture content of the lithium phosphorus sulfur chlorine powder is ≤200ppm. Then the lithium phosphorus sulfur chlorine powder is mixed with p-xylene and ultrasonically dispersed and stirred in sequence to obtain a solid electrolyte slurry with a solid content of 60wt%. The stirring speed is 1500rpm and the time is 1h.

[0102] S3: Under drying conditions with a dew point temperature of -40℃, a solid electrolyte slurry is coated onto one side of carbon paper at a casting speed of 0.05 m / min. After drying at 60℃, 80℃, 80℃, and 80℃ for 10 min respectively, cold pressing is performed to form a compaction density of 2.3 g / cm³ on one side of the carbon paper. 3 A solid electrolyte layer with a thickness of 20 μm;

[0103] S4: Under a pressure of 3MPa, lithium metal with a thickness of 15μm is rolled onto the side of carbon paper away from the solid electrolyte layer to form an electrode layer with a thickness of 10μm. During the rolling process, the solid electrolyte layer and the electrode layer form an interpenetrating structure to obtain a solid electrolyte-electrode composite.

[0104] Example 4

[0105] This embodiment provides a method for preparing a solid electrolyte-electrode composite, the method comprising:

[0106] S1: The carbon cloth with a porosity of 30%, a pore size of 5μm, and a thickness of 60μm is vacuum dried at 80℃ until the moisture content of the carbon cloth is ≤200ppm.

[0107] S2: The lithium indium chloride powder was vacuum dried at 80°C until the moisture content of the lithium indium chloride powder was ≤200ppm. Then, the lithium indium chloride powder was mixed with toluene and ultrasonically dispersed and stirred in sequence to obtain a solid electrolyte slurry with a solid content of 30wt%. The stirring speed was 1200rpm and the time was 2h.

[0108] S3: Under dry conditions with a dew point temperature of -48℃, a solid electrolyte slurry is coated onto one side of the carbon cloth. After drying at 80℃ for 40 minutes, it is cold-pressed to form a compaction density of 2.0 g / cm³ on one side of the carbon cloth. 3 A solid electrolyte layer with a thickness of 18 μm;

[0109] S4: Under a pressure of 2MPa, lithium metal with a thickness of 40μm is rolled onto the side of the carbon cloth away from the solid electrolyte layer to form an electrode layer with a thickness of 37μm. During the rolling process, the solid electrolyte layer and the electrode layer form an interpenetrating structure to obtain a solid electrolyte-electrode composite.

[0110] Example 5

[0111] This embodiment provides a method for preparing a solid electrolyte-electrode composite, the method comprising:

[0112] S1: The carbon cloth with a porosity of 60%, a pore size of 2μm, and a thickness of 70μm is vacuum dried at 80℃ until the moisture content of the carbon cloth is ≤200ppm.

[0113] S2: The lithium indium chloride powder was vacuum dried at 80°C until the moisture content of the lithium indium chloride powder was ≤200ppm. Then, the lithium indium chloride powder was mixed with p-xylene and ultrasonically dispersed and stirred in sequence to obtain a solid electrolyte slurry with a solid content of 50wt%. The stirring speed was 1200rpm and the time was 2h.

[0114] S3: Under drying conditions with a dew point temperature of -42℃, a solid electrolyte slurry is coated onto one side of the carbon cloth. After drying at 60℃ for 50 minutes, it is cold-pressed to form a compaction density of 2.5 g / cm³ on one side of the carbon cloth. 3 A solid electrolyte layer with a thickness of 20 μm;

[0115] S4: Under a pressure of 2MPa, lithium metal with a thickness of 20μm is rolled onto the side of the carbon cloth away from the solid electrolyte layer to form an electrode layer with a thickness of 26μm. During the rolling process, the solid electrolyte layer and the electrode layer form an interpenetrating structure to obtain a solid electrolyte-electrode composite.

[0116] Example 6

[0117] The difference between this embodiment and Embodiment 1 is that in step S1, the porosity of the carbon paper is 25%, while the remaining process parameters and operating conditions are the same as in Embodiment 1.

[0118] Example 7

[0119] The difference between this embodiment and Embodiment 1 is that in step S1, the porosity of the carbon paper is 65%, while the remaining process parameters and operating conditions are the same as in Embodiment 1.

