3846 results about "Solid-state battery" patented technology

The invention discloses a solid-state battery performance testing method and system based on data analysis, and relates to the field of battery performance testing, and the method comprises the steps: building a multi-physics field coupled digital twinborn model, collecting a strain signal and temperature field distribution of a failure region according to a three-dimensional physics field state map of the failure region, and when abnormally abruptly changed, carrying out the testing of the performance of a solid-state battery. Triggering multi-stage early warning, matching physical failure evidences with a historical database, extracting an optimal test parameter combination through a meta-learning framework, dynamically adjusting a charging and discharging strategy and monitoring frequency, generating a real-time data stream, and updating parameters of a multi-physics field coupled digital twin model through a back propagation algorithm. According to the method, the test parameters are dynamically optimized through the meta-learning framework, the performance of the solid-state battery is monitored and predicted, the safety and the reliability of the solid-state battery are improved, and a charging and discharging strategy is optimized to prolong the service life of the battery.

The embodiment of the invention provides a synthesis method and application of lithium sulfide. The synthesis method of the lithium sulfide comprises the following steps: providing a sulfur source and a lithium source; performing first treatment on the sulfur source to obtain sulfur vapor; performing second treatment on the lithium source to obtain molten metal lithium; and in an inert atmosphere, introducing the sulfur vapor into the molten metal lithium, and reacting to generate lithium sulfide. According to the synthesis method and application of the lithium sulfide provided by the embodiment of the invention, the sulfur source is converted into the sulfur vapor, the lithium source is converted into the molten metal lithium, and the gas-liquid out-phase reaction is carried out in the inert atmosphere, so that the reaction efficiency and the purity are improved, the process is simplified, the cost is reduced, and the high-purity requirement can be met; the purity can be improved through raw material pretreatment of sulfur steam and molten metal lithium, and the strict requirement of a solid-state battery for high-purity lithium sulfide is met.

The invention belongs to the technical field of solid-state battery materials, and discloses an inorganic solid-state electrolyte lanthanum lithium zirconate surface interface non-metallic element doped modified material using a plasma technology and a preparation method and application thereof, which can reduce the interface impedance of an electrolyte and improve the electrochemical performance of the electrolyte. By using the plasma technology, impurities such as lithium carbonate and the like on the surface of the inorganic solid electrolyte lanthanum lithium zirconate can be etched, a lithium-loving protective layer can be generated in situ on a surface interface, and the air stability of the electrolyte block is improved. According to the invention, multi-aspect modification can be realized by combining a plasma technology with a plurality of non-metallic element excitation sources, corresponding gain protection layers can be formed according to different requirements, and performance exertion of the battery in different fields is facilitated. When the inorganic solid electrolyte lanthanum lithium zirconate modified material obtained by the method disclosed by the invention is in contact with lithium metal to form a battery, the inorganic solid electrolyte lanthanum lithium zirconate modified material shows relatively low interface contact resistance and excellent cycling stability, and has a good application value.

The invention relates to the technical field of solid-state batteries, in particular to oxyhalide solid-state electrolyte as well as a preparation method and application thereof. The method comprises the following steps: taking molten salt LiaMbXc as a raw material, reacting with an oxide AdOf in a molten state, removing steam impurities by utilizing a high-temperature vacuumizing mode, and cooling to prepare the oxyhalide solid electrolyte; according to the invention, the molten salt raw material is molten at high temperature to form the ion melt, and the oxygen element is introduced to replace part of halogen, so that the hardness of the target electrolyte is reduced after cooling, the deformability at room temperature is improved, and the obtained electrolyte is high in conductivity and wide in antioxidant electrochemical window. The prepared oxyhalide solid electrolyte is used for preparing a positive electrode, the adhesion force between the electrolyte and positive electrode material particles, the actual microscopic contact area and the ion migration rate are improved through melt permeation, the problem of a positive electrode interface is effectively relieved, and the electrochemical performance of an all-solid-state battery is improved.

