121 results about "Specific energy density" patented technology

The invention relates to a silicon-carbon composite negative electrode material and a preparation method thereof, belonging to the technical field of lithium ion battery materials. The preparation method of the silicon-carbon composite negative electrode material comprises the following steps: uniformly mixing a silane coupling agent and a porous carbon material in an organic solvent and performing spray drying to obtain a modified porous carbon material; in the presence of silane gas, performing heat preservation of the modified porous carbon material at 1000 to 1200 DEG C for 1 to 6 h; thencooling to 600 to 800 DEG C, and in the presence of a gas dopant, performing heat preservation for 1 to 6 h to obtain a silicon-carbon material, wherein the gas dopant is one or a combination of morethan one of NH3, N2O, NO and N2O4; and in the presence of carbon source gas, performing heat preservation of the silicon-carbon material at 700 to 900 DEG C for 1 to 12 h, thereby obtaining the silicon-carbon compositie negative electrode material. The silicon-carbon composite negative electrode material prepared by the invention has the characteristics of high specific capacity, high conductivityand good cycle performance, and can be applied to lithium ion batteries with high specific energy density.

The invention discloses a preparation method of a positive electrode material (carbon-coated iron-manganese-lithium phosphate) of a lithium ion battery, and relates to the technical field of preparation of positive electrode materials of lithium ion batteries. The preparation method comprises the following steps: preparing a high-activity iron-manganese precursor mixture by oxidation-reduction reaction, and treating a lithium source, a phosphorus source, a carbon source and the iron-manganese precursor mixture by the steps of mixing, drying, sintering and the like so as to obtain the positive electrode material (carbon-coated iron-manganese-lithium phosphate) of the lithium ion battery. The preparation method has the characteristics of high reaction activity of the synthesized iron-manganese precursor, no need of the grinding procedure in mixing materials, low sintering temperature, short temperature-maintaining time and the like; the prepared positive electrode material (carbon-coated iron-manganese-lithium phosphate) of the lithium ion battery has the advantages that the first discharging capacity is up to 155.2mAh/g when the rate is 0.1C, the discharging capacity is more than 140mAh/g when the rate is 0.2C, so that the good electro-chemical performance and rate performance are shown, and simultaneously, all performance indexes of the material give consideration to the processing performance. Compared with the lithium iron phosphate material, the working voltage of the synthesized material and specific energy of the material are increased, so that the benefit is brought for increasing the specific energy density of a battery core at the later stage.