Hydrothermal-Assisted Sintering Strategy Towards Porous- and Hollow-Structured LiNb₃O₈ Anode Material

Porous- and hollow-structured LiNb₃O₈ anode material was prepared by a hydrothermal-assisted sintering strategy for the first time. The phase evolution was studied, and the formation mechanism of the porous and hollow structure was proposed. The formation of the unique structure can be attributed to the local existence of liquid phase because of the volatilization of Li element. As the anode material, the initial discharge capacity is 285.1 mAhg^-1 at 0.1 C, the largest discharge capacity reported so far for LiNb₃O₈. Even after 50 cycles, the reversible capacity can still maintain 77.6 mAhg^-1 at 0.1 C, about 2.5 times of that of LiNb₃O₈ samples prepared by traditional solid-state methods. The significant improvement of Li storage capacity can be attributed to the special porous and hollow structure, which provides a high density of active sites and short parallel channels for fast intercalation of Li⁺ ions through the surface.