One-step growth of the interconnected carbon nanotubes/graphene hybrids from cuttlebone-derived bi-functional catalyst for lithium-ion batteries

Carbon nanotubes/graphene hybrid materials with excellent physicochemical properties can be widely ap-plied in the fields of energy storage, electrocatalysis, sensing, etc. Reducing the self-stacking and achiev-ing covalent interaction between carbon nanotubes and graphene are important to ensure a stable hi-erarchical architecture and effective mass transfer. Herein, we propose a one-step strategy to synthesize 3D interconnected carbon nanotubes/graphene hybrids on the easy-to-remove biomass-derived substrate. The calcined natural cuttlebone as bi-functional catalyst precursor can simultaneously grow carbon nan-otubes and graphene by one-step chemical vapor deposition without the addition of extra metal catalysts, while the interconnected structure can act as the porous template for graphene growth. The simultane-ous growth process can obtain covalent bonding between carbon nanotubes and graphene, while the crystalline quality and interlayer space can be adjusted by different carbon sources and growth parame-ters (e.g., temperature). The one-step grown carbon nanotubes/graphene hybrids with seamless interfaces and hierarchical interconnected 3D structure can effectively enhance the electron transfer as well as the electrolyte infiltration efficiency. When utilized as lithium-ion batteries (LIBs) anode, a high specific ca-pacity (544 mAh g -1 at 0.1 A g -1 ), good rate capability (200 mAh g -1 at 6.4 A g -1 with an ultrashort charge time of 113 s), and excellent cyclic stability can be achieved. This simple and one-step carbon nanotubes/graphene hybrids fabrication strategy can be easily scale-up and applied in various fields.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.