Constructing Hollow Nanofibers To Boost Electrochemical Performance: Insight into Kinetics and the Li Storage Mechanism for CrNb49O124

• Published in: ACS applied energy materials 2019-04, Vol.2 (4), p.2672-2679
• Main Authors: Ye, Wuquan, Yu, Haoxiang, Cheng, Xing, Zhu, Haojie, Zheng, Runtian, Liu, Tingting, Long, Nengbing, Shui, Miao, Shu, Jie
• Format: Article
• Language: English
• ISSN: 2574-0962; 2574-0962
• DOI: 10.1021/acsaem.9b00010

There is considerable interest in the titanium niobium oxides employed as the high performance anode hosts for lithium ion batteries in recent years. However, due to the low electronic conductivity, these compounds are also greatly compromised in practical application. Here, we successfully construct the CrNb49O124 nanotube, which has similar properties as titanium niobium oxides but higher electronic conductivity (1.78 × 10–2 S cm–1) via an electrospinning route with excellent long cycle life and high rate capacity. It delivers a high capacity of 340 mAh g–1 at 60 mA g–1, and the first cycle Coulombic efficiency is 88.9%, which is higher than the traditional Li4Ti5O12 anode material (capacity) and other Nb-based compounds (capacity and efficiency). Furthermore, it also exhibits a superior electrochemical kinetics (5.29 × 10–13 cm2 s–1). In addition, the Li storage mechanism of the CrNb49O124 nanotube is studied through a homemade in situ X-ray diffraction (XRD) experiment, which reveals an outstanding electrochemical reversibility. All the boosting electrochemical performances can be ascribed to the hollow nanostructure. Therefore, our approach provides an efficient strategy of constructing hollow CrNb49O124 nanofibers to be employed as anode materials.