166results about How to "Improved high-magnification performance" patented technology

The invention relates to the field of negative electrode materials of lithium ion batteries, and specifically to a nanometer lithium titanate/graphene composite negative electrode material and a preparation process thereof. According to the invention, micron-sized lithium titanate prepared by the solid phase method is subjected to ultrafine ball milling to obtain nanometer powder, and the nanometer lithium titanate powder and graphene are uniformly compounded and subjected to heat treatment so as to obtain a high performance lithium ion battery negative electrode material; the invention is characterized in that uniform distribution of graphene in the nanometer lithium titanate powder is realized through in situ compounding; the weight of graphene in the composite negative electrode material accounts for 0.5 to 20%, and the weight of lithium titanate accounts for 80 to 99.5%. The lithium ion battery negative electrode material has good electrochemical performance, 1C capacity greater than 165 mAh/g, 30C capacity greater than 120 mAh/g and 50C capacity greater than 90 mAh/g. Nanometer lithium titanate in the lithium ion battery negative electrode material prepared in the invention has high phase purity; the preparation process of the material is simple and is easy for industrial production.

The invention discloses a multielement functional modified binder for a polymer lithium ion battery. The binder takes a biomass polymer or a synthetic polymer as the substrate, takes a hydrophilic monomer and an oleophilic monomer as the functional modified monomer; and then the binder is prepared through a free radical graft copolymerization reaction or a Michael addition reaction in a modification manner. The binder has a multi-branch structured three-dimensional space network body, so that more active sites in contact with the electrode active material can be provided, and the uniformity and the smoothness of the electrode slurry in film-forming can be improved; the peeling strength of the active materials and the conductive agent on the metal substrate is reinforced; and meanwhile, the binder is excellent in elasticity and binding force, can be applied to water/organic solvent and can be applied to the positive electrode and negative electrode of the lithium ion battery; the conduction of electrons/ions in the charging-discharging process can be promoted; the electrochemical interface impedance of the pole piece is lowered; the high rate capacity and the cycling stability of the positive electrode material and the negative electrode material of the lithium battery are relatively improved; in addition, the synthetic raw material is wide in source, so that the cost can be obviously lowered; and therefore, the binder has a wide market prospect.

The invention relates to a polyvinylpyrrolidone modified graphene coated sulfur/porous carbon composite anode material and a preparation method thereof, which relates to a sulfur/carbon composite material applied to a lithium-sulfur secondary battery anode material and a preparation method of the composite material, and solves the technical problem of the existing lithium-sulfur battery anode material graphene-coated sulfur-containing composite material that the electrochemical property is low. The polyvinylpyrrolidone modified graphene coated sulfur/porous carbon composite material is characterized in that the outer surface of a sulfur/porous carbon composite material particle is uniformly coated with a polyvinylpyrrolidone modified graphene slab layer, a graphene conductive network is formed between every two adjacent particles, and a grading core-shell structure is formed. The preparation method comprises the steps of adding the sulfur/porous carbon composite material into graphene slurry modified by the polyvinylpyrrolidone, and mixing the sulfur/porous carbon composite material with the graphene slurry, and coating the sulfur/porous carbon composite material with the graphene slurry modified by the polyvinylpyrrolidone. The anode material is high in specific capacity, long in cycle life and good in high-rate performance.

The invention relates to a three-dimensional graded carbon-clad NaTi<2>(PO<4>)<3>/C micrometer flower electrode material and a preparation method and application thereof. The diameter of the three-dimensional graded carbon-clad NaTi<2>(PO<4>)<3>/C micrometer flower electrode material is 5-10 micrometers, the thickness of a carbon-clad NaTi<2>(PO<4>)<3>/C nanosheet subunit is only 1-5 nanometers, mesopores with pore diameters of 2-30 nanometers are formed in the carbon-clad NaTi<2>(PO<4>)<3>/C nanosheet subunit, the thickness of a surface carbon layer is 2-5 nanometers, and the nanosheet subunits are in over joint to form a three-dimensional conductive network. The three-dimensional graded carbon-clad NaTi<2>(PO<4>)<3>/C micrometer flower electrode material has the advantages that the three-dimensional graded carbon-clad NaTi<2>(PO<4>)<3>/C micrometer flower is prepared by a simple and practical solovothermal method combined with a high-temperature calcination method, and is endowed with excellent high rate performance and stable long-circulation capability when taken as a positive electrode active material of a sodium ion battery. The process is simple, the three-dimensional graded carbon-clad NaTi<2>(PO<4>)<3>/C micrometer flower electrode material is high in practicable and is high in safety coefficient, the requirement on a device is low due to the adoption of the solovothermal method and the calcination processing, production can be expanded, and market promotion is promoted.

