Novel peapoded Li4Ti5O12 nanoparticles for high-rate and ultralong-life rechargeable lithium ion batteries at room and lower temperatures

Abstract

In this paper, a novel peapod-like Li₄Ti₅O₁₂–C composite architecture with high conductivity is firstly designed and synthesized to be used as anode materials for lithium-ion batteries. In the synthesis, Na₂Ti₃O₇ nanotubes act as precursors and sacrificial templates, and glucose molecules serve as the green carbon source, thus the peapod-like Li₄Ti₅O₁₂–C composite can be fabricated by a facile hydrothermal reaction and the subsequent solid-state process. Compared to the previous reports, the as-prepared samples obtained by our new strategy exhibit excellent electrochemical performances, such as outstanding rate capability (an extremely reversible capability of 148 mA h g⁻¹, 125 mA h g⁻¹ at 30 C and 90 C, respectively) as well as excellent cycling performance (about 5% capacity loss after 5000 cycles at 10 C with 152 mA h g⁻¹ capacity retained). The low-temperature measurements also demonstrate that the electrochemical performances of the peapod-like Li₄Ti₅O₁₂–C composite are remarkably improved at various rate currents (at the low-temperature of −25 °C, a high Coulombic efficiency of about 99% can be achieved after 500 cycles at 10 C).