Patent ID: 7999991

Claim:
A method of preparing an electrode containing lithium nickel oxide, in which nickel has a single oxidation number, the method comprising the steps of: a) preparing an electrode comprising a lithium nickel oxide (Li x Ni 1-y O, herein, 0.4<x<1, and 0<y<1) layer formed on a conductive substrate; and b) applying an oxidation voltage to the electrode, and then applying a reduction voltage to the electrode, wherein the oxidation voltage and the reduction voltage are applied to the electrode by using a voltage applying means, which can contact with an entire outer circumference of the electrode, is disposed on the entire outer circumference of the electrode, and contacts with the electrode; or by using a voltage applying means which is disposed on the outer circumference of the electrode with a predetermined interval and contacts with the electrode, and the lithium nickel oxide is represented by following Formula 1: Li x Ni 1-y O wherein 0.4<x<1 and 0<y<1. [Formula 1]