▎ 摘　　要

NOVELTY - A cathode material comprises silicon oxide particles. The mol ratio (A) of oxygen and silicon on the surface of the silicon oxide particles is greater than the mol ratio (B) of oxygen and silicon inside. The mol ratio (A) and the mol ratio (B) at any point more than 25 nm away from the surface of the silicon oxide particles satisfies, (A)/(B) is more than 1.5. USE - Cathode material is used as electrode in electrochemical devices used in electronic devices (all claimed). ADVANTAGE - The electrochemical device that uses the cathode has better performance and lower volume expansion during charging and discharging cycle. DESCRIPTION OF DRAWING(S) - The drawing shows a graphical diagram illustrating focused ion beam- transmission electron microscope line scanning element distribution. (Drawing includes non-English language text)