886results about How to "High discharge specific capacity" patented technology

The invention relates to a nano carbon material with a network structure consisting of polymer chains, in particular to a nano carbon sulfur composite material with a network structure suitable to be used in a secondary lithium sulfur battery anode and a preparation method thereof. The carbon sulfur composite material is formed by adopting the following steps of: introducing functional groups onto carbon particles by adopting the electric conductivity and the porosity of a carbon material and the reaction capacity of similar condensed aromatics of the carbon material and by means of an irreversible chemical reaction; introducing the polymer chains, wherein the polymer chains are stretched, bent and cross-linked on the surfaces of the carbon particles to form a cross-linked network structure; and compounding a sulfur element or a polysulfide (m is more than 2) containing -Sm- structure into the network structure to form the nano carbon sulfur composite material with the network structure. The carbon sulfur composite material has a rich cross-linked network structure, nano-scale network pores constrain the sulfur element or the polysulfide (m is more than 2) containing the -Sm- structure in the network, and the active substances are limited in a certain region to react, so that the composite material has predominant electrochemical performance.

The invention relates to a gradient distribution multivariate composite material precursor as well as a preparation method of the gradient distribution multivariate composite material precursor and an application in preparation of a lithium ion battery anode material. The precursor is prepared from the following molecular formula: NixCoyMnzM1-x-y-z(OH)2, wherein x is more than 0.2 and less than 0.8, y is more than 0.1 and less than 0.5, z is more than 0 and less than 0.6, and M is a doped metal ion and comprises one or more of Mg, Ca, Zn, Al, Cr, Zr and Ti; the precursor comprises a core part and an outer layer shell part in which multiple layers are sequentially covered in the core; a molecular formula composition of the core part is NikConMnmM1-k-n-m(OH)2, wherein k is more than 0.5 and less than 1, n is more than 0.05 and less than 0.5, and m is more than 0 and less than 0.6; and the outer layer shell part is used for controlling the proportion of the raw material components and a preparation process to ensure that the material composition of the outer layer shell part is distributed in a gradient mode. Compared with a ternary material with a uniform internal structure, the lithium ion battery anode material has the advantages that the high specific discharge capacity is developed; and meanwhile, the cycling stability, the high-temperature cycling stability and the rate capability of the materials also can be greatly improved.

The invention relates to a carbon-sulfur-shell matter composite material having a network dual-core shell structure and a preparation method thereof. The carbon-sulfur-shell matter composite material has a carbon-sulfur-shell three layer structure, a central core (inner core) is nano carbon particles, sulfur elemental or a polysulfide containing-Sm-structure (m>2) is directly deposited on the nano carbon particles, or functional groups are introduced onto the nano carbon particles by use of polycyclic aromatic hydrocarbon like reaction capacity of the carbon material and through an irreversible chemical reaction, polymeric chains are introduced in, a crosslinked network structure is formed through stretching, bending and crosslinking of the polymeric chains on the surface of the nano carbon particles, the sulfur elemental or the polysulfide containing the-Sm-structure (m>2) is composited onto the crosslinked network structure to form a nano sulfur layer having a network structure, then a mono-core shell nano composite material having a network structure is obtained and is used as a second layer (outer core) of the carbon-sulfur-polymer composite material having the network dual-core shell structure, an outermost layer is a shell matter layer, electronic and/or ionic conductivity of the material are/is improved, dissolving loss of discharge products can be further inhibited, and structural stability of the material is improved. The material is suitable for positive poles of lithium sulfur batteries, and has a prominent effect on improvement of cycle stability of the lithium sulfur batteries.

The invention relates to an application of a porous carbon material with a grading pore structure in a lithium-air cell anode, and is characterized in that the carbon material has mutually communicated grading pore structure distribution which has a mesoporous structure for depositing the discharge products and a macroporous structure suitable for transmission of oxygen and an electrolyte. When the carbon material is taken as a material of the lithium-air cell anode, the space utilization rate of carbon material can be increased at maximum limitation during a charge and discharge process, specific discharge capacity, voltage platform and multiplying power discharge capability of the cell can be effectively increased, so that the energy density and power density of the lithium-air cell can be increased. The porous carbon material has the advantages that the preparation technology is simple, the material source is wide, the grading pore carbon material pore structure enables regulation and control, the regulation and control modes are various, and the doping of metal/metal oxide can be easily and simultaneously realized.

