Effect of Praseodymium Doping on Structural and Electrochemical Performance of Lithium Titanate Oxide (Li4Ti5O12) as New Anode Material for Lithium-Sulfur Batteries
In spite of their high theoretical energy density and potentially low cost, lithium-sulfur batteries face several challenges in their path toward widespread adoption, among which introduction of an appropriate anode seems to be one of the most difficult. We report herein on a modified anode based on lithium titanate oxide (Li4Ti5O12) (LTO) doped with praseodymium (Pr) element. A fairly simple sol–gel procedure was employed to prepare praseodymium-doped lithium titanate oxide (Pr-LTO). Different techniques were then applied for structural and morphological characterization of LTO and Pr-LTO, including x-ray diffraction analysis, Brunauer–Emmett–Teller surface area measurements, and scanning electron microscopy. Although the LTO and Pr-LTO electrodes were prepared using similar procedures, the Pr-LTO electrode exhibited higher capacity as well as better cycling efficiency compared with LTO. The Pr-LTO electrode demonstrated high rate capability along with reversible capacity of 173 mAh g−1, 116 mAh g−1, and 62 mAh g−1 at 0.05 C, 1 C, and 2 C, respectively. Electrochemical impedance spectroscopy also confirmed that Pr-LTO had higher electronic conductivity and faster lithium-ion diffusion compared with LTO.