Ultra-small SnO2 nanoparticles decorated on three-dimensional nitrogen-doped graphene aerogel for high-performance bind-free anode material

Abstract

Tin dioxide (SnO2) has attracted extensive research attention as promising anode materials for lithium ion batteries due to high theoretical capacity. However, its application is largely hindered by poor electronic conductivity and drastic volume change during the conversion reaction and alloying processes. Herein, we report a three-dimensional nitrogen-doped graphene aerogel decorating ultra-small SnO2 nanoparticles (3–6 nm) by a facile one-step hydrothermal process. Nanoscaled SnO2 nanoparticles facilitate limited volume expansion and shortened lithium diffusion pathways, nitrogen-doping increases the positive charge density of carbon atoms adjacent to the nitrogen atom, while the three-dimensional porous graphene aerogel has excellent electronic conductivity and facile electrolyte infiltration, thus prompting the composite electrode excellent electrochemical performance. When used as bind-free anode electrode, the graphene aerogel/SnO2 composite delivers a high discharge capacity of 1812.0 mAh g−1 in the initial cycle, and the capacity can retain at 778 mAh g−1 after 100 cycles, demonstrating its promising candidate as anode material for energy storage.