60 results about "Lithium aluminate" patented technology

The invention relates to the technical field of lithium batteries, in particular to a preparation method of a high-temperature-resistant lithium battery cell. The invention discloses a preparation method of a high-temperature-resistant lithium battery cell, which is characterized in that through full-chain synergy of modification of positive and negative electrode materials, electrolyte optimization and structural design, a positive electrode adopts nickel cobalt lithium aluminate with a core-shell structure, and a metal organic framework coordination layer, polyaniline-polyacrylic acid multilayer coating and foam aluminum foil 3D printing coating are combined. The negative electrode takes silicon-carbon core-shell particles as a substrate, and breaks through the expansion bottleneck of a silicon-based negative electrode through metal organic framework confinement coating, polyaniline-polyacrylic acid cross-linked network modification and foam copper foil functionalization. The electrolyte adopts a film-forming additive and lithium difluorophosphate to form a stable SEI film, and internal resistance increase at high temperature is inhibited. The aramid fiber coating diaphragm and the aluminum alloy shell are matched, so that the thermal stability of the battery cell is remarkably improved, the battery cell can stably work in a wide temperature range environment, high energy density and long cycle life are comprehensively realized, and key support is provided for a long-endurance and high-safety battery.

The invention belongs to the technical field of waste lithium battery recovery, and particularly relates to a method for selectively extracting lithium from a waste lithium battery positive electrode material based on activation and oxidation, which comprises the following steps: mixing the waste lithium battery positive electrode material, an oxidizing agent, an activating agent and a solvent, stirring and leaching, and carrying out solid-liquid separation to obtain a lithium-rich leaching solution and valuable metal leaching residues; wherein the activating agent is one or more than two of divalent ferrite, divalent cobalt salt, divalent manganese salt, divalent copper salt and monovalent silver salt, and the waste lithium battery positive electrode material is selected from one or more than two of waste nickel cobalt lithium manganate batteries, waste nickel cobalt lithium aluminate batteries, waste lithium cobalt oxide batteries and waste lithium manganate batteries. Through the synergistic effect of the oxidizing agent and the activating agent, preferential extraction of lithium in the raw material is achieved in one step, the problem that the lithium loss amount is large in the later lithium extraction process is solved, and the method has the advantages of being easy and convenient to operate, short in technological process, good in lithium selectivity, high in lithium leaching rate, wide in temperature application range and low in recovery cost.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a lithium nickel cobalt aluminate / carbon composite positive electrode material with a core-shell structure and a spray drying process thereof, the lithium nickel cobalt aluminate / carbon composite positive electrode material comprises the following raw materials: a lithium source, an iron source, a phosphorus source, a carbon source and a solvent; the method specifically comprises the following steps: S1, dissolving a lithium source, an iron source, a phosphorus source and a carbon source in a solvent, mixing according to a stoichiometric ratio, adjusting the pH value by using ammonia water or citric acid, and adding a binder to adjust the viscosity to obtain a precursor solution; s2, atomizing the precursor solution into tiny liquid drops by a centrifugal or pressure type spray dryer through a nozzle or a centrifugal disc, and staying the liquid drops in a tower for 4-10 seconds to obtain a dried microsphere precursor; s3, presintering the dried microsphere precursor in an inert atmosphere at 300-400 DEG C through a firing device, and removing volatile components; and S4, cooling the pre-sintered and dried microsphere precursor, and calcining in the firing device again to form crystals.

The invention discloses a long-life lithium manganese iron phosphate positive electrode material and a preparation method thereof, and relates to the technical field of lithium ion battery positive electrode materials. The long-life lithium manganese iron phosphate positive electrode material comprises lithium manganese iron phosphate, a middle coating layer and a carbon coating layer, the surface of the lithium manganese iron phosphate is coated with the middle coating layer, the surface of the middle coating layer is coated with the carbon coating layer, the middle coating layer contains metal fluoride and aluminum-containing sinter, and the aluminum-containing sinter comprises aluminum oxide and lithium metaaluminate. The synergistic coating of the middle coating layer and the carbon coating layer can effectively reduce the contact between the positive electrode material and an electrolyte, inhibit the generation of surface side reactions, improve the stability of the electrode material structure, and have low manganese dissolution and excellent cycle life.

