Presentation Title：Delocalized electronic engineering of TiNb₂O₇ enables low temperature capability for high-areal-capacity lithium-ion batteries

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 TiNb₂O₇ anode is modulated by dopant and O-vacancies for enhanced low-temperature dynamics. For the first time, femtosecond laser-based transient absorption spectroscopy is employed to depict carrier dynamics of TiNb₂O₇, which verifies the localized structure polarization accounting for reduced transport overpotential, facilitated electron/ion transport, and improved Li+adsorption. At high-mass loading and −30 °C, TNO-x@N microflowers exhibit a high capacity retention (75.4% of the electrode at 25oC) and cyclability (92.9% after 250 cycles at 1 C). Even at −40 °C, a competitive areal capacity of 1.32 mAh cm⁻² 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.

Bio：

Yan Zhang is an Associate Researcher (Postdoctoral Fellow) in the School of Chemistry and Chemical Engineering at Harbin Institute of Technology. Her current research focuses on niobium-based electrochemical energy storage, encompassing the design of high-efficiency niobium-based catalysts, the development of wide-temperature-range electrolytes, and the stability enhancement of niobium-based anodes for low-temperature lithium-ion batteries. She has participated in several national and provincial-level projects, including sub-projects of the National Key R&D Program of China, Civil Aerospace Pre-research Projects, and General Programs of the National Natural Science Foundation of China. Dr. Zhang has published over 20 high-impact papers in prestigious international journals, such as Journal of the American Chemical Society, Nature Communications,Matter, Angewandte Chemie International Edition, and Energy Storage Materials.