Liquid Processed Nano As4S4/SWCNTs Composite Electrodes for High-Performance Li-Ion and Na-Ion Battery Anodes.

Abstract

The liquid-phase exfoliation process has been successfully applied to nonlayered materials to produce quasi-2D nanoplatelets. A slight variation in bonding anisotropy in the starting material can result in the formation of 2D platelet-shaped particles with a relatively low aspect ratio. This advancement offers a promising strategy to create 2D materials from previously unexplored materials. In this study, we investigate the liquid-phase exfoliation of arsenic sulfide (As4S4), an intriguing nonlayered van der Waals material. The liquid exfoliation process generates highly disordered, low aspect ratio quasi-2D platelets. These As4S4 flakes can be easily mixed with carbon nanotubes to create nanocomposite anodes, which are appropriate for use in both Li-ion and Na-ion batteries eliminating the need for extra binders or conductive additives. The As4S4/SWCNT electrodes exhibit impressive low-rate capacities of 1202 mA h g-1 at 0.1 A g-1 for Li-ion cells and 753 mA h g-1 at 0.05 A g-1 for Na-ion cells, along with commendable cycling stability over more than 300 cycles. Detailed quantitative rate assessment clearly shows that these electrodes are limited by solid-state diffusion and emphasizing the possibility of reaching a capacity that comes close to the theoretical value which confirms the near full utilization of the active material.