240results about How to "Facilitate de-intercalation" patented technology

The invention relates to a preparation method of a carbon-coated sodium-micron-scale lithium titanate composite anode material. The method comprises steps as follows: lithium salt is dissolved in an aqueous solution of absolute ethyl alcohol, and the solution is marked a solution a; an organic titanium compound and a carbon source are dissolved in absolute ethyl alcohol, and the solution is marked a solution b; a chelating agent M is dissolved in absolute ethyl alcohol, ultrasonic dispersion is performed, and the solution is marked a solution c; the solution c is slowly dropwise added to the solution b while stirring, and white sol is obtained; then the solution a is slowly dropwise added to the white sol; after the sol is aged, heating, stirring, drying, grinding, sieving and calcination are performed, and the carbon-coated lithium titanate composite anode material is obtained. Lithium titanate has narrower particle size distribution and more uniform particle distribution, and sodium-micron-scale particles are uniformly inlaid to form particles with high tap density; the particle structure is loose and porous, the specific surface area of a formed electrode is larger, getting off of lithium ions in the lithium titanate material is facilitated, and the stability of the crystal structure of the lithium ions in the charge and discharge process is guaranteed.

The invention provides a high-nickel ternary cathode material coated with a fast ion conductor and a preparation method thereof. The high-nickel ternary cathode material is spherical or spheroidic secondary particles composed of primary particles, the diameter of the high-nickel ternary cathode material is 1-30 [mu]m, and the chemical formula of the high-nickel ternary cathode material is LiNi0.8Co0.1Mn0.1O2. The preparation method comprises the following steps of: weighing raw materials for synthesizing the fast ion conductor in proportion, and uniformly dispersing the raw materials in a solvent to obtain a mixed solution; adding the high-nickel ternary precursor into the mixed solution, and then performing stirring, drying and grinding to obtain high-nickel ternary precursor powder coated with the fast ion conductor; and uniformly mixing the obtained precursor powder with a lithium salt, and performing sintering to obtain the high-nickel ternary cathode material coated with the fastion conductor. The fast ion conductor material is used as a coating substance of the ternary cathode material and can provide a fast transmission channel for lithium ion transmission, so that the purpose of reducing the internal resistance of the battery is achieved; and after coating, the cycling stability of the battery is improved under the condition that the specific discharge capacity of thebattery is not reduced.

The present invention relates to the preparation method of lithium ion battery electrode material, especially relates to a kind of preparation method of spinel type lithium titanate; In the present invention firstly disperses surfactant, lithium source, titanium source in absolute ethanol and ball mills to obtain the precursor and then drying, calcining, grinding, tableting, calcining, regrinding and other treatments on the precursor, and finally obtain the spinel-type lithium titanate; the present invention uses a surfactant as a dispersant to make The raw materials are mixed more uniformly and dispersed better, and lithium titanate materials with small and uniform particle size and good electrochemical performance can be synthesized at lower calcination temperature and shorter calcination time; High, synthetic materials have good dispersion performance, small particle size, simple process, high production efficiency, environmental friendliness, and easy large-scale production.

The invention discloses a preparation method of a lithium-rich anode material having a chemical formula of xLi2O.yMOb (wherein M is at least one of Mn, Ni, Co and Al, x/y is greater than 0.51 and lower than 0.95, and b is not lower than 1 and not greater than 2). The method comprises the following steps: 1, weighing raw materials comprising a lithium sauce and at least one of a manganese source, a cobalt source, a nickel source and an aluminum source according to the molar ratio in xLi2O.yMOb; 2, adding a liquid into the raw materials, and grinding to form a slurry, wherein the median particle size D50 of particles of the slurry is less than 0.05mum; 3, drying the slurry in a spray manner; and 4, roasting the material obtained after drying. The method has the advantages of simple process and easy industrialized production; the primary particles of the obtained powder are small, and the secondary particles are spherical in shape; and the lithium-rich anode material prepared through adopting the method has a large discharge specific capacity, and the specific energy of the lithium ion battery prepared through using the lithium-rich anode material is high.

