Liu, J.Wang, Z.Lu, Z.Zhang, L.Xie, F.Vasileff, A.Qiao, S.-Z.2021-09-232021-09-232019ACS Materials Letters, 2019; 1(4):389-3982639-49792639-4979https://hdl.handle.net/2440/132238Although Na2Ti3O7-based anodes have been widely investigated in sodium-ion batteries (SIBs), their Na+ storage properties especially high-rate capability and long-term cycling durability are far from practical application, because of their intrinsic low conductivity and unsatisfied Na+ diffusion resistance. Here, we report the surface engineering of Na2Ti3O7 nanotube arrays grown in situ on Ti foil through a hydrothermal method and subsequent NH3-assisted calcination. Benefiting from the effective surface modification, the as-derived free-standing electrode possesses highly crystalline surface with favorable Na+ diffusion kinetics and self-incorporation of abundant Ti3+ for improved electronic conductivity. These features enable the electrode to achieve remarkable reversible capacity (237.9 mAh g–1), ultra-high rate capability (88.5 mAh g–1 at 100 C = 17.7 A g–1), and excellent cycling stability (92.32% capacity retention at 50 C after 5000 cycles), which are superior to the counterpart without surface modification, as well as almost all Na2Ti3O7-based anode materials reported so far for SIBs. The outstanding electrochemical performance demonstrates the feasibility of proposed surface modulation in designing more efficient electrode materials for energy storage.en© 2019 American Chemical SocietyNanotubes, diffusion; electrodes; transmission electron microscopy; electrical conductivityJournal article10.1021/acsmaterialslett.9b002132021-09-23557911Liu, J. [0000-0002-4726-0972]Xie, F. [0000-0002-6133-6558]Vasileff, A. [0000-0003-1945-7740]Qiao, S.-Z. [0000-0002-1220-1761] [0000-0002-4568-8422]