Rapid Synthesis of Fast-Charging TiNb2O7 for Lithium-Ion Storage via Ultrafast Carbothermal Shock

TL;DR

A new ultrafast method creates a better anode material for fast-charging lithium-ion batteries by altering the atomic structure of titanium niobium oxide.

Contribution

A novel ultrafast carbothermal shock method synthesizes TiNb2O7 with optimized atomic structure for enhanced lithium-ion battery performance.

Findings

TNO-1200 showed a specific capacity of 125 mAh/g after 3000 cycles at 10 C with 98% capacity retention.

The expanded lattice and unit-cell volume improved lithium-ion migration channels and reduced diffusion energy barriers.

Cation disorder suppressed polarization effects, and EDS confirmed uniform element distribution without impurities.

Abstract

The development of fast-charging lithium-ion batteries urgently requires high-performance anode materials. In this paper, through an ultrafast carbothermal shock (CTS) strategy, titanium niobium oxide (TiNb2O7, TNO) with an optimized structure was successfully synthesized within 30 s. By regulating the synthesis temperature to 1200 °C, the TNO-1200 material was obtained. Its lattice parameters (a-axis: 17.6869 Å) and unit-cell volume (796.83 Å3) were significantly expanded compared to the standard structure (a-axis: 17.51 Å, volume ~790 Å3), which widened the lithium-ion migration channels. Rietveld refinement and atomic position analysis indicated that the partial overlap of Ti/Nb atoms and the cooperative displacement of oxygen atoms induced by CTS reduced the lithium-ion diffusion energy barrier. Meanwhile, the cation disorder suppressed the polarization effect. Electrochemical tests showed that after 3000 cycles at a current density of 10 C, the specific capacity of TNO-1200 reached 125 mAh/g, with a capacity retention rate of 98%. EDS mapping confirmed the uniform distribution of elements and the absence of impurity phases. This study provides an efficient synthesis strategy and theoretical basis for the design of high-performance fast-charging battery materials through atomic-scale structural engineering.

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