An object of the present invention is to provide a multi-component system (cobalt-nickel-manganese three-component system) cathode active material for a lithium secondary battery which has improved characteristic as compared with conventional lithium secondary batteries and a layered rock salt structure. A plate-like particle or a film for a lithium secondary battery cathode active material is represented by the following general formula:

Li_p(Co_x,Ni_y,Mn_z)O₂  General formula

• • (wherein 0.97≦p≦1.07, 0.1<x≦0.4, 0.3<y≦0.5, 0.1<z≦0.5, x+y+z=1)

The particle or the film contains cobalt and lithium and has a layered rock salt structure. The (003) plane is oriented so as to intersect the plate surface of the particle or film.

The invention discloses a graphite/silicon@carbon core-shell structure composite spherical cathode material and a preparation method thereof. By means of the material, the volume expansion effect of silicon in the lithium de-intercalation process can be inhibited, and a high-capacity lithium iron battery silicon/carbon composite cathode material is obtained. By means of the technical scheme, a spherical graphite/silicon framework precursor serves as the core of the composite cathode material, and an amorphous pyrolytic carbon or graphite-like carbon material wrapping layer serves as the shell; nanometer or micrometer silicon is embedded in flake graphite cracks to form a graphite framework, the volume expansion effect of silicon in the lithium de-intercalation process is inhibited through the mechanical characteristics of the graphite framework, then a spherical framework is formed by mixing and granulating 3-20 wt% of nanometer or micrometer silicon, 50-80 wt% of flake graphite and 10-40 wt% of amorphous pyrolytic carbon or graphite-like carbon, and an amorphous pyrolytic carbon or graphite-like carbon spherical composite conductive carbon net structure wrapping a graphite/silicon surface is formed.

The invention discloses a method for preparing a three-dimensional carbon nanomaterial by activating shaddock peel with a strong base. The method comprises the steps that the shaddock peel is washed to be clean and then subjected to freeze drying, a sulfuric acid solution is added for a hydrothermal reaction, and a biomass precursor is obtained; the biomass precursor is subjected to washing, suction filtration and drying and then mixed with the strong base to be subjected to carbonization in a tubular atmosphere furnace, and a carbonization product is obtained; the carbonization product is subjected to washing and suction filtration and then dried, and the three-dimensional carbon nanomaterial, namely, a carbon negative electrode material used for sodium-ion batteries is obtained. The strong base activated shaddock peel negative electrode material prepared through the method has a three-dimensional porous connected nantostructure, the specific surface area is large, more attachment sites are provided for sodium ions, micropores can be beneficial for entering of electrolyte to increase the contact area with the electrode material, a condition is provided for rapid transmission of the sodium ions, and the capacity of the material is increased.

The invention discloses a hollow nano cubic NiCo2O4 dual-metal oxide material and a preparation method thereof, and belongs to a metallurgical powder material and preparation thereof. The material disclosed by the invention is in the structure of a hollow nano cross cube of which the diameter is 500nm, the highest reversible capacity is 1160mAh/g, the capacity is greater than or equal to 1060mAh/g after circulating 100 times, the specific capacity is kept at 84%, and the performance is stable. According to the preparation method, a polyvinyl pyrrolidone (PVP) solution dissolved into high-purity water and ethanol is taken as a solvent, NiC12.6H2O and CoC12.6H2O are taken as metal sources, and S2O3<2+> and a home-made Cu2O nano cubic template from selective erosion are utilized at proper temperature, thereby finally generating the NiCo2O4 dual-metal oxide with the hollow nano cubic structure. The hollow nano cubic NiCo2O4 dual-metal oxide material is simple in preparation technology, and low in cost, and has industrial prospect.

The invention relates to a flexible negative electrode with MnO2 attached onto carbon fibers of a lithium ion battery and a preparation method of the flexible negative electrode. A metal oxide in the prior art is wrapped inside the carbon nanofibers, and thus, the contact of the metal oxide serving as an active substance with an electrode and the de-intercalation process of the metal oxide with lithium ions are not promoted; and further, the metal oxide is Fe2O3, Fe3O4, Co3O4 and the like, and such metal oxide has a defect of relatively high de-intercalation lithium potential. The preparation method is characterized by comprising the following steps of firstly, preparing a flexible carbon nanofiber net, which comprises electrostatic spinning, pre-oxidation of a polymer nanofiber net and high-temperature calcination; secondly, preparing a flexible composite fiber thin film with an MnO2 nanowire attached onto the surfaces of the carbon nanofibers, placing the flexible carbon nanofiber net in a KMnO4 solution, and completing high-temperature reaction under process conditions of a reaction temperature of 150-200 DEG C and reaction time of 30-60 minutes; and finally, cutting the flexible carbon nanofiber net into the flexible negative electrode with MnO2 attached onto the carbon fibers of the lithium ion battery.

