29256 results about "Electrode material" patented technology

The invention relates to the field of lithium battery negative electrode materials, and particularly discloses a silicon-carbon composite negative electrode material for a lithium ion battery and a preparation method of the silicon-carbon composite negative electrode material. The method comprises the following steps: preparing a porous carbon substrate, and depositing silicon nanoparticles in pores and on the surface of the porous carbon substrate by adopting a fluidized bed chemical vapor deposition process and taking silane as a silicon source to obtain a silicon-carbon core material; continuously carrying out carbon coating on the surface of the silicon-carbon core material in the fluidized bed by taking acetylene as a carbon source to form a carbon coating layer; and leading out the obtained material from the fluidized bed, taking acetylene as a carbon source, and carrying out carbon coating on the surface of the primary carbon coating layer again by adopting the rotary furnace to form a secondary carbon coating layer. According to the preparation method, a porous carbon matrix and double-layer functional carbon coating process is adopted, so that the volume expansion of silicon in the circulation process is remarkably inhibited, the interface side reaction is reduced, and the circulation stability of the material is effectively improved.

Embodiments described herein relate generally to apparatuses and processes for forming semi-solid electrodes having high active solids loading by removing excess electrolyte. In some embodiments, the semi-solid electrode material can be formed by mixing an active material and, optionally, a conductive material in a liquid electrolyte to form a suspension. In some embodiments, the semi-solid electrode material can be disposed onto a current collector to form an intermediate electrode. In some embodiments, the semi-solid electrode material can have a first composition in which the ratio of electrolyte to active material is between about 10:1 and about 1:1. In some embodiments, a method for converting the semi-solid electrode material from the first composition into the second composition includes removing a portion of the electrolyte from the semi-solid electrode material. In some embodiments, the method includes mechanically compressing the intermediate electrode to remove the portion of electrolyte from the semi-solid electrode material.

The invention discloses a lithium iron phosphate positive electrode material, a preparation method thereof and a lithium battery, and relates to the technical field of lithium ion batteries. According to the method, the pressing index of the lithium iron phosphate positive electrode material is tested by adopting a specific method, so that the pressing index meets a specific range, meanwhile, the average circularity of larger particles in a Dv50-Dv100 range meets a proper range, the lithium iron phosphate positive electrode material has better particle movement capability, and the particles can move at a higher speed to be rearranged during pressing, so that the particle size of the lithium iron phosphate positive electrode material is reduced, and the quality of the lithium iron phosphate positive electrode material is improved. Therefore, the positive pole piece with high compaction density can be obtained, the charge-discharge capacity of the battery can be improved, and meanwhile, the particles can be prevented from being broken when being pressed, so that the positive pole piece has good anti-pressure capability. By adopting the lithium iron phosphate positive electrode material provided by the invention, the lithium battery has relatively high energy density and capacity retention ratio.

The invention discloses a silicon-carbon negative electrode material and a preparation method and application thereof.The silicon-carbon negative electrode material comprises a porous carbon substrate, a silicon element distributed in pore channels of the porous carbon substrate and carbon coating the outer surfaces of the porous carbon substrate and the silicon element, the porous carbon substrate is prepared after two times of activating treatment, and the silicon element is prepared after two times of activating treatment. The porous carbon has dendritic pore channels and meets at least one of the following conditions: a, the volume ratio of micropores is 10-30%; b, the volume ratio of mesopores is 60-90%; c, the volume ratio of macropores is 0-10%; d, the specific surface area is not less than 200m < 2 > / g; e, the pore volume is not less than 0.4 cm < 3 > / g; and f, the average particle size D50 is 1-20 [mu] m. By activating the porous carbon substrate, more buffer spaces can be provided for volume expansion of nano silicon particles from the angle of substrate preparation, and the cycling stability of the silicon-carbon negative electrode material is remarkably improved.

