High Quality Pyrazinoquinoxaline-Based Graphdiyne for Efficient Gradient Storage of Lithium Ions
Lei Gao, Xun Ge, Zicheng Zuo, Fan Wang, Xiaoyan Liu, Mengmeng Lv, Siqi Shi, Lanting Xu, Taifeng Liu, Qinghai Zhou, Xiang Ye, Shengxiong Xiao
Abstract
N-doping of graphdiyne with atomic precision is very important for the study of heteroatom doping effect and the structure–properties relationships of graphdiyne. Here we report the bottom-up synthesis and characterizations of high-quality pyrazinoquinoxaline-based graphdiyne (PQ-GDY) film. First-principle studies of the layered structure were performed to examine the stacking mode, lithium binding affinity, and bulk lithium storage capacity. Three-stage insertion of 14 lithium atoms with binding affinities in the order of pyrazine nitrogen > diyne carbon > central aromatic ring were confirmed by both lithium-ion half-cell measurements and DFT calculations. More than half of the lithium atoms preferentially bind to pyrazine nitrogen, and a reversible capacity of 570.0 mA h g–1 at a current density of 200 mA g–1 after 800 cycles was achieved. Such a high capacity utilization rate of 97.2% provides a good case study of N-doped GDY with atomic precision.