Effect of additives on the electrochemical properties of Fe2O3/C nanocomposite for Fe/air battery anode

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2016-02, Vol.762, p.59-65
• Main Authors: Hang, Bui Thi, Thang, Doan Ha
• Format: Article
• Language: English
• Subjects: Fe2O3/C nanocomposite electrode; Iron–air battery anode; K2S additive; LiOH additive; Nanocarbon
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2015.12.012

In this paper, Fe2O3/C nanocomposite electrodes were prepared by loading Fe2O3 nanoparticles on various types of carbon via a chemical method for Fe/air battery anode. The effect of various additives, such as carbons, LiOH, and K2S, on the electrochemical properties of Fe2O3/C nanocomposite electrodes was investigated. The effects of LiOH and K2S additives depended on the employed carbon. For Fe2O3/C nanocomposite electrodes, the LiOH additive improved their cyclability and capacity retention, but had an insignificant effect on hydrogen evolution. The K2S additive had no beneficial effects on cyclability, but promoted the dissolution of iron to Fe(II) and significantly suppressed hydrogen evolution. Therefore, the LiOH additive provided more benefits than the K2S additive for the Fe2O3/C nanocomposite material. •The morphology of carbons as well as their characteristics strongly affected the electrochemical properties of the Fe2O3/C nanocomposite electrodes.•The dispersion of Fe2O3 nanoparticles on the carbon surface will maximize the contact between the active material and the carbon additive. Such dispersion of iron oxide will improve the cycling performance of the Fe2O3/C nanocomposite electrodes.•When LiOH and K2S additives were added to the electrolyte, the hydrogen evolution was significantly suppressed, the redox reaction of iron was promoted. The adsorption of Li+ into the oxide lattice improves the ionic conductivity of oxide film, which in turn improves the redox reaction of iron. Ion sulfide interacts with Fe(I), Fe(II), or Fe(III) in the oxide film to promote the dissolution of iron and enhance the bulk conductivity of the electrode, thereby improving cycleability of the Fe2O3/C nanocomposite electrodes.