The present invention relates to a battery comprising at least a positive electrode, a negative electrode and an electrolyte as composing elements, wherein the positive electrode and/or the negative electrode comprise an active material of nitroxyl radical compound represented by the following general formula (1) as a starting material or a reaction product of at least a discharge reaction of electrode reactions: ##STR00001## wherein Ar represents substituted or unsubstituted aromatic heterocyclic group containing nitrogen wherein one endocyclic nitrogen atom or at least one of plural endocyclic nitrogen atoms exists as N-oxide; the substituent R.sub.1 represents hydrogen atom, halogen atom, hydroxyl group, nitro group, nitroso group, cyano group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted aralkyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted aryloxycarbonyl group, or substituted or unsubstituted acyl group, wherein one or more of the atoms may be substituted with sulfur atom, silicon atom, phosphorus atom or boron atom; R.sub.1 may be the identical with Ar and a ring structure may be formed between R.sub.1 and Ar.