The invention relates to the technical field of solid-state batteries, in particular to a eutectic solid-state electrolyte diaphragm, a preparation method thereof and a solid-state battery. The preparation method of the eutectic solid electrolyte diaphragm comprises the following steps: mixing oxygen-containing lithium tetrachloroaluminate and imide lithium salt, melting and quenching, and pressing; wherein the chemical formula of the oxygen-containing lithium aluminum tetrachloride is LiAlCl < 4-2x > O < x >, and x < lt > is greater than or equal to 0.01; 2; the imide lithium salt comprises lithium bis (fluorosulfonyl) imide and / or lithium bis (trifluoromethylsulfonyl) imide. The preparation method is simple and low in cost, is similar to a traditional liquid battery process, and can quickly realize batch production; and the eutectic solid electrolyte diaphragm prepared by the method has high ionic conductivity, wide electrochemical window, good thermal stability and good interface compatibility.

The invention discloses an in-situ polymerization gel polymer electrolyte, a preparation method thereof and a silicon-based lithium ion battery, and belongs to the technical field of solid electrolyte. Fluorine-atom-containing fluoromethacrylate is introduced into polyethylene glycol diacrylate for copolymerization modification, in-situ polymerization is carried out in the battery to form a three-dimensional network structure, and a copolymer of polyethylene glycol diacrylate (PEGDA) and fluoromethacrylate is used as a skeleton, so that liquid electrolyte can be firmly locked in a polymer matrix; a chemical integrated interface is generated in the battery curing stage, and the interface performance is improved. Compared with a liquid electrolyte, the electrolyte battery has the advantages that the cycle life is greatly prolonged and the safety is improved on the premise that the capacity is well exerted. Moreover, the positive electrode material is well compatible with various positive electrode materials such as nickel cobalt lithium manganate and nickel cobalt lithium aluminate, and a comprehensive solution for buffering volume change, stabilizing an interface and improving safety is provided for the silicon-based lithium ion battery.

This invention discloses a preform for the hot top of a crystallizer specifically for semi-continuous casting of aluminum-lithium alloys and its manufacturing method. Addressing the problems of severe interfacial reactions between existing refractory materials and molten aluminum-lithium alloys, resulting in poor forming quality of semi-continuous casting ingots, this invention employs a gradient composite structure design: lithium aluminate is introduced into the working layer to thermodynamically suppress interfacial reactions by increasing the intrinsic lithium chemical sites; the insulation layer contains β-lithium nepheline and lithium aluminate to improve the insulation performance and thermal shock resistance of the hot top. Furthermore, by using a gradient distribution of lithium compound concentrations and types, combined with a multi-stage sintering process, the interlayer bonding strength is improved. Results show that this invention not only significantly reduces the interfacial reaction between the molten aluminum-lithium alloy and the hot top during semi-continuous casting, improving the forming quality of aluminum-lithium alloy ingots, but also extends the service life of the preform.

The invention belongs to the technical field of quantum dot glass ceramics, and relates to high-modulus multiphase quantum dot glass ceramics as well as a preparation method and application thereof. The microcrystalline glass comprises eucryptite (LiAlSiO4), lithium aluminate (LiAlO2) and quantum dots (CsPbBr3), wherein the eucryptite (LiAlSiO4) and the lithium aluminate (LiAlO2) are main crystalline phases. The surface of the LiAlO2 crystal phase is coated with the LiAlSiO4 crystal phase or gaps of the LiAlO2 crystal phase are filled with the LiAlSiO4 crystal phase to form a multi-phase reinforced structure, and the CsPbBr3 quantum dot glass ceramic has excellent water stability and deformation resistance. The preparation method comprises the following steps: respectively preparing a basic glass batch and a CsPbBr3 quantum dot precursor, and carrying out melting, water quenching and grinding on the glass batch to obtain basic glass powder; the preparation method comprises the following steps: placing a quantum dot precursor at the bottom of a platinum crucible by adopting a layered loading process, then covering basic glass powder, and finally obtaining the quantum dot microcrystalline glass through melting homogenization, casting molding and controlled heat treatment. The method is simple in process and high in controllability; the obtained product is excellent in comprehensive performance and good in application prospect.

