Nano-Sized Iron Oxide Material for Sodium Ion Batteries

Abstract

In lithium ion batteries, iron oxide as one transition metal oxide is an excellent electrode material, possessing high lithium stroge capacity, low cost, abundant reserves, environmental-friendly[1-3]. However, iron oxide suffers from poor electrical conductivity and large volumetric expansion during cycling. Accordingly, the researchers seek many atrategies to improve the cyclability and structure stability [4-5]. In this work, iron oxide with a size of about 100 nm (inset in Fig. 1) was employed in sodium ion batteries. Furthermore, binder-free, self-standing iron oxide film electrodes were prepared by vacuum filtration method using chemically obtained graphene oxide sheets (GO), electric conductor (super P) and iron oxide powder. Iron oxide film electrode delivers an initial discharge capacity of 1116.8 mAh g-1 and exhibit an initial Coulombic efficiency of 66.7% at the rate of 0.02C. The cycle performance was shown in Fig. 1. The capacity fades rapidly in the first 5 cycles, then fades laggardly in the subsequent cycles, with a stable capacity of 519.9 mAh/g after 40 cycles. Fig.1 The cycle performance of iron oxides in sodium ion batteries at 0.02C. The inset is the SEM of iron oxide. This work was supported by Shanghai Sailing Program (18YF1417000). Reference s : [1] L. Zhang, H. B. Wu, S. Madhavi, et al. J. Am. Chem. Soc. 134, 2012, 17388. [2] B. Wang, J. S. Chen, H. B. Wu, et al. J. Am. Chem. Soc. 133, 2011, 17146. [3] B. Wang, G. Wang, H. Wang. Electrochim. Acta, 156, 2015, 1. [4] X. Cao, B. Zheng, X. Rui, et al. Angewandte Chemie, 53,2014, 1404. [5] W. Xiao, Z. Wang, H. Guo, et al. J. Alloy & Compound, 560, 2013, 208. Figure 1