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

Yan Zhang; Yingjie Wang; Wei Zhao; Pengjian Zuo; Yujin Tong; Geping Yin; Tong Zhu; Shuaifeng Lou

doi:10.1038/s41467-024-50455-1

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

Nat Commun. 2024 Jul 26;15(1):6299. doi: 10.1038/s41467-024-50455-1.

Authors

Yan Zhang^#¹, Yingjie Wang^#², Wei Zhao¹, Pengjian Zuo¹, Yujin Tong³, Geping Yin⁴, Tong Zhu⁵, Shuaifeng Lou⁶

Affiliations

¹ State Key Laboratory of Space Power-Sources, Harbin Institute of Technology, Harbin, China.
² Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing, China.
³ Faculty of Physics, University of Duisburg-Essen, Duisburg, Germany.
⁴ State Key Laboratory of Space Power-Sources, Harbin Institute of Technology, Harbin, China. yingeping@hit.edu.cn.
⁵ Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing, China. Tongzhubit@bit.edu.cn.
⁶ State Key Laboratory of Space Power-Sources, Harbin Institute of Technology, Harbin, China. shuaifeng.lou@hit.edu.cn.

^# Contributed equally.

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 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 TiNb₂O₇, which verifies the localized structure polarization accounting for reduced transport overpotential, facilitated electron/ion transport, and improved Li⁺ adsorption. At high-mass loading of 10 mg cm^-2 and -30 °C, TNO_-x@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^-1). 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.

Abstract

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