Toyota '929 app on lithium-ion battery

First published claim:

A production method of active material particles, the method comprising: a raw material hydroxide formation step of supplying ammonium ions to an aqueous solution of a transition metal compound to precipitate particles of a transition metal hydroxide from the aqueous solution, the aqueous solution containing at least one transition metal element that composes a lithium transition metal oxide; a mixing step of mixing the transition metal hydroxide with a lithium compound to prepare an unfired mixture; and a calcining step of calcining the mixture to obtain active material particles, wherein the raw material hydroxide formation step includes: a nucleation stage in which the transition metal hydroxide is precipitated from the aqueous solution; and a particle growth stage in which the transition metal hydroxide is grown in a state where a pH of the aqueous solution is lowered from the nucleation stage, and wherein the aqueous solution has a pH of 12 to 13 in the nucleation stage, and the aqueous solution has a pH of 11 or higher and lower than 12 in the particle growth stage.