62results about How to "Reduce the first irreversible capacity" patented technology

The invention discloses a modified silicon monoxide material and a preparation method thereof. The modified silicon monoxide material is the modified silicon monoxide material used for a lithium battery negative electrode. The modified silicon monoxide material is prepared by the following steps: reacting raw materials silicon, silicon dioxide and metal silicate under high-temperature and vacuum conditions to prepare silicon monoxide, and reacting metal steam with silicon monoxide in the preparation process to form metal silicate in situ; wherein the metal silicate is uniformly dispersed around the silicon and the silicon monoxide to form silicon-containing particles, and the carbon material is coated on the surfaces of the silicon-containing particles. The silicate in the modified siliconmonoxide material is uniformly dispersed, the carbon material is uniformly coated, and the modified silicon monoxide material shows high specific capacity, high initial coulombic efficiency, excellent cycle performance and rate capability when used as the lithium ion battery negative electrode material. Moreover, the preparation method disclosed by the invention is low in raw material price and beneficial to industrial implementation, so that the modified silicon monoxide has a very wide application prospect.

The invention discloses a preparation method of a sheet-shaped boron-doped porous silicon electrode material. The preparation method comprises the steps of (1) immersing boron-doped P-type silicon debris with an inorganic acid for 6-24 hours, and performing washing and drying to obtain boron-doped silicon powder; (2) uniformly mixing the boron-doped silicon powder and magnesium powder according toa mole ratio being 1:(1-2.5) to obtain a mixed material, and performing thermal processing on the mixed material under inert atmosphere to generate Mg2Si powder; (3) oxidizing the Mg2Si powder undera high temperature of 400-850 DEG C to obtain a reaction product, immersing the reaction product with the inorganic acid, cleaning and washing the reaction product with an HF solution, and obtaining the sheet-shaped boron-doped porous silicon electrode material after drying. The grain size of the prepared sheet-shaped boron-doped porous silicon electrode material is 0.2-5 micrometers, the specificarea is (10-100) m<2> / g, and the pore diameter is 20-70 nanometers. The sheet-shaped boron-doped porous silicon electrode material has favorable cycle stability and high specific capacity.

The invention provides a method for preparing a modified graphite negative electrode material of a sodium ion battery and aims at solving the problem of lacking of a suitable negative electrode material of the sodium ion battery at present. The method comprises the steps of preparing paste graphite oxide by using a Hummer method, cladding the graphite oxide with asphalt, phenolic resin or glucose as carbon precursors, and carrying out carbonization heat treating on the graphite oxide clad with the carbon precursors under an inert gas atmosphere. The method has the advantages of being simple, wide in raw material sources, suitable for large-scale industrial production, and the like. According to the obtained modified graphite negative electrode material, the carbon layer spacing is not less than 0.35nm, and the thickness of the carbon clad layer is 0.01-1 micron.

The invention provides a lithium-rich anode material for a lithium ion battery and a preparation method thereof. The chemical formula of the anode material is Li[LixCo1-x-y-z-a NiyMnzCea]O2, wherein x is more than 0 and less than 1, y is more than or equal to 0 and less than 1, z is more than or equal to 0 and less than 1 and alpha is more than 0 and less than or equal to 0.3. The preparation process is as follows: firstly, mixing cobalt salt, nickel salt, manganese salt, ceric salt and water at ratio of 1-x-y-z-a:y:z:a, thereby obtaining a first solution; mixing oxalic acid matters, urea and water, thereby obtaining a second solution; under inert gas shielding, mixing the first solution with the second solution and performing coprecipitation reaction, thereby obtaining an oxalate precursor; milling and mixing lithium source with oxalate precursor, roasting the mixed powder, and then obtaining the lithium-rich anode material for the high-capacity lithium ion battery. The lithium-rich anode material provided by the invention is uniform in size distribution, excellent in high-magnification charge and discharge performance, low in initial irreversible volume and high in cycling stability.

