Amorphous carbon samples intended for use as effective battery anode materials were studied using solid-state 13C and 1H NMR spectroscopy. The study revealed a number of changes in the amorphous state that occurred during additional processing of the synthesized sample. It was found that sample milling resulted in the appearance of an additional signal in the 13C NMR spectrum with a chemical shift of δ = 110 ppm, attributed to oxides, and an intense proton NMR signal. In the annealed sample, a ratio of sp2- to sp3-hybridized carbon atoms of 21:6 was detected. 1H and 13C NMR studies of the processed samples and modeling showed that thermal annealing at temperatures above 600°C leads to a transition from amorphous carbon to partially ordered graphene-like domains. This structuring is confirmed by the appearance of resonances in the high-field region of the spectrum [δ(1H) = −7.5–7.0 ppm, δ (13C) = −22 ppm], which arise due to increased bulk susceptibility and strong diamagnetic ring currents in limited interlayer spaces (~8–10 Å). The calculated values of the ring currents correspond to currents induced in π-conjugated fragments consisting of 37–61 hexagonal rings, which provides the first spectroscopic fingerprint of nanoconfined protons in regions of the order of 8–10 Å in the obtained carbon materials.