The invention discloses a positive electrode material and a preparation method thereof, a battery and a power utilization device. The positive electrode material comprises an inner core; the first coating layer comprises a first coating material, and the first coating material comprises at least one of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte and a polymer composite solid electrolyte; the first coating layer coats the inner core, the second coating layer coats the inner core, the first coating layer coats the second coating layer, the second coating layer comprises a second coating material, and the second coating material comprises a halide solid electrolyte. The coating layer plays a certain role in isolating the material of the inner core from the external environment, and the situation that the material in the inner core has side reaction with external substances or the property of the material is changed due to other reasons is reduced. Therefore, the performance stability of the positive electrode material is kept.

The embodiment of the invention relates to a lithium cobalt oxide positive electrode material with a composite phase as well as a preparation method and application of the lithium cobalt oxide positive electrode material. The chemical general formula of the lithium cobalt oxide positive electrode material with the composite phase is AXCo (1-y) M (1y) O2, wherein x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 0.03, A is Li or Li and Na, and M1 is one or more of A1, Zr, Ni, Mn, Y, Nb, La, Fe, Cu, Cr, Ti, W, Mg, Mo or Yb; the composite phase of the lithium cobalt oxide positive electrode material comprises an O2 phase, a T2 phase and an O3 phase; wherein the sum of the molar ratios of the O2 phase and the T2 phase in the composite phase is greater than or equal to 90%, and the molar ratio of the O3 phase is less than or equal to 10%. By regulating and controlling the composite phase proportion of the lithium cobalt oxide positive electrode material, the rate capability, the structural stability under high voltage, the stability of a thermodynamic structure, the specific capacity, a discharge platform and other characteristics of the positive electrode material can be effectively improved, so that the lithium cobalt oxide positive electrode material with high energy density and high stability is realized.

The invention provides a doped and coated composite sodium battery positive electrode material as well as a preparation method and application thereof. The doped and coated composite sodium battery positive electrode material comprises an inner core and a coating layer on the surface of the inner core, the chemical general formula of the inner core is NabNixFeyMnzMjO2, x + y + z + j = 1, 0.2 < = x < = 0.6, 0.2 < = y < = 0.5, 0.2 < = z < = 0.5, 0 < j < = 0.2, 0.8 < = b < = 1.2; the coating layer comprises a ferric sodium pyrophosphate material; raw materials for preparing the doped and coated composite sodium battery positive electrode material comprise an inner core, a phosphoric acid ferric sodium pyrophosphate precursor material and a sodium source. The metal elements are doped in the inner core, and the surface is coated with the ferric sodium pyrophosphate material with relatively high stability, so that the inner core can be prevented from being in direct contact with an electrolyte, and the cycle performance of the sodium battery positive electrode material is improved.

The invention discloses a composite positive electrode material and a preparation method thereof, a positive plate and a lithium ion battery. The composite positive electrode material comprises lithium iron phosphate and a carbon coating layer coating the surface of the lithium iron phosphate, wherein the integral intensity ratio ID / IG of a D peak to a G peak of the carbon coating layer in a Raman spectrum is 0.2-0.9, and the resistivity of the composite positive electrode material is 0.1-10 omega.cm. According to the preparation method, the graphitization degree of the carbon coating layer is controlled within a proper range (ID / IG is 0.2-0.9), so that good conductivity is ensured, and structural instability caused by excessive graphitization is avoided. The moderate graphitization degree is beneficial to formation of an ordered carbon layer structure, provides more electron transport channels and reduces the potential barrier of electron migration, so that the conductivity of the composite material is greatly improved, and the resistivity is reduced to an excellent level of 0.1-10 omega.cm.

The invention provides a silicon-carbon negative electrode material fluidized bed reaction system, and relates to the technical field of fluidized bed equipment. Comprising a raw material conveying system, a fluidized bed reactor, a high-temperature discharging system, a process gas inlet pipeline and a protection system. According to the scheme, the uniformity and safety of the fluidization reaction can be improved, and the working efficiency can be improved.

