▎ 摘　　要

NOVELTY - Positive electrode material for lithium ion battery, comprises positive electrode material coat/covered with a functionalized graphene. The average coverage of the positive electrode active material particle by the functionalized graphene is greater than or equal to 80 %. The functionalization rate as measured by X-ray-photoelectron spectroscopy is 0.3-1.3. The functionalization rate is calculated by dividing the summation of ((peak area based on a C-O single bond)+(peak area based on C=O double bond)+(peak area based on a COO coupling/bonding)) by the (peak area based on C-C, C=C, and a C-H coupling/bonding). USE - Positive electrode material for lithium ion battery (claimed), used in information-related mobile communication electronic devices, such as a mobile telephone and a laptop computer. ADVANTAGE - The positive electrode material enables to obtain high voltage and high energy density from lithium ion battery due to reduction of size and weight. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing positive electrode material which involves preparing the precursor particle/grains coated/covered with a graphene oxide by carrying out liquid phase mixing of a graphene oxide dispersion liquid and the positive electrode active material particle and restoring precursor particle/grain to obtain desired product.