[0120] Example 8

[0121] The difference between this embodiment and Embodiment 1 is that in step S1, the pore size of the carbon paper is 1 μm, while the other process parameters and operating conditions are the same as in Embodiment 1.

[0122] Example 9

[0123] The difference between this embodiment and Embodiment 1 is that in step S1, the pore size of the carbon paper is 6μm, while the other process parameters and operating conditions are the same as in Embodiment 1.

[0124] Example 10

[0125] The difference between this embodiment and Embodiment 1 is that in step S3, the casting speed is 0.02 m / min, resulting in a solid electrolyte layer with an average thickness of 25 μm. The remaining process parameters and operating conditions are the same as in Embodiment 1.

[0126] Example 11

[0127] The difference between this embodiment and Embodiment 1 is that in step S3, the casting speed is 1m / min, resulting in a solid electrolyte layer with a thickness of 8μm. The remaining process parameters and operating conditions are the same as in Embodiment 1.

[0128] Example 12

[0129] The difference between this embodiment and Embodiment 1 is that, in step S3, the compaction density of the solid electrolyte layer is 1.5 g / cm³. 3 The remaining process parameters and operating conditions are the same as in Example 1.

[0130] Example 13

[0131] The difference between this embodiment and Embodiment 1 is that, in step S3, the compaction density of the solid electrolyte layer is 3 g / cm³. 3 The remaining process parameters and operating conditions are the same as in Example 1.

[0132] Example 14

[0133] The difference between this embodiment and Embodiment 1 is that in step S3, the solid electrolyte slurry is coated onto one side of the carbon paper under dry conditions with a dew point temperature of -30°C. The remaining process parameters and operating conditions are the same as in Embodiment 1.

[0134] Example 15

[0135] The difference between this embodiment and Embodiment 1 is that in step S3, the solid electrolyte slurry is coated onto one side of the carbon paper under dry conditions with a dew point temperature of -60°C. The remaining process parameters and operating conditions are the same as in Embodiment 1.

[0136] Comparative Example 1

[0137] The difference between this comparative example and Example 1 is that, in step S1, a dense carbon nanotube film is used instead of carbon paper, while the remaining process parameters and operating conditions are the same as in Example 1.

[0138] Comparative Example 2

[0139] The solid electrolyte-electrode composite provided in this comparative example eliminates the porous carbon material layer, that is, positive and negative electrode sheets are directly placed on both sides of the solid electrolyte layer to obtain a stacked battery cell. Its preparation process includes:

[0140] S1: The lithium phosphorus sulfur chlorine powder was vacuum dried at 80°C until the moisture content of the lithium phosphorus sulfur chlorine powder was ≤200ppm. Then the lithium phosphorus sulfur chlorine powder was mixed with p-xylene and ultrasonically dispersed and stirred in sequence to obtain a solid electrolyte slurry with a solid content of 40wt%. The stirring speed was 1200rpm and the time was 2h.

[0141] S2: The solid electrolyte slurry from step S1 is coated onto the surface of the PTFE membrane, with the thickness of the doctor blade being 300 μm. It is then dried at 100°C for 12 h to obtain the dried solid electrolyte layer. The solid electrolyte layer is then transferred to the surface of the positive electrode sheet using a roller press.

[0142] S3: Under a pressure of 2MPa, lithium metal with a thickness of 30μm is rolled to the side of the solid electrolyte layer away from the positive electrode to obtain a stacked cell.

[0143] The solid electrolyte-electrode composites from Examples 1-15 and Comparative Example 1, and the stacked cells from Comparative Example 2 were assembled into an all-solid-state battery. The assembly process included:

