SILICON OXIDE, AND METHOD FOR PREPARING SAME

The present invention relates to a method of preparing silicon oxide, in which the amounts of silicon and oxygen are appropriately controlled by decreasing the amount of the oxygen from silicon oxide containing a relatively large amount of oxygen, silicon oxide prepared by the method, and a secondary battery including the same. According to the method of preparing silicon oxide, silicon oxide (first silicon oxide) including a relatively large amount of oxygen is heat treated in a reducing atmosphere to decrease the amount of the oxygen in the silicon oxide (first silicon oxide) and to prepare silicon oxide (second silicon oxide) including silicon and oxygen in an appropriate amount (Si:SiO=1:0.7-0.98), thereby improving capacity and initial efficiency and securing stability and cycle properties (lifetime characteristics) of the secondary battery.