4results about How to "Valence stable" patented technology

This invention belongs to the field of wet electronic chemicals technology, specifically relating to a method for preparing electronic-grade hydrogen peroxide. The method includes the following steps: adjusting the concentration of raw hydrogen peroxide, and then filtering it sequentially through a reverse osmosis membrane, a modified cation exchange resin, an anion exchange resin, and a mixed ion exchange resin to obtain electronic-grade hydrogen peroxide. The modified cation exchange resin used is modified based on conventional cation exchange resin through pore expansion and grafting, optimizing the spatial matching of pore structure and functional sites. This achieves passivation of metal ions, enhanced adsorption capacity, and improved oxidation resistance, as well as a deep synergistic effect of these three effects. Ultimately, it achieves the dual goals of efficient purification and stable operation of the resin in the hydrogen peroxide system. The resulting electronic-grade hydrogen peroxide can reduce the content of single impurity metal ions to below 5 ppt, meeting the requirements of SEMI G5 standards, and can be directly applied to high-end manufacturing fields such as semiconductor wafer cleaning.

The invention relates to a solid sulfur positive electrode catalytic material, a preparation method and an application, the solid sulfur positive electrode catalytic material comprises a carrier, a first transition metal atom and a second transition metal atom, the first transition metal atom and the second transition metal atom are loaded on the carrier, the carrier is a nitrogen-doped carbon material, and the electronegativity difference value delta EN of the first transition metal atom and the second transition metal atom is more than or equal to 0.01 and less than or equal to 0.5. The solid sulfur positive electrode catalytic material disclosed by the invention can generate a dynamic electron buffer effect in a sulfur conversion reaction process of an all-solid-state battery, and is beneficial to adjusting the charge state of a metal center through reversible electron migration between diatoms during charging and discharging, so that the excessive oxidation or reduction of active sites is inhibited; the structural stability and the valence reversibility of the material in long-term circulation are improved. Meanwhile, the synergistic effect of double atoms can enhance the electron interaction with sulfur substances, so that the solid-solid interface reaction energy barrier can be reduced, and the sulfur conversion reaction kinetics can be improved.

This application discloses a method for repairing lithium-ion battery cathode active materials, relating to the field of battery recycling and repair technology. The method first involves soaking failed lithium iron phosphate electrodes in an organic solvent, followed by pyrolysis, air jet milling, and classification to obtain purified lithium iron phosphate powder. This powder is then mixed with a lithium-phosphorus supplement, a silane coupling agent, and a dispersant, and ball-milled and dried to obtain a repair precursor. Subsequently, the precursor is sintered in stages under an inert atmosphere. Finally, the product is subjected to air jet milling and classification to obtain the repaired lithium iron phosphate cathode active material. This method achieves uniform adhesion of the lithium-phosphorus supplement through the silane coupling agent. Utilizing the targeted positioning effect of hydroxymethylated modified guanidine phosphate and the lithium source supply of lithium oxalate, lithium vacancies are filled in situ during sintering, maintaining the stability of the Fe element valence state, effectively improving the electrochemical activity and cycle stability of the material.

The invention relates to a composite positive electrode material which is of a core-shell structure and comprises an inner core, a first coating layer and a second coating layer, and the inner core is sequentially coated with the first coating layer and the second coating layer from inside to outside. The first coating layer comprises barium selenide, and the second coating layer comprises carbon quantum dots. In the application, double-layer coating of the first coating layer and the second coating layer is constructed on the surface of the inner core, and the barium selenide and the carbon quantum dots can synergistically form a perfect and reliable conductive network, so that the overall electronic conductivity of the composite positive electrode material can be remarkably improved, the charge transfer impedance can be reduced, and the migration of active ions can be promoted; and thus, the high-rate performance and the cycle performance of the composite positive electrode material can be improved.