Key control of metal impurities

1) Establish a method for detecting magnetic metal impurities ① After weighing the powder with electronic weighing, put it into the PTFE ball mill ② Put the prepared magnet into the powder, put ultrapure water ③ The ball mill stirs at a speed of 200 ± 5 rpm 30±10 minutes ④After stirring, take out the internal magnet (avoid touching the positive active material on the surface of the magnet directly with your hands or other appliances. After washing with ultrapure water, use ultrasonic to clean for 15±3 seconds. ⑥The method of item ⑤ is repeated many times-lithium iron phosphate: 20 times; other materials: 5-8 times ⑦The washed magnet is transferred to a 100ml beaker. (Beware of foreign matter mixing) ⑧In the beaker, pour it out After 6ml of aqua regia (hydrochloric acid:nitric acidu003d3:1), add ultrapure water with magnet immersion degree. Then heat for about 20 minutes. ⑨ Transfer the heated solution to a 100ml volumetric flask, rinse at least 3 times, and The rinsing solution is also transferred to the volumetric flask, and finally the prepared solution is fixed to volume with ultrapure water, and the prepared solution is sent to AAS for quantitative decomposition of the iron, chromium, copper, zinc, nickel, and cobalt content (the lithium iron phosphate plus one lithium Element). Statement: Some pictures and content of articles published on this site are from the Internet, if there is any infringement, please contact to delete the previous article: What is the principle of lithium battery?