To overcome two main drawbacks of SnO2 as anode material in lithium‐ion batteries, low conductivity and poor cycling stability, SnO2/Sn@TiO2@C composite is prepared via one‐pot hydrothermal reaction to synthesize SnO2/C precursor‐assembled hollow nanospheres and then coated with TiO2 and resorcinol‐formaldehyde resin. After calcination, multi‐shelled hollow nanospheres of SnO2/Sn@TiO2@C are formed. When used as anode material in lithium‐ion batteries, the as‐prepared composite exhibits high discharge capacity of 1565 mAh g−1 at 0.5 A g−1. After 300 cycles at 1 A g−1, the discharge capacity still reaches 961 mAh g−1 with capacity fading rate of just 0.11 % per cycle. The average discharge capacity reaches 395 mAh g−1 even at 5 A g−1. The superior lithium storage performance mainly benefits from the unique multi‐shelled hollow nanosphere structure. The coating TiO2 and amorphous carbon increase structural and cycling stabilities of SnO2/Sn hollow nanospheres. The outermost carbon shell further enhances electronic conductivity of the composite. The hollow nanosphere structure also endows SnO2/Sn nanoparticles with high electrochemical activity. This work proposes a feasible synthesis and structure design strategy for the development of advanced SnO2‐based composite materials.
Hollow mesoporous nanospheres MoO2/C are successfully constructed through metal chelating reaction between molybdenum acetylacetone and glycerol as well as the Kirkendall effect induced by diammonium hydrogen phosphate. MoO2 nanoparticles coupled by amorphous carbon are assembled to unique zigzag-like hollow mesoporous nanosphere with large specific surface area of 147.7 m2 g-1 and main pore size of 8.7 nm. The content of carbon is 9.1%. As anode material for lithium-ion batteries, the composite shows high specific capacity and excellent cycling performance. At 0.2 A g-1, average discharge capacity stabilizes at 1092 mAh g-1. At 1 A g-1 after 700 cycles, the discharge capacity still reaches 512 mAh g-1. Impressively, the composite preserves intact after 700 cycles. Even at 5 A g-1, the discharge capacity can reach 321 mAh g-1, exhibiting superior rate capability. Various kinetics analyses demonstrate that in electrochemical reaction, the proportion of the surface capacitive effect is higher, and the composite has relatively high diffusion coefficient of Li ions and fast faradic reaction kinetics. Excellent lithium storge performance is attributed to the synergistic effect of zigzag-like hollow mesoporous nanosphere and amorphous carbon, which improves reaction kinetics, structure stability and electronic conductivity of MoO2. The present work provides a new useful structure design strategy for advanced energy storage application of MoO2.
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