<p>Currently, there is an active search for suitable anode materials for a lithium-ion power source. Lithium-ion power sources are the subject of extensive research due to their superior properties, including energy density and power, making them suitable for a wide range of modern applications, including in electric vehicles, medicine, and energy storage systems. One of the attractive anode materials for lithium-ion power sources are NiO/C mixtures or NiO@C composites. However, the existing schemes for their production seem to be complicated, expensive, and time-consuming, which may complicate their realization on a semi-industrial scale. The present work investigates the behavior of a NiO/C anode, which was obtained in the simplest and most accessible way via thermally synthesis. The anode was used to create experimental half-cell lithium-ion power source samples. The performance and energy characteristics of NiO/C mixtures with the different NiO content were studied by means cyclic voltammetry, galvanostatic testing, and EIS. The stability of the discharge capacity of NiO/C anode samples of 355–370 mAh g⁻¹ as well as the stability of ohmic resistance during repeated cycling was shown. The paper also analyses ways for further optimizing the NiO/C anode composition.</p>