Insight into a robust graphdiyne@carbon nanotubes electrode for rapid lithium-ion storage

Abstract

Graphdiyne (GDY) has emerged as a promising high-capacity anode material for lithium-ion batteries (LIBs), benefiting from its abundant active sites, extended π-conjugated structure, and hierarchical pore architecture. However, its intrinsic semiconductor-like conductivity severely restricts charge transport kinetics, resulting in inadequate rate performance and poor cycling stability under high current densities. To address this limitation, we rationally designed a graphdiyne@carbon nanotube (GDY@CNT) heterostructure electrode through a mild and sustainable approach. The integrated architecture not only establishes multidimensional pathways for efficient electron conduction and accelerated interfacial charge transfer, but also introduces robust C–O–C covalent linkages that effectively mitigate structural strain during prolonged lithiation/delithiation cycles. As a result, the GDY@CNT electrode achieves a high reversible capacity of 1284.6 mA h g⁻¹ at 0.1 A g⁻¹ and retains 439.4 mA h g⁻¹ after 600 cycles at 1 A g⁻¹, exhibiting exceptional rate capability and long-term cyclability. Kinetic investigations and theoretical calculations further demonstrate a lower ion diffusion barrier, rapid electrochemical kinetics and pseudocapacitive-dominated Li⁺ storage mechanism of the heterostructured GDY@CNT. This study offers valuable insights into interfacial charge regulation and transport optimization in GDY-based composites and carbonaceous anodes for high-performance LIBs.