The invention relates to a composite solid electrolyte membrane with high ceramic content and a preparation method and application thereof. The preparation method comprises the following steps: mixing ceramic solid electrolyte particles activated by a silane coupling agent with an in-situ polymerization solution containing a cross-linking agent, an organic monomer, a plasticizer, a lithium salt, an ultraviolet light initiator and a thermal initiator to form solid electrolyte slurry, wherein the ceramic solid electrolyte particles account for 60-90% of the total mass of the composite solid electrolyte membrane; the preparation method comprises the following steps: coating a positive pole piece with solid electrolyte slurry, initiating shallow organic matter monomers and a cross-linking agent to generate in-situ polymerization through an ultraviolet light initiator, covering a negative pole piece for hot pressing treatment, initiating residual organic matter monomers and the cross-linking agent to generate in-situ polymerization through a thermal initiator, and forming a composite electrolyte membrane with high ceramic content. The invention also discloses an all-solid-state battery containing the composite solid electrolyte membrane. The solid-state battery containing the in-situ formed composite solid-state electrolyte membrane has relatively high cycling stability.

The invention discloses a preparation method and application of a sulfide solid electrolyte membrane based on a gradient polymer / ionic liquid composite binder, and an all-solid-state battery, and belongs to the technical field of all-solid-state batteries. The method comprises the following steps: firstly coating a polymer / ionic liquid / sulfide electrolyte composite layer through a gradient coating process, filling particle gaps under low pressure by utilizing the plasticizing effect of ionic liquid, and reducing the porosity of an interface; and then coating a polymer / sulfide electrolyte surface layer to provide mechanical support and inhibit side reaction of the electrode. According to the design, the electrolyte membrane still keeps high ionic conductivity under the working pressure of a commercial power battery module, and the interface impedance is reduced compared with that of a traditional homogeneous membrane. Through the innovative gradient structure and material combination, the ion transmission bottleneck of the sulfide electrolyte under the low-pressure condition is solved, excellent interface stability and process compatibility are achieved, and a key technical scheme is provided for all-solid-state battery industrialization.

The invention provides a solid electrolyte slurry, an electrode slurry, a solid electrolyte sheet, an electrode sheet, a solid battery monomer, a battery device and a power utilization device.The solid electrolyte slurry comprises a sulfide solid electrolyte material, a solvent and a binder dissolved in the solvent, and the solvent is a non-polar solvent, a weak-polar solvent or a mixed solvent of the non-polar solvent and the weak-polar solvent; the binding agent comprises a polyacrylate binding agent and a non-polar polyolefin binding agent. The slurry disclosed by the invention has high dispersity, high suspension property and good cohesiveness, and can enable the solid-state battery monomer to have high initial coulombic efficiency when being used in the solid-state battery monomer.

The invention provides a positive pole piece, a preparation method thereof and a sulfide all-solid-state battery. The positive pole piece comprises a positive current collector and a positive material layer arranged on the surface of the positive current collector, the positive electrode material layer comprises a modified positive electrode active material, an antioxidant, a sulfide electrolyte material, a conductive agent and a positive electrode binder, the modified positive electrode active material comprises an inner core and an oxide coating layer arranged on the surface of the inner core, and the inner core is a lithium-containing positive electrode active material. When the positive electrode plate containing the antioxidant and the modified positive electrode active material provided by the invention is applied to the sulfide all-solid-state battery, the synergistic effect of the antioxidant and the modified positive electrode active material can be exerted, so that the rate capability and the cycling stability of the sulfide all-solid-state battery are improved.

The invention relates to the technical field of solid-state battery energy conversion, and discloses a high-safety sodium-ion battery energy conversion method based on a solid-state electrolyte, which comprises the following steps: identifying an interface dynamic mismatch risk time period in a charging and discharging process, and applying micro-amplitude high-frequency acoustic vibration disturbance to a solid-state electrolyte and a sodium negative electrode interface in the time period, sodium ion microscopic distribution is regulated and controlled through the acoustic streaming effect, contact stress is dredged, dendritic crystal early nucleation is inhibited, dynamic reconstruction and optimization of the interface state are achieved, the solid-state sodium-electricity interface is converted into dynamic self-adaption from static mismatch, the ion transmission uniformity is actively maintained through the acoustic streaming effect, and dynamic reconstruction and optimization of the interface state are achieved. And meanwhile, real-time sensing of an interface state and dynamic adjustment of acoustic vibration parameters are realized in combination with an acoustic probing mechanism, so that the interface stability and dendritic crystal inhibition capability are effectively improved, and the energy conversion efficiency and the safety performance of the battery are remarkably enhanced.