The invention discloses a surface-modified lithium cobaltate material and a preparation method thereof. The lithium cobaltate material comprises a core particle and a surface-modified layer coating the core particle, wherein the core particle is a lithium cobaltate-based positive material with a structural formula as follows: LixCo(1-y)MyO2, wherein x is greater than 1 and not greater than 1.2, y is not less than 0 and not greater than 0.1, M is a doping element; the surface-modified layer comprises a Li<+1> conducting layer and an electrolyte isolating layer; the core particle is coated by the Li<+1> conducting layer and the electrolyte isolating layer in sequence. According to the invention, by sufficiently utilizing dynamic characteristic that different substances react with residual Li salt on the surface of the lithium cobaltate, and characteristic of final reaction product performance, the lithium cobaltate material with double coating layers is prepared. The material is high in comprehensive performances, has high discharge capacity, high cycling stability and the like. The preparation method disclosed by the invention is simple in process and easily realizes industrial production.

The invention relates to a high-capacity silicon-carbon composited anode material, a preparation method and application thereof, wherein the silicon-carbon composited anode material comprises the following compositions in parts by weight: 1-30 parts of silicon materials, 30-120 parts of carbon materials, and 10-80 parts of pyrolytic carbon. The silicon materials in the silicon-carbon composited anode material disclosed by the invention are uniformly adhered to the surfaces of carbon material particles, and then the outer layers of the carbon material particles are wrapped with the pyrolytic carbon, therefore, the silicon-carbon composited anode material disclosed by the invention has the advantages of lower first irreversible specific capacity, higher specific capacity, excellent cycle performance, low preparation cost and the like; and the first discharge capacity of the silicon-carbon composited anode material is greater than 450 mAh.g<-1> under a 0.2 C discharge ratio, and the retention rate of capacity after 50 cycles is more than 80%.

The present invention discloses a high-voltage ternary positive electrode material for lithium-ion battery and preparation method thereof. The chemical formula of the material is LiNi_0.6-xMg_xCo_0.2-yAl_yMn_0.2-zTi_zO_2-dF_d, wherein 0<x,y,z,d≤0.05. The precursor of the positive electrode material is synthesized by gradient co-precipitation method and the positive electrode material is prepared by solid phase method. The content of nickel in the synthesized precursor particles has a gradient distribution from the inside to the outside. The obtained precursor is mixed and grinded evenly with the lithium source and the fluorine source at a certain ratio and put into the tube furnace. The obtained precursor is then pre-sintered in the oxygen-enriched air atmosphere and then heated up to be sintered, to obtain the target product. The positive electrode material for lithium-ion battery prepared by the method is free from impurity phase and has a good crystallinity, which is a high energy density positive electrode material.

An electrode material of Fe¿CLi phosphate and its composite metal phosphate is electrode material of LiFePO4 and LiFePO4 / MxP in high density spherical shape with diameter of 2micro m. The electrode material of LiFePO4 and LiFePO4 / MxP can be prepared by low ¿C temperature controllable one ¿C stage atomizing process in short flow.

The invention discloses a cathode material for a fast lithium ion conductor phase-modified lithium ion battery and a preparation method thereof. The key points of the technical scheme are as follows: the cathode material for the fast lithium ion conductor phase-modified lithium ion battery is a composite material consisting of a rare-earth element doped composite layered lithium ion battery cathode material xLi2MO3 (1-x) LiN(1-y)RyO2 (M is Mn, Ti or Sn, N is Mn, Ni, Co, Fe, Cr, V or Mo, R is one or more than one of Sc, Y, Pr, Nd, La, Ce, Sm, Yb, Eu and Gd, x is larger than 0 and smaller than 1, and y is larger than 0 and smaller than 0.2) and a fast lithium ion conductor, wherein the molar ratio of the fast lithium ion conductor to the rare-earth element doped composite layered lithium ion battery cathode material is n:1, and n is larger than 0 and smaller than or equal to 0.15. The invention also discloses a preparation method of the cathode material for the fast lithium ion conductor phase-modified lithium ion battery. The cathode material for a fast lithium ion conductor phase-modified lithium ion battery has the advantages of high specific capacity, good rate capacity, stability in recycling and strong temperature adaptation.