The invention discloses an electrochemical device and an electronic device, the electrochemical device comprises a positive pole piece, a negative pole piece and a non-aqueous electrolyte, the positive pole piece comprises a positive pole material layer, the negative pole piece comprises a negative pole material layer, and the negative pole material layer comprises a negative pole material; the positive electrode material layer comprises a nickel cobalt lithium manganate material and / or a nickel cobalt lithium aluminate material, the mass content of a nickel element in the positive electrode material layer is m%, and m is larger than or equal to 29 and smaller than or equal to 56.5; the negative electrode material comprises a silicon element, the mass content of the silicon element in the negative electrode material layer is e%, and e is larger than or equal to 3.5 and smaller than or equal to 60; the non-aqueous electrolyte comprises fluoroethylene carbonate and a compound shown in a formula I, based on the total mass of the non-aqueous electrolyte, the mass content of the compound shown in the formula I is a%, the mass content of fluoroethylene carbonate is b%, a is larger than or equal to 0.5 and smaller than or equal to 20, b is larger than or equal to 1 and smaller than or equal to 30, and a / b is larger than 0.2 and smaller than or equal to 4.

The present disclosure relates to a halogen-doped nickel-cobalt-lithium aluminate, a preparation method and application thereof, the method comprising the following steps: S1, mixing nickel hydroxide with an aluminum source in a first solid phase to obtain a first solid material; S2, mixing the first solid material with a cobalt source in a second solid phase, and performing a first heat treatment on the obtained mixture in a first oxygen-containing atmosphere to obtain a second solid material; S3, mixing the second solid material with a lithium source in a third solid phase, and performing a second heat treatment on the obtained mixture in a second oxygen-containing atmosphere; the cobalt source and / or the aluminum source contain halogen. The method has simple steps, is conducive to industrial scale-up implementation and batch production, and the prepared halogen-doped nickel-cobalt-lithium aluminate has relatively uniform mixing of elements; when used as a positive electrode material of a lithium ion battery, the halogen-doped nickel-cobalt-lithium aluminate has a high specific capacity and good cycle performance.

The application discloses a lithium aluminate composite saggar and a preparation method and application thereof, and belongs to the technical field of saggar, wherein the saggar comprises an inner surface working layer and an outer matrix layer from inside to outside; the thickness of the inner surface working layer is 1-3 mm; the inner surface working layer comprises the following preparation raw materials in parts by weight: synthetic lithium aluminate 5-20 parts, kaolin 2-10 parts, fused zirconium mullite 0-10 parts, zirconium oxide 0-15 parts, zirconium silicate 0-10 parts, spinel 60-80 parts, alumina 0-10 parts, organic binder 0-5 parts, and water 1-5 parts. The synthetic lithium aluminate is added in the saggar formula system, the structure is solidified during saggar firing, according to the principle of Fick's first law, the addition of lithium aluminate can slow down the alkali corrosion of the material to the saggar, effectively restrict the volume change in the positive electrode material, and effectively improve the service life of the saggar.

The invention relates to the technical field of lithium ion batteries, and discloses a lithium ion battery cell and a method for detecting the dissolved amount of transition metal. The lithium ion battery cell comprises a roll core formed by winding a positive plate, a diaphragm and a negative plate, electrolyte and a metal shell used for placing the roll core, the positive plate comprises a positive current collector and a positive active material substance layer coated on at least one surface of the positive current collector, and the negative plate comprises a negative current collector and a positive active material substance layer coated on at least one surface of the positive current collector. The positive electrode active material substance layer comprises one or more of lithium iron phosphate, lithium iron manganese phosphate, nickel cobalt lithium manganate, nickel cobalt lithium aluminate, nickel cobalt manganese lithium aluminate, spinel lithium manganate, spinel nickel lithium manganate and layered lithium manganate, and the dissolved amount of transition metal Mn in the battery cell is less than or equal to 0.02 g / Ah.