The invention discloses a multi-element functional modification polyvinyl alcohol-based lithium ion battery aqueous binder and application of the binder in an electrochemical energy storage device. According to the binder, polyvinyl alcohol is taken as substrate, and hydrophilic monomers and oleophylic monomers are taken as functional modification monomers. Through adoption of Michael addition reaction modification preparation, the binder has good water solubility, elasticity and bonding performance. Through application of the binder in the preparation process of the lithium ion battery electrode plate, the homogeneity of electrode slurry can be improved. Therefore, the electrode slurry can form film on a current collector evenly and flatly, the material of the electrode plate will not fall off, the capacity will not be reduced, the high rate capability and circulation stability of the lithium ion battery cathode and anode materials can be greatly improved, and the service life of the battery can be effectively extended.

The invention relates to the technical field of a lithium ion battery, in particular to a preparation method of a spherical hard carbon negative electrode material of a high-capacity lithium ion battery. The preparation method is characterized by comprising the following steps of (1) material mixing; (2) precrosslinked polymerization reaction; (3) crushing and grading; (4) polymer powder pelletizing treatment; (5) oxidation stability treatment; (6) pre-carbonization treatment; (7) carbonization treatment. Compared with the prior art, the preparation method has the advantages that the raw material sources are wide; the preparation process is simple; the structure and the processing performance of a precursor organic carbon source can be effectively improved through the precrosslinked polymerization reaction; the prepared spherical hard carbon has unique appearance and good pore diameter distribution, and also has the advantages of particle granularity distribution uniformity, high stacking density and the like; high capacity, high first coulombic efficiency, excellent high-rate performance and excellent circulation performance are also realized.

The invention discloses a three-dimensional porous compound film of a super-capacitor and a preparation method thereof. The preparation method comprises the following steps of: reacting for 60-180 seconds by the cathodic electro-deposition method to generate a three-dimensional porous nano nickel film; reacting for 100-400 seconds to deposit by using the three-dimensional porous nano nickel film as the carrier and the cathodic electro-deposition method, compounding a cobalt hydroxide nano sheet layer on the three-dimensional porous nano nickel film and preparing the three-dimensional porous nano nickel/cobalt hydroxide nano sheet compounded film for the super-capacitor, wherein the aperture of the three-dimensional porous nano nickel layer is 5-10 microns; the distance between the sheets of the cobalt hydroxide nano sheet layers is 10-300 nm; the thickness of the compound film is 30-200 microns; and the weight ratio of the cobalt hydroxide nano sheet to the three-dimensional porous nono nickel film is 5:100 to 20:100. The compound film disclosed by the invention has high capacitance, high power, high energy density and high cycle life and has wide application prospect in the fields such as electric automobiles, communication and signal control and the like.

The invention provides a large-capacity power lithium battery which can be used in the field of vehicles as a power source and a preparation method thereof. The large-capacity power lithium battery of the invention is prepared by stacking and packaging a positive electrode, the thin film of a gel-state polymer electrolyte and a negative electrode, wherein the active material of the negative electrode is modified lithium titanate, the active material of the positive electrode is one or more of a ternary material, lithium manganate and ferric lithium manganate, and the thin film of the gel-state polymer electrolyte is prepared by mixing and drying a lithium salt, the solution of an organic solvent and a conductive polymer solution. The power lithium battery has the characteristics of environmental friendliness, excellent high magnification performance, excellent heat dispersion and the like. The preparation is simple, environmental pollution and leakage do not exist, the storage service life is long, enlargement is easy and the temperature range for use is wide. The large-capacity power lithium battery can be used as the power source and applied to the fields such as hybrid electric vehicle, electric vehicle and the like.

