136 results about "Fast ion conductor" patented technology

The invention relates to a lithium ion battery and a preparation method thereof. The lithium ion battery comprises a positive pole piece, a negative pole piece and a gel electrolyte, the gel electrolyte is formed by polymerizing an electrolyte prepolymerization solution, and the mass percentages of a cross-linking agent, a monomer and an initiator in the electrolyte prepolymerization solution are A%, B% and C% respectively; a positive electrode material layer in the positive electrode plate is formed by coating the surface of a positive electrode current collector with positive electrode slurry; the positive electrode slurry comprises a fast ion conductor, and the mass percentage content of the fast ion conductor in the positive electrode slurry is X%; the lithium ion battery satisfies the following relational expressions: the formula 1: 5 < B / A < 10; in the formula 2, C / (A + B) is more than 0.005 and less than 0.02; formula 3: 1.7 < = (A + B + C) / X < = 5.5. According to the scheme provided by the invention, a high-performance organic-inorganic hybrid network can be constructed, and the cycle performance of the battery is remarkably improved while the thermal shock performance of the battery is improved.

The invention discloses a lithium-rich manganese-based positive electrode material with a fast ion conductor coating layer and bulk phase doping and a preparation method of the lithium-rich manganese-based positive electrode material, the surface of the lithium-rich manganese-based positive electrode material is coated with the coating layer composed of amorphous Li3PO4, the interior of the bulk phase is doped with other elements, the structural formula of the lithium-rich manganese-based positive electrode material is Li < 1 + a > Mn M < c > O < 2 >, m is one or more than one of Ni, Co, A1, Cr, Fe, Mg and Ce, 0 lt; a is less than or equal to 0.2, 0lt; b < = 1, 0lt; c < = 1, and a + b + c = 1. The method comprises the following steps: (1) fully mixing a lithium-rich manganese-based positive electrode material precursor, a certain proportion of lithium salt and a proper amount of phosphate; and (2) sintering the uniformly mixed sample in a certain atmosphere to obtain the lithium-rich manganese-based positive electrode material with the fast ion conductor coating layer and the bulk phase doping structure. The first coulombic efficiency of the lithium-rich positive electrode material is improved, the cycling stability and the rate capability of the lithium-rich positive electrode material are improved, and the requirements of a power battery can be met.

The invention provides a lithium nickel manganese oxide positive electrode material and a preparation method thereof, a lithium ion battery and electric equipment, and relates to the field of lithium ion batteries. Comprising an inner core and a coating layer, the chemical general formula of the inner core is Li Ni < x > Mn < y > M < z > M'wO < 4 >; m comprises one or more of Al, Mg, Co, Mn, Ni, Ti, Zr, W, Nb, P, Sb, F, Sr and Se; m'comprises one or more of Mg, Co, Mn, Ni, Ti, Zr, W, Nb, P, Sb, F, Sr and Se; the coating layer comprises a LiM ''O-type fast ion conductor, and M'' comprises one or more of Mg, Al, Co, Mn, Ni, Ti, Zr, W, Nb, Sb, La and Se. According to the lithium nickel manganese oxide positive electrode material, M and M'are cooperatively doped, and then fast ion conductor coating is performed, so that the ion conductivity of the positive electrode material and the structural stability of the material under high voltage are remarkably improved.

The invention belongs to the technical field of battery positive electrode materials, and particularly relates to a high-rate manganese-based positive electrode material and a preparation method and application thereof.The high-rate manganese-based positive electrode material sequentially comprises a manganese-based active core, a mesoporous fast ion conductor shell layer and a pretreatment layer formed by coating the surface of the manganese-based active core with a boron-containing compound in situ from inside to outside, and the functionalized carbon nanotube three-dimensional conductive network penetrates through the active core and the shell layer. The preparation method comprises the following steps: carrying out boron-containing compound liquid phase pretreatment on a manganese-based active core to form a surface pretreatment layer, carrying out oxidation functionalization and lithiation modification on carbon nanotubes in sequence to construct an embedded three-dimensional conductive network, carrying out ball milling-ultrasonic dispersion to prepare precursor sol, and carrying out coating to form a fast ion conductor shell layer. According to the high-rate manganese-based positive electrode material and the preparation method thereof, through the synergistic effect of multiple structures, dissolution of manganese ions and collapse of the material structure are effectively inhibited, the high-rate performance and cycling stability of the material are improved, and the high-rate manganese-based positive electrode material has a good industrialization prospect.

