Orthorhombic Lithium Titanium Phosphate as an Anode Material for Li-ion Rechargeable Battery

Rhombohedral lithium titanium phosphate, LiTi2(PO4)(3), has been considered a suitable anode material for aqueous lithium-ion batteries. However, the electrochemical behaviors of pure lithium-rich polymorphs have not been described yet even Li-rich phase may show better electrochemical properties than conventional LiTi2(PO4)(3) at the expense of somewhat lowered capacity. We have synthesized orthorhombic Li1.5Ti2(PO4)(3) (OLTP) and rhombohedral LiTi2(PO4)(3) (RLTP) via sol-gel reactions and studied their fundamental electrochemical properties using galvanostatic charge/discharge and cyclic voltammetry (CV). Their feasibility as anode materials in LiFePO4//LixTi2(PO4)(3) configurations using aqueous electrolytes were also considered. The faster kinetics of the orthorhombic lithium titanium phosphate in this study were attributed to higher If diffusivity and electrical conductivity, making this material an attractive alternative for conventional rhombohedral LiTi2(PO4)(3). (C) 2015 Elsevier Ltd. All rights reserved.