[0144] The solid electrolyte-electrode composite is cut into the required shapes and stacked sequentially with the positive electrode sheet of an all-solid-state battery to form a stacked cell. After encapsulation and isostatic pressing, the desired all-solid-state soft-pack battery is obtained. The positive electrode sheet is a stacked composite positive electrode sheet, prepared as follows: 65%-89% ternary 811 positive electrode material, 5%-20% solid electrolyte, 5%-10% conductive agent, and 1-5% polytetrafluoroethylene binder are weighed. These three components are first uniformly mixed using a mixer, and then placed in a ball mill and crushed at 600 rpm for 1-3 hours to obtain a uniformly mixed nano-composite positive electrode material. The above mixture is then heated under high shear force at 80℃-120℃ to shear and deform the polytetrafluoroethylene particles, causing them to mix. The powder is then subjected to vertical rolling, with the composite cathode powder passing through the gap between two hot rollers from top to bottom and forming the powder. The pressure of the vertical rollers is 5-20t, the temperature is 100-200℃, and the gap width between the two hot rollers is 20-50μm. After vertical rolling, horizontal rolling is performed, with the pressure of the horizontal rollers being 5-20t and the gap width between the two horizontal rollers being 20-50μm. This yields the formed composite cathode film, which is then rolled onto the surface of the current collector to obtain the completed cathode electrode sheet.

[0145] The electrochemical performance of the solid electrolyte-electrode composites in Examples 1-15 and Comparative Example 1, as well as the all-solid-state battery assembled from stacked cells in Comparative Example 2, was tested using the following parameters:

[0146] (1) Resistance test: An AC internal resistance meter was used to perform an ACR test on each battery under test, and the AC internal resistance and corresponding voltage value of each battery under test were recorded. The test temperature was fixed at 25℃.

[0147] (2) Cyclic Performance Test: Three batteries were selected for capacity calibration. Based on the actual capacity of the cells, cyclic charge-discharge tests were performed. The test steps were as follows: 1C constant current charging to 4.3V, 4.3V constant voltage charging to 0.05C, resting for 10 minutes, constant current discharging to 2.75V, and resting for 10 minutes. The above steps were repeated until the cell discharge capacity dropped below 80% of the calibrated capacity. The test temperature was fixed at 25℃.

[0148] (3) Rate Performance Test: Three batteries were selected for capacity calibration. Based on the actual capacity of the cells, rate performance tests were performed. The test method involved continuous discharge at currents of 0.2C, 0.33C, 0.5C, 1C, 2C, and 3C. Before each discharge, the cells were charged to 4.2V using a constant current of 1C, followed by a constant voltage charge to 0.05C using a constant voltage of 4.2V. The test temperature was fixed at 25℃.

[0149] The results of electrochemical performance tests on all-solid-state batteries assembled from the solid electrolyte-electrode composites in Examples 1-15 and Comparative Examples 1-2 are shown in Table 1.

[0150] Table 1

[0151]

[0152]

[0153] From the data in Table 1, we can obtain:

[0154] (1) The solid electrolyte-electrode composites prepared in Examples 1-5 are assembled into all-solid-state batteries with low resistance, good rate performance and excellent cycle performance. This shows that the present invention, through the interpenetration structure of the solid electrolyte layer and the electrode layer and the synergistic effect between the porous carbon material layer, can not only increase the contact area between the solid electrolyte and the electrode, reduce the current density and suppress lithium dendrite growth, but also has excellent mechanical strength, which can provide sufficient support strength to withstand the huge volume change stress during lithium metal deposition / stripping. This solves the problem of insufficient mechanical strength of the solid electrolyte membrane, thereby further improving the cycle stability and rate performance of the solid battery.

[0155] (2) The all-solid-state battery assembled from the solid electrolyte-electrode composite prepared in Example 6 has a higher resistance than that of Example 1, and its cycle performance and rate performance are both lower than those of Example 1. This is because the porosity of the porous carbon material layer in Example 6 is too low, and the electrolyte cannot form a continuous permeation network in the porous carbon material layer. The contact area with the electrode is reduced, and the internal resistance polarization is increased, which leads to a decrease in the rate performance and cycle performance of the battery. The all-solid-state battery assembled from the solid electrolyte-electrode composite prepared in Example 7 has a resistance that is not much different from that of Example 1, but its cycle performance and rate performance are both lower than those of Example 1. This is because the porosity of the porous carbon material layer in Example 7 is too high. The presence of a large number of voids leads to a decrease in the mechanical strength of the porous carbon material layer, which cannot maintain a good pore structure during cycling, resulting in the cell being prone to short circuits and a decrease in cycle stability.

