Architecting Pyrenyl-graphdiyne Nanowalls for High Capacity and Long-life Lithium Storage

Graphdiyne,as the novel carbon allotrope,which is composed of sp2-and sp-hybridized carbon,has exhibited excellent catalytic activity and conductivity.It has been applied in series of fields,such as Li-battery,catalyst and energy conversion.Expanding well-defined structures and useful applications of graphdiyne is still full of challenges in material chemistry.Herein,we optimized the synthesis condition of pyrenyl-graphdiyne to obtain the nanowall structure.Compared with the typical nanosheet structure,the pyrenyl-graphdiyne nanowalls(Pyr-GDY-NWs)have more area for lithium insertion.Lithium-ion battery featuring Pyr-GDY-NWs-based electrode exhibits a high reversible specific capacity up to 1464 mA·h/g,which is triple than that of the commercial graphite.We also used the theoretical calculation to investigate the mechanism of Li storage in Pyr-GDY-NWs.The experiment and theoretical data showed that Pyr-GDY-NWs had the potential application in lithium batteries.Therefore,Pyr-GDY with a defined structure would be applied in energy storage and energy conversion.     

新型二维碳化物晶体储锂性能的理论研究

MXenes是一类新型的二维金属碳化物或碳氮化物.本文使用密度泛函理论,分别研究了其中Ti₂C、Nb₂C和V₂C的结构与储锂性能,以及表面氟(F)官能团对其结构和储锂性能的影响.吸附能、态密度和电荷布居的计算结果表明:该二维晶体表面可以吸附双层锂原子. Ti₂C、V₂C和Nb₂C最高储Li的理论比容量分别为995.04、941.31、541.93 mAh·g^-1.此外, F官能团可以有效提高这三种二维晶体锂化结构的稳定性与导电性.