8 results about "Lithium doping" patented technology

This invention discloses a method and application for preparing oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composites from recycled waste lithium manganese oxide materials. The method involves reducing and leaching waste lithium manganese oxide cathode powder in a mixed solution of C2H4O2 and H2O2 to obtain a lithium manganese oxide leachate. The pH of the leachate is adjusted with ammonia water and used as an electrodeposition stock solution. Electrochemical deposition is performed on hydrophilic carbon cloth using constant voltage electrodeposition to obtain a MnO2-carbon cloth composite. The MnO2-carbon cloth composite is then used as an ion sieve and immersed in the electrodeposition solution for a period of time to obtain a lithium-ion-doped MnO2-carbon cloth composite. The lithium-ion-doped MnO2-carbon cloth composite is calcined in a muffle furnace to obtain an oxygen-defect-containing lithium-ion-doped MnO2-carbon cloth composite, which is used as a cathode material for zinc-ion batteries. This composite exhibits excellent zinc storage performance, with a specific capacity as high as 120 mAh / g after 1200 charge-discharge cycles at a current density of 1 A / g. Under ultra-high current density (A / g), the specific capacity remains stable at 75 mAh / g after 5000 charge-discharge cycles.

This invention relates to the field of lithium-ion battery technology, specifically to a composite electrode material and its preparation method. The preparation method includes the following steps: using tin, red phosphorus, and lithium salt in a molar ratio of 3.5–3.9:3:0.5–0.1 as raw materials, ball milling is performed in an inert gas to obtain lithium-doped tin phosphide material; the lithium-doped tin phosphide material and carbon nanotube material are mixed uniformly, and calcined under a protective atmosphere to construct a carbon conductive network on the surface of the lithium-doped tin phosphide material to obtain modified tin phosphide material; the modified tin phosphide material is mixed uniformly with additives to obtain the composite electrode material. This invention achieves multi-dimensional modification of tin phosphide anode material through stepwise synergistic processing, solving the technical problem of decreased electrochemical performance of existing tin phosphide anode materials due to volume expansion and lithium loss.

The application provides a double-coating lithium iron phosphate positive electrode sheet, a preparation method and application thereof. The preparation method comprises the following steps: mixing modified large-particle lithium iron phosphate, modified small-particle lithium iron phosphate, a conductive agent, a binder and a solvent to obtain a first slurry and a second slurry; adopting double-layer slot extrusion coating to coat the first slurry on the surface of a current collector and coat the second slurry on the surface of the first slurry; and drying and rolling to obtain the double-coating lithium iron phosphate positive electrode sheet; the modified large-particle lithium iron phosphate is doped with Ti and Nb, and the modified small-particle lithium iron phosphate is doped with Mg and Al. The application adopts a multi-element doped positive electrode material combined with a double-layer coating preparation method to avoid the shortcomings of LFP materials, improve the rate performance, high-temperature performance and cycle performance of LFP, and has the advantages of simple preparation process and easy industrial production. The prepared positive electrode material and the secondary battery using the same have excellent comprehensive performance, and have a wide application prospect in the field of power batteries.

The present invention relates to expanded carbon for improving the output of a secondary battery and a method for manufacturing the same. The present invention comprises a method for manufacturing expanded carbon for enhancing the output of a secondary battery, wherein the method comprises the steps of: mixing lithium metal into a water-soluble oil and then mixing carbon to produce a mixture; reacting the mixture at 200 to 450°C while applying pressure to produce a lithium-carbon compound in which lithium is incorporated between carbon layers; and heat-treating the lithium-carbon compound to produce expanded carbon in which lithium is detached and removed from the lithium-carbon compound, thereby expanding the carbon layers; wherein the heat treatment is characterized by rapidly heating the lithium-carbon compound to 450 to 1,000°C by passing an electric current through it. The technical gist of the invention is the expanded carbon produced thereby.

This invention relates to the field of secondary battery technology, and particularly to a high-rate coal-based hard carbon composite material, its preparation method, and its application. The preparation method includes the following steps: S1. Mixing and reacting a coal-based material with an aqueous solution of an organic oxidant, filtering, and drying to obtain an oxidized coal-based material; S2. Mixing and grinding the oxidized coal-based material with lithium carboxymethyl cellulose to obtain a hard carbon precursor material; S3. Mixing the hard carbon precursor material, catalyst, and metal powder evenly, adding the mixture to a resin solution for even dispersion, drying, and carbonization to obtain the coal-based hard carbon composite material. Through chemical reaction, lithium doping of the coal-based material reduces irreversible capacity and improves initial efficiency and specific capacity; simultaneously, the carbonization of lithium carboxymethyl cellulose forms pores, increasing specific capacity, and its catalysis causes the carbon-based material to form an isotropic carbon structure, improving the material's power performance; and silver doping further improves the material's electronic conductivity and power performance.

This invention discloses a positive electrode active material, a positive electrode sheet, and an electrochemical device, relating to the field of electrochemical energy storage. The positive electrode active material includes lithium cobalt oxide in the O2 phase doped with Al and M, wherein the molar ratio of Co, Al, and M in the lithium cobalt oxide is (1-b-c):b:c, satisfying the relationship 0.00004≤c×b×(E M‑0 / 600)≤0.00085; M is a metallic element with a bond energy of 600-800 kJ / mol with O, and the ionic radius of the M ion in its six-coordinate structure is 0.6-0.75 Å. This application uses Al doping in lithium cobalt oxide to enhance interfacial and structural stability, and broadens the Li-O bond through the large ionic radius and high metal-oxygen bond energy of the cation M. + Migration channel, alleviate Li + The lattice stress during the insertion / extraction process enhances the structural robustness of O2-phase lithium cobalt oxide from multiple dimensions, including bulk material structure, ion transport kinetics, and surface stability, thereby improving its overall performance under high-pressure cycling.

This invention relates to a high-performance lithium-doped nickel oxide / zinc oxide / silicon heterojunction ultraviolet detector, its fabrication method, and its applications. From bottom to top, an n-type Si wafer, an n-type ZnO interlayer, and a lithium-doped p-type NiO thin film are stacked sequentially. A top electrode layer is disposed on the upper surface of the lithium-doped p-type NiO thin film layer, and a bottom electrode layer is disposed on the area of ​​the n-type Si wafer not covered by the n-type ZnO interlayer and the lithium-doped p-type NiO thin film layer. This invention uses magnetron sputtering to sequentially fabricate the n-type ZnO interlayer and the lithium-doped p-type NiO thin film layer on the n-type Si wafer, and uses electron beam evaporation to fabricate the top and bottom electrode layers. Compared with existing technologies, the heterojunction ultraviolet detector fabricated by this invention exhibits both low dark current and low visible light response, and the process is simpler, lower in cost, and can be fabricated on a large area with high feasibility for mass production.

The application relates to the technical field of negative electrode material preparation, in particular to a silicon-carbon composite material and a preparation method and application thereof. The silicon-carbon composite material comprises a silicon-carbon inner core, a first shell layer covering the silicon-carbon inner core and a second shell layer covering the first shell layer; the silicon-carbon inner core comprises doped porous carbon and nano-silicon arranged on the doped porous carbon, and the doped porous carbon is doped with metal and rare earth oxide; the first shell layer comprises a polymer-based positive temperature coefficient thermosensitive material; and the second shell layer comprises lithium-doped amorphous carbon. The silicon-carbon composite material has excellent initial efficiency, cycle performance, rate performance, fast charging performance and safety performance.