The invention discloses a negative electrode interface modification material, a negative electrode plate, a positive electrode interface functional layer, a positive electrode plate, a solid-state battery and a power utilization device, and relates to the technical field of batteries, the negative electrode interface modification material comprises a first polymer matrix, a reinforcing filler, a conductive agent and a lithium salt, the modulus of the reinforcing filler is greater than 50 GPa. The tensile strength of the negative electrode interface modification material can be improved through the first polymer matrix, breakage of a negative electrode interface modification layer is reduced, interface impedance is reduced, meanwhile, the first polymer matrix can be matched with the expansion coefficient of a silicon-based material, and bulging of a negative electrode plate is reduced. The modulus of the reinforcing filler is greater than 50GPa, so that the modulus of the negative electrode interface modification layer can be improved, the expansion of the silicon-based active material is further inhibited, the conductive agent can relieve the problem that the flexible substrate interface of the copper foil and the negative electrode interface modification layer possibly causes unsmooth electron transmission, and the lithium salt can improve the ion conduction capability and reduce the interface impedance.

The invention discloses a high-interface-stability composite solid electrolyte membrane as well as a preparation method and application thereof. The composite solid electrolyte membrane comprises a gradient aperture three-dimensional porous skeleton formed by sintering inorganic solid electrolyte particles, a polymer electrolyte filled in a pore channel, and a plastic interface stable layer positioned between the electrolyte membrane and an electrode. The preparation method comprises the following steps: preparing a gradient aperture porous framework through a pore-forming agent template method and a tape casting technology, dipping and filling a polymer electrolyte precursor solution in a solution, accelerating in-situ polymerization by adopting electric induction, and performing hot-pressing treatment. The composite solid-state electrolyte membrane has high ionic conductivity, excellent interface compatibility and high mechanical strength, can effectively inhibit the growth of lithium dendrites, can be applied to solid-state batteries such as lithium metal batteries, lithium sulfur batteries and lithium air batteries, and can remarkably prolong the cycle life and improve the safety performance of the batteries, and the preparation process is suitable for large-scale production.

The invention belongs to the technical field of solid-state batteries, and provides a lithium-sulfur-phosphorus-chlorine-bromine solid-state electrolyte, a preparation method thereof and an all-solid-state battery. The preparation method comprises the following steps: mixing lithium sulfide and phosphorus sulfide, and carrying out ball milling to obtain a lithium-sulfur-phosphorus ternary mixture; in protective gas, the lithium-sulfur-phosphorus ternary mixture, lithium chloride and lithium bromide are mixed and then subjected to ball milling, and a lithium-sulfur-phosphorus-chlorine-bromine mixture is obtained; and carrying out heat treatment on the lithium-sulfur-phosphorus-chlorine-bromine mixture in protective gas to obtain the lithium-sulfur-phosphorus-chlorine-bromine solid electrolyte. The lithium-sulfur-phosphorus-chlorine-bromine solid electrolyte provided by the invention not only improves the electrochemical stability, but also maintains the high ionic conductivity characteristic.

The invention discloses a mixed ion conductor layer for a lithium metal negative electrode, a preparation method of the mixed ion conductor layer and an all-solid-state battery, and belongs to the technical field of sulfide all-solid-state batteries. The preparation method comprises the following steps: synthesizing a sulfide electrolyte 70 (0.75 Li2S-0.25 P2S5)-30LiI through a liquid phase, introducing graphene oxide and a lithium salt precursor 2, 5-dihydroxy-1, 4-benzene diphosphate in the electrolyte preparation process, and carrying out heat treatment and pressing to obtain a mixed ion conductor layer; the graphene oxide can isolate the sulfide electrolyte layer from the lithium metal negative electrode, interface reaction is avoided, and a special porous and interlayer structure provides a transverse growth space for lithium metal deposition. And meanwhile, the lithium diphosphate-based MOF among the graphene layers ensures the rapid movement of lithium ions, enhances the bulk diffusion of lithium at the negative electrode end, reduces the local current density, plays a role in dredging the distribution of the lithium ions, and remarkably prolongs the cycle life of the sulfide all-solid-state battery.

