MoS2 as a long-life host material for potassium ion intercalation
potassium ion intercalation, potassium battery, MoS2, phase evolution, potassium ion diffusion
ABSTRACT 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.
Tsinghua University Press
Xiaodi Ren,Qiang Zhao,William D. McCulloch,Yiying Wu, MoS2 as a long-life host material for potassium ion intercalation. NanoRes.2017, 10(4): 1313–1321