The invention provides a method for efficiently improving the performance of a nickel ternary material, which comprises the following steps: adding a solution containing aluminum ions into a positive electrode material, grinding, uniformly mixing, heating and calcining in an air atmosphere to obtain a modified high-nickel ternary material, preparing lithium titanate, putting the lithium titanate and the modified high-nickel ternary material into an organic solvent, uniformly mixing, heating, stirring, evaporating to dryness, grinding and sieving to obtain a precursor; and heating the precursor for 1-2 hours at the temperature of 700-800 DEG C in an inert atmosphere, and naturally cooling. According to the method, the high-nickel ternary material is subjected to surface treatment through a solution containing aluminum ions, Li2CO3 and LiOH existing on the surface of the high-nickel material are absorbed to reduce the content of lithium salt impurities in the positive electrode material, alkaline residues on the surface of the electrode material are reduced, and the interface transfer impedance of the electrode material is reduced; and meanwhile, a small amount of lithium metaaluminate is synthesized to coat the surface of the ternary material, so that the cycling stability and thermodynamic property of the high-nickel material are improved.

The invention relates to the technical field of positive electrode material modification, in particular to a positive electrode material and a modification method thereof. The modification method of the positive electrode material provided by the invention comprises the following steps: S1, mixing a precursor, a lithium source and a doping material, and carrying out primary sintering to obtain a primary sintered material, the doping material comprising an aluminum source, an antimony source and a zirconium source; s2, washing the first sintered material with water, and carrying out solid-liquid separation to obtain an intermediate; and S3, mixing the intermediate with boric acid and lithium metaaluminate, and carrying out secondary sintering to obtain the modified positive electrode material. The three elements of aluminum, zirconium and antimony are doped, so that the direct-current resistance is effectively reduced, the side reaction in the material is reduced, and the de-intercalation rate of lithium ions is improved. According to the invention, before coating, residual alkali on the surface of the material is washed off by setting the step of washing and coating, so that the cycle performance of the positive electrode material is further improved, and meanwhile, boric acid and lithium metaaluminate are used for isolating the contact between the positive electrode material and an electrolyte to a great extent, so that the cycle performance of the material is improved.

The invention relates to the technical field of batteries, in particular to a negative plate and a lithium ion secondary battery comprising the same. The negative plate comprises a negative active coating, the negative active coating comprises a silicon-based material, and the silicon-based material comprises silicon-carbon particles and a coating layer located on the outer surfaces of the silicon-carbon particles; the coating layer comprises a first coating layer and a second coating layer; the second coating layer at least comprises lithium metaaluminate; based on the total weight of the silicon-based material, the mass content of Al in the second coating layer is A, and the unit is ppm; a plurality of first concave parts are arranged on the surface of the negative electrode active coating on at least one side surface of the negative electrode current collector, the depth of each first concave part is H, and the unit is mu m; and the mass content A of Al in the silicon-based material and the depth H of the first concave part meet the condition that H / A is more than or equal to 0.002 and less than or equal to 0.669. According to the lithium ion secondary battery, the structural stability of the negative plate is remarkably improved, and the lithium ion secondary battery has excellent rate capability and cycle performance.

The invention relates to the technical field of solid-state batteries, in particular to a eutectic solid-state electrolyte coating diaphragm, a solid-state battery and a preparation method of the solid-state battery. The preparation method of the eutectic solid electrolyte coated diaphragm comprises the following steps: coating a base membrane with slurry, and then drying; the slurry is mainly composed of oxygen-containing lithium tetrachloroaluminate and lithium bis (fluorosulfonyl) imide, the chemical formula of the oxygen-containing lithium tetrachloroaluminate is LiAlCl4-2xOx, and x < lt > is larger than or equal to 0.01; 2. The eutectic solid electrolyte coated diaphragm prepared by the invention contains the eutectic solid electrolyte, and the interface wettability between the eutectic solid electrolyte and the base membrane is good, so that the lithium ion transmission efficiency can be improved; and the eutectic solid electrolyte can uniformly permeate into the base membrane and the positive and negative electrode materials through a hot pressing process, so that the contact uniformity is improved, and the interface impedance between the electrode and the eutectic solid electrolyte is reduced, thereby improving the battery performance.

