38results about How to "Fast charge and discharge rate" patented technology

The negative electrode or anode for a secondary electrochemical cell comprising a mixture of graphite or "hairy carbon" and a lithiated metal oxide, a lithiated mixed metal oxide or a lithiated metal sulfide, and preferably a lithiated metal vanadium oxide, is described. A most preferred formulation is graphite mixed with lithiated silver vanadium oxide or lithiated copper silver vanadium oxide.

The invention discloses a method for preparing graphene from raw graphite ores through electrolysis. The method comprises the steps of crushing raw microcrystal graphite ores, sieving, and recycling raw materials which are not insufficiently crushed; preparing an electrode from raw microcrystal graphite ore powder or insufficiently-delaminated raw ores; electrolyzing the prepared electrode in an electrolytic tank, carrying out solid-liquid separation, and further delaminating a solid obtained by separation to obtain the insufficiently-delaminated raw ores and coarsely-prepared graphene; and separating and extracting graphene from the coarsely-prepared graphene. The method has the advantages of low cost, simple preparation process and device, simplicity in operation, good product quality, high process safety and large-scale production.

The present invention relates to a negative electrode and a secondary battery including the same, comprising: a current collector; a first active material layer, which comprises a first active material particle and is disposed on the current collector; and a first pattern and a second pattern, which are alternately arranged on the first active material layer while being spaced from each other, wherein the first pattern comprises a first pattern active material particle, the second pattern comprises a second pattern active material particle, the first pattern is thicker than the second pattern,and the second pattern has a volume expansion rate larger than that of the first pattern.

The invention relates to a preparation method of a praseodymium cobalt phosphorous-doped lithium manganese silicate composite positive material. The chemical formula of the praseodymium cobalt phosphorous-doped lithium manganese silicate is as follows: LiMn<1-x-y>CoxPrySi<1-z>PzO4, wherein x is 0.2 to 0.25, y is 0.01 to 0.02, and z is 0.22 to 0.34. The method comprises the following steps of (1) preparing a praseodymium cobalt phosphorous-doped lithium manganese silicate precursor; (2) thermally treating the praseodymium cobalt phosphorous-doped lithium manganese silicate precursor and crushing the praseodymium cobalt phosphorous-doped lithium manganese silicate precursor to obtain the precursor powder, dispersing carbon black and active carbon into acetone to form conductive carbon dispersion liquid, mixing the precursor powder and the conductive carbon dispersion liquid, and ball milling the mixture; and (3) drying, placing the mixture with 1:1 (mol)CO / CO2 into a purging intermittent converter, sintering the mixture, and grinding and filtering the mixture to obtain a product. According to the prepared praseodymium cobalt phosphorous-doped lithium manganese silicate composite positive material, the rare earth element Pr and the metal element Co are doped in the lithium manganese silicate so as to modify Mn, and partial Si elements are substituted by the P element, so that the electron conductivity and substance activity can be improved.

The invention relates to a preparation method of a multi-element doped lithium iron phosphate composite positive pole material. The chemical formula of the multi-element doped lithium iron phosphate is Li1-xKxFe1-yZnyP1-zSzO4, wherein x=0.1-0.2, y=0.2-0.3, and z=0.15-0.25. The method comprises the following steps: (1) weighing lithium acetate, iron oxalate, ammonium dihydrogen phosphate, ammonium hydrogen sulfate, zinc nitrate and potassium carbonate according to the molar weights of Li, K, Fe, Zn, P and S in the chemical formula, mixing, dissolving in deionized water to form a mixed solution, and performing nitrogen gas reduction reaction to obtain a mixture; (2) performing spray drying to obtain a spherical solid; and (3) presintering, adding starch accounting for 1-2wt% of the presintering product, uniformly grinding, and performing secondary sintering to obtain the multi-element doped lithium iron phosphate composite positive pole material. According to the prepared multi-element doped lithium iron phosphate composite positive pole material for a lithium ion battery, K, Zn and S are doped to modify the lithium iron phosphate to improve the ion diffusion performance and inhibit the aggregation phenomenon; and the surface of the lithium iron phosphate is coated with a carbon layer.