The invention discloses a preparation method of an all-solid-state battery unit, the all-solid-state battery unit and an all-solid-state battery module. The preparation method comprises the following steps: 1) pressing and pre-calcining a positive electrode unit to form a sintered laminated body; (2) alternately overlapping at least one negative electrode and the sintered laminated body in the step (1) to form an all-solid-state battery laminated body, and pressurizing the laminated body; (3) carrying out low-temperature primary calcination on the all-solid-state battery laminated body in the step (2); (4) carrying out high-temperature secondary calcination on the all-solid-state battery laminated body obtained in the step (3); wherein the positive electrode unit in the step 1 comprises a solid electrolyte layer, a composite electrode layer and a current collector layer; the composite electrode layer comprises a high ion channel layer and a high electron channel layer. The stable particle space is constructed through multiple times of calcination, the interface impedance between the electrode layer and the electrolyte layer and the interface impedance between the electrode layers are reduced, the densification between the solid electrolyte and the electrode is improved, and the battery capacity and the cycle performance are improved.

The invention provides a composite positive pole piece, a preparation method thereof and a solid-state battery. The composite positive pole piece comprises a positive pole current collector and a positive pole diaphragm arranged on the surface of the positive pole current collector, the positive pole diaphragm comprises a positive pole active material, a conductive agent and a first binder, a three-dimensional pore of the positive pole diaphragm comprises a halide solid electrolyte and a second binder, the three-dimensional pore is the positive pole active material, and the second binder is a second binder. And a gap between the conductive agent and the first binder. According to the composite positive pole piece provided by the invention, the halide solid electrolyte is contained in the three-dimensional pores of the positive pole piece, so that the contact area between the positive pole active material and the electrolyte is maximized, and the diffusion length of ions in the positive pole piece is shortened; the method is used for reducing the interface impedance between a positive electrode active material and an electrolyte in the battery so as to improve the rate capability and the cycling stability of the battery.

The invention provides a solid-state battery and a preparation method thereof, and particularly relates to the technical field of solid-state batteries. The solid-state battery is composed of a plurality of laminated units, the laminated unit comprises a positive pole piece, an all-solid-state electrolyte membrane and a negative pole piece which are sequentially stacked according to a sandwich structure; among the positive pole piece, the all-solid-state electrolyte membrane and the negative pole piece, convex structures and concave structures which are uniformly arranged are distributed on any two mutually contacted surfaces of the positive pole piece, the all-solid-state electrolyte membrane and the negative pole piece. When the components of the solid-state battery are overlapped, the convex structures and the concave structures on the surfaces of the solid-state battery can be mutually engaged to form a stable micro-embedded structure, the interface bonding strength between the positive electrode and the electrolyte and between the negative electrode and the electrolyte is greatly enhanced through physical embedding, and the problem of unstable bonding in the prior art is solved. Meanwhile, the uniform concave-convex structure ensures the controllability and consistency of the interface contact area, effectively reduces and stabilizes the interface impedance, improves the performance consistency of the pole piece, and further improves the production yield and the overall performance stability of the battery.

The present invention belongs to the technical field of polymer binders, and particularly relates to a solid-state battery binder and a preparation method thereof, the solid-state battery binder comprises: a viscous monomer which is an acrylate monomer having a C3-C12 alkyl side chain; the lithium-supplying monomer is a monomer containing phosphate ester or a monomer which contains hydroxyl and amino and is easy to prepare phosphate ester through a phosphate esterification reaction; the lithium-conducting monomer is polyethylene glycol acrylate containing an ethyoxyl structure and a derivative of the polyethylene glycol acrylate; the adhesive monomer, the lithium-supplying monomer and the lithium-conducting monomer are polymerized together through a multifunctional integrated design, the adhesive has high solubility in an ester solvent due to a large number of ester groups contained in the adhesive, so that the bonding effect and the ionic conductivity of the solid-state battery can be improved, and the adhesive provided by the invention has high bonding force, and can be applied to the lithium-ion battery. The composite material has the advantages of high conductivity, high flexibility, high ionic conductivity, high solubility, high electrochemical stability, high temperature resistance and excellent comprehensive performance.