The invention relates to the technical field of lithium ion battery positive electrode materials, and discloses a modified high-nickel NCA positive electrode material and a preparation method and application thereof. The modified high-nickel NCA positive electrode material comprises an inner core, a first coating layer and a second coating layer which are sequentially arranged from inside to outside, the inner core comprises nickel cobalt lithium aluminate doped with a hafnium element; the first coating layer comprises copper oxide; and the second coating layer comprises a lithium fast ion conductor. In the modified high-nickel NCA positive electrode material provided by the invention, hafnium doping stabilizes a crystal structure from a bulk phase angle, double-layer coating synergistic effect inhibits side reaction from an interface angle, and the two layers cooperate to solve the problem of bulk phase-interface synergistic attenuation of the material, so that the positive electrode material has high capacity, long cycle life and excellent rate capability.

The invention relates to the technical field of positive electrode materials, in particular to a high-rate lithium nickel cobalt aluminate positive electrode material and a preparation method thereof. The invention provides a preparation method of a high-rate nickel cobalt lithium aluminate positive electrode material, which comprises the following steps: S1, mixing a nickel cobalt precursor, a lithium source, an aluminum source and a zirconium source, and sintering to obtain a first sintered material; and S2, mixing the lithium titanium phosphate and the sintering material, then mixing the mixture with the single-walled carbon nanotubes, and sintering the mixture to obtain the high-rate lithium nickel cobalt aluminate positive electrode material. The lithium titanium phosphate and the single-arm carbon nanotube are used for coating modification, so that the contact between the positive electrode material and an electrolyte can be isolated to a great extent, and the cycle performance of the material is improved; the surface of the material is coated with the single-arm carbon nanotubes and aluminum, so that the migration rate of lithium ions can be increased, and lithium titanium phosphate has high ionic conductivity, so that the lithium ions are allowed to quickly diffuse in a three-dimensional channel to form a continuous ion transmission network.

Method (200) for manufacturing a battery cell (10), comprising: in a vacuum or an inert atmosphere, applying (206) an etching process to remove a passivation layer from a primary surface (41, 42) of a solid electrolyte (40); subsequent application (208) of a surface coating (51, 52) to the primary surface (41, 42); and Arranging (210) the solid electrolyte (40) including the surface coating (51, 52) between an anode (20) and a cathode (30) in the battery cell (10); wherein the application (208) of the surface coating (51, 52) comprises the application of an ionically conductive coating to the primary surface (41, 42); wherein the application of the ionically conductive coating to the primary surface (41, 42) comprises the application of lithium aluminate, LiAlO2, or lithium niobate, LiNbO3, to the primary surface (41, 42); and wherein the solid electrolyte (40) is a lithium-filled garnet material.

The invention discloses lightweight low-carbon concrete and a preparation method thereof, and relates to the technical field of concrete. The coconut shell fibers are modified with the assistance of enzymolysis by utilizing triisopropanolamine, a physical adsorption layer is formed by the triisopropanolamine through microwave irradiation, then the physical adsorption layer cooperates with lithium aluminate in a concrete matrix, the condensation speed and the early strength of the concrete are improved, meanwhile, the volcanic slag is used as lightweight aggregate, and the cost is reduced. The preparation method comprises the following steps: firstly, preparing the concrete to improve the mechanical property and corrosion resistance of the concrete, then replacing part of cement with coconut shell ash, pretreating coconut shells with a calcium salt solution before the coconut shell ash is prepared to enhance the mechanical property of the concrete, and then during a calcining process, adding ammonia gas and silicon dioxide in the coconut shells to improve the mechanical property of the concrete. Meanwhile, calcium and ammonia gas react to generate calcium nitride, so that the corrosion resistance and the mechanical property of the concrete are further enhanced.

The invention belongs to the technical field of positive electrode materials, and particularly relates to a composite coated nickel cobalt lithium aluminate positive electrode material as well as a preparation method and application thereof. The invention provides a preparation method of a composite coated nickel cobalt lithium aluminate positive electrode material. The preparation method comprises the following steps: (1) preparing a nickel cobalt lithium aluminate precursor; (2) mixing the nickel cobalt lithium aluminate precursor with a lithium salt, and sintering to obtain a nickel cobalt lithium aluminate positive electrode material; (3) mixing the nickel cobalt lithium aluminate positive electrode material with the coating liquid, and annealing to obtain a composite coated nickel cobalt lithium aluminate positive electrode material; the coating liquid comprises a fluorine source and phosphate. The composite coated nickel cobalt lithium aluminate positive electrode material provided by the invention has high capacity, high cycle performance, high rate performance and high temperature resistance.

