35results about How to "Lower specific capacity" patented technology

The invention discloses a preparation method of an Al<3+>-doped regular-octahedron-shaped lithium nickel manganese oxide material. The method is characterized by, accurately weighing an aluminium source, a manganese source, a nickel source and a lithium source according to stoichiometric ratio; mixing the weighed manganese source, the nickel source and Al2O3 and carrying out ball milling; drying the mixture obtained after ball milling into powders; weighing oxalic acid powders and mixing the oxalic acid powders with the mixture dried into powders; adding PEG into the obtained mixture, carryingout stirring to obtain grey-black colloidal mixture, and preheating the grey-black colloidal mixture to obtain black precursor powders; mixing and ball milling the obtained black precursor powders and the weighed lithium source; and keeping the obtained mixture for 5-24 h under the temperature of 800 DEG C, and then, reducing the temperature to less than 600 DEG C and keeping the mixture for 5-24h and then, carrying out annealing to reach room temperature to obtain a submicron-level Al<3+>-doped regular-octahedron-shaped lithium nickel manganese oxide material. The method obtains the Al<3+>-doped regular-octahedron-shaped lithium nickel manganese oxide material by combining a low-cost high-temperature solid phase method and a polymer auxiliary method; and the material is high in cost performance.

The invention discloses a preparation method of a nickel iron sulfide / foam nickel nano composite electrode material, The nickel-iron sulfide was prepared by calcination method combined with alcoholicheat method. The nickel-iron sulfide was directly grown on the surface of nickel foam, the material does not need processing and can be used as that electrode material of the supercapacitor directly,The invention can overcome the shortcomings of easily falling off active material and increasing electrode impedance in the process of electrochemical cycle of electrode material, and innovatively combines cobalt-nickel sulfide nanostructure and foam nickel to construct three-dimensional hollow interconnected nanostructure, increases ion nanochannels, and effectively improves the comprehensive capacitance performance of electrode material.

The invention discloses a silicon-containing porous amorphous alloy negative electrode material for a lithium ion battery and a preparation method thereof, belonging to the field of electrochemical power sources. The negative electrode material mainly comprises 10 to 60 at% of Si, 10 to 35 at% of B and 0 to 55 at% of Fe, with the balance being other elements. The preparation method comprises the following steps: adding Si-containing Fe-based amorphous alloy (an amorphous nanocrystal composite material) into dilute hydrochloric acid for corrosion so as to remove Fe; and then successively carrying out standing, pumping filtration, washing, drying, ultrasonic crushing and sieving so as to obtain the silicon-containing porous amorphous alloy material. The preparation method which prepares the silicon-containing porous amorphous alloy material by using a chemical corrosion method has the advantages of simple preparation process and low cost; and the prepared silicon-containing porous amorphous alloy material has excellent electrochemical properties like high specific capacity and a stable discharge platform when used as the negative electrode material for the lithium ion battery, and has good application prospects.

The invention discloses a CNTs (carbon nanotubes)-doped tin oxide negative electrode material for a lithium-ion battery and a preparation method thereof. The preparation method comprises the following steps: firstly, compositely electroplating a CNTs-doped tin plating layer with the thickness of 10-15 microns on one side of the surface of a substrate of a pretreated copper strip; and secondly, anodizing the material obtained in the first step to obtain a mesoporous oxide, and performing heat treatment to finally obtain the lithium-ion battery negative electrode material with CNTs-uniformly-doped mesoporous tin oxide layer on one side of the surface of the substrate of the copper strip. The mesoporous diameter is 3-10nm and the obtained oxide layer has the thickness of 5-10 microns. The first specific discharge capacity of the lithium-ion battery negative electrode material can be as high as 650mAh / g, and after 50 cycles, the specific capacity is attenuated by only 0.8%-5%. The preparation method is simple in process, and large-scale industrial production can be carried out.

The invention discloses a method of preparing nickel-manganese spinel cathode material through magnetic field texturing, which includes steps of: 1) performing coprecipitation to nickel salt and manganese salt to prepare a Ni-Mn precursor; 2) uniformly mixing the Ni-Mn precursor with a lithium source, and calcining the mixture to prepare a nickel-manganese spinel material; 3) crushing and sievingthe nickel-manganese spinel material and stirring and mixing the nickel-manganese spinel material with an additive in a stirrer, and during the stirring, applying an external magnetic field to the slurry. By means of interaction between Mn<3+> and the magnetic field, texturing is achieved in the magnetic field, so that the cathode slurry can face to the contact direction of an electrolyte with (111) crystal face as most as possible when coating an aluminum foil, thereby solving the problems of capacity degradation and poor high temperature cycle performance during charge / discharge process of the nickel-manganese spinel material; in the invention, when being used for assembling a battery, a cathode plate has excellent cycle and rate performance, is high in energy density, and has excellentapplication prospect in the fields such as power cars, large-size power plants and the like.

The invention relates to a sulfur / nitrogen / silicon co-doped graphite composite negative electrode material and a preparation method thereof, belonging to the technical field of preparation of lithium ion battery materials. The technical solution is: (1) Weigh 1~5g of sulfur-containing organic compound and 1~5g of nitrogen-containing organic compound into 500g of organic solvent, stir evenly, add 100g of graphite into it and stir evenly, after filtering, transfer to the tube type In the furnace, under an inert atmosphere, heat up to 200-500°C and keep it warm for 1-6 hours, then cool down to room temperature in an inert atmosphere to obtain graphite composite material A; into the surface layer of the graphite composite material A, and then carbonized to obtain a sulfur / nitrogen / silicon co-doped graphite composite negative electrode material. The invention improves the specific capacity of the graphite material by doping sulfur in the graphite material, and improves the electrical conductivity of the sulfur through nitrogen doping; the expansion of the material can be reduced and the liquid absorption capacity of the material can be improved.