Structural Effect of 10um Depth Surface Relief on the Cycling Behavior of Lithium Metal Anode

Abstract

Lithium metal anodes (LMAs) are required to fulfill higher energy density battery system beyond lithium ion batteries (LIBs). However, practical application of LMAs has been hindered from poor cycle life and safety issue caused by lithium (Li) dendrite growth and inhomogeneous Li plating/stripping. Recently, the Li surface patterning technique was developed for the lower surface current density and stable Li plating/stripping for LMB. Nevertheless, the impact of various factors such as the pattern morphology and charge-discharge condition on Li anode was much unexplored. Here, we report the comparison of the cycling behavior of 10 μm depth continuous and discontinuous surface relief on lithium anode under the Li overflow conditon with varying induced current density. Both continuous and discontinuous surface relief efficiently reduced dendritic Li growth and improved Li plating/stripping behavior than the bare Li anode. The most controlled Li plating/stripping was observed along the discontinuous surface relief. This result affects the improved cycle performance and lowered overpotential of surface patterned lithium metal anode. Furthermore, it was revealed that the 10 μm depth surface relief can not only be applied on the thin (20 μm) Li anode but also enhance cycling stability.