Hierarchical 3D Porous Hydrogen-Substituted Graphdiyne for High-Performance Electrochemical Lithium-Ion Storage

Graphdiyne (GDY) has realized significant achievementsin lithium-ionbatteries (LIBs) because of its unique pi-conjugated skeletonwith sp- and sp(2)-hybridized carbon atoms. Enriching theaccessible surface areas and diffusion pathways of Li ions can realizemore storage sites and rapid transport dynamics. Herein, three-dimensionalporous hydrogen-substituted GDY (HsGDY) is developed for high-performanceLi-ion storage. HsGDY, fabricated via a versatile interface-assistedsynthesis strategy, exhibits a large specific surface area (667.9m(2) g(-1)), a hierarchical porous structure,and an expanded interlayer space, which accelerate Li-ion accessibilityand lithiation/delithiation. Owing to this high pi-conjugated,conductive, and porous framework, HsGDY exhibits a large reversiblecapacity (930 mA h g(-1) after 100 cycles at 1 A g(-1)), superior cycle (720 mA h g(-1) after300 cycles at 1 A g(-1)), and rate (490 mA h g(-1) at 5 A g(-1)) performances. Densityfunctional theory calculations of the low diffusion barrier in thelamination and vertical directions further reveal the fast Li-iontransport kinetics of HsGDY. Additionally, a LiCoO2-HsGDYfull cell is constructed, which exhibits a good practical charge/dischargecapacity of 128 mA h g(-1) and stable cycling behavior.This study highlights the advanced design of next-generation LIBsto sustainably develop the new energy industry.

Automated summary

Graphdiyne (GDY) has achieved significant advancements in lithium-ion batteries (LIBs) due to its unique structure. The development of three-dimensional porous hydrogen-substituted GDY (HsGDY) with a large specific surface area, hierarchical porous structure, and expanded interlayer space has shown high-performance Li-ion storage capabilities. The HsGDY exhibits a large reversible capacity, superior cycle and rate performances, and fast Li-ion transport kinetics.