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.