MoS2 as a long-life host material for potassium ion intercalation

• Published in: Nano research Vol. 10; no. 4; pp. 1313 - 1321
• Main Authors: Ren, Xiaodi, Zhao, Qiang, McCulloch, William D., Wu, Yiying
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01-04-2017; Springer Nature B.V
• Subjects: Anodes; Atomic/Molecular Structure and Spectra; Batteries; Biomedicine; Biotechnology; Chemistry and Materials Science; Condensed Matter Physics; Diffusion coefficient; Diffusion rate; Electrochemistry; Electrode materials; Intercalation; Materials Science; Molybdenum disulfide; Nanotechnology; Potassium; Research Article; X-ray diffraction; MoS; phase evolution; potassium battery; potassium ion intercalation; potassium ion diffusion
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-016-1419-9

Electrochemical potassium ion intercalation into two-dimensional layered MoS2 was studied for the first time for potential applications in the anode in potassium-based batteries. X-ray diffraction analysis indicated that an intercalated potassium compound, hexagonal K0.4MoS2, formed during the intercalation process. Despite the size of K^＋, MoS2 was a long-life host for repetitive potassium ion intercalation and de-intercalation with a capacity retention of 97.5% after 200 cycles. The diffusion coefficient of the K^＋ ions in KxMoS2 was calculated based on the Randles-Sevcik equation. A higher K^＋ intercalation ratio not only encountered a much slower K^＋ diffusion rate in MoS2, but also induced MoS2 reduction. This study shows that metal dichalcogenides are promising potassium anode materials for emerging K-ion, K-O2, and K-S batteries.