Abstract <p>The main regularities of electrochemical transformations of lithium octasulfide in a 1 M LiN(CF₃SO₂)₂ solution in sulfolane on the surface of carbon nanomaterials synthesized by low-temperature pyrolysis of ethanol vapors in an argon atmosphere on aluminum foil in the presence of a nickel catalyst were studied. It was found that the depth of electrochemical transformations of sulfur and long-chain lithium polysulfides on the surface of the synthesized carbon nanomaterials is close to 100%. The carbon materials were characterized by Raman spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The Raman spectra of the synthesized carbon materials show characteristic D and G bands with maxima at 1323 and 1589 cm^–1, respectively. The D/G intensity ratio is 0.7, indicating a significant proportion of <i>sp</i>³-hybridized carbon atoms. SEM micrographs reveal carbon fibrous structures with diameters of 25–35 nm. The synthesized carbon nanomaterials contain (%): carbon 96, oxygen 2.8, iron 0.3, and nickel 0.9.</p>