The invention discloses a preparation method of a biomass hard carbon material for a negative electrode of a sodium ion battery, which adopts cheap and easily available biomass as a carbon source to prepare a hard carbon material for the negative electrode of the sodium ion battery by a simple and convenient method, and can effectively reduce the cost of the sodium ion battery. At the same time, the hard carbon material has large carbon layer spacing and can accommodate sodium ion intercalation and desorption, and the prepared sodium ion battery has excellent electrochemical performance and good industrial prospect, and is very suitable for a large-scale energy storage system.

The invention relates to the field of lithium ion battery materials, and provides an Al/La co-doped high-nickel ternary precursor with a core-shell structure and a preparation method thereof, and a positive electrode material prepared from the precursor. The preparation method mainly comprises the following three steps: step 1, synthesizing an Al-doped high-nickel ternary precursor with rod-like primary particles under the condition of a low pH value; 2, increasing the pH value on the basis of the step 1, growing a La-doped high-nickel ternary precursor shell with needle-shaped primary particles by taking the Al-doped high-nickel ternary precursor as an inner core so as to synthesize an Al/La co-doped high-nickel ternary precursor with a core-shell structure; and 3, mixing the Al/La co-doped high-nickel ternary precursor with the core-shell structure and a lithium salt, and carrying out high-temperature calcination in an oxygen atmosphere to obtain the Al/La co-doped ternary positive electrode material with the core-shell structure. Due to the unique co-doped core-shell structure, the stability of an internal structure is effectively enhanced, the generation of mixed phases such ascation mixing and rock salt structures is inhibited, the breakage of grain boundaries is reduced, the average oxidation state of manganese ions is improved, the Jahn-Teller effect is effectively inhibited, the rapid attenuation of the capacity in a cycle process is reduced, the cycle stability of the material is remarkably improved, and the cycle life of the material is remarkably prolonged. Theproduct synthesized by adopting a coprecipitation method is uniform in component, good in sphericity, good in reproducibility, easy in condition control, low in preparation cost, high in economic value and wide in application prospect.

The invention discloses a cathode active substance of a lithium secondary battery, wherein the cathode active substance contains a lithium vanadium oxide and carbon, and the lithium vanadium oxide comprises LiVO2 and Li2V2O4. The cathode active substance of a lithium vanadium oxide mixed crystal can improve the specific capacity of the battery, has simple procedures for a preparation process and low production cost, and is suitable for industrial production.

An object of the present invention is to provide a lithium secondary battery which has improved capacity, durability, and rate characteristic as compared with conventional lithium secondary batteries. A plate-like particle or a film for a lithium secondary battery cathode active material is represented by the following general formula:

General formula: Li_p(Ni_x,Co_y,Al_z)O₂

(wherein 0.9≦p≦1.3, 0.6<x≦0.9, 0.1<y≦0.3, 0≦z≦0.2, x+y+z=1)

The particle or the film contains cobalt and lithium and has a layered rock salt structure. The (003) plane is oriented so as to intersect the plate surface of the particle or film.

The invention discloses an electrospinning preparation method for cobaltosic oxide carbon nanometer fibers for a sodium-ion battery. An electrospinning precursor liquid is prepared from Co2+ salts, polyvinylpyrrolidone and an organic solvent, a Co2+ salt/PVP composite fiber membrane by adopting an electrospinning method, then preparing Co3O4 carbon nanometer fibers through an air atmosphere calcination technology, and prepared Co3O4 crystals have a regular hexagonal nano-sheet structure and are uniformly inlaid in the carbon nanometer fibers to enable a material to have larger specific surface area. According to the electrospinning preparation method, with unique carbon nanometer fiber porous structure and ultrathin nano-sheet crosslinking structure, permeation of electrolyte and electron/ion transfer are effectively promoted, the diffusion path of sodium ions in the material is shortened, embedding and disembedding of the sodium ions are facilitated, the capacitance is higher, the cycling stability is better, and the dynamics performance of the material is greatly improved. The electrospinning preparation method is simple in technology and low in cost.

