Millimeter-sized few-layer graphene sheets with aligned channels for fast lithium-ion charging kinetics

• 作者: Yu-Qi Zhou Xiao-Ling Dong Wen-Cui Li Guang-Ping Hao Dong Yan An-Hui Lu
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（4）
• 页码范围: 62-69
• 页数: 8页
• 语种: 英文

摘要

Assembly of the top-down graphene units mostly results in 3D porous structure with randomly orga-nized pores.The direct bottom-up synthesis of macroscopic 2D graphene sheets with organized pores are long sought in materials chemistry field,but rarely achieved.Herein,we present a self-catalysis-assisted bottom-up route using L-glutamic acid and iron chloride as starting materials for the fabrication of the millimeter-sized few-layer graphene sheets with aligned porous channels parallel to the 2D direc-tion.The amino-and carboxyl-functional groups in L-glutamic acid can coordinate with iron cations,thus allowing an atomic dispersion of iron cations.The pyrolysis thus initiated the growth of graphene cat-alyzed by in-situ generated iron nanoparticles,and a dynamic flow of iron nanoparticles eventually led to the formation of millimeter-sized few-layer graphene sheets with aligned channels(60-85 nm in diameter).Used as anodes in lithium-ion batteries,these graphene sheets showed a good rate capability(142 mA h g-1 at 2 A g-1)and high capacity retention of 93％at 2 A g-1 after 1200 cycles.Kinetic analysis revealed that lithium ions storage was dominated by diffusion behavior and capacitive behavior together,in that graphene sheets with aligned channels could accelerate electron transfer and shorten lithium ions transport pathway.This work provides a novel approach to prepare unique porous graphene materials with specific structure for energy storage.