TiO₂ nanotube layers (TNTs) decorated with Al₂O₃/MoS₂/Al₂O₃ are investigated as a negative electrode for 3D Li-ion microbatteries. Homogenous nanosheets decoration of MoS₂, sandwiched between Al₂O₃ coatings within self-supporting TNTs was carried out using atomic layer deposition (ALD) process. The structure, morphology, and electrochemical performance of the Al₂O₃/MoS₂/Al₂O₃-decorated TNTs were studied using scanning transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and chronopotentiometry. Al₂O₃/MoS₂/Al₂O₃-decorated TNTs deliver an areal capacity almost three times higher than that obtained for MoS₂-decorated TNTs and as-prepared TNTs after 100 cycles at 1C. Moreover, stable and high discharge capacity (414 µAh cm⁻²) has been obtained after 200 cycles even at very fast kinetics (3C).

We present the electrochemical performance of silicon nanotube vertical arrays possessing thin porous sidewalls as a negative electrode for Li-ion batteries. The Si nanotubes were fabricated by using sacrificial zinc oxide nanowire template on stainless steel substrate. Gravimetric capacity of 1670 mAh.g^-1 was obtained after 30 cycles. The high capacity values are the result of the large active area offered by the porous Si nanotube array structures.