The application provides a modified lithium-rich manganese-based material, a modification method of the lithium-rich manganese-based material, a secondary battery and an electric device. The modified lithium-rich manganese-based material comprises a lithium-rich manganese-based material co-doped with anions and cations and a fast ion conductor material, and a chemical formula of the lithium-rich manganese-based material is xLi2MnO3·(1-x)LiNi y Co z Mn a O2, wherein 0

The invention provides a lithium-rich manganese-based solid-state battery positive electrode material as well as a preparation method and application thereof, and relates to the technical field of solid-state battery positive electrode materials, the lithium-rich manganese-based solid-state battery positive electrode material comprises a lithium-rich manganese-based positive electrode material body and a composite coating layer of a fast ion conductor layer and an electronic conductor layer, and the composite coating layer coats the surface of the lithium-rich manganese-based positive electrode material body. Aiming at the problems of poor interface contact between a lithium-rich manganese base and a sulfide solid electrolyte in an all-solid-state battery, difficulty in ion transmission and unstable structure in a circulation process, the invention provides a lithium-rich manganese-based positive electrode material which can simultaneously realize high interface ion / electron conduction, excellent interface stability and effective inhibition of bulk phase structure degradation. Therefore, the electrochemical performance of the material in a solid-state battery is obviously improved.

The invention relates to the technical field of preparation of a lithium ion battery positive electrode material, in particular to a lithium-rich manganese-based positive electrode material with a gradient buffer layer, a preparation method of the lithium-rich manganese-based positive electrode material and an all-solid-state battery. The lithium-rich manganese-based composite material sequentially comprises a lithium-rich manganese-based core material, a gradient buffer layer wrapping the lithium-rich manganese-based core material and a surface modification layer wrapping the gradient buffer layer from inside to outside, and the gradient buffer layer sequentially comprises a spinel inner layer, a fast ion conductor middle layer and a self-repairing polymer outer layer from inside to outside. According to the invention, the gradient buffer layer is constructed outside the lithium-rich manganese-based core material, so that the problem of poor stability of the positive electrode material is solved, the surface modification layer is constructed outside the gradient buffer layer, and the problem of poor interface contact is cooperatively solved through precise spatial arrangement of all functional layers and optimization of ion and electron transmission paths. The method realizes bulk phase structure stability and interface dynamic repair, and is especially suitable for a high-energy-density all-solid-state lithium battery system.

The invention relates to the technical field of lithium ion batteries, in particular to an ultrahigh-nickel ternary positive electrode material as well as a preparation method and application thereof. The preparation method of the ultrahigh-nickel ternary positive electrode material provided by the invention comprises the following steps: mixing a first vinyl polymer, a precursor, a metal oxide and a solvent to obtain a spinning solution A; mixing a second vinyl polymer, a lithium source and a solvent to obtain a spinning solution B; respectively depositing the spinning solution A and the spinning solution B by adopting an opposite electrostatic spinning technology to obtain a film-shaped material, and sintering to obtain a matrix material; and coating the surface of a base material by a wet method to prepare a fast ion conductor coating layer, and carrying out second sintering to obtain the ultrahigh-nickel ternary positive electrode material. According to the method provided by the invention, the agglomeration phenomenon of the ultra-high nickel positive electrode material in the sintering process is effectively reduced, so that the lithium ion battery containing the ultra-high nickel ternary positive electrode material has relatively high capacity and excellent cycle performance.

The application provides a high-flexibility dielectric positive electrode binder and a preparation method thereof and a solid-state battery positive electrode. The high-flexibility dielectric positive electrode binder comprises a fluoropolymer matrix and a fast ion conductor; the fluoropolymer matrix is a copolymer of vinylidene fluoride (VDF) and a fluorine-containing comonomer, the fast ion conductor is in a one-dimensional nanowire shape and is dispersed in the fluoropolymer matrix; and the mass fraction of the fast ion conductor is 1% to 20% based on the fluoropolymer matrix. The application can simultaneously solve three core problems of physical continuity of an ion conduction path in the positive electrode, inhibition of a space charge layer at an interface and mechanical coating of active particles, thereby significantly improving the rate performance, cycle stability and actual energy density of the solid-state battery.

