In−situ preparation of ultrathin graphdiyne layer decorated aluminum foil with improved cycling stability for dual−ion batteries

Dual−ion batteries (DIBs) are a new kind of battery operated across a high voltage range with safer performance and low cost. However, the relative low capacity and poor cyclic stability restricts the application when aluminium (Al) anode was used to increase the capacity of the DIBs. Graphdiyne (GDY) as a new kind of carbonaceous allotropeis provides a facile and controllable strategy by in−situ preparation of ultrathin GDY layer on Al surface to promote the formation of stable SEI layer and solve the volume expansion of Al anode. Therefore, we report the fabrication of ultrathin GDY layer decorated on Al foil for both anode and current collector in DIB devices. The butadiyne linkages with large triangle−like intramolecular pores in GDY molecular are expected to provide efficient pathways for the orderly lithium intercalation to buffer the massive volume expansion and pulverization of Al and improve the formation of stable SEI layer during lithiation–delithiation cycles. As a result, the assembled Al−GDY based DIBs could deliver an improved reversible capacity of approximately 125 mAh g⁻¹ at 1 C and show an improved cycling stability of 88% capacity retention more than 450 cycles than commercial Al foil, suggesting remarkable improvement on cycling stability.