Enhancing electrochemical energy storage capacity and rate performance of the anode with a 3D interconnected carbon tube-NiO-SnO 2 composite scaffold

Tin dioxide (SnO 2 ) possesses great potential as an anode material for lithium-ion batteries (LIBs) owing to its high theoretical specific capacity. However, the irreversible conversion of Sn to SnO 2 and enormous volume variation during the charge/discharge process limit the battery energy storage performance. In this study, ultrafine NiO and SnO 2 nanoparticles (NPs) decorated on a three-dimensionally (3D) interconnected and structurally integrated carbon tube (CT) scaffold (NiO/SnO 2 -NPs@3D-CT) is developed as an anode, eliminating any inactive component in the electrode. The NiO not only contributes to the capacity but also undergoes reduction to Ni during the lithiation process, which catalyzes Li 2 O decomposition and facilitates the reversible conversion of Sn to SnO 2 . Additionally, the open space of the 3D scaffold can host a large number of NiO/SnO 2 NPs and results in a short diffusion distance of Li + between the electrolyte and the Li + host. The interconnected 3D-CT network serves as a fast electron transport channel. Consequently, the unique structure endows the anode with high Li-ion storage capacity (928.5 mA h g −1 at a current density of 1 A g −1 after 200 cycles) and superior high-rate performance; for instance, a reversible capacity of 633.5 mA h g −1 can be achieved even at a current density of 4 A g −1 . We believe that the unique, integrated 3D structure holds great promise as an anode for LIBs and that its applications can be further extended to other fields.