Embodiments provide a method of producing micro-sized Si—C composites or doped Si—C and Si alloy-C with interconnected nanoscle Si and C building blocks through converting commercially available SiO_x (0<x<2) to a silicon framework by calcination, followed by etching and then by carbon filling by thermal deposition of gas containing organic molecules that have carbon atoms.

The invention discloses a power polymer lithium ion battery and a fabricating process thereof. A positive plate comprises modified lithium iron phosphate, conductive agent, positive adhering agent, dispersant and positive current collector. A negative plate comprises graphite, conductive agent, negative adhering agent and negative current collector. The fabricating process comprises the following steps: firstly, dispersing the conductive agent; secondly, dispersing the modified lithium iron phosphate; thirdly, adding the efficient organic adhering agent so as to increase the adhering property among grains of the conductive agent, between the conductive agent and the positive material, and between the conductive agent and the positive material and the current collector, and to increase the electrode contact conductivity and electron conductivity, thereby greatly improving the battery high-rate charge and discharge property. The invention has the advantages of simple process, easy control, good product safety and long circulation service life.

The invention provides a modified lithium titanate material and a preparation method thereof. The modified lithium titanate material is characterized in that a molecular formula of the lithium titanate material is LiaMpNqTixO12, wherein M and N in the molecular formula are doped and modified metal ions; a is equal to 4; p is more than 0 and less than 0.1; q is more than 0 and less than 0.1; p+q is more than 0 and less than or equal to 0.1; p+q+x is equal to 5; and the metal elements M and N respectively are one of La, Ce, Pr, Nd, Sm, Gd, Dy, Zr, Mn, Ta, Hf and V. The invention further provides a preparation method of the modified lithium titanate material. Compared with the conventional lithium titanate preparation method, the preparation method provided by the invention has the advantages that the reaction temperature is reduced, and the reaction time is reduced. Furthermore, the preparation process is simple; the preparation period is short; and the preparation method is applicable to industrial mass production. Moreover, the modified lithium titanate prepared by the method has the properties of good charging and discharging properties, good circulation property and high-rate property.

The invention relates to a method of a lithium vanadium phosphate-coated ternary material of a lithium ion battery. The active electrode material of lithium vanadium phosphate is used as a coating material, and can form a uniform coating layer at the surface of the ternary material. A preparation method comprises the following steps of (1) preparing the ternary material; (2) mixing the ternary material and the lithium vanadium phosphate; (3) calcining a mixed sample under the reduction atmosphere. The method has the advantages that the transmission rate of lithium ions of the surface-coated lithium vanadium phosphate material is quick, and the large rate property of the material is improved; the lithium vanadium phosphate material has good stability, the erosion of electrolyte to the ternary material of an inner core is effectively inhibited, the coated ternary material integrates the advantages of the ternary material and the lithium vanadium phosphate, and the good rate property and cyclic property are realized.

The invention discloses a lithium titanate/porous carbon composite material. The invention further discloses a preparation method of the lithium titanate/porous carbon composite material. The prepapration method comprises the following steps: weighing lithium hydroxide monohydrate, tetrabutyl titanate and porous carbon according to a certain stoichiometric ratio; adding ethanol and de-ionized water and uniformly mixing; transferring a stirred suspension solution into a hydrothermal reaction kettle and reacting at 180 DEG C for 24h to 48h to obtain precursor slurry; drying and crushing the precursor slurry to obtain precursor powder; treating the precursor powder in an inert atmosphere at the temperature of 500 DEG C to 700 DEG C for 5 to 10 hours to obtain the lithium titanate/porous carbon composite material. The composite material prepared by the technical scheme provided by the invention has excellent rate performance and low-temperature property.

