TECHNOLOGY FOCUS - ELECTRONICS - Preferred Components: The electrochemical cell further comprises at least one of components (a)-(c) as above per se, or (d) platinum particle in the carbon material. The electrochemical cell further comprises silicon particle in the negative electrode.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The graphene skeleton surface of the carbon compound is inclined at an angle of 10 degrees or more and 60 degrees or less with respect to the column axial direction of the columnar structure. The ends of the columnar structure include a hollow structure having a recess. A compound, in which the graphene skeleton surface of the carbon compound is inclined at an angle of 5 degrees or more and 80 degrees or less with respect to the column axial direction of the columnar structure, is not less than 5% and not more than 90% of the carbon compound. A diameter of the columnar structure is 30-500 nm. In the material, oxygen atoms are bonded to some of carbon atoms of the graphene skeleton. The carbon material further comprises at least one of: (a) at least one metal particle comprising iron, cobalt, manganese or platinum; (b) at least one metal ion comprising iron, cobalt, or manganese; and (c) at least one phosphorus compound comprising monophosphate, organophosphate, or polyphosphoric acid. Preferred Method: The step of substituting of the some of carbon atoms with the nitrogen atoms is carried out by performing treatment on the carbon fiber with an acidic solution containing potassium permanganate, and treating the carbon fiber using hydrazine or ammonia, and heating the carbon fiber after the treatment. EXAMPLE - Carbon nano fiber having a diameter of 100-400 nm was produced by a thermal chemical vapor deposition under a flow of methane, hydrogen, or argon, using an iron microparticle having a diameter of 100-400 nm as a catalyst. Then, the carbon nano fiber was reacted to be oxidized in the presence of 0.04 mol potassium permanganate in a mixed solvent of 1 mol sulfuric acid and 0.15 mol nitric acid. The obtained oxide was heated and filtered in the aqueous hydrazine solution. The obtained powder was heated at 800 degrees C under the flow of argon, and then the carbon material was obtained.