Hydrothermal Synthesis of Sodium Titanium Phosphate Nanoparticles as Efficient Anode Materials for Aqueous Sodium-Ion Batteries

Sodium titanium phosphate (NaTi₂(PO₄)₃, NTP) with a sodium superionic conductor structure is considered as an efficient anode material for aqueous sodium-ion batteries because of its moderate potential range and high structural stability. In this study, a series of NTP nanoparticles (NPs) were synthesized using a facile and cost-effective hydrothermal method without further calcination to explore the influence of reaction time on their crystalline structures and morphologies. The NTP NPs hydrothermally synthesized for 5 h were subsequently subjected to a carbon-coating procedure, and the resulting carbon-coated NTP NPs exhibited remarkable reversible capacities, rate capabilities, and cycling performances. These features were attributable to the nanotailoring of the NTP NPs, which reduced both the ionic and electronic transporting paths, and continuous carbon layers coated on the NTP surfaces to promote their electronic conductivities.