The invention discloses a high-performance electrode, a preparation method thereof and a solid-state battery. The high-performance electrode comprises a positive electrode, a current collector and a negative electrode, and the current collector is located between the positive electrode and the negative electrode; the negative electrode comprises a metal lithium composite material layer, and the metal lithium composite material layer comprises a granular metal lithium composite material or a pressure-deformed granular metal lithium composite material. The metal lithium composite material comprises: a lithium-containing core; the middle layer is constructed on the surface of the inner core and comprises a first framework formed by interweaving a first framework material, a second framework formed by a second framework material inserted into the first framework, and a limiting polymer for fixing the relative positions of the first framework and the second framework; and a housing comprising a conductive polymer layer and a lithium fast ion conductor distributed in the conductive polymer layer. The high-performance electrode has excellent cycle performance and high safety characteristics.

The invention discloses a positive electrode active material and a lithium ion secondary battery. The positive electrode active material comprises a lithium-rich manganese-based material, a first coating layer and a second coating layer, the first coating layer comprises a first fast ion conductor and coats part of the surface of the lithium-rich manganese-based material; the second coating layer comprises a first region and a second region which are connected with each other, the first region coats the lithium-rich manganese-based material which is not coated by the first coating layer, and the first region comprises lithium halide or a compound formed by the lithium halide and a second fast ion conductor; and the second region is coated with the first coating layer and comprises a compound formed by lithium halide and the first fast ion conductor or a compound formed by lithium halide, the first fast ion conductor and the second fast ion conductor. The two coating layers are closely connected in space and function, rapid ion / electron continuous transmission, stable interface chemistry and lasting physical protection are jointly achieved, and the rate capability and the cycling stability of the battery are improved while high-capacity exertion of the lithium-rich manganese-based material is guaranteed.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a modified single-crystal ternary positive electrode material as well as a preparation method and application thereof. The modified single crystal ternary positive electrode material comprises an inner core, a coating layer 1 and a coating layer 2 which are laminated in sequence, the general formula of the inner core is LixNiaCobMncLpO2 + q, x is more than or equal to 1.00 and less than or equal to 1.20, a is more than or equal to 0.10 and less than or equal to 0.60, b is more than or equal to 0.10 and less than or equal to 0.30, c is more than or equal to 0.10 and less than or equal to 0.30, p is more than or equal to 0.0001 and less than or equal to 0.03, q is more than or equal to 0 and less than or equal to 0.03, and L comprises at least one of Mg, Al, Ti, Zr, Y and Sb; the coating layer 1 comprises a fast ion conductor; and the coating layer 2 comprises a conductive polymer. According to the modified single crystal ternary positive electrode material provided by the invention, the rate capability and the cycle life are both considered while the high capacity is maintained.

The invention provides a multi-modified high-nickel ternary positive electrode material, a preparation method thereof and a solid-state battery. The multi-modified high-nickel ternary positive electrode material comprises a high-nickel ternary core, a fast ion conductor coating layer and a polymer ceramic nanofiber composite coating layer, wherein the fast ion conductor coating layer and the polymer ceramic nanofiber composite coating layer are sequentially arranged on the surface of the high-nickel ternary core. According to the multi-modified high-nickel ternary positive electrode material disclosed by the invention, a dual cooperative defense system of the fast ion conductor layer and the polymer ceramic composite layer is constructed, so that the interface problems of surface side reaction, transition metal dissolution and the like are effectively solved, and a bulk phase structure is indirectly stabilized through external constraint and reduction of surface induction factors; therefore, the comprehensive improvement of the capacity, the rate capability and the cycle performance of the high-nickel material under the conditions of high voltage and long cycle is realized.