Embodiments described herein relate generally to electrochemical cells having pre-lithiated semi-solid electrodes, and particularly to semi-solid electrodes that are pre-lithiated during the mixing of the semi-solid electrode slurry such that a solid-electrolyte interface (SEI) layer is formed in the semi-solid electrode before the electrochemical cell formation. In some embodiments, a semi-solid electrode includes about 20% to about 90% by volume of an active material, about 0% to about 25% by volume of a conductive material, about 10% to about 70% by volume of a liquid electrolyte, and lithium (as lithium metal, a lithium-containing material, and / or a lithium metal equivalent) in an amount sufficient to substantially pre-lithiate the active material. The lithium metal is configured to form a solid-electrolyte interface (SEI) layer on a surface of the active material before an initial charging cycle of an electrochemical cell that includes the semi-solid electrode.

The lithium nickel manganese oxide positive electrode material, the preparation method thereof and the electrochemical device are characterized in that the lithium nickel manganese oxide positive electrode material provided by the embodiment of the invention comprises a base material and a coating layer located on the surface of the base material, the general formula of the base material is Li (LiaNixMnyMbO4), the element M comprises at least one of Ti, Zr, Al, Nb and Mo, and a is more than or equal to 0.02 and less than or equal to 0.06; 0.45 < = x < = 0.55, 1.4 < = y < = 1.6; 0.05 < = b < = 0.55; a + x + y + b = 2, and the coating layer contains phosphate. According to the lithium nickel manganese oxide positive electrode material, through doping and coating technologies, under the condition that the capacity is not sacrificed, the gas production phenomenon is effectively reduced, the cycling stability of the lithium nickel manganese oxide positive electrode material is improved, and the service life of an electrochemical device applying the lithium nickel manganese oxide positive electrode material is prolonged.

Embodiments described in this application relate generally to a system, an apparatus and / or methods for manufacturing electrodes by infusion electrolyte into compacted electrode materials. In some embodiments, a working electrode materials can be produced using an infusion mixing and manufacturing process. In some embodiments, a single-sided finished electrode can be produced directly from a dry powder mixture using an infusion mixing and manufacturing process. In some embodiments, a double-sided finished electrode can be produced directly from a dry powder mixture using an infusion mixing and manufacturing process. The electrodes produced by an infusion mixing and manufacturing process generally perform better than those produced by non-infusion processes.

The invention discloses a waste lithium iron phosphate positive electrode material recycling method and a lithium iron phosphate material, and the method comprises the following steps: calcining a waste lithium iron phosphate positive electrode material to obtain a lithium iron phosphate / carbon powder material; the element content of the lithium iron phosphate / carbon powder is obtained, and the amount of lithium, iron and phosphorus needing to be supplemented is determined; lithium, iron and phosphorus are supplemented to the lithium iron phosphate / carbon powder, then a reducing agent is added and mixed, a mixture is obtained, and the reducing agent comprises at least one of a non-amino acid reducing agent and an amino acid reducing agent; and calcining the mixture to obtain the recycled and regenerated lithium iron phosphate material. According to the method, elements missing in the waste lithium iron phosphate material are analyzed and supplemented, and the type of the reducing agent is adjusted, so that efficient repair of the waste lithium iron phosphate material is realized. The repairing efficiency of the waste lithium iron phosphate material is high, and the battery assembled by the repaired lithium iron phosphate material has excellent rate capability and cycle performance.

A composite positive electrode material, a preparation method therefor and the use thereof. The composite positive electrode material comprises an inner core and a carbon coating layer covering at least part of the surface of the inner core and / or embedded in the inner core; the inner core comprises NaFePO4 and a compound represented by formula 1; Na4+xFe3-y(PO4)2+zP2O7 formula 1, where -0.15≤x≤0.8, 0≤y≤0.5, and -0.2≤z≤0.2; the particle size of NaFePO4≤100 nm. When being used for batteries, the composite positive electrode material can improve the capacities and rate capabilities of the batteries.

