Preparation, structural, and characterizations of SnO2‐coated TiNb2O7 anode materials for lithium‐ion batteries

Abstract

AbstractSnO2‐coated TiNb2O7 powders were synthesized via the solution coating method in the present research. The SnO2 layers with a thickness of 3–5 nm were homogeneously coated on the surface of TiNb2O7 particles. TiNb2O7 coated with SnO2 of 5 mol% with high Li+ diffusion coefficient delivered the discharge capacity of 319.5 mAh/g, which was 6.6% higher than that of the non‐coated samples. The enhancement of capacity for the coated TiNb2O7 was owing to the low charge‐transfer resistance of 17.5 Ω in contrary to the non‐coated TiNb2O7 (27.8 Ω). SnO2‐coated TiNb2O7 possessed an improved capacity retention of 85.2% at 5 C after 100 cycles, superior to the non‐coated TiNb2O7 (79.8%). On the other hand, the excessive amounts of SnO2 coating led to the reduction in the capacity of the prepared samples. The excessive amounts of SnO2 layers suppressed the Li+ diffusion and increased the charge‐transfer resistance. The obtained results in this study indicated that coating of TiNb2O7 with appropriate amounts of SnO2 significantly improved the electrochemical performance of TiNb2O7.