The invention relates to a preparation method for secondary battery cathode material, more particularly to a preparation method thereof which is formed by coating graphite by using nano-intermediate phase asphalt. The key point of the method is that nano-processing is carried out to the intermediate phase asphalt which is in semi-liquid state, the nano-intermediate phase asphalt in the semi-liquidstate is sprayed on the substrate surface of the graphite by a nano-spray device, then even coating is realized, finally, the secondary battery cathode material is obtained by the traditional processes of drying, carbonization and graphitization. The adoption of the method can improve the coating evenness and the spherical completeness in a greater degree, thus further reducing the first-time irreversible capacity of the graphite, improving the cyclical stability and having the advantages that the charging and discharging voltage of the secondary battery is low, the charging and discharging platform is long and the cycle life is good.

The present invention relates to a carbonaceous lithium ion cell negative electrode material with core-shell structure and its preparation method, belonging to the field of carbon material and chemical power supply technology. The described negative electrode material is formed from core portion and shell portion. The core portion is graphite obtained after the graphite intercalation compound is disintercalated, the shell portion is amorphous carbon obtained by pyrolysis of organics. Said invention also provides the concrete steps of its preparation method.

The invention discloses a method for preparing a lithium ion battery cathode material by utilizing biomass gasification furnace filter residue. The method comprises the following steps: (1) mixing the biomass gasification furnace filter residue with a surface active agent to obtain a mixture, grinding the mixture adequately, removing the surface active agent in a water washing manner, carrying out the suction filtration, and obtaining the filter residue for standby use; (2) placing hydrochloric acid into the filter residue obtained in the step (1), adequately removing impurities, and filtering and washing the filter residue to be neutral for standby use; (3) placing the filter residue obtained in the step (2) into a mixed solution of polyethyleneimine and ethnoal, carrying out the oscillation, washing the polyethyleneimine and the ethanol after the adequate oscillation, filtering the mixed solution, and obtaining the filter residue for standby use; (4) placing nitric acid with mass fraction of 55 to 70 percent into the filter residue obtained in the step (3), adequately stirring the nitric acid and the filter residue under the temperature of 35 to 45 DEG C, carrying out the modification, washing the nitric acid, and filtering and drying to obtain the lithium ion battery cathode material. The prepared lithium ion battery cathode material is high in capacity, high in primary efficiency, good in cycling performance, safe and pollution-free; the method is simple in process flow, low in cost and applicable to the mass production.

The invention discloses a lithium ion battery graphite anode material and a preparation method thereof. The preparation method comprises the following steps: roasting green coke with a median particle diameter D50 of 3-7 micrometers and volatile ingredients of 10wt percent-20wt percent, carbonizing, graphitizing, and fractionating to obtain the lithium ion battery graphite anode material, wherein the after fractionating, the median particle diameter D50 of the lithium ion battery graphite anode material is controlled to be 6-10 micrometers, and the maximum particle size is not more than 30 micrometers. The preparation method provided by the invention is simple; the industrialized large-scale production is easily realized; the prepared lithium ion battery graphite anode material is small in particle diameter, excellent in rate performance, small in first-time reversible capacity and good in use stability, and has good cycle performance.

The invention discloses a silicon-based cathode composite material for a lithium ion battery and a preparation method thereof. The cathode composite material is a Si / CuOx / C composite material (0<=x<=1) with a porous structure. Silicon with a porous structure is used as a base, and CuOx particles are inserted in the pores, and carbons with different forms are distributed on a surface and pore walls of the silicon-based material. The preparation method of the cathode composite material comprises steps that silicon material realizes pore-forming through an in situ catalytic reaction between silicon and halogenated hydrocarbon, and reaction condition parameters are regulated to control pore size, distribution and amount of porosity of the silicon material; a post-modification technology is employed to carry out modifications on the surface and the pore walls of the porous silicon, so as to obtain the Si / CuOx / C composite material with a porous structure. The porous silicon-based cathode composite material has low production costs, simple process and no pollution, and is suitable for industrialized production; besides the porous silicon-based cathode composite material has high charge and discharge capacity, small initial irreversible capacity and good cycle performance.