The invention discloses a lithium aluminate composite sagger and a preparation method and application thereof, and belongs to the technical field of saggers, the sagger comprises an inner surface working layer and an outer matrix layer from inside to outside; the thickness of the inner surface working layer is 1-3mm; the inner surface working layer comprises the following preparation raw materials in parts by weight: 5-20 parts of synthetic lithium aluminate, 2-10 parts of kaolin, 0-10 parts of fused zirconium mullite, 0-15 parts of zirconium oxide, 0-10 parts of zirconium silicate, 60-80 parts of spinel, 0-10 parts of aluminum oxide, 0-5 parts of an organic binder and 1-5 parts of water. The synthetic lithium aluminate is added into a sagger formula system, the structure is cured when the sagger is fired, and according to the principle of the Fick's first law, the added lithium aluminate can slow down the alkali corrosion of the material to the sagger, effectively restrict the volume change in the positive electrode material and effectively prolong the service life of the sagger.

The invention provides a lithium battery electrolyte as well as a preparation method and application thereof. The lithium battery electrolyte is prepared from the following raw materials: thionyl chloride, lithium tetrachloroaluminate, sulfur dioxide and nitrogen trifluoride. Nitrogen trifluoride is added into the electrolyte, the nitrogen trifluoride reacts with a metal lithium negative electrode to generate a lithium fluoride enriched solid electrolyte interface with high ionic conductivity on the surface of the electrode in situ, so that the lithium ion transmission efficiency is remarkably improved, and the voltage hysteresis phenomenon is effectively improved. The preparation method is simple in process and remarkable in effect, and a new solution is provided for development of high-performance lithium thionyl chloride batteries.

The invention discloses a silicon-carbon composite negative electrode material and a preparation method and application thereof. The silicon-carbon composite negative electrode material comprises an inner core and a coating layer coating the inner core, the inner core comprises one or more silicon nanowires with the pipe diameter of 2-10 nm and the pipe length of 10-20 nm, magnesium silicate is dispersed and distributed on the surface layers of the silicon nanowires, the magnesium silicate is one or two of Mg2SiO4 and MgSiO3, fast ion conductors are uniformly distributed on the surfaces of the nanowires, and the fast ion conductors are uniformly distributed on the surfaces of the nanowires. The fast ion conductor is one of lithium aluminate, lithium metaphosphate and lithium phosphate; and the coating layer is a high-conductivity outer carbon layer. The silicon-carbon composite negative electrode material provided by the invention has the advantages that the rate performance and the cycle performance of the material are improved, and the structural strength of the material is also improved.

The invention provides a secondary battery and an electronic device, the secondary battery comprises a positive pole piece and an electrolyte, the positive pole piece comprises a positive pole current collector and a positive pole material layer arranged on at least one surface of the positive pole current collector, the positive pole material layer comprises nickel cobalt lithium aluminate, based on the mole number of metal elements except lithium in the positive pole material layer, the molar percentage content of the aluminum element is C1%, and C1 is more than or equal to 2 and less than or equal to 20; the electrolyte comprises a first component, and the first component is at least one of lithium difluorophosphate, lithium tris (pentafluoroethyl) trifluorophosphate or lithium trifluoroacetate; based on the mass of the electrolyte, the mass percentage content of the first component is m1%, and m1 is larger than or equal to 0.2 and smaller than or equal to 6. The secondary battery provided by the invention can give consideration to high-temperature cycle performance, high-temperature storage performance and dynamic performance.

The invention provides a lithium nickel cobalt aluminate positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing and sintering a lithium nickel cobalt aluminate primary sintering material and a cobalt source to obtain a secondary sintering material; and mixing and sintering a tungsten source, a lithium source and the secondary sintering material to obtain the nickel cobalt lithium aluminate positive electrode material. According to the preparation method disclosed by the invention, a fast ion conductor layer is formed by firstly coating a cobalt source and then coating a tungsten source and a lithium source, and meanwhile, the cobalt source and the lithium source in secondary coating form a lithium cobalt oxide coating layer, so that a surface layered structure of the positive electrode material is reconstructed, and a lithium cobalt oxide coating layer and a lithium tungstate coating layer are generated on the surface of nickel cobalt lithium aluminate; the interface characteristic of the positive electrode material is improved, and the cycle performance of the material is improved while the discharge capacity is improved.

The present invention belongs to the field of lithium-ion battery negative electrodes, and discloses a silicon-carbon negative electrode material with a nano-homogeneous structure, comprising a hard carbon matrix, a soft carbon coating layer on the surface of the hard carbon matrix, nano-silicon and a lithium aluminate film wrapped on the surface of the nano-silicon distributed inside the hard carbon matrix. The silicon-carbon negative electrode material has high structural density and good stability. The present invention also discloses a method for preparing the silicon-carbon negative electrode material: first, a dispersion of white carbon black and lithium aluminum hydride is prepared, hard carbon materials are added to mix, dried to obtain a solid, sintered, impregnated, roasted, crushed, and shaped. The method has low cost and good safety. The lithium aluminate formed by reduction is wrapped on the surface of the nano-silicon, and the uniformity is improved, which further inhibits the expansion of silicon. It can also be used as an artificial SEI film to prevent the reduction and decomposition of the electrolyte, reduce lithium consumption, and improve the coulombic efficiency during the charge and discharge cycle. The application of the silicon-carbon negative electrode material in lithium batteries is also disclosed, which has a significant improvement in electrical performance.

This invention relates to the field of lithium-ion battery material preparation technology, specifically to a graphite composite material, its preparation method, and its application. The invention first synthesizes and coats titanium niobate on the graphite surface in situ using an organic niobium source and an organic titanium source via chemical deposition. Simultaneously, aluminum hydroxide is obtained in situ through the reaction of an organic base with an aluminum-based coupling agent. Subsequent carbonization treatment yields a porous alumina-doped titanium niobate-coated graphite composite material. Finally, a lithium titanium niobate and lithium aluminate dual-coated graphite composite material with good fast-charging performance, high initial efficiency, and high energy density is prepared through a chemical reaction between an organic lithium salt and the porous alumina-doped titanium niobate-coated graphite composite material, followed by sintering.

The invention provides an electrolyte for improving the cycle performance of a lithium metal battery, a preparation method and the lithium metal battery. The electrolyte comprises an organic solvent, a lithium salt and an additive, and the molar concentration of the lithium salt in the electrolyte is 2-3 mol / L; the mass ratio of the additive to the lithium salt is (1-7): (93-99), and the additive at least comprises one of fluoroethylene carbonate and tris (pentafluorophenyl) borane. According to the invention, by optimizing the components of the electrolyte, particularly by taking lithium bis (fluorosulfonyl) imide and lithium bis (oxalato) borate as additives, the stability of a solid electrolyte interface film is synergistically improved, the compatibility of the electrolyte and an electrode is improved, the growth of lithium dendrites is inhibited, and the stability of the electrolyte in a circulating process is improved, so that the performance of the lithium metal battery is improved. Particularly, the cycle performance of a nickel cobalt lithium manganate ternary lithium metal battery and a nickel cobalt lithium aluminate ternary lithium metal battery is improved.

The present application relates to the technical fields of lithium ion battery material preparation, in particular to a porous lithium salt aerogel coated graphite composite material and an aerogel coating reaction tank, the porous lithium salt aerogel coated graphite composite material comprises a core structure and a shell structure, the core structure is graphite particles, and the shell structure is a porous lithium metahydroxy aluminate / lithium metasilicate / lithium metatitanate ternary composite; by coating the porous lithium salt composite on the surface of graphite, the liquid absorption and retention capacity of the material is improved by using the large specific surface area of the porous lithium salt itself, sufficient lithium ions are provided for subsequent charging and discharging, and the rate performance is improved.