Na2Ti3O7/C Nanofibers for High-Rate and Ultralong-Life Anodes in Sodium-Ion Batteries

Graphical The unique structure of these one-dimensional nanofibers with two-dimensional nanosheets on the surface is successfully synthesized. Large specific surface area can greatly shorten the diffusion routes for both electrons and ions. Besides, the carbon matrix can dramatically improve the overall conductivity. As a result, the anode exhibits excellent electrochemical capability for sodium-ion batteries. Na 2 Ti 3 O 7 /C nanofibers are successfully synthesized through an electrospinning process followed by hydrothermal treatment. The unique structure of these one-dimensional nanofibers with two-dimensional nanosheets on the surface is presumed to significantly shorten the diffusion routes for both electrons and ions. Meanwhile, the carbon matrix with a certain degree of graphitization can dramatically improve the overall conductivity. As a result, the Na 2 Ti 3 O 7 /C nanofiber electrode reveals an impressive electrochemical capability as the anode material of sodium-ion batteries. It demonstrates a reversible capacity of 110 mA h g −1 after 500 cycles at a rate of 1 C. Moreover, with almost no capacity degradation, the discharge capacity of the Na 2 Ti 3 O 7 /C nanofiber electrode remains at 58 mA h g −1 after 1500 cycles at the high rate of 50 C. This superior electrochemical performance places the Na 2 Ti 3 O 7 /C nanofibers as an anode material with great promise for sodium-ion batteries that could be applied in large-scale energy storage.