Li_3Sb0_4: A new high rate anode material for lithium-ion batteries

摘要

Electrochemical properties of Li_3Sb0_4 have been investigated as an anode in lithium-ion coin cells. X-ray powder diffraction of the material, synthesized by the conventional solid state technique with thermal treatment at 800 ℃ in air, confirmed a monoclinic structure with lattice parameters of a = 5.159 Å, b = 6.048 Å, c = 5.144Å and ss=109°. Electrochemical measurements in 2032 type coin cells show that Li insertion and extraction in this material take place at 0.72 and 1.05 V vs Li/Li~(-1) respectively. Although the material shows a low average reversible capacity of 81 mAhg~(-1) at a current density of 0.05 mAcm~(-2) (C/5), an excellent rate performance with nearly 100% Coulombic efficiency has been observed. Continuous cycling up to 200 cycles at current densities of 0.05,4.0 and 8.0 mAcm~(-2) shows that by increasing the current rate from C/5 to 43 C i.e. 215 times, the average reversible capacity decreases only 10%. Thus, the material might be very useful for applications requiring high rate of charge and discharge.