The invention discloses a preparation method for a nitrogen-doped porous carbon sphere-sulfur composite positive material. The preparation method comprises the following steps of: performing spray pyrolysis on a nitrogen-containing carbon source, silica sol and de-ionized water to obtain a spherical nitrogen-doped pyrolytic carbon-silicon dioxide composite, adding the composite into excessive hydrofluoric acid for reaction, and washing and drying the reactants to obtain nitrogen-doped porous carbon spheres; and adding a sulfosalt solution into the nitrogen-doped porous carbon spheres under a vacuum condition, adding glycerin, which is taken as a dispersing agent, into the carbon spheres, adding an acid solution to the carbon spheres under magnetic stirring, and filtering and washing the mixture, and performing vacuum drying on the washed mixture to obtain the nitrogen-doped porous carbon sphere-sulfur composite positive material. The sulfur content of the prepared composite material is 50 to 90 percent, sulfur particles are more uniformly distributed in porous structures of the porous carbon spheres, and carbon and sulfur particles are more closely bound. The material is high in mechanical stability, specific discharge capacity and cycle performance. The method is simple in process, easy to operate, pollution-free and suitable for industrial implementation and batch production.

The invention discloses a preparation method of a metal organic skeleton MIL-101(Cr)@S/graphene composite material as the cathode material of a lithium sulfur battery. The preparation method comprises the following steps of: evenly loading sulfur into a three-dimensional pore channel of MIL-101(Cr) by a melting diffusing method, and mixing with graphene, so that the MIL-101(Cr)@S/graphene composite material can be prepared. The metal organic skeleton crystal material in the composite material is has superhigh specific surface area and pore volume and has a skeleton structure which has medium-mirco double pores, so that the dual effects of dispersing and fixing the sulfur grains can be played, and the whole electrical conductivity of the composite material can be improved due to graphene, so that the polarization of the material can be weakened, the discharge multiplying power performance can be improved, the coulomb efficiency can be improved and the like. The electrochemical performance test shows that the discharge specific capacity of the MIL-101(Cr)@S/graphene composite material prepared by the method can reach 1087mAh/g under the condition that the multiplying power is less than 0.1C, and the discharge specific capacity of the MIL-101(Cr)@S/graphene composite material prepared by the method is respectively kept at 807 and 387mAh/g under the condition that the multiplying power is 0.8C and 2.4C when the circulation times is 116 and 150. The preparation method has the advantages that the preparation method has the characteristics of being simple in process, convenient to operate, good in material performance and the like, and is suitable for large-scale industrial production.

The invention provides a preparation method of an S/TiO2 composite material for an anode of a sodium-sulfur battery. The preparation method comprises the following steps: dissolving butyl titanate, a template agent and a hydrolysis inhibitor into absolute ethyl alcohol; adding a mixed solution of de-ionized water and the absolute ethyl alcohol to form semi-transparent sol; transferring the sol into a high-pressure reaction kettle to react; calcining a solid product in air to remove the template agent to obtain meso-porous titanium dioxide; dispersing the meso-porous titanium dioxide into a sodium thiosulfate solution dissolved with a surfactant; adding hydrochloric acid to react; washing the solid product by a lot of the de-ionized water and drying; and eating under the protection of an inert atmosphere to obtain the S/TiO2 composite material. The meso-porous titanium dioxide prepared by the preparation method is large in specific surface area, high in porosity and strong in adsorption capability; the electrical conductivity of sulfur can be improved and a lot of nano sulfur and polysulfide can be contained; the polysulfide can be effectively prevented from being dissolved and diffused in electrolyte, and the utilization rate of the sulfur is improved; meanwhile, the structure of the meso-porous titanium dioxide is stable and a pore channel cannot be easily damaged, so as to have buffering effects on volume expansion and retraction in a charging/discharging process of a sulfur electrode.

The invention discloses a positive electrode material for a compound lithium ion battery. LiFePO4 is adopted as matrix, and Li3V2 (PO4)3 or LiVPO4F is adopted to wrap the surface of LiFePO4 particles or to exist among LiFePO4 particles or to directly form a solid solution with LiFePO4, and the molar ratio of LiFePO4 and Li3V2 (PO4)3 or LiVPO4F is (1-100):(100-1). The compound lithium ion battery of the invention has excellent performances of charge/discharge and magnification, and the positive electrode material of the compound lithium ion battery is suitable for producing power cells.

