SnO₂@PANI Core-Shell Nanorod Arrays on 3D Graphite Foam: A High-Performance Integrated Electrode for Lithium-Ion Batteries

The rational design and controllable fabrication of electrode materials with tailored structures and superior performance is highly desirable for the next-generation lithium ion batteries (LIBs). In this work, a novel three-dimensional (3D) graphite foam (GF)@SnO₂ nanorod arrays (NRAs)@polyaniline (PANI) hybrid architecture was constructed via solvothermal growth followed by electrochemical deposition. Aligned SnO₂ NRAs were uniformly grown on the surface of GF, and a PANI shell with a thickness of ∼40 nm was coated on individual SnO₂ nanorods, forming a SnO₂@PANI core-shell structure. Benefiting from the synergetic effect of 3D GF with large surface area and high conductivity, SnO₂ NRAs offering direct pathways for electrons and lithium ions, and the conductive PANI shell that accommodates the large volume variation of SnO₂, the binder-free, integrated GF@SnO₂ NRAs@PANI electrode for LIBs exhibited high capacity, excellent rate capability, and good electrochemical stability. A high discharge capacity of 540 mAh g^-1 (calculated by the total mass of the electrode) was achieved after 50 cycles at a current density of 500 mA g^-1. Moreover, the electrode demonstrated superior rate performance with a discharge capacity of 414 mAh g^-1 at a high rate of 3 A g^-1.