Plasma‐Produced Vertical Carbonous Nanoflakes for Li‐Ion Batteries

An effective method to produce vertically‐oriented carbonous nanoflakes (VCNFs) on copper foils using an advanced custom‐designed plasma‐enhanced horizontal tube furnace deposition system under different RF powers at 850 °C without using any binder or catalyst materials is demonstrated. The morphology and structure of the synthesized carbonous materials are investigated using Raman spectroscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, and high‐resolution transmission electron microscopy. It is shown that the VCNFs can be effectively synthesized at moderate RF powers. When the RF power is 660 W, VCNFs which are only 2 atomic carbon layers thin, can be grown. The thickness and level of structural defects in the VCNFs can also be controlled by changing the RF power. A plausible growth mechanism for VCNFs under the plasma conditions is proposed. The synthesized VCNFs are applied as a cathode material for Li‐ion batteries. The coin‐type batteries demonstrate stable efficiency (∼99%) and specific capacity (110 mAh g −1 ) over 100 charge‐discharge cycles.