Determination of the chemical diffusion coefficient of