This invention belongs to the field of battery active materials technology, specifically disclosing a lithium manganese iron phosphate composite material, its preparation method, and a secondary battery. The lithium manganese iron phosphate composite material includes a core and a first coating layer (carbon layer) and a second coating layer (fast ion conductor layer) sequentially covering the core from the inside out; the core comprises lithium manganese iron phosphate material LiFe. x Mn 1‑x D y PO4, 0 < x < 1, 0 ≤ y ≤ 0.1, D is the doping element; the fast ion conductor layer includes the fast ion conductor Li. a M b A c O d X e M represents titanium and / or zirconium, A represents nitrogen and / or phosphorus, and X represents at least one of fluorine, chlorine, bromine, or iodine, where 1 ≤ a ≤ 4, 0 ≤ b ≤ 5, 0 ≤ c ≤ 3, 0 ≤ d ≤ 12, and 0 ≤ e ≤ 2. This invention improves the structural stability and conductivity of lithium manganese iron phosphate by coating it with a fast ion conductor and a carbon bilayer, thereby enhancing the cycle life and rate performance of secondary batteries.

The lithium battery electrode plate comprises an electrode plate base body, a current guiding layer is arranged on the electrode plate base body, a self-adaptive buffer layer is arranged on one side of the current guiding layer, an ion enrichment layer is arranged on the side, away from the current guiding layer, of the self-adaptive buffer layer, and a conductive coating is arranged on the electrode plate base body. An interface fusion layer is arranged on one side, far away from the self-adaptive buffer layer, of the ion enrichment layer, and the current guide layer is a contact interface layer of the electrode plate substrate; the carbon nanotube array current guide layer which is distributed in a non-continuous net shape is arranged on the electrode plate base body, and is matched with the fast ion conductor material ion enrichment layer with higher ion conductivity to form a conduction-ion transmission synergistic structure, so that rapid and uniform conduction of charges can be guaranteed, efficient enrichment and migration of ions can be realized, and the service life of the electrode plate is prolonged. And the rate capability and the energy output efficiency of the battery are obviously improved.

This invention provides a separator and a base membrane, the base membrane comprising a central region and a peripheral region adjacent to the central region, the peripheral region comprising a first region located above the central region and a second region located below the central region; a first coating coated on the central region of the base membrane; and a second coating coated on the first and second regions of the base membrane; the first coating comprising first ceramic particles, a first binder, and a wetting agent; the second coating comprising a fast ion conductor material, second ceramic particles, and a second binder; wherein the ceramic particles in the first coating constitute 80%~95% by mass in the second coating, the fast ion conductor material in the second coating constitutes 10%~30% by mass, and the thickness T2 of the second coating is greater than the thickness T1 of the first coating. The separator of this invention can significantly improve interfacial contact performance, reduce interfacial impedance, and avoid puncture damage to the separator from the electrode edges; it also solves the problem of insufficient electrolyte wetting in the central region.

The application discloses a surface modification modified lithium-rich manganese-based positive electrode material, and a preparation method thereof. The lithium-rich manganese-based positive electrode material is coated with a fast ion conductor coating layer and a spinel structure layer rich in oxygen vacancies. The spinel structure layer is in-situ generated on the surface of the lithium-rich manganese-based positive electrode material, and the fast ion conductor coating layer is coated on the surface of the spinel structure layer. The application can improve the electrical properties of the lithium-rich manganese-based positive electrode material, including improving the initial specific discharge capacity and coulombic efficiency, and improving the cycle stability and rate characteristics, so that the lithium-rich manganese-based positive electrode material can meet the development requirements of high-power electronic devices, such as electric vehicles.

The invention relates to a positive electrode material, a pole piece and an electrochemical device and an electric device comprising the same, and belongs to the technical field of electrochemical energy storage. The positive electrode material provided by the invention comprises a base material and a coating layer coating the surface of the base material, the coating layer comprises Li-doped Co3O4, and a value in lattice constants of the Li-doped Co3O4 is 8.085-8.09. According to the positive electrode material provided by the invention, the Li-doped Co3O4 coating layer structure is arranged on the surface of the base material, and the coating layer has characteristics similar to a fast ion conductor microcosmically and has excellent electronic conductivity and lithium ion conduction capability, so that the dynamic behavior of charges in a high-speed transmission process is promoted; the capacity retention ratio and platform voltage stability of the battery under the high-rate charge-discharge condition are effectively improved, the gas production behavior of the positive electrode material in the circulation process is effectively relieved, and particle fragmentation is inhibited, so that the overall performance and reliability of the battery are improved.