The invention discloses a preparation method of a graphene/stannic oxide composite nanofiber membrane and an application, and relates to anode materials for lithium-ion batteries. The preparation method comprises the following steps: adding graphene to deionized water and carrying out ultrasonic treatment; adding NaOH and stannic chloride under a stirring condition, and mixing the deionized water evenly to obtain a mixed solution; transferring the mixed solution to a reaction kettle for reaction, and filtering, cleaning and drying the mixed solution to obtain graphene/stannic oxide composite nano-particles; ultrasonically dispersing the graphene/stannic oxide composite nano-particles into a mixed solvent of methanol and water, and adding PVAc to obtain a spinning precursor solution; carrying out high-pressure electrospinning on the spinning precursor solution to obtain a PVAc/graphene/stannic oxide composite nanofiber membrane; and carrying out drying and thermal treatment to obtain the porous graphene/stannic oxide composite nanofiber membrane, wherein the diameters of fibers in the composite nanofiber membrane are 800-1200nm and the lengths are greater than 0.5mm. A conductive agent and a binder do not need to add, and the graphene/stannic oxide composite nanofiber membrane can be directly applied to preparation of the lithium-ion battery as an electrode material.

The invention provides a low-temperature type lithium iron phosphate anode material and a preparation method of the low-temperature type lithium iron phosphate anode material. The method comprises the following steps of: proportioning lithium carbonate, metallic oxide, iron phosphate and glucose according to the molar ratio as follows: Li: R: Fe: P: C= (1.1-x): x: 1: 1: 0.8, wherein x=0.01-0.03, C is C in the glucose, and R is a doped metal ion; directly mixing, adding absolute ethyl alcohol of which the gross weight is 2-3 times as heavy as the gross weight of the mixture; ball-milling by means of wetting phase, and evenly mixing; drying, smashing and pelleting the ball-milled sizing agent; calcinating for 2-5h under the temperature of 300-500 DEG C in an inert atmosphere furnace under the status of open setting; cooling to be room temperature; calcinating the power for 8-12h under the temperature of 500-800 DEG C in the inert atmosphere furnace under the compacting status that the surface pressure is 10kg/cm<3>; and secondarily sintering and synthesizing so as to obtain the lithium iron phosphate anode material. The synthesized material is classified and screened by means of fluid energy milling to obtain the nanometer-level lithium iron phosphate anode material, wherein the material is good in electrical conductivity, and the low-temperature performance of a manufactured battery can be effectively improved.

The invention provides a preparation method of a LiMnxFe1-xPO4 positive electrode active material. The method comprises the following steps that a soluble trivalent manganese salt solution, a soluble ferric iron salt solution and a soluble phosphate radical-containing substance solution are blended to form a mixed solution, the mixed solution undergoes a reaction to produce a MnxFe1-xPO4.2H2O precursor, and LiMnxFe1-xPO4 is prepared from the MnxFe1-xPO4.2H2O precursor. The invention also provides the LiMnxFe1-xPO4 positive electrode active material obtained by the preparation method. The LiMnxFe1-xPO4 positive electrode active material has the advantages of uniform particle size distribution, perfect morphology, no agglomeration, small particle size and material electroconductivity improvement. A cell prepared from the LiMnxFe1-xPO4 positive electrode active material has excellent rate discharge performance, especially has high-rate discharge performance, has a high cell charging-discharging capacity, stable cell charging-discharging performances and good cycle performances, lays the foundation in excellent positive electrode active material development and is conducive to material application and cell development.

The invention provides a silicon-based composite material and a preparation method thereof. The silicon-based composite material provided by the invention comprises a silicon-based matrix, a fast ionconductor layer coating the surface of the silicon-based matrix, and a carbon layer coating the surface of the fast ion conductor layer. A fast ion conductor of the fast ion conductor layer is LiAlSixOy, x is greater than or equal to 1, and y is greater than or equal to 1. According to the invention, the specific fast ion conductor layer LiAlSixOy and the carbon coating sequentially coat the surface of the silicon-based matrix, so that problems of relatively high charge transmission impedance and relatively low power output of the silicon-based negative electrode material are effectively improved, and the rate capability is improved; and meanwhile, the specific double coating layers are matched, so that the expansion of the silicon-based material is effectively relieved, and the cycle performance is improved.