Cu2s As a Superior Anode for Sodium-Ion Batteries

Abstract

There has been an ever-increasing demand on renewable clean energies (e.g., solar energy and wind energy), given the facts that fossil fuels (i.e., petroleum, coal, and natural gas) are depleting and causing environmental issues. Because of their intermittent operations, however, these renewable clean energies rely on large-scale electrical energy storage (EES) systems to realize their wide implementation in the grids. To this end, sodium-ion batteries (SIBs) have been highly regarded as the promising EES candidates, due to their low cost and natural abundance. One of the biggest challenges for SIBs lies in developing high-performance anodes [1-3] that enable high capacity and long-term stable cyclability. In this regard, conversion-based materials (e.g., metal oxides and metal sulfides) hold great promise, but have not been well explored. In this context, we recently investigated copper sulfide (Cu2S) as a high-performance anode for SIBs. Our study revealed that Cu2S could achieve a sustainable capacity of ~300 mAh/g. In addition, our study also demonstrated that Cu2S could realize high rate capability up to 10 C and long-term cyclability. In the study, we characterized Cu2S as a new anode using galvanostatic cycling, cyclic voltammetry, electrochemical impedance spectroscopy, high-magnification scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. This study provides an in-depth understanding on Cu­2S electrochemistry in SIBs. Meng, X., Atomic-scale surface modifications and novel electrode designs for high-performance sodium-ion batteries via atomic layer deposition. Journal of Materials Chemistry A, 2017. 5: p. 10127-10149.Li, L., et al., Recent progress on sodium ion batteries: potential high-performance anodes. Energy & Environmental Science, 2018. 11(9): p. 2310-2340.Luo, W., et al., Na-Ion Battery Anodes: Materials and Electrochemistry. Accounts of Chemical Research, 2016. 49(2): p. 231-240. Figure 1