The invention discloses a coated and modified high-nickel polycrystalline positive electrode material and a preparation method and application thereof, the coated and modified high-nickel polycrystalline positive electrode material provided by the invention comprises secondary polycrystalline particles composed of primary particles, the primary particles are arranged along the radial direction and are in contact with each other to form a grain boundary; a first coating layer is arranged at the grain boundary of the primary particle and the surface of the secondary polycrystalline particle, and the first coating layer comprises a fast ion conductor; and a second coating layer is also arranged on the first coating layer on the surface of the secondary polycrystalline particle. According to the coated and modified high-nickel polycrystalline positive electrode material, the lithium ion diffusion coefficient of the first coating layer is high, the diffusion impedance of lithium ions at the grain boundary can be reduced, and the interface lithium ion conduction is improved; the lithium ion diffusion coefficient of the second coating layer is lower than that of the first coating layer, and the second coating layer is used as a protective layer and can prevent the interface side reaction of the high-nickel polycrystalline positive electrode material and electrolyte, so that the electrochemical performance of the high-nickel polycrystalline positive electrode material is greatly improved.

The invention relates to the technical field of lithium ion batteries, and discloses an aromatic ring bridged phosphate additive for high-nickel positive electrode interface modification and a lithium ion battery. The additive has the general formula: [(RO) mP (= O)] k-L-[P (= O) (OR) n] j, where L is a rigid aromatic or cycloaliphatic linking group, R is alkyl or fluoroalkyl, k + j > = 2. The additive molecule has a plurality of Lewis-based phosphoryl (P = O) anchor points. When the battery is charged to a high voltage, the electrolyte is strongly combined with the surface of a high-nickel positive electrode with high activity and a high electron-deficient state through a multi-anchor-point synergistic adsorption mechanism, and is subjected to preferential oxygenolysis. After decomposition, the phosphoryl part forms an inorganic interface phase rich in LixPOy fast ion conductors, the rigid aromatic ring skeleton is converted into a high-stability conjugated carbon network, and the inorganic interface phase and the high-stability conjugated carbon network construct an inorganic-organic composite enhanced catholyte interface film (CEI). The CEI has excellent compactness, stability and mechanical properties, and can effectively inhibit electrolyte oxygenolysis and positive electrode interface side reaction. The additive is combined with an in-situ polymerization gel electrolyte, so that long-acting and stable interface modification can be realized, and the cycling stability of the high-nickel battery under high cut-off voltage is greatly improved.

This invention relates to a fast-ion conductor-coated all-solid-state manganese-based cathode material for lithium-ion batteries and its preparation method, belonging to the field of lithium-ion battery technology. It includes a lithium-rich manganese-based cathode material substrate and a fast-ion conductor coating layer (Li) covering the surface of the substrate. 1+2 / 3a Nb 1‑4 / 3a W a O3, 0.1≤a≤0.4; the coating layer is 0.5%~2% of the bulk mass, and the coating layer thickness is 5~20nm; it is obtained by adding the positive electrode material bulk to Nb-W sol and adding lithium salt, drying to form a gel-coated precursor powder, and then calcining. This invention uses Li 1+2 / 3a Nb 1‑4 / 3a W a The O3 fast ion conductor coating strategy modifies the interface of the cathode material, and significantly improves the overall performance of the all-solid-state lithium-ion battery by constructing a stable interface layer.

The invention provides a nickel cobalt lithium manganate single-crystal positive electrode material and a preparation method and application thereof. The preparation method comprises the following steps: mixing a nickel-cobalt-manganese precursor, a lithium salt and a primary sintering modifier, and then performing primary sintering in a mixed atmosphere to obtain a primary sintering material; the mixed atmosphere comprises oxygen-containing gas and doping gas, and the doping gas comprises CO2 and / or water vapor; and mixing the primary sintering material and a secondary sintering modifier in oxygen-containing gas for secondary sintering, and mixing the primary sintering material and a tertiary sintering modifier in oxygen-containing gas for tertiary sintering to obtain the nickel cobalt lithium manganate single crystal positive electrode material. According to the invention, CO2 and / or water vapor are / is introduced into the atmosphere of the first sintering as doping gas to improve residual alkali of the first sintering material, controllable free lithium is formed on the surface of the material, and the controllable free lithium reacts with the second sintering modifier to form an ultrathin embedded fast ion conductor, so that the effects of reducing the DCR of the material and improving the power performance of a battery cell are achieved, the production cost can be greatly reduced, and the production efficiency is improved. The method is suitable for industrial production of the ternary positive electrode material.

