Gradient Graphdiyne Induced Copper and Oxygen Vacancies in Cu 0.95 V 2 O 5 Anodes for Fast-Charging Lithium-Ion Batteries.

Vacancies can significantly affect the performance of metal oxide materials. Here, a gradient graphdiyne (GDY) induced Cu/O-dual-vacancies abundant Cu 0.95 V 2 O 5 @GDY heterostructure material has been prepared as a competitive fast-charging anode material. Cu 0.95 V 2 O 5 self-catalyzes the growth of gradient GDY with rich alkyne-alkene complex in the inner layer and rich alkyne bonds in the outer layer, leading to the formation of Cu and O vacancies in Cu 0.95 V 2 O 5 . The synergistic effect of vacancies and gradient GDY results in the electron redistribution at the hetero-interface to drive the generation of a built-in electric field. Thus, the Li-ion transport kinetics, electrochemical reaction reversibility and Li storage sites of Cu 0.95 V 2 O 5 are greatly enhanced. The Cu 0.95 V 2 O 5 @GDY anodes show excellent fast-charging performance with high capacities and negligible capacity decay for 10 000 cycles and 20 000 cycles at extremely high current densities of 5 A g -1 and 10 A g -1 , respectively. Over 30 % of capacity can be delivered in 35 seconds.