The invention discloses a carbon-silicon negative electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: S1, carrying out mixed reaction on a lithium source compound, a lanthanum source compound and a titanium source compound to obtain a mixed reactant; mixing the mixed reactant with a carbon source compound, and dispersing and emulsifying to obtain element-doped microspheres; s2, carbonizing the element-doped microspheres in the step S1 to obtain carbides, and activating the carbides to obtain a porous carbon material; and S3, performing silicon deposition on the porous carbon material in the S2 to obtain silicon deposition porous carbon, and performing carbon deposition on the silicon deposition porous carbon to obtain the carbon-silicon negative electrode material. The carbon-silicon negative electrode material disclosed by the invention is high in lithium ion transmission rate, the problem of poor electronic conductivity of silicon is solved, and the electrical property of a battery can be effectively improved.

Described herein are variations of an analyte monitoring system, including an analyte monitoring device. For example, an analyte monitoring device may include a skin-penetrating microneedle array for use in measuring analyte, such as in a continuous manner. The microneedle array may include, for example, at least one microneedle comprising a working electrode comprising an analyte-sensing aptamer that selectively and reversibly binds to analyte. The working electrode comprises at least one thiol-based passivation molecule that provides protection of the working electrode from, by way of example, foulants and interferents. For example, a sensor may be configured to generate a signal that is indicative of a concentration of an analyte in a fluid, the sensor comprising a working electrode comprising an electrode material, a biorecognition layer disposed at least partially on the electrode material and comprising a biorecognition element that selectively and reversibly binds to an analyte, and an at least partially desiccated hydrogel disposed on the biorecognition layer. For example, a working electrode may be configured to generate a signal indicative of a concentration of an analyte in a fluid, the working electrode comprising an electrode material, a biorecognition element disposed on the electrode material that selectively binds to the analyte, wherein the biorecognition element is functionalized with a redox-active molecule and is configured to change conformation upon binding the analyte to move the redox-active molecule, closer to, or further from, the electrode material, and a passivation element comprising a zwitterionic peptide disposed on the electrode material.

The invention discloses a preparation method of a high-compaction lithium manganese iron phosphate positive electrode material, which comprises the following steps: placing a manganese source, an iron source and a phosphorus source in deionized water, stirring, carrying out primary high-speed ball milling, carrying out constant-temperature water bath, adding an oxidizing agent, stirring and oxidizing, and drying the slurry to obtain manganese iron phosphate precursor powder; carrying out primary sintering on the ferromanganese phosphate precursor powder to obtain a ferromanganese phosphate primary sintering material; putting the ferromanganese phosphate primary sintering material into deionized water, adding a lithium source and a carbon source at the same time, and performing stirring, secondary high-speed ball milling and drying to obtain lithium ferromanganese phosphate precursor powder; and carrying out secondary sintering on the lithium manganese iron phosphate precursor powder to obtain the high-compaction lithium manganese iron phosphate positive electrode material. The void ratio is well reduced and good carbon coating is realized by means of secondary grinding and secondary sintering, and compared with the prior art, the method has the advantages that good capacity can be maintained, the powder compaction density of the material can be improved, the conductivity can be improved, and the specific surface area of the material can be effectively reduced.

The invention provides a high-rate and high-first-effect biomass hard carbon composite negative electrode material and a preparation method and application thereof, the hard carbon composite negative electrode material has a core-shell structure, the core-shell structure comprises a core, an inner shell and an outer shell, the core comprises biomass hard carbon containing P and graphite microcrystals, the inner shell comprises graphene, and the outer shell comprises a carbon nanotube. According to the invention, the surface of the biomass hard carbon is coated with the graphene layer, the carbon nanotubes grow on the surface of the graphene in situ, and transition metal synergistically induces the hard carbon to be arranged and grow along the graphene layer in a high-temperature carbonization process, so that the graphene coating layer is tightly coated, and the cycle performance of the material is improved; transition metal ions catalyze graphitization to generate a more regular and ordered graphite-like layer microcrystalline structure coating layer, so that the defects of graphene and carbon nanotubes are reduced, and the first coulombic efficiency is improved; in addition, the ion transmission capability is improved by phosphorus doping, the electron transmission capability is improved by graphite microcrystals generated by catalysis in hard carbon, and the rate capability is ensured by synergistic improvement of ion transmission and electron transmission.

