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

High areal capacity and low-temperature ability are critical for lithium-ion batteries (LIBs). This paper explores modulating the active electronic states of TiNb₂O₇ using dopants and oxygen vacancies to enhance low-temperature performance. Femtosecond laser-based transient absorption spectroscopy reveals that localized structure polarization leads to improved electron/ion transport and Li⁺ adsorption. At a high mass loading of 10 mg cm⁻² and −30 °C, TiNb₂O₇@N microflowers show stable cycling with 92.9% capacity retention over 250 cycles. Even at −40 °C, a competitive areal capacity of 1.32 mAh cm⁻² is achieved.

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