Microwave-Assisted Coal-Derived Few-Layer Graphene as an Anode Material for Lithium-Ion Batteries.

Faridul Islam,Rou Wang,Behdad Moghtaderi,Arash Tahmasebi,Jianglong Yu,Jialong Wang

doi:10.3390/ma14216468

Abstract

A few-layer graphene (FLG) composite material was synthesized using a rich reservoir and low-cost coal under the microwave-assisted catalytic graphitization process. X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were used to evaluate the properties of the FLG sample. A well-developed microstructure and higher graphitization degree were achieved under microwave heating at 1300 °C using the S5% dual (Fe-Ni) catalyst for 20 min. In addition, the synthesized FLG sample encompassed the Raman spectrum 2D band at 2700 cm−1, which showed the existence of a few-layer graphene structure. The high-resolution TEM (transmission electron microscopy) image investigation of the S5% Fe-Ni sample confirmed that the fabricated FLG material consisted of two to seven graphitic layers, promoting the fast lithium-ion diffusion into the inner surface. The S5% Fe-Ni composite material delivered a high reversible capacity of 287.91 mAhg−1 at 0.1 C with a higher Coulombic efficiency of 99.9%. In contrast, the single catalyst of S10% Fe contained a reversible capacity of 260.13 mAhg−1 at 0.1 C with 97.96% Coulombic efficiency. Furthermore, the dual catalyst-loaded FLG sample demonstrated a high capacity—up to 95% of the initial reversible capacity retention—after 100 cycles. This study revealed the potential feasibility of producing FLG materials from bituminous coal used in a broad range as anode materials for lithium-ion batteries (LIBs).

Highlights

Lithium-ion batteries (LIBs) are remarkable in many aspects owing to their high energy density, long cycling life, and low pollution levels [1,2,3]
The typical XRD diffraction peaks of the porous carbon materials were catalytically graphitized at 1300 ◦ C with different catalyst percentages (Figure 1)
Coal-based few-layer graphene (FLG) materials were successfully fabricated from bituminous coal through dual catalytic graphitization (Fe and Ni) at 1300 ◦ C under the microwave process

Summary

Introduction

Lithium-ion batteries (LIBs) are remarkable in many aspects owing to their high energy density, long cycling life, and low pollution levels [1,2,3]. Recent research has focused on improving the electrochemical performances of LIBs in such areas as stability, cycling capacity, and cost-effectiveness by looking at employing different kinds of carbon materials as anode materials. Carbon composite materials such as graphene, boron-doped carbon foam, artificial graphite scrap, and anthracite-based graphite have been used as anode materials to enhance electrochemical performance. The FLG adhesion strength between the current collector and the active materials contributes to making a high-density electrical path and a high mechanical electrode strength within the electrode These facilities are highly effective in functional materials volume change during the charge/discharge process and smooth the electron transfer. The high production costs and complex procedures have affected their large-scale industrial applications

Methods

Results

Conclusion