The invention relates to a doped modified argyrodite type solid electrolyte and a preparation method thereof, and belongs to the technical field of all-solid-state battery materials. The chemical formula of the electrolyte is Li < 5.5 + 2x + 2y > P < 1-x-y > Y < x > Bi < y > S < 4.5-1.5 x-1.5 y > O < 1.5 x + 1.5 y > Cl < 1.5 >, x is greater than or equal to 0.01 and less than or equal to 0.04, and y is greater than or equal to 0.01 and less than or equal to 0.04; the yttrium element and the bismuth element are doped at the P site of the argyrodite type electrolyte, and the oxygen element is doped at the S site of the argyrodite type electrolyte. After the argyrodite type electrolyte is in contact with metal lithium, an interface protection layer rich in lithium oxide can be formed in situ at an interface in a circulating process, so that lithium can be uniformly deposited, the generation of interface side reaction is inhibited, the interface stability of the argyrodite type electrolyte to a lithium metal negative electrode is improved, and the polarization voltage of a symmetrical battery is reduced; and the cycling stability of the all-solid-state lithium metal battery is enhanced.

The invention discloses a composite sulfide solid-state electrolyte and a preparation method and application thereof, and relates to the technical field of solid-state batteries. The composite sulfide solid electrolyte comprises sulfide solid electrolyte particles and nano ion conductor particles which are stable to water vapor, wherein the nano ion conductor particles are uniformly distributed on the surfaces and gaps of the sulfide solid electrolyte particles to form a composite structure. Therefore, through the composite structure that the nano ion conductor particles are uniformly distributed on the surfaces of the sulfide particles and in the gaps, the surface coverage of the sulfide solid electrolyte can be increased, the hydrolysis reaction rate can be reduced, and the sulfide solid electrolyte is well protected while the reduction amplitude of the lithium ion conductivity is reduced; the stability to air is improved; and the electrochemical stability is also improved. In addition, the method is simple in process, has good mass production capacity, and has high application value for actual production.

The invention belongs to the technical field of new energy materials, and particularly relates to siloxane crosslinking modified polyether solid electrolyte and a preparation method thereof. According to the solid electrolyte, the electrophilic ring-opening polymerization reaction of a polymer monomer with an epoxy group is utilized, siloxane is used as a cross-linking agent, polyether chain structures are connected together to form a cross-linked network structure, the ionic conductivity can be increased, and the mechanical strength and the high-temperature dimensional stability can be improved; the lithium ion transference number is increased, the polarization is reduced, and the battery rate capability is improved; the oxidation stability of the electrolyte is improved; the decomposition reaction of polyether at high temperature is inhibited; the thermal stability and the flame retardant property of the polymer electrolyte are remarkably improved, so that the safety of a solid-state battery is improved.

The utility model provides an all-solid-state battery capable of preventing short circuit, and belongs to the technical field of all-solid-state batteries. The all-solid-state battery comprises a solid electrolyte layer, positive plates and negative plates, the positive plates and the negative plates are alternately stacked, the solid electrolyte layer is arranged between the positive plates and the negative plates, an insulating frame layer is further arranged between the positive plates and the negative plates, and the insulating frame layer is of a hollow quadrilateral frame structure. The inner frame is smaller than the positive plate, and the outer frame is larger than the positive plate. The lithium ion battery can prevent the structural integrity of the electrolyte layer from being damaged by the shearing effect generated by the edge of the pole piece under high voltage, so that the battery is short-circuited due to contact of the positive and negative pole pieces, the yield of the lithium ion battery is obviously improved, the short-circuit rate of the battery is reduced, and the cycle performance of the battery is improved.

The invention relates to the technical field of lithium ion batteries, in particular to a modified positive electrode material, a preparation method and application thereof, a positive electrode plate and an all-solid-state battery. The modified positive electrode material comprises a positive electrode material matrix, a singlet oxygen quencher serving as an inner coating layer and a conductive polymer serving as an outer coating layer, wherein the quenching rate constant of the singlet oxygen quencher is greater than or equal to 1 * 10 < 6 > M <-1 >. S <-1 >. The modified positive electrode material provided by the invention adopts double-layer coating, so that the problem of interface stability caused by oxygen evolution on the surface of the positive electrode material is solved; meanwhile, the modified positive electrode material is applied to the lithium ion battery, especially an all-solid-state battery, so that the cycling stability and safety of the lithium ion battery at high temperature and high pressure are improved.

