A Preliminary Study on Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> as a Novel Electrode Material for Calcium Ion Batteries

The electrochemical behaviors of a spinel lithium titanate oxide (Li 4 Ti 5 O 12 , LTO) electrode during as a novel electrode for calcium ion batteries were investigated during the charging and discharging to understand its electrochemical properties. The electrochemical performance of the LTO electrode was improved by the addition of dimethyl carbonate to the PC-based electrolyte. The initial charge and discharge capacities were ~262 and ~85 mAh g –1 , respectively. The results of the X-ray diffraction analysis showed that the lattice constant of LTO increased after charging, indicating that calcium ions were inserted into Li 4 Ti 5 O 12 during the charging.