Interlayer-Expanded MoS(2) Enabled by Sandwiched Monolayer Carbon for High Performance Potassium Storage

Potassium-ion batteries (PIBs) have aroused a large amount of interest recently due to the plentiful potassium resource, which may show cost benefits over lithium-ion batteries (LIBs). However, the huge volume expansion induced by the intercalation of large-sized potassium ions and the intrinsic sluggish kinetics of the anode hamper the application of PIBs. Herein, by rational design, nano-roses assembled from petals with a MoS(2)/monolayer carbon (C-MoS(2)) sandwiched structure were successfully synthesized. The interlayer distance of ultrathin C-MoS(2) was expanded from original MoS(2) of 6.2 to 9.6 Å due to the formation of the MoS(2)-carbon inter overlapped superstructure. This unique structure efficiently alleviates the mechanical strain, prevents the aggregation of MoS(2), creates more active sites, facilitates electron transport, and enhances the specific capacity and K(+) diffusion kinetics. As a result, the prepared C-MoS(2)-1 anode delivers a high reversible specific capacity (437 mAh g(−1) at 0.1 A g(−1)) and satisfying rate performance (123 mAh g(−1) at 6.4 A g(−1)). Therefore, this work provides new insights into the design of high-performance anode materials of PIBs.