Electrochemical behavior of interconnected Ti2Nb10O29 nanoparticles for high-power Li-ion battery anodes

Abstract We synthesized polycrystalline Ti 2 Nb 10 O 29 nanofibers (NFs) via a simple post-annealing process of as-electrospun polymeric NFs as an anode material for Li-ion batteries (LIBs). During the first discharge/charge process, the Ti 2 Nb 10 O 29 NFs annealed at 900 °C exhibited insertion/extraction capacities of up to 344 and 304 mAh g −1 , corresponding to 19.1 and 16.7 mol Li + per formula unit, respectively. This material exhibited excellent rate capability (93 mAh g −1 at 15 A g −1 ) and a higher average diffusion coefficient (D Li  = ∼1.5 × 10 −12  cm 2  s −1 ) than Ti 2 Nb 10 O 29 powder (∼6.9 × 10 −13  cm 2  s −1 ). This performance can be attributed to the unique nanostructure of firmly interconnected, highly crystalline Ti 2 Nb 10 O 29 nano-grains, which facilitates the Li + and electron transport. The kinetics obtained from current-voltage curves indicate a mixture of diffusion-limited and capacitive processes. The suggested electro-spinning/post annealing approach can effectively provide a simple route towards high-quality Ti 2 Nb 10 O 29 NF-based anodes for high-performance LIBs.