Embodiments described herein relate generally to systems and methods for continuously and / or semi-continuously manufacturing electrochemical cells with semi-solid electrodes. In some embodiments, a method can include mixing an active material, a conductive material, and an electrolyte to form a semi-solid electrode material. The method further includes drawing a vacuum on the semi-solid electrode material, compressing the semi-solid electrode material to form an electrode brick, and dispensing a portion of the electrode brick onto a current collector via a dispensation device to form an electrode. In some embodiments, the current collector is disposed on a pouch material. In some embodiments, the dispensation device includes a top blade for top edge control and two side plates for side edge control. In some embodiments, the method can further include conveying the electrode through the top blade and the two side plates to shape the electrode.

The invention discloses a lithium iron phosphate positive electrode material and a preparation method and application thereof, and belongs to the technical field of lithium iron phosphate positive electrode materials. The lithium iron phosphate positive electrode material comprises a lithium iron phosphate matrix and a carbon coating layer coating the surface of the lithium iron phosphate matrix, the average standard deviation of the thickness of a carbon coating layer in the lithium iron phosphate positive electrode material is # imgabs0 #, and sigma (d) is more than or equal to 0.05 nm and less than or equal to 0.35 nm; the average standard deviation of the carbon content in the lithium iron phosphate positive electrode material is sigma (Cwt%), and sigma (Cwt%) is larger than or equal to 0.02 wt% and smaller than or equal to 0.35 wt%. The lithium iron phosphate positive electrode material has a uniform carbon coating layer, and the thickness of the carbon coating layer and the carbon content at each position are relatively consistent, so that the improvement of the carrier mobility of the lithium iron phosphate positive electrode material is facilitated, and the further improvement of the electrochemical performance of a battery prepared from the lithium iron phosphate positive electrode material is facilitated.

The invention relates to the technical field of lithium iron phosphate production, and discloses a carbon-coated titanium-doped lithium iron phosphate positive electrode material and a preparation method thereof.The preparation method comprises the following steps that 1, a ferrous solution and a phosphorus source solution are mixed in proportion, dopamine hydrochloride is added, a pH regulator is dropwise added in the stirring state, the pH of the solution is adjusted to 4.0-5.5, a reaction is conducted, a titanium source solution is added, and a reaction solution is obtained; after uniformly stirring, continuously dropwise adding a pH regulator to regulate the pH value of the solution to 5.5-6.5; the iron phosphate octahydrate coated with the titanium-embedded polydopamine is obtained; 2) calcining the titanium-embedded polydopamine-coated ferrous phosphate octahydrate in an inert gas atmosphere to obtain carbon-coated titanium-doped anhydrous ferrous phosphate; 3) mixing the carbon-coated titanium-doped anhydrous ferrous phosphate with lithium phosphate and a carbon source, ball-milling, mixing, spray-drying and calcining to obtain a carbon-coated titanium-doped lithium iron phosphate positive electrode material; the synthesis process is simple, and energy consumption is reduced.

The invention discloses a composite polycrystalline positive electrode material which is prepared by permeating and coating a polycrystalline positive electrode material with an oxyhalide solid electrolyte, and the oxyhalide solid electrolyte comprises one or more of Li-Ta-O-Cl, Li-Nb-O-Cl, Li-Zr-O-Cl and Li-Al-O-Cl. The specific oxyhalide electrolyte is adopted to carry out permeation coating on the polycrystalline positive electrode material, uniform coating on the surface of the polycrystalline positive electrode material and grain boundaries in particles is completed, capacity utilization in the particles of the polycrystalline positive electrode material is achieved, and the capacity utilization rate of the particles of the polycrystalline positive electrode material is improved through the coating effect of the oxyhalide with high ionic conductivity. Ion transmission inside and in gaps of the polycrystalline positive electrode material particles is regulated, interface impedance is reduced, energy density is improved, and the application prospect is wide.

