LiTi(HPO 3 ) 2 A New Polyanion Based Anode for Lithium Ion Battery

Lithium titanium (III) phosphite, LiTi(HPO 3 ) 2 , a new material, has been synthesized under hydrothermal conditions. The solid-state structure of this material was determined from powder X-ray diffraction data in the tetragonal system, space group I 2d. The anionic inorganic skeleton is a 3D-framework structure, which is built up by TiO 6 octahedral units linked together via bridging HPO 3 pseudo pyramids, giving rise to tunnels along all the three crystallographic directions. IR and Raman spectroscopic studies show the vibrational modes of the (HPO 3 ) 2- oxoanions. This three dimensional structure shows interesting electrochemical behavior. The as-synthesized phase exhibits an insertion host for reversible accommodation of Li + at ̴ 0.7 V and thus can be used as low voltage anode for lithium ion batteries. LiTi(HPO 3 ) 2 phosphite reversibly performs with excellent cycling stability and 100% columbic efficiency for 100 cycles at C/2 rate. After rapid cycling at different C-rates, the initial battery capacity has been recovered with a minimal loss of 3.7 %. Reference: F. Cherkaoui El Moursli, A. Lallaoui, Z. Edfouf, I. Saadoune, M. Abd-lefdil, Nouveau matériau d’insertion pour batteries rechargeables, le phosphite de titane (III) et de lithium LiTi(HPO 3 ) 2 . Patent OMPIC N° 40700. Figure 1