The recent synthesis of self-assembled single-wall MoS2−xIy (x≈0 and y≈1/3) NTs bundles has given a new material, which can reversibly exchange lithium in non-aqueous electrolytes. It has been found that a relatively large amount of lithium can be inserted into the MoS2−xIy NTs bundles (up to 3 mol of Li per MoS2 mol). The amount of inserted lithium and, also, the reversibly extracted lithium, depends on the quality of MoS2−xIy NTs bundles and their prior treatment. Comparing their electrochemical properties with layered 2H-MoS2, one finds a significant increase in the amount of inserted lithium and a decrease by about 0.7 V in the potential at which lithium insertion takes place. Furthermore the decrease of electron spin resonance (ESR) signal of lithiated nMoS2−xIy NTs bundles exposed to the air is slower than the decrease of ESR signal of lithiated layered 2H-MoS2 crystals which suggests that lithiated MoS2−xIy NTs bundles are less air-sensitive than the lithiated layered 2H-MoS2 crystals. These differences are attributed to the particular one-dimensional topology of self-assembled MoS2−xIy NTs bundles.