The invention discloses a ternary lithium battery electrolyte and a high-temperature resistant, high-capacity and high-safety lithium battery core. According to the lithium battery core, a high-temperature resistant high-safety electrolyte is prepared by adopting a novel lithium salt of a conductive lithium salt LiBOB (lithium bis(oxalate)borate) and a lithium salt LiFSI (lithium bis(fluorosulfonyl)imide) and adding a proper amount of additive of FEC (fluoroethylene carbonate), MMDS (methylene methanedisulfonate) and TMP (trimethyl phosphate). A novel ternary positive electrode material coatedwith a mixture of nano titanium dioxide and a ternary material (LiNi0.8Co0.1Mn0.1O2) is adopted by a positive electrode, and a mixture of mesocarbon microbeads MCMB and carbon nanotubes is adopted bya negative electrode, thereby preparing the novel high-temperature resistant high-capacity lithium-ion power battery core for an automobile. According to the prepared battery core, the cycle performance is improved, and meanwhile, the problem of high-temperature air expansion is well solved.

The invention relates to a lithium ion battery composite cathode material which is characterized by being prepared from powder which is formed by uniformly coating amorphous carbon on the surfaces ofin situ composite Li3V2(PO4)3 and LiFePO4, wherein the powder contains the components in percentage by weight: 75.0-74.0 percent of LiFePO4, 21.8-21.8 percent of Li3V2(PO4)3 and 2.3-4.8 percent of amorphous carbon. A preparation process of the composite cathode material adopts a carbothermic reduction solid phase sintering method which comprises the following steps: mixing raw materials of FePO4,Li2CO3, NH4H2PO4 and NH4VO3 according to a stoichiometric ratio; adding petroleum coke accounting for 15-25 percent of the total weight of the raw materials; and after adding acetone to ball mill andmix the raw materials on a ball milling machine, and calcining the raw materials in argon atmosphere at 600-700 DEG C for 8-12 hours. When used as a cathode of a lithium ion battery, the composite cathode material has the advantages of simple preparation method, high charge and discharge capacity, good performance of high multiplying power charge and discharge, good cyclical stability, and the like.

The invention relates to a NiS2 mesoporous nanosphere material and a preparation method thereof. The material can serve as a long-life and high-rate sodium-ion battery negative electrode active material, a plurality of NiS2 subunit nano-particles are regularly stacked to form mesoporous nanosphere structures with uniform shapes, mesopores are formed among the NiS2 subunit nano-particles, the sizes of the mesopores are mainly distributed within the range of 3-4 nanometers, mesoporous nanospheres are free from agglomeration and good in dispersity, the diameters of the NiS2 subunit nano-particles are 150-200 nanometers, and the specific surface area of each mesoporous nanosphere is 49.1m<2>g<1>. The material has the advantages that the NiS2 mesoporous nanosphere material is successfully synthesized and shows excellent high-rate performance, cycling stability and long service life when serving as the sodium-ion battery negative electrode active material, and the material is a potential applied material for a high-power and long-life sodium-ion battery.

The invention relates to a preparation method for a carbon-coated lithium ion battery positive electrode material. The preparation method comprises the following steps: successively adding a carbon source dispersion liquid, a phosphorus source dispersion liquid, a lithium source dispersion liquid and a ferric iron source dispersion liquid into a solution of a dispersant or deionized water; fully mixing an obtained mixed liquid so as to obtain a uniformly dispersed solution or turbid liquid; drying the mixed liquid to obtain a precursor and then pre-decomposing and sintering the precursor so as to obtain the single-phase carbon-coated lithium ion battery positive electrode material lithium iron phosphate. According to the method, usage of the ferric iron source enables cost for raw materials to be substantially reduced; process temperature of the synthesized material is low, high-temperature processing time is short, a preparation period for the material is substantially shortened, and production cost is effectively reduced; there is no requirement for raw materials, so the source of the raw materials is broadened. The synthesized lithium iron phosphate has the advantages of a particle size of 60 to 550 nm, good particle dispersion, high conductivity, great specific capacity, a long cycle life, etc. and can meet needs of practical application of a lithium ion battery.