The invention relates to a preparation method of a potassium and manganese doped lithium iron phosphate composite anode material with high conductivity. The chemical formula of the multielement doped lithium iron phosphate composite anode material is Li(1-x)KxFe(1-y)MnyPO4, wherein x=0.15-0.3 and y=0.3-0.35. the preparation method comprises following steps: (1) a nano lithium iron phosphate precursor is prepared; and (2) acetylene black and polyethylene glycol are mixed, and the mixture is dispersed in ethanol by ultrasonic dispersion so as to obtain a conductive carbon dispersion liquid; the nano lithium iron phosphate precursor and the conductive carbon dispersion liquid are mixed, and the mixed solution is subjected to ball milling by a planetary ball mill; and the substances obtained after ball milling are dried, and are subjected to sintering in the presence of a reducing protective atmosphere so as to obtain the products. The potassium and manganese doped lithium iron phosphate composite anode material is used for lithium ion batteries; lithium iron phosphate is modified by doping of K and Mn, so that ion diffusivity is increased, generation of agglomeration is inhibited, and a conductive carbon-carbon network on the surface of lithium iron phosphate is formed.

The invention provides a production method of a natural needle-coke composite graphite cathode material. According to the production method, needle coke serves as a raw material A, natural graphite serves as a raw material B, pitch micropowder serves as a raw material C, graphene conductive agent serves as a raw material D, and a carbon nano tube serves as a raw material E. The raw materials are subjected to mechanical processing, surface modification, deep chemical modification, doping and the like, and then, the cathode material, which is long in cycle life, high in charging and discharging rate, high in high-and-low temperature performance, good in processing performance and suitable for power batteries, is prepared. The cathode material is simple in production process, high in production efficiency, low in cost, safe in processing process and capable of being applied to industrial production. The production method has the advantages that through addition of a mixed material of the graphene conductive agent and the carbon nano tube, electricity conducting performance of the cathode material is improved; graphitization is performed in a coarse powder state, so that particle surface oxidation active points, oxidation degree and material loss rate can be reduced, and volume and yield of the cathode material can be increased.

The invention relates to a charging-discharging module based on a giant permittivity ceramic capacitor and a preparation method of the charging-discharging module. The module is provided with at least two giant permittivity ceramic capacitor bodies, wherein the two giant permittivity ceramic capacitor bodies are connected in serial or / and in parallel, and each giant permittivity ceramic capacitor body is sequentially provided with a lower silver electrode layer, a lower electric-breakdown-resistant layer, an intermediate dielectric layer, an upper electric-breakdown-resistant layer and an upper silver electrode layer. The preparation method comprises the following steps of preparing the intermediate dielectric layer of the giant permittivity ceramic capacitor body; covering the lower electric-breakdown-resistant layer on the lower surface of the intermediate dielectric layer; covering the upper electric-breakdown-resistant layer on the upper surface of the intermediate dielectric layer; coating conductive silver paste on the lower surface of the lower electric-breakdown-resistant, and thermally treating the silver paste to obtain the lower silver electrode layer; coating conductive silver paste on the upper surface of the upper electric-breakdown-resistant layer, thermally treating the silver paste to obtain the upper silver electrode layer, and obtaining the giant permittivity ceramic capacitor body; and assembling the produced giant permittivity ceramic capacitor bodies in serial or / and in parallel to obtain the charging-discharging module based on the giant permittivity ceramic capacitor.

The invention relates to a preparation method of a silver doped carbon-silicon composite negative electrode material. The preparation method comprises the following steps of: (1) preparing a carbon-silicon composite material; and (2) adding the carbon-silicon composite material into glycol solution, performing ultrasonic treatment and suction filtration, washing, drying, crushing, performing ball milling, sieving for later use, weighing corresponding amounts of AgNO3 and polyvinylpyrrolidone, dissolving in ammonia water solution, stirring, preparing potassium borohydride solution, preparing distilled water and ammonia water into mother liquor, holding in a reaction kettle, putting the spare carbon-silicon composite material in the mother liquor, dropwise adding mixed solution of the AgNO3 and the polyvinylpyrrolidone and the potassium borohydride solution into the mother liquor while stirring, centrifuging a reaction product, taking out precipitate, diluting, performing suction filtration, washing and drying to obtain the silver doped carbon-silicon composite negative electrode material. Ag with more superior conduction performance is doped in a prepared lithium ion battery, so that the lithium ion battery has the characteristics of high capacity, high conductivity and high cyclical stability.

The invention relates to the field of electrochemistry, in particular to a three-dimensional crosslinked structure composite electrode material and a preparation method thereof and application. The composite electrode material comprises multiple space units, amorphous carbon and silica nanoparticles, wherein the space unit is formed by cross-linking of adjacent sheet layers, and the sheet layer is formed by two-dimensional transition metal carbide or carbonitride; the amorphous carbon is dispersed and supported in the space unit; and the silica nanoparticles are coated in the space units. The composite electrode material can be used as a lithium ion battery negative electrode material, and has the advantages of high mass ratio capacity, good cycle property, long service life, high power and the like.