The invention discloses a preparation method of graphene loaded with anatase type nano titanium dioxide and an application thereof. The preparation method comprises the following steps: preparing graphite oxide from crystalline flake graphite; carrying out reduction reaction on the graphite oxide to obtain graphene by taking hydrazine hydrate as a reducing agent and sodium dodecyl benzene sulfonate as a dispersing agent; preparing titanium hydroxide colloidal solution by taking tetrabutyl titanate as a titanium source; mixing the ethanol solution of graphene and the titanium hydroxide colloidal solution, stirring and calcining to prepare the graphene loaded with anatase type nano titanium dioxide. The graphene loaded with anatase type nano titanium dioxide prepared by the method can be mixed with copper powder to prepare the negative electrode of a nickel-hydride secondary battery. The method provided by the invention has the advantages of simple preparation process and low cost and is easy to operate. When the prepared graphene loaded with anatase type nano titanium dioxide is used as the active material of the cathode of the secondary battery, the effects of high discharge specific capacity and good circulation stability are achieved.

The invention discloses a preparation method of a cathode material of a lithium ion battery coated with metal oxides on the surface, which comprises the following steps of: 1, dissolving an easily soluble metal salt into a solvent to form a solution under the heating condition; 2, adjusting the pH value of the solution in the step 1 with an alkali solution under the stirring condition to ensure that the solution forms a sol matter; 3, putting a lithium-containing cathode material into the sol matter under the stirring condition, reacting for a period of time to ensure that hydrolysate evenly deposits and absorbs on the surface of the lithium-containing cathode material; 4, drying the lithium-containing cathode material absorbed with the hydrolysate on the surface; and 5, roasting the dried lithium-containing cathode material to form the lithium-containing cathode material coated with the metal oxides on the surface. The preparation method is easy and reliable; and the lithium-containing cathode material coated with the metal oxides on the surface can remarkably improve the energy density, the safety and the charge and discharge circulating stability of the lithium ion battery.

The invention relates to a quinone compound anode material for an aqueous lithium ion battery. The quinone compound anode material is quinone polymers directly connected through C-C bonds or connected through N atoms or S atoms, or is a quinone compound formed by in-situ composition of a quinone compound monomer with a high-conductivity carbon material during the polymerization process, and the high-conductivity carbon material is selected from one or more of graphite oxide, carbon black, carbon nano tube and expanded graphite. The material has the advantages of high molecule designability, high discharging specific capacity (the maximum can reach 200mAh g<-1>, appropriate electrode potential (2-2.8V to Li/Li<+>), high rate capability and cycle performance and the like, and the aqueous lithium ion battery prepared from the material has the advantages of long cycle life, high efficiency, safety, low cost, environmental friendliness and the like.

The invention relates to a lithium ion secondary battery which consists of a shell, a positive electrode plate, a diaphragm, a negative electrode plate and electrolyte. The positive electrode plate consists of a positive electrode current collector and a negative electrode active material bonded on the positive electrode current collector; the negative electrode plate consists of a negative electrode current collector and a negative electrode active material bonded on the negative electrode current collector; the positive electrode active material is an iron phosphate ferrovanadium lithium composite material of a nano oxide doped with an M element; the negative electrode active material is a lithium titanate composite material; the M element is selected from any one or the combination of at least two of aluminum, lithium, boron, silver, copper, chromium, zinc, titanium, gallium, germanium, zirconium, tin, silicon, iron, cobalt, nickel, vanadium, magnesium, calcium, strontium, barium, tungsten, molybdenum, niobium, yttrium, lanthanum, selenium and cadmium; the lithium oil secondary battery has the obvious characteristics of excellent electrical chemical performance, high safe performance, long cycle service life, low cost, environment friendliness and the like, is beneficial to widening the application range of the lithium ion battery, and has important practical significance and wide market prospect.

The invention provides a cobaltosic oxide multi-shell hollow sphere cathode material for a lithium ion battery and a preparation method thereof. The method comprises the steps of: taking a carbon sphere prepared by a hydrothermal method as a template; controlling the quantity of cobalt ions in the carbon sphere and the entering depth thereof by controlling the ratio of water to ethanol in a cobalt salt solution, the temperature of the solution and the adsorption capacity of the carbon sphere; and preparing single-shell, dual-shell, tri-shell and four-shell cobaltosic oxide hollow spheres. The lithium ion battery of taking the cobaltosic oxide multi-shell hollow sphere as a cathode has large specific surface area and a plurality of lithium ion storage sites; the specific capacitance is improved; meanwhile, the appropriate multi-shell cavity structure not only can adjust the electrode structure and volume change, but also can effectively reduce the transmission distance between the lithium ion and electrons. Thus, the cycling performance and rapid charge and discharge capacity are obviously improved. The method disclosed by the invention is convenient and concise to operate, and high in controllability, and has a wide application prospect; and the performance of the lithium ion battery can be obviously improved.