A high performance lithium metal anode enabled by CF4 plasma treated carbon paper

Abstract

To substantially boost the energy density of secondary batteries, research studies on lithium metal anodes are booming to develop technologies on lithium metal batteries. However, suffering from lithium dendritic growth and volume expansion, the batteries are still far from practical applications. Herein, carbon paper (CP) is superficially fluorinated by CF₄ plasma to endow the obtained composite lithium metal anode with both high areal capacity and long lifespan. The decreasing intensity of plasma from the upper surface to the bottom in the CP matrix achieves a higher F content and a lower conductivity on the top side, thus guiding more lithium to deposit inside the matrix. Besides, the fluorinated carbon paper (FCP) possesses flatter lithium plating in contrast to typical dendrites. As a result, the cells employing FCP as the anode achieve stable cycling over 350 cycles at a high areal capacity of 3 mA h cm⁻² and a current density of 1 mA cm⁻².