Abstract
High-performance Li-ion batteries require materials with well-designed and controlled structures on nanometre and micrometre scales. Electrochemical properties can be enhanced by reducing crystallite size and by manipulating structure and morphology. Here we show a method for preparing hierarchically structured Li₄Ti₅O₁₂ yielding nano- and microstructure well-suited for use in lithium-ion batteries. Scalable glycothermal synthesis yields well-crystallized primary 4–8 nm nanoparticles, assembled into porous secondary particles. X-ray photoelectron spectroscopy reveals presence of Ti⁺⁴ only; combined with chemical analysis showing lithium deficiency, this suggests oxygen non-stoichiometry. Electron microscopy confirms hierarchical morphology of the obtained material. Extended cycling tests in half cells demonstrates capacity of 170 mAh g⁻¹ and no sign of capacity fading after 1,000 cycles at 50C rate (charging completed in 72 s). The particular combination of nanostructure, microstructure and non-stoichiometry for the prepared lithium titanate is believed to underlie the observed electrochemical performance of material.
References: Hierarchically structured lithium titanate for ultrafast charging in long-life high capacity batteries - Mateusz Odziomek, Frédéric Chaput, Anna Rutkowska, Konrad Świerczek, Danuta Olszewska, Maciej Sitarz, Frédéric Lerouge & Stephane Parola - Nature Comm. 26 mai 2017 - 10.1038/ncomms15636