The utility model discloses a solid-state battery testing device with a balanced pressurization function. The solid-state battery testing device is used for improving the precision of stacking pressure and the electrochemical performance of a solid-state battery during testing of the solid-state battery. The die comprises an upper cover plate, an upper base plate, an upper pole column plate, an upper pole column, a sealing washer, a pressure stud, a pressure stabilizing column, an upper die shell, a lining, a lower die shell, a solid-state battery, a lower pole column, a lower pole column plate, a pressure sensor, a lower base plate and a lower cover plate. The plurality of voltage stabilizing columns with the same height are uniformly arranged on the upper pole column plate, and the plurality of pressure sensors are correspondingly and uniformly arranged on the lower pole column plate, so that uniform stress in the plane of the solid-state battery in the testing process is ensured, and the performance and the data repeatability of the solid-state battery are improved. In addition, the change condition of the plane internal stress of the solid-state battery can be known according to real-time pressure data. The solid-state battery performance testing device is suitable for performance testing of various solid-state batteries, and has a wide application prospect in solid-state battery research.

Provided are: a negative electrode composite material for a negative electrode for a solid-state battery, the negative electrode composite material being capable of being used even when a high-capacity negative electrode active material having a large volume change rate and a sulfide-based solid electrolyte that is reactive with an ionic liquid are used in the negative electrode composite material; and a solid-state battery using the negative electrode composite material. As a result, it is possible to achieve a solid-state battery in which loss of an ion conduction path during charging and discharging of the solid-state battery is suppressed, and a decrease in capacity during a charging and discharging cycle is suppressed. The negative electrode composite material contains a specific ionic liquid. Specifically, in a negative electrode composite material containing a negative electrode active material, a solid electrolyte, and an ionic liquid, the negative electrode active material is a silicon-based negative electrode active material, the solid electrolyte is a sulfide-based solid electrolyte, and the ionic liquid contains an anion having a donor number of 9 or less as determined from the half-wave potential of a noble metal.

A method for synergistically preparing lithium sulfide by vacuum molten salt based on hydrogen sulfide-lithium salt reaction belongs to the technical field of battery materials, and comprises the following steps: placing a lithium salt solid in a reactor, introducing a molten salt medium on the surface of the lithium salt or in a reaction system, introducing purified hydrogen sulfide gas under a vacuum auxiliary condition, controlling the reaction temperature to be 200-500 DEG C, and reacting for 1-2 hours; and adjusting the flow rate of hydrogen sulfide to be 50-1000mL / min and the retention time to be 5-180min, continuously exhausting gas to discharge water vapor in the reaction process, stopping introducing hydrogen sulfide gas after the reaction is finished, cooling the system to room temperature under the protection of inert gas, taking out the product, washing to remove residual fused salt, and carrying out vacuum drying to obtain the high-purity lithium sulfide. The prepared lithium sulfide has high purity (greater than or equal to 99.90%), low defect density and an excellent crystal structure, and can be widely applied to lithium-sulfur batteries, all-solid-state batteries and novel energy storage technologies, so that the energy density is improved, the cycle life is prolonged, and the energy consumption is reduced.

The invention relates to a solid-state battery positive electrode material layer and a solid-state battery, belongs to the technical field of solid-state batteries, and is used for solving at least one of the problems that an existing solid-state battery is easy to crack, poor in contact and large in resistance, and a solid-state electrolyte battery prepared by a physical vapor deposition method is thin in electrode thickness, low in capacity and the like. A plurality of holes are formed in the positive electrode material layer, the diameter of each hole is 0.1-10 [mu] m, the opening area of each hole in the unit area of the positive electrode material layer accounts for 20-60% of the total area, and each hole is of a through hole structure. The positive electrode material layer of the solid-state battery is provided with a plurality of holes with through hole structures, the solid electrolyte is embedded into the holes, the holes are filled with the solid electrolyte, the solid electrolyte covers the positive electrode material layer, and the holes have specific diameters and opening areas, so that the ionic conductivity is improved, and the service life of the solid-state battery is prolonged. The thickness of the prepared positive electrode material layer can be designed as required.

