Positive electrode active material for non-aqueous electrolyte secondary battery having rare earth hydroxide and/or oxyhydroxide

A positive electrode active material for non-aqueous electrolyte secondary battery,

• wherein particles of at least one compound selected from neodymium hydroxide, neodymium oxyhydroxide, samarium hydroxide, samarium oxyhydroxide, praseodymium hydroxide, europium hydroxide, europium oxyhydroxide, gadolinium hydroxide, gadolinium oxyhydroxide, lanthanum hydroxide, lanthanum oxyhydroxide, yttrium hydroxide, and yttrium oxyhydroxide are uniformly dispersed and adhered on an entire surface of a positive electrode active material particle containing at least one element selected from nickel and cobalt,
• wherein the positive electrode active material is prepared by adding a solution of salt selected from neodymium salt, samarium salt, praseodymium salt, europium salt, gadolinium salt, lanthanum salt and yttrium salt to a solution dispersing the positive electrode active material particle and depositing a hydroxide selected from neodymium hydroxide, samarium hydroxide, praseodymium hydroxide, europium hydroxide, gadolinium hydroxide, lanthanum hydroxide and yttrium hydroxide on the surface of the positive electrode active material particle;
• and
• heat-treating the positive electrode active material particle depositing the hydroxide on the surface,
• wherein a pH of the solution dispersing the positive electrode active material particle is 6 to 10.