Delocalized electronic engineering of TiNb<sub>2</sub>O<sub>7</sub> enables low temperature capability for high-areal-capacity lithium-ion batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39060232.
- Also identified by DOI 10.1038/s41467-024-50455-1 and PMC identifier 11282191.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
High areal capacity and low-temperature ability are critical for lithium-ion batteries (LIBs). However, the practical operation is seriously impeded by the sluggish rates of mass and charge transfer. Herein, the active electronic states of TiNb<sub>2</sub>O<sub>7</sub> material is modulated by dopant and O-vacancies for enhanced low-temperature dynamics. Femtosecond laser-based transient absorption spectroscopy is employed to depict carrier dynamics of TiNb<sub>2</sub>O<sub>7</sub>, which verifies the localized structure polarization accounting for reduced transport overpotential, facilitated electron/ion transport, and improved Li<sup>+</sup> adsorption. At high-mass loading of 10 mg cm<sup>-2</sup> and -30 °C, TNO<sub>-x</sub>@N microflowers exhibit stable cycling performance with 92.9% capacity retention over 250 cycles at 1 C (1.0-3.0 V, 1 C = 250 mA g<sup>-1</sup>). Even at -40 °C, a competitive areal capacity of 1.32 mAh cm<sup>-2</sup> can be achieved. Such a fundamental understanding of the intrinsic structure-function put forward a rational viewpoint for designing high-areal-capacity batteries in cold regions.