The invention discloses a high-performance lithium-rich manganese oxide positive electrode material, a preparation method thereof and application of the high-performance lithium-rich manganese oxide positive electrode material to an all-solid-state battery. The lithium-rich manganese oxide positive electrode material coats / composites a lithium-rich manganese positive electrode base material and a lithium ion conductor or a conductive agent in situ through a freeze-drying method. In-situ coating / compounding of a lithium ion conductor or a conductive agent on the lithium-rich manganese oxide positive electrode material is realized through freeze drying, the interface impedance is effectively reduced, the interface stability is improved, and the lithium ion and electron transmission efficiency is improved. The lithium-rich manganese oxide positive electrode material prepared by the invention can inhibit the release and side reaction of lattice oxygen in the cycle process, and improve the structural stability and cycle life of the material; meanwhile, the freeze-drying method can maintain the nano dispersity and uniformity of the material, full solid-solid contact between the lithium-rich manganese material and a lithium ion conductor or a conductive agent is realized, and the high specific capacity of the lithium-rich manganese positive electrode material in all-solid-state battery application is ensured. The prepared lithium-rich manganese-based all-solid-state battery has the reversible specific capacity as high as 273 mAh / g, the bottleneck that the capacity release of the lithium-rich manganese oxide positive electrode material in an all-solid-state battery system is limited is broken through, the strategy provides a new design thought and technical path for the construction of the high-specific-energy all-solid-state battery positive electrode material, the adopted process is simple and controllable, and the method is suitable for industrial production. The method is suitable for large-scale preparation.

The invention provides a preparation method of sulfide electrolyte and a solid-state battery. The method comprises the following steps: uniformly mixing lithium sulfide and lithium chloride, and pre-sintering the uniformly mixed substance at the temperature of 600-1000 DEG C to obtain a composite precursor; and uniformly mixing the composite precursor with phosphorus pentasulfide, and sintering the uniformly mixed substance to obtain the sulfide electrolyte. The method is used for achieving the effect of improving the ionic conductivity of the sulfide electrolyte.

The invention provides a positive electrode active material and a preparation method thereof, a positive electrode and a solid-state battery, and particularly relates to the technical field of solid-state batteries. The positive electrode active material has a core-shell structure, and the core-shell structure comprises a core layer and a coating layer coating the core layer; the core layer is made of a lithium-rich manganese-based material; and the coating layer is made of a fast ion conductor and a halide solid electrolyte. The fast ion conductor in the coating layer of the positive electrode active material can improve the ionic conductivity of the surface layer of the positive electrode active material, promote rapid migration of lithium ions and assist in improving the initial coulombic efficiency. Meanwhile, the coating layer improves the chemical stability of the positive electrode active material, effectively inhibits the interface side reaction between the positive electrode body and the sulfide electrolyte, and relieves the structural degradation in the cycle process. The coating layer can also be used as a buffer layer to inhibit stress generated by volume shrinkage and expansion in charge and discharge cycles, maintain good contact of an electrode interface, and realize improvement of the electrochemical performance of the material.

The invention relates to a sulfide composite solid-state electrolyte membrane, a preparation method thereof and a solid-state battery, and belongs to the technical field of solid-state electrolyte materials. The preparation method comprises the following steps: mixing a component A, a component B and a solvent under anhydrous and anaerobic conditions, and carrying out a heating reaction to obtain a precursor solution containing a high-molecular polymer; mixing the sulfide solid electrolyte with the precursor solution, and adding a solvent to adjust the solid content to 25-60% to obtain electrolyte slurry; coating the electrolyte slurry on the surface of a base material, drying to form a film on the surface of the base material, and removing the base material to obtain a sulfide composite solid electrolyte film; wherein the mass ratio of the effective components in the sulfide solid electrolyte to the effective components in the precursor solution is (99.5-90): (0.5-10). The sulfide composite solid electrolyte membrane has relatively good flexibility, and good contact between the membrane and an electrode can be maintained, so that the interface resistance is reduced.