The invention discloses a PVDF-HFP-based composite solid electrolyte synergistically optimized by an ionic liquid and F127. The PVDF-HFP-based composite solid electrolyte comprises the following components in percentage by mass: 20-50% of PVDF-HFP, 10-20% of F127 and the balance of ionic liquid. 5 to 25 percent of F127; 15-30% of an inorganic ceramic fast ion conductor; 15 to 30% of LiTFSI (LiTFSI); and 5-40% of ionic liquid IL. According to the PVDF-HFP-based composite solid electrolyte synergistically optimized by the ionic liquid and the F127, the flexibility of the solid electrolyte can be improved, the interface contact can be improved, and meanwhile, the good ionic conductivity can be ensured; after being prepared into an electrolyte membrane, the electrolyte membrane is applied to a lithium-sulfur battery, so that the technical problems of low energy density and low safety caused by large electrolyte volume, shuttle effect and flammability in the lithium-sulfur battery can be solved.

The application relates to a positive electrode material with interface pre-distortion and bonding synergistic modification and a preparation method thereof, and belongs to the technical field of lithium ion batteries. The surface layer of the positive electrode material body is doped with rare earth element ions, and the surface of the positive electrode material body is a lithium-containing fast ion conductor network layer. The space and chemical synergy of the rare earth element and the TM element integrates the high-nickel positive electrode body phase and the surface heterojunction network into a high-cohesion whole, effectively resists anisotropic volume shrinkage in a cycle process, fundamentally alleviates internal stress concentration and inhibits the generation of harmful microcracks and O3-O1 irreversible phase change. The structural stability and the electrochemical performance of the material are significantly improved.

The application relates to the technical field of lithium batteries, and particularly discloses a positive plate, a preparation method thereof and a lithium battery. The positive plate comprises a current collector and a positive active material layer arranged on at least one side surface of the current collector, the positive active material layer comprises a main body area and edge areas arranged on both sides of the main body area, the edge areas are prepared from edge area slurry, and the edge area slurry comprises high-voltage positive materials coated with fast ion conductors. The positive plate provided by the application can provide a fast transmission channel for lithium ions in the discharging process by arranging high-voltage positive materials coated with fast ion conductors on the edge areas, so that the accumulation of lithium ions on the edge of the positive plate is avoided; meanwhile, the potential difference between the high-voltage positive materials and the main body materials can promote the spontaneous diffusion of the lithium ions embedded in the edge areas to the main body area, effectively reduces the lithium precipitation phenomenon on the negative edge, and makes the capacity retention rate of the battery reach 93.7% after 1000 cycles.

The invention provides a ternary positive electrode material with a tantalum-phosphorus coating layer as well as a preparation method and application of the ternary positive electrode material. The ternary positive electrode material comprises a high-nickel ternary material core and the tantalum-phosphorus coating layer coating the exterior of the high-nickel ternary material core, and the tantalum-phosphorus coating layer comprises the following components: a tantalum compound, a phosphorus compound and a fast ion conductor Li3PO4. In the ternary positive electrode material, a tantalum-phosphorus coating layer with crack resistance, high ionic conductivity and excellent stability is constructed through synergistic interface modification of a tantalum-containing component and a phosphorus-containing component, and dual functions are synchronously realized: 1, the tantalum-containing component strengthens the near-surface mechanical strength by virtue of a strong Ta-O bond; secondly, residual lithium is converted by utilizing a phosphorus component, a fast ion conductor Li3PO4 is generated in situ, and a fast lithium ion transmission channel is constructed; the high-nickel ternary lithium battery prepared from the ternary positive electrode material shows excellent cycle performance and rate capability under severe working conditions, and is suitable for improving the energy density of the battery in the prior art.

