Porous nitrogen-doped Sn/C film as free-standing anodes for lithium ion batteries.

[Display omitted] • Porous nitrogen-doped Sn/C fibers (P-Sn/C-N Fs) film are fabricated using green, high-nitrogen folic acid as nitrogen source. • The P-Sn/C-N Fs film as a free-standing electrode for lithium ion batteries exhibits outstanding electrochemical performance. • After-cycled P-Sn/C-N Fs electrode still maintains structural integrity. The key to the development of wearable electronic equipment lies in the design of flexible batteries, in which the electrodes with outstanding mechanical behavior are quite important. Herein, porous nitrogen-doped Sn/C fibers (P-Sn/C-N Fs) film has been successfully synthesized via simple electrospinning and subsequent calcination process in which folic acid and polymethylmethacrylate (PMMA) play the role of introducing nitrogen and forming pores, respectively. The introduction of nitrogen improves the electronic conductivity of the material, and the presence of porous structure increases the specific surface area. More importantly, when the P-Sn/C-N Fs film is used directly as a free-standing electrode for lithium ion batteries, it exhibits outstanding electrochemical performance. The P-Sn/C-N Fs film exhibits a discharge capacity of 712.1 mAh g−1 at 500 mA g−1 after 500 cycles. Even at the high current density of 5 A g−1, it displays a high discharge capacity of 429.1 mAh g−1 after 1000 cycles. These findings indicate that the P-Sn/C-N Fs film has the potential to be applied as free-standing anode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]