[0156] (3) The all-solid-state batteries assembled from the solid electrolyte-electrode composites prepared in Examples 8 and 9 have higher resistance than those in Example 1, and lower cycle performance and rate performance than those in Example 1. This is because the pore size of the porous carbon material layer in Example 8 is too low, which easily causes blockage, thus preventing the electrolyte from penetrating into the electrode to form a uniform interface layer. In Example 9, the pore size of the porous carbon material layer is too high, and the surface tension cannot support the distribution of the electrolyte in the pores. It will continue to penetrate until it flows out of the porous carbon material layer, thus preventing the formation of a uniform solid electrolyte layer on the surface of the porous carbon material layer.

[0157] (4) The all-solid-state battery assembled from the solid electrolyte-electrode composite prepared in Example 10 has a lower cycle performance than that of Example 1. This is because the casting speed of the solid electrolyte slurry in Example 1 is too low, and the solid electrolyte slurry is easy to accumulate, forming a wavy solid electrolyte layer on the surface of the porous carbon material layer. The all-solid-state battery assembled from the solid electrolyte-electrode composite prepared in Example 11 has a higher resistance than that of Example 1, and its cycle performance and rate performance are both lower than those of Example 1. This is because the casting speed of the solid electrolyte slurry in Example 11 is too high, which easily produces scratches.

[0158] (5) The all-solid-state battery assembled from the solid electrolyte-electrode composite prepared in Example 12 has a higher resistance than that of Example 1, and its cycle performance and rate performance are lower than those of Example 1. The all-solid-state battery assembled from the solid electrolyte-electrode composite prepared in Example 13 has lower cycle performance than that of Example 1. This is because the compaction density of the solid electrolyte in Example 12 is too low, and the compaction density of the solid electrolyte in Example 13 is too high. As the compaction density increases, although the ionic conductivity of the solid electrolyte layer increases, the mechanical strength of the porous carbon material layer gradually decreases. Therefore, the present invention adjusts the compaction density of the solid electrolyte layer to the range of 2.0 to 2.5 g / cm3, which can balance the ionic conductivity of the solid electrolyte layer and the mechanical strength of the porous carbon material layer.

[0159] (6) The all-solid-state battery assembled from the solid electrolyte-electrode composite prepared in Example 14 has a higher resistance than that in Example 1, and its cycle performance and rate performance are lower than those in Example 1. The all-solid-state battery assembled from the solid electrolyte-electrode composite prepared in Example 15 has performance that is not much different from that in Example 1. This is because the dew point temperature in Example 14 is too high and the dew point temperature in Example 15 is too low. When the dew point temperature is too high, the solid electrolyte slurry is prone to hydrolysis during the drying process. When the dew point temperature is further reduced, the performance of the battery will not be further improved, but the cost will be increased instead.

[0160] (7) Comparative Example 1 uses a dense carbon nanotube film instead of a porous carbon material layer, which cannot form an interpenetrating structure between the solid electrolyte and the electrode layer, and lithium ions cannot migrate; while Comparative Example 2 omits the porous carbon material layer, and neither can achieve the synergistic effect between the interpenetrating structure of the solid electrolyte and the electrode layer and the porous carbon material layer of this application. The performance of the assembled batteries is lower than that of Example 1. This shows that the solid electrolyte-electrode composite provided by this invention, through the synergistic effect between the interpenetrating structure of the solid electrolyte and the electrode layer and the porous carbon material layer, can not only increase the contact area between the solid electrolyte and the electrode, reduce the current density, and inhibit the growth of lithium dendrites; but also has excellent mechanical strength, which can provide sufficient support strength, thereby withstanding the huge volume change stress during lithium metal deposition / stripping, solving the problem of insufficient mechanical strength of the solid electrolyte film, thereby further improving the cycle stability and rate performance of the solid battery.

