K2S and FeS were employed as additives for electrolyte and electrode, respectively, to suppress hydrogen evolution and improve the cycleability of the Fe/C composite air battery anode. The effects of these additives on the electrochemical properties of Fe/C composite electrodes were investigated using cyclic voltammetry (CV). The results showed that both K2S and FeS significantly suppressed hydrogen evolution on the Fe/C electrode characteristics. Among the carbons used, nano-carbons such as tubular carbon nanofibers (CNF), platelet CNF, vapor-grown carbon fibers (VGCF) and acetylene black (AB) improved the discharge capacity of the Fe/C electrode with additive to electrolyte or electrode. The FeS additive showed a larger beneficial effect for the Fe/C composite electrode than K2S in term of cycleability and capacity.