PURPOSE: To provide a large initial capacity and enhance charge/discharge cycle stability by pulverizing positive electrode active material composed mainly of a vanadium pentoxide in a planetary ball mill, then pulverizing it in a jet mill, and pulverizing it again in the planetaty ball mill.
CONSTITUTION: Positive electrode active material composed mainly of a vanadium pentoxide is pulverized first in a planetaty ball mill, next in a jet mill, and again in the planetaty ball mill. Positive electrode material having a particle diameter of a submicron degree can be for the first time obtained by the three steps of pulverizing. In the positive electrode material thus obtained and having a small average particle diameter, a surface area is increased to increase an apparent diffusion coefficient of Li ion and an initial discharge capacity per weight. In this method, a positive electrode of high performance can be provided.
DEMACHI ATSUSHI
NOGUCHI MINORU
SATO KENJI
MIYASHITA KOICHI
