Micro-structured lepidocrocite-type H1.07Ti1.73O4 as anode for lithium-ion batteries with an ultrahigh rate and long-term cycling performance

The lepidocrocite-type H1.07Ti1.73O4 microsized structures with a tap density of 0.88 g.cm(-3) were prepared through the ion exchange method with K0.8Li0.27Ti1.73O4 powder as the precursor, and they exhibited good rate performance and outstanding cycle stability as an anode material for lithium ion batteries (LIB). The ion exchange method provides favorable conditions for H1.07Ti1.73O4 as an anode electrode material for LIBs. X-ray photoelectron spectroscopy (XPS) result demonstrates the existence of defects in the nonstoichiometric H1.07Ti1.73O4, which have a beneficial effect on the LIB performance. The electrochemical performance test proves that the half-cell with microsized H1.07Ti1.73O4 as the anode electrode can maintain a specific capacity of 129.5 mAh.g(-1) after 1100 cycles and 101 mAh.g(-1) after 3000 long cycles at high current densities of 2.0 and 5.0 A.g(-1), respectively. In addition, the small volume change rate of 3.6% in H1.07Ti1.73O4 during Li ion insertion was confirmed by real-time in situ transmission electron microscopy (TEM). The LiFePO parallel to H1.07Ti1.73O4 full battery exhibits a long-term cycling stability with a specific capacity of 73.8 mAh.g(-1) at a current density of 500 mA.g(-1) after 200 cycles.

Automated summary

The microsized H1.07Ti1.73O4 structures prepared through the ion exchange method exhibit excellent performance as an anode material for LIBs, showing good rate capability and outstanding cycle stability. The nonstoichiometric H1.07Ti1.73O4 with defects demonstrated beneficial effects on the LIB performance. Additionally, real-time in situ transmission electron microscopy confirmed a low volume change rate during Li ion insertion, contributing to the long-term cycling stability of the full battery system.