[0161] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A solid-state electrolyte-electrode composite, characterized by, The solid electrolyte-electrode composite includes a porous carbon material layer, with a solid electrolyte layer and an electrode layer respectively disposed on both sides of the porous carbon material layer, and the solid electrolyte layer and the electrode layer forming an interpenetrating structure. The interpenetrating structure is located inside the porous carbon material layer and on both sides of the porous carbon material layer, and there is a gap between the interpenetrating structure and the surface of the solid electrolyte layer away from the porous carbon material layer. The electrode layer includes a lithium metal layer or a lithium alloy layer; The interpenetrating structure is formed by rolling the electrode layer onto the porous carbon material layer; The porosity of the porous carbon material layer is 30-60%; The pore size of the porous carbon material layer is 2~5μm.

2. The solid electrolyte-electrode composite according to claim 1, characterized in that, The thickness of the porous carbon material layer is 50~100μm.

3. The solid electrolyte-electrode composite according to claim 1, characterized in that, The thickness of the solid electrolyte layer is 10~20μm.

4. The solid electrolyte-electrode composite according to claim 1, characterized in that, The compaction density of the solid electrolyte layer is 2.0~2.5 g / cm³. 3 .

5. The solid electrolyte-electrode composite according to claim 1, characterized in that, The compaction density of the solid electrolyte layer is 2.2-2.3 g / cm 3 .

6. The solid electrolyte-electrode composite according to claim 1, characterized in that, The thickness of the electrode layer is 10~48μm.

7. The solid electrolyte-electrode composite according to claim 1, characterized in that, The porosity of the porous carbon material layer is 40-50%.

8. The solid electrolyte-electrode composite according to claim 1, characterized in that, The pore size of the porous carbon material layer is 3~4μm.

9. The solid electrolyte-electrode composite according to claim 1, characterized in that, The porous carbon material layer includes a carbon fiber layer.

10. The solid electrolyte-electrode composite according to claim 9, characterized in that, The carbon fiber layer includes carbon paper or carbon cloth.

11. The solid electrolyte-electrode composite according to claim 9, characterized in that, The carbon fiber layer is carbon paper.

12. The solid electrolyte-electrode composite according to claim 1, characterized in that, The solid electrolyte layer is made of either sulfide electrolyte or halide electrolyte.

13. The solid electrolyte-electrode composite according to claim 12, characterized in that, The sulfide electrolyte includes any one or a combination of at least two of lithium phosphorus sulfide chloride, lithium germanium phosphorus sulfide, lithium phosphorus sulfide chloride derivatives, or lithium germanium phosphorus sulfide derivatives.

14. The solid electrolyte-electrode composite according to claim 12, characterized in that, The sulfide electrolyte is lithium, phosphorus, sulfur, and chlorine.

15. The solid electrolyte-electrode composite according to claim 12, characterized in that, The halide electrolyte includes any one or a combination of at least two of lithium indium chloride, lithium yttrium chloride, lithium zirconium chloride, lithium indium chloride derivatives, lithium yttrium chloride derivatives, or lithium zirconium chloride derivatives.

16. The solid electrolyte-electrode composite according to claim 12, characterized in that, The halide electrolyte is lithium indium chloride.

17. A method for preparing a solid electrolyte-electrode composite according to any one of claims 1-16, characterized in that, The preparation method includes: A solid electrolyte slurry is coated on one side of a porous carbon material layer to form a solid electrolyte layer. An electrode is rolled to the other side of the porous carbon material layer to form an electrode layer. The solid electrolyte layer and the electrode layer form an interpenetrating structure during the rolling process. The electrode layer comprises lithium metal and lithium alloy layers.

18. The preparation method according to claim 17, characterized in that, The porous carbon material layer is dried before being coated with the solid electrolyte slurry.

19. The preparation method according to claim 17, characterized in that, The drying temperature of the porous carbon material layer is 60~100℃.

20. The preparation method according to claim 17, characterized in that, The drying process of the porous carbon material layer is carried out under vacuum conditions.

21. The preparation method according to claim 18, characterized in that, After the drying process, the moisture content of the porous carbon material layer is ≤200ppm.

22. The preparation method according to claim 18, characterized in that, The preparation process of the solid electrolyte slurry includes: mixing and dispersing solid electrolyte powder with a solvent to obtain the solid electrolyte slurry.

23. The preparation method according to claim 22, characterized in that, The solid electrolyte powder is dried and then mixed and dispersed with the solvent.

