| 摘要 |
PROBLEM TO BE SOLVED: To provide a precursor of a positive electrode active material by removing residual liquid from a precipitate of alkaline metal halide obtained through solution reaction, adjusting the content of the product, and reducing it at a temperature not more than a melting point of the alkaline metal halide. SOLUTION: A boiled mixture of an aqueous solution containing 1 mol FeCl3 as 40 wt.% solution and an aqueous solution containing 0.924 mol NaOH as 50 wt.% solution is cooled to 25 deg.C, neutralized with a 2.076 molar ammonium aqueous solution, and then cooled down to 5 deg.C, so that brown slurry is obtained. The slurry is dripped in liquid nitrogen, a solid material so formed is separated and dried under a reduced pressure at -30 deg.C for 2 days, and aggregated particles is pressed at 2.55 kbar using a press. The aggregated particles thus pressed are sintered at 610 deg.C for one hour in hydrogen gas with the oxygen partial pressure of 2×10<-22> , NH4 Cl in it is evaporated and iron oxide is reduced as well, so that a solid porous body with spherical fine powder of iron whose diameter is 1μm or less being disposed therein is obtained. The solid porous body is charged, being supported with a mechanical support which gives a metallic conductive path, and thus converted into a positive electrode active material.
|
