Abstract: A method includes: (1) adding a food-grade manganese sulfate solution and a complexing agent solution into a sodium ferrocyanide solution for a precipitation reaction to generate Prussian white crystal nucleus; (2) replacing the food-grade manganese sulfate solution with an industrial-grade manganese sulfate solution, and keeping other conditions unchanged, so that the Prussian white crystal nucleus grow continuously to obtain a slurry; and (3) successively subjecting the slurry to an aging reaction, solid-liquid separation, washing and drying to obtain a Prussian white product with a specific particle size. The food-grade manganese sulfate solution, and the sodium ferrocyanide solution are subjected to the precipitation reaction, and then the industrial-grade manganese sulfate solution are added to continue a precipitation reaction. The particle size of the Prussian white is regulated by controlling an adding time of the two manganese sulfate solutions.

Abstract: A compositely coated ternary precursor, and a preparation method therefor and use thereof are provided. The material includes a ternary precursor and a coating layer attached to a surface of the ternary precursor, wherein the coating layer is obtained from a precipitation reaction of a first metal ion and a first polyanion. The metal ion and the polyanion can undergo a precipitation reaction to form a precipitate, to form a uniformly distributed coating layer on the surface of the ternary precursor. After the coated precursor is sintered into a cathode material, part of the coating can form a protective layer on the surface of the material; and the other part of the coating can permeate into the material to form bulk phase doping.

Abstract: A method for regulating a particle size of Prussian white, includes (1) adding a food-grade manganese sulfate solution and a complexing agent solution into a sodium ferrocyanide solution for a precipitation reaction to generate Prussian white crystal nucleus; (2) replacing the food-grade manganese sulfate solution with an industrial-grade manganese sulfate solution, and keeping other conditions unchanged, so that the Prussian white crystal nucleus grow continuously to obtain a slurry; and (3) successively subjecting the slurry to an aging reaction, solid-liquid separation, washing and drying to obtain a Prussian white product with a specific particle size. The food-grade manganese sulfate solution, and the sodium ferrocyanide solution are subjected to the precipitation reaction, and then the industrial-grade manganese sulfate solution are added to continue a precipitation reaction.

Abstract: The present disclosure discloses a preparation method of a ternary precursor, including: S1: mixing a first metal salt solution with a soluble nickel salt, a soluble cobalt salt, and a soluble manganese salt, ammonia water, and a sodium hydroxide solution, adjusting a pH, and heating and stirring a resulting mixture to allow a reaction; and aging and filtering a resulting slurry to obtain a precursor seed crystal; S2: adding the precursor seed crystal to a dilute acid solution, and stirring and filtering a resulting mixture to obtain an acidified seed crystal; and S3: mixing a second metal salt solution with a soluble nickel salt, a soluble cobalt salt, and a soluble manganese salt, a sodium hydroxide solution, and the acidified seed crystal, adjusting a pH, and heating and stirring a resulting mixture to allow a reaction; and aging, filtering, and drying a resulting slurry to obtain the ternary precursor.

Abstract: A ratchet screwdriver includes a ratchet wheel; a pawl base assembly, for inserting into the ratchet wheel, and a plurality of pawl pieces for engaging with teeth, the rear end of the pawl base assembly connecting to a handle of a screwdriver while the front end connecting to a head of the screwdriver; a rings assembly adjustably mounted on the ratchet wheel; the pawl base assembly includes a center rod and a pedestal, the rear part of the center rod is provided with a first positioning slot, the center rod passes through the center hole of the pedestal, the center rod is clamped at the first positioning slot by a first clamping member. Compared with the prior art, the overall structure is more rational and practical, and is safer and more reliable in use, and is capable of loosening or tighten a screw quickly.

Abstract: A ratchet screwdriver includes a ratchet wheel; a pawl base assembly, for inserting into the ratchet wheel, and a plurality of pawl pieces for engaging with teeth, the rear end of the pawl base assembly connecting to a handle of a screwdriver while the front end connecting to a head of the screwdriver; a rings assembly adjustably mounted on the ratchet wheel; the pawl base assembly includes a center rod and a pedestal, the rear part of the center rod is provided with a first positioning slot, the center rod passes through the center hole of the pedestal, the center rod is clamped at the first positioning slot by a first clamping member. Compared with the prior art, the overall structure is more rational and practical, and is safer and more reliable in use, and is capable of loosening or tighten a screw quickly.