Background and overview[1-2]
Ferric phosphate hydrate dehydrates when heated to 140°C, is soluble in hydrochloric acid and sulfuric acid, and is insoluble in water and nitric acid. Ferric phosphate hydrate is obtained by the reaction between disodium hydrogen phosphate or phosphoric acid solution and ferric chloride solution. It can be used as food and feed additives, fertilizers and medicines. Iron phosphate hydrate can also be lithiated to obtain LiFePO electrode material.
Preparation[1]
CN201710176851.5 provides a method for preparing amorphous nanospherical active iron phosphate hydrate with short reaction time, small and uniform product particle size, and the iron phosphate obtained by lithiation of the iron phosphate hydrate prepared by this method Lithium has a large tap density, and the battery products produced have good high-rate charge and discharge performance. Use the following steps:
(1) Weigh 2 grams of urea, dissolve it in 50ml of distilled water, and stir for 30 minutes to obtain solution 1;
(2) Weigh 1 gram of sodium dodecyl sulfate (SDS), dissolve it in 50 ml of distilled water, and stir for 30 minutes to obtain solution 2;
(3) Mix solution 1 and solution 2 to obtain solution A;
(4) Weigh 1.01 grams (2.5 mmol) of iron nitrate nonahydrate as an iron source, dissolve it in 90 ml of distilled water, and stir for 30 minutes to obtain a solution of iron nitrate nonahydrate;
(5) Add the ferric nitrate nonahydrate solution obtained in step (4) dropwise to the solution A obtained in step (3), and stir for 30 minutes to obtain solution B;
(6) Weigh a phosphoric acid solution with a silicone mass concentration of 85%. The molar ratio of phosphoric acid in the phosphoric acid solution to the iron nitrate nonahydrate weighed in step (4) is 1:1; add the phosphoric acid solution to the step (3) Stir and mix the obtained solution A for 1 hour to obtain a clear and transparent solution C;
(7) React the clear and transparent solution C obtained in step (6) in a hydrothermal reactor with a polytetrafluoroethylene liner at 80°C for 8 hours;
(8) Cool naturally at room temperature, wash alternately with ethanol and distilled water three times each, and centrifuge to obtain a white precipitate; dry the white precipitate at 110°C to obtain a white powder, which is amorphous nanospherical active phosphoric acid Iron hydrate.
