Controllable Design of MoS2 Nanosheets Grown on Nitrogen-Doped Branched TiO2 /C Nanofibers: Toward Enhanced Sodium Storage Performance Induced by Pseudocapacitance Behavior.

In this work, expanded MoS2 nanosheets grown on nitrogen-doped branched TiO2 /C nanofibers (NBT/C@MoS2 NFs) are prepared through electrospinning and hydrothermal treatment method as anode materials for sodium-ion batteries (SIBs). The continuous 1D branched TiO2 /C nanofibers provide a large surface area to grow expanded MoS2 nanosheets and enhance the electronic conductivity and cycling stability of the electrode. The large surface area and doping of nitrogen can facilitate the transfer of both Na+ ions and electrons. With the merits of these unique design and extrinsic pseudocapacitance behavior, the NBT/C@MoS2 NFs can deliver ultralong cycle stability of 448.2 mA h g-1 at 200 mA g-1 after 600 cycles. Even at a high rate of 2000 mA g-1 , a reversible capacity of 258.3 mA h g-1 can still be achieved. The kinetic analysis demonstrates that pseudocapacitive contribution is the major factor to achieve excellent rate performance. The rational design and excellent electrochemical performance endow the NBT/C@MoS2 NFs with potentials as promising anode materials for SIBs.