Graphene oxide-regulated nanoscale construction of SnO2/N-doped carbon/rGO composite anodes from a tin naphthalocyanine precursor for lithium storage.

Designing nanoscale composite architectures that integrate conversion/alloying-type oxide nanocrystals with conductive carbon frameworks is an effective strategy for improving the lithium-storage behavior of high-capacity anodes. Herein, we develop a coupled molecular precursor/GO-regulated nanoscale construction strategy for SnO2/N-doped carbon/reduced graphene oxide composite anodes. Specifically, tert-butyl-substituted tin naphthalocyanine (tBuSnNc) is employed as a molecular precursor and combined with GO to construct a SnO2/N-doped carbon/reduced graphene oxide composite anode (tBuSnNc/GO-C) via thermal conversion. In this design, tBuSnNc enables the in situ formation of SnO2 active species within an N-doped carbonaceous matrix, while GO-derived rGO acts as a structural regulator to promote an open wrinkled sheet-like framework with hierarchical porosity and improved active-site accessibility. Benefiting from this coupled precursor/structure design, tBuSnNc/GO-C delivers a reversible capacity of 926.4 mAh g-1 after 200 cycles at 0.1 A g-1 and retains 511.1 mAh g-1 at 1 A g-1, outperforming the GO-free counterpart. Kinetic analyses indicate lower charge-transfer resistance, higher apparent Li+ diffusion coefficients under identical testing and calculation conditions, and a slightly enhanced surface-controlled response, with the capacitive contribution reaching 92.83% at 2.0 mV s-1. Moreover, a prelithiated tBuSnNc/GO-C//LiFePO4 full cell delivers a stable reversible capacity of approximately 143 mAh g-1 over 50 cycles, suggesting preliminary compatibility of the composite anode in a full-cell configuration. This work demonstrates a GO-regulated nanoscale construction strategy based on molecular precursor conversion, providing a design route for improving the lithium-storage behavior of SnO2-based nanocomposite anodes.