Synthesis of Li ₂Ti ₃O ₇ Anode Materials by Ultrasonic Spray Pyrolysis and Their Electrochemical Properties

Abstract

Ramsdellite-type lithium titanate (Li ₂Ti ₃O ₇) powders were synthesized by performing ultrasonic spray pyrolysis, and their chemical and physical properties were characterized by performing Scanning Electron Microscope (SEM), powder X-ray Diffraction (XRD), and Inductively Coupled Plasma (ICP) analyses. The as-prepared Li ₂Ti ₃O ₇ precursor powders had spherical morphologies with hollow microstructures, but an irregularly shaped morphology was obtained after calcination above 900 °C. The ramsdellite Li ₂Ti ₃O ₇ crystal phase was obtained after the calcination at 1100 °C under an argon/hydrogen atmosphere. The first rechargeable capacity of the Li ₂Ti ₃O ₇ anode material was 168 mAh/g at 0.1 C and 82 mAh/g at 20 C, and the discharge capacity retention ratio was 99% at 1 C after the 500th cycle. The cycle performance of the Li ₂Ti ₃O ₇ anode was also highly stable at 50 °C, demonstrating the superiority of Li ₂Ti ₃O ₇ anode materials reported previously.