TRANSITION METAL COMPLEX HYDROXIDE PARTICLE AND MANUFACTURING METHOD THEREFOR, POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY AND MANUFACTURING METHOD THEREFOR, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a positive electrode active material which enables the enhancement of a nonaqueous electrolyte secondary battery in all of the capacity, output and cycle characteristics.SOLUTION: In a method for manufacturing a positive electrode active material, the pH value of an aqueous solution for nucleus creation, including at least a metal compound including a transition metal and an ammonium ion donor is controlled within a range of 12.0-14.0 to create nuclei (a nucleus creation step) and then, the pH value of an aqueous solution for growing particles each including the nucleus is controlled to be lower than the pH value in the nucleus creation step within a range of 10.5-12.0 to grow the particles (a particle growth step). In this method, the nucleus creation step and the particle growth step are arranged so that the initial atmospheres in the steps are each a non-oxidizing atmosphere; in the particle growth step, the control of the atmosphere in which the atmosphere is switched from the non-oxidizing atmosphere to an oxidizing atmosphere, and then switched to a non-oxidizing atmosphere again is performed at least once. The complex hydroxide particles obtained by the reaction of crystallization like this are used as a precursor to obtain the positive electrode active material.SELECTED DRAWING: Figure 1