Article Title

Facile synthesis and electrochemical sodium storage of CoS₂ micro/nano-structures

Authors

Xue Liu, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China
Kai Zhang, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China
Kaixiang Lei, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China
Fujun Li, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China
Zhanliang Tao, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China
Jun Chen, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China

Keywords

cobalt disulfide, micro/nano-structures, sodium storage mechanism, cycling stability

Abstract

We report the synthesis and electrochemical sodium storage of cobalt disulfide (CoS2) with various micro/nano-structures. CoS2 with microscale sizes are either assembled by nanoparticles (P-CoS2) via a facile solvothermal route or nanooctahedrons constructed solid (O-CoS2) and hollow microstructures (H-CoS2) fabricated by hydrothermal methods. Among three morphologies, H-CoS2 exhibits the largest discharge capacities and best rate performance as anode of sodium-ion batteries (SIBs). Furthermore, H-CoS2 delivers a capacity of 690 mA·h·g−1 at 1 A·g−1 after 100 cycles in a potential range of 0.1–3.0 V, and ~240 mA·h·g−1 over 800 cycles in the potential window of 1.0–3.0 V. This cycling difference mainly lies in the two discharge plateaus observed in 0.1–3.0 V and one discharge plateau in 1.0–3.0 V. To interpret the reactions, X-ray diffraction (XRD) and transmission electron microscopy (TEM) are applied. The results show that at the first plateau around 1.4 V, the insertion reaction (CoS2 + xNa+ + xe− → NaxCoS2) occurs; while at the second plateau around 0.6 V, the conversion reaction (NaxCoS2 + (4 − x) Na+ + (4 − x)e− → Co + 2Na2S) takes place. This provides insights for electrochemical sodium storage of CoS2 as the anode of SIBs.

Graphical Abstract

DOI

https://doi.org/10.1007/s12274-016-0981-5

Publisher

Tsinghua University Press

Recommended Citation

Xue Liu,Kai Zhang,Kaixiang Lei,Fujun Li,Zhanliang Tao,Jun Chen, Facile synthesis and electrochemical sodium storage of CoS2 micro/nano-structures. NanoRes.2016, 9(1): 198–206