The present application relates to a kind of lithium-rich manganese-based positive electrode material, preparation method, positive plate and sulfide solid-state battery.The preparation method includes: mixing lithium-rich manganese-based precursor, lithium source, fast ion conductor material and hard ball milling beads, ball milling activation, obtain mixed material;The mixed material is sintered, and lithium-rich manganese-based positive electrode material is obtained;The fast ion conductor material includes LiNbO3, Li2ZrO3, LiTaO3 or Li3PO4-ZrO2 compound;The hard ball milling bead includes first hard ball milling bead and second hard ball milling bead, and the average diameter of first hard ball milling bead is greater than second hard ball milling bead.The present application is based on ball milling activation process and introduces fast ion conductor in raw material, realizes the body phase doping of lithium-rich manganese-based positive electrode material, while forming nanoscale modification layer on the surface of lithium-rich manganese-based positive electrode material, fundamentally optimizes solid-solid interface contact and ion transport kinetics, provides key material basis for high-performance solid-state battery.

This invention provides a lithium cobalt oxide cathode material coated with a lithium aluminum titanium phosphate composite, which has a core-shell structure, comprising a doped lithium cobalt oxide core material inside the core-shell structure and a coating layer formed on the surface of the doped lithium cobalt oxide core material; the chemical formula of the doped lithium cobalt oxide core material is: LiCo 1‑a‑b‑c Mg a Al b Ce c The coating layer comprises lithium aluminum titanium phosphate, cerium titanate, lithium cerium phosphate oxide, and lithium cerium phosphate. This invention's lithium aluminum titanium phosphate composite coating modified lithium cobalt oxide cathode material overcomes the defect of a sharp performance drop under high temperature and high pressure applications when lithium aluminum titanium phosphate is coated alone. The oxygen vacancies and coating structure provided by the composite coating layer of lithium aluminum titanium phosphate, cerium titanate, lithium cerium phosphate oxide, and lithium cerium phosphate enhance the structural continuity between the bulk phase and the coating layer, as well as the conductivity of the fast ion conductor, thereby enabling the material to maintain good cycle retention and capacity characteristics under high temperature and high pressure.

The invention discloses a high-voltage positive electrode compatible sulfide fast ion conductor and application thereof, and belongs to the technical field of all-solid-state batteries. The sulfide fast ion conductor meets the following conditions: 1) EF1-EF2 is less than 1.3 eV, EF1 is the Fermi energy level of the sulfide fast ion conductor, and EF2 is the 85% lithium removal state of LiNi0. 5Mn1. 5O4, namely the Fermi energy level of Li0. 15Ni0. 5Mn1. 5O4; 2) the average barde charge number of S atoms is not less than 7.1 e; the general chemical formula of the sulfide fast ion conductor is Lix-yMS4-y-zZzXy, M is selected from at least one of Al, Ga, In, Si, Ge, Sn, Sb, Bi, P and As, X is selected from at least one of F, Cl, Br and I, Z is selected from at least one of O and Se, and x, y and z meet the conditions that x is larger than or equal to 3 and smaller than or equal to 5, y is larger than or equal to 0 and smaller than or equal to 1, z is larger than or equal to 0 and smaller than or equal to 1, and y + z is larger than or equal to 0 and smaller than or equal to 1. By screening and optimizing the Fermi level and the Babbit charge number of the sulfide fast ion conductor, the chemical compatibility of the material and a high-voltage oxide positive electrode can be remarkably improved, the electrochemical stability of the material is enhanced, and the energy density and the cycle life of an all-solid-state battery can be synchronously improved.

This application discloses a lithium cobalt oxide cathode material, its preparation method, and a solid-state battery. The lithium cobalt oxide cathode material includes a lithium cobalt oxide core and a rock salt phase layer and a fast ion conductor layer sequentially coated on the surface of the lithium cobalt oxide core. The rock salt phase layer is made of cobalt oxide, and the fast ion conductor layer is made of Li. x M y O z Wherein, M includes at least one of Sm, Gd, La, Nd, Zr, Nb, and W, and x, y, and z are all greater than 0. This application, by forming a rock salt phase layer and a fast ion conductor layer on the surface of the lithium cobalt oxide core, can weaken the side reactions between the layered lithium cobalt oxide core and the sulfide electrolyte, reduce the impedance introduced by the space charge layer, and improve the interfacial diffusion capability of lithium ions, thereby achieving the effect of reducing interfacial impedance and improving the cycle performance and rate performance of solid-state batteries.