Single-crystal TiNb2O7 materials via sustainable synthesis for fast-charging lithium-ion battery anodes

• Published in: Journal of energy storage Vol. 95; p. 112482
• Main Authors: Yu, Fan, Wang, Senhao, Yekani, Rana, La Monaca, Andrea, Demopoulos, George P.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024
• Subjects: Fast-charging LIB anode; Li-ion intercalation mechanism; Single-crystal materials; Sustainable hydrolytic co-precipitation; Titanium niobate (TiNb2O7); Fast-charging LIB anode; Titanium niobate (TiNb2O7); Single-crystal materials; Sustainable hydrolytic co-precipitation; Li-ion intercalation mechanism
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2024.112482

TiNb2O7 (TNO) has emerged as a promising fast-charging anode for lithium-ion batteries (LIBs). However, research on TNO anode materials has been mostly restricted to synthesis of polycrystalline with limited associated mechanistic studies. Herein, we report a novel scalable aqueous synthesis method yielding sub-micron size single-crystal TNO particles following calcination that enables fast-charging anode fabrication. The sustainable co-precipitation process yields amorphous intermediate hydroxides which upon thermal conversion induced crystallization form single crystals. The obtained TNO monocrystalline anode material under 900 °C calcination (TNO-900C) delivers a high gravimetric capacity (279 mAh/g at 1st cycle) and a high volumetric capacity (351.7 mAh/cm3 at the initial cycle) at 0.5C rate. Additionally, the TNO anode delivers a remarkable capacity of 223 mAh/g at 5C and a high retention of 81.4 % after 200 cycles. In addition, TNO-900C illustrates outstanding fast-charging performance with a reversible capacity of 200 mAh/g at 10C. The intercalation mechanism and diffusion behavior of the monocrystalline TNO anodes are elucidated by electrochemical kinetic analysis (GITT, CV, and EIS). The remarkable fast charging Li-ion storage performance can be attributed to a high Li+ diffusion coefficient (1.37 × 10−13 cm2/s), low polarization, and high structural stability. [Display omitted] •Single-crystal TiNb2O7 materials exhibiting remarkable fast-charging performance•Novel synthesis method featuring hydrolytic precipitation and calcination for sustainable production•High Li+ diffusion kinetics and redox intercalation mechanism revealed by electrochemical characterization