Bamboo-Shaped Zn2+-Doped Li4Ti5O12 Nanofibers: One-Step Controllable Synthesis and High-Performance Lithium-Ion Batteries

Abstract

Bamboo-shaped Zn2+-doped Li4Ti5O12 nanofibers with the diameter of approximately 300 nm have been synthesized via a one-step controllable electrospinning method in this work. The structure and morphology of the as-prepared materials have been characterized by XRD, TEM, SEM, EDS-mapping, BET, ICP-OES and XPS. Fortunately, the introduction of Zn2+ ions cannot interrupt the original cubic spinel structure and one-dimentional bamboo-shaped nanostructure of Li4Ti5O12. The effects of two different kinds of Zn doping behaviors: substitutional doping and interstitial doping on the properties of bamboo-shaped Li4Ti5O12 nanofibers have been studied in detail. The comparative experiments prove that interstitial doping bamboo-shaped Li4Ti5O12 nanofibers exhibit the biggest lattice volume and best electrochemical performances than substitutional doping and undoped bamboo-shaped Li4Ti5O12 nanofibers. Particularly, the reversible capacity of interstitial doping Li4Ti5O12 electrode is up to 142.8 mA h g−1 and still remains at 141.7 mAh g−1 after 1000 cycles at a current rate of 5 C.