24. The preparation method according to claim 22, characterized in that, The drying temperature of the solid electrolyte powder is 60~100℃.

25. The preparation method according to claim 22, characterized in that, The drying process of the solid electrolyte powder is carried out under vacuum conditions.

26. The preparation method according to claim 23, characterized in that, After the drying process, the moisture content of the solid electrolyte powder is ≤200ppm.

27. The preparation method according to claim 22, characterized in that, The solvent is a non-polar solvent.

28. The preparation method according to claim 22, characterized in that, The solvent includes any one or a combination of at least two of p-xylene, toluene, n-heptane, p-xylene derivatives, toluene derivatives, or n-heptane derivatives.

29. The preparation method according to claim 22, characterized in that, The solvent is p-xylene and / or n-heptane.

30. The preparation method according to claim 22, characterized in that, The dispersion process includes: after the solid electrolyte powder is mixed with the solvent, it is then subjected to ultrasonic dispersion and stirring dispersion in sequence.

31. The preparation method according to claim 30, characterized in that, The stirring and dispersing speed is 1000~1500 rpm.

32. The preparation method according to claim 30, characterized in that, The stirring and dispersion time is 1 to 3 hours.

33. The preparation method according to claim 22, characterized in that, The solid electrolyte slurry has a solid content of 20~60wt%.

34. The preparation method according to claim 17, characterized in that, The coating method for the solid electrolyte slurry includes casting coating.

35. The preparation method according to claim 34, characterized in that, The casting speed of the coating is 0.05~0.4m / min.

36. The preparation method according to claim 34, characterized in that, The casting coating is performed under dry conditions.

37. The preparation method according to claim 36, characterized in that, The dew point temperature of the drying conditions is -50 to -40°C.

38. The preparation method according to claim 17, characterized in that, After the solid electrolyte slurry is coated onto one side of the porous carbon material layer, it is dried and cold-pressed in sequence to form the solid electrolyte layer.

39. The preparation method according to claim 38, characterized in that, The drying temperature is 60~100℃.

40. The preparation method according to claim 38, characterized in that, The drying time is 10-80 minutes.

41. The preparation method according to claim 17, characterized in that, The solid electrolyte layer has a compaction density of 2.0 to 2.5 g / cm 3 .

42. The preparation method according to claim 17, characterized in that, The compaction density of the solid electrolyte layer is 2.2-2.3 g / cm 3 .

43. The preparation method according to claim 17, characterized in that, The electrode, with a thickness of 15~50μm, is rolled onto the side of the porous carbon material layer away from the solid electrolyte layer to form an electrode layer.

44. The preparation method according to claim 17, characterized in that, The rolling pressure is 1~3MPa.

45. The preparation method according to claim 17, characterized in that, The preparation method includes: S1: A porous carbon material layer with a porosity of 30-60%, a pore size of 2-5 μm, and a thickness of 50-100 μm is subjected to vacuum drying at 60-100°C until the moisture content of the porous carbon material layer is ≤200 ppm. S2: The solid electrolyte powder is vacuum dried at 60~100℃ until the moisture content of the solid electrolyte powder is ≤200ppm. Then the solid electrolyte powder is mixed with a solvent and ultrasonically dispersed and stirred in sequence to obtain a solid electrolyte slurry with a solid content of 20~60wt%. The stirring speed is 1000~1500rpm and the time is 1~3h. S3: coating the solid electrolyte slurry to one side of the porous carbon material layer under dry conditions at a dew point temperature of -50 to -40°C, drying at 60 to 100°C for 10 to 80 min, cold-pressing, and forming a solid electrolyte layer having a compacted density of 2.0 to 2.5 g / cm 3 , a thickness of 10 to 20 μm on one side of the porous carbon material layer; S4: Under a pressure of 1~3MPa, an electrode with a thickness of 15~50μm is rolled onto the side of the porous carbon material layer away from the solid electrolyte layer to form an electrode layer with a thickness of 10~48μm. The solid electrolyte layer and the electrode layer form an interpenetrating structure during the rolling process to obtain the solid electrolyte-electrode composite.

46. ​​An all-solid-state battery, characterized in that, The all-solid-state battery includes the solid electrolyte-electrode composite as described in any one of claims 1-16.

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