The invention belongs to the technical field of battery positive electrode materials, and discloses a tellurium and niobium doped and carbon nitride coated positive electrode material and a preparation method thereof, the chemical formula is LiNi < x > Co < y > Mn < 1-x-y-u-v > Te Nb < v > O < 2 > at C < 3 > N < 4 >, x is greater than or equal to 0.5 and less than or equal to 0.98, 0 lt; yt; Yt; 0, 0.5, 0 lt; u < = 0.1, 0lt; v < = 0.1, 1-x-y-u-vgt; 0. A Te / Nb co-doping mode is adopted, and Te and Nb are synergistically modified, so that the crystal structure of the material is stabilized, and good mechanical stability and cycle performance of the material are kept; lithium ions migrated on the surface of the positive electrode material and carbonate on the surface of the material are inhibited from forming lithium carbonate, so that the technical problem of battery gas expansion is solved; the carbon nitride coating provides additional transmission channels and adsorption sites for lithium ions, reduces the interface resistance at the same time, contributes to faster migration of the lithium ions under a low-temperature condition, and improves the first coulombic efficiency, the rate and the cycle performance of the battery at a low temperature.

The invention provides a silicon-carbon negative electrode material and a preparation method thereof. The preparation method comprises the following steps: a) mixing a phenol monomer, an aldehyde solution, ammonia water and water, dropwise adding a boric acid solution for reaction, and curing to obtain boron-containing phenolic resin; b) carbonizing the boron-containing phenolic resin obtained in the step a), mixing with alkali, and activating to obtain boron-doped porous carbon; and c) carrying out silicon deposition on the boron-doped porous carbon obtained in the step b) by adopting a gaseous silicon source, carrying out carbon coating by adopting a gaseous carbon source, and cooling to obtain the silicon-carbon negative electrode material. Compared with the prior art, the preparation method provided by the invention has the advantages that a conductive network can be formed by doping the boron element, the electron concentration can be improved, the electron transfer rate is favorably improved, the conductivity of the material is effectively enhanced, and the rate capability of the negative electrode material is effectively improved; meanwhile, the residual carbon rate in the porous carbon preparation process can be greatly increased, and the cost of the whole silicon-carbon negative electrode material is effectively reduced.

The invention discloses a pre-lithiated silicon-carbon negative electrode material as well as a preparation method and application thereof. The pre-lithiated silicon-carbon negative electrode material comprises composite particles and a surface coating layer coating the outer surfaces of the composite particles, the mass of the composite particles accounts for 85%-99% of the total mass of the pre-lithiated silicon-carbon negative electrode material; the composite particles are compounds of pre-lithiated porous carbon and nano silicon particles; the composite particles are obtained by uniformly depositing nano silicon particles in pores of pre-lithiated porous carbon; the mass of the pre-lithiated porous carbon accounts for 15-95% of the total mass of the composite particles; the pre-lithiated porous carbon comprises lithium metal particles and porous carbon, and the lithium metal particles are attached to the surfaces of pores of the porous carbon; the mass of the lithium metal particles accounts for 0.1-10% of the total mass of the pre-lithiated silicon-carbon negative electrode material; when the pre-lithiated silicon-carbon negative electrode material is applied to the lithium battery, the first-circle coulombic efficiency of the lithium battery can be improved.

Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus, the intermediate layer can serve as a current collector for the electrochemical cell.

The invention discloses a silicon-carbon negative electrode material, porous carbon and a preparation method, the porous carbon is prepared by mixing ammonium fluoride and a pre-carbonized material to prepare a premix; and putting the premix in an inert atmosphere, and carrying out pre-activation, drying, carbonization, activation and crushing treatment to obtain the composite material. And uniformly depositing the nano silicon particles into the porous carbon skeleton through a mature CVD (Chemical Vapor Deposition) process to obtain the silicon-carbon composite material. Fluorine and nitrogen co-doping modification can increase the defect degree of a carbon skeleton, efficiently relieve mechanical stress accompanied by lithium storage volume expansion of the silicon negative electrode in a micro scale, provide abundant lithium ion transport and mass transfer channels and enhance the conductivity of porous carbon, and ammonium fluoride is used as a supplementary activator besides water vapor, so that the porosity of the porous carbon is further improved, and the conductivity of the porous carbon is improved. An effective space is provided for uniform deposition of silicon, the fluorine-containing carbon layer can induce formation of a high-stability SEI film rich in LiF on the surface of the nano silicon material, and the interface stability and coulombic efficiency of the silicon negative electrode are further improved.

The invention relates to a surface-modified lithium-rich manganese-based positive electrode material, a preparation method and a lithium ion battery, and the preparation method comprises the following steps: uniformly mixing a lithium-rich manganese-based precursor, a lithium source and a metal oxide required by garnet type solid electrolyte to obtain a mixture; and performing gradient temperature calcination on the mixture in an oxidizing atmosphere to obtain the surface-modified lithium-rich manganese-based positive electrode material, the surface-modified lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based material, a disordered spinel self-protection layer coated on the surface of the lithium-rich manganese-based material, and a garnet type solid electrolyte coated on the surface of the disordered spinel self-protection layer, the gradient temperature calcination comprises the following steps: calcining at the nucleation temperature of the lithium-rich manganese-based material, and then heating to the nucleation temperature of the garnet type solid electrolyte for calcining. The lithium-rich manganese-based positive electrode material can solve the problems of low first coulombic efficiency and poor rate capability of the lithium-rich manganese-based positive electrode material in related technologies.

The invention belongs to the technical field of battery materials, and particularly relates to a method for preparing a porous carbon structure containing a sub-nanoscale ionic conduction improvement layer by utilizing atomic layer deposition and application. The invention discloses a porous carbon-silicon negative electrode structure, which is characterized in that a sub-nano-scale ion conduction improvement layer is added between a porous carbon substrate and silicon particles, and the sub-nano-scale ion conduction improvement layer comprises silicon carbide, aluminum phosphide, aluminum nitride, aluminum oxide, lithium phosphate, aluminum phosphate and lithium aluminum phosphate. Meanwhile, the invention also discloses a preparation method of the porous carbon-silicon negative electrode structure, namely, a sub-nano-scale ion conduction improvement layer is deposited on the porous carbon substrate through an atomic layer deposition method, so that the binding force between the sub-nano-scale ion conduction improvement layer and silicon particles and an ion transport channel are increased, and the ion conduction of a vapor deposition silicon-carbon negative electrode material is improved; the polarization of the material is effectively reduced, so that the rate capability of the battery is improved, and the cycling stability of the porous carbon structure battery is improved.

The invention provides a positive electrode material and a preparation method thereof, a positive electrode plate and a battery, the positive electrode material comprises lithium manganese iron phosphate particles, a first shell layer and a second shell layer, the first shell layer and the second shell layer sequentially coat the surfaces of the lithium manganese iron phosphate particles, the material of the first shell layer comprises nanoscale SiO2 particles, and the material of the second shell layer comprises nanoscale TiO2 particles. The surfaces of the lithium manganese iron phosphate particles are sequentially coated with the SiO2 layer and the TiO2 layer, so that the contact between the lithium manganese iron phosphate particles and an electrolyte can be reduced, the side reaction between the lithium manganese iron phosphate particles and the electrolyte in the electrochemical reaction process is reduced, the cycle life attenuation of the battery is relieved, the dissolution of Mn element is reduced, and the service life of the battery is prolonged. Therefore, the battery impedance increase caused by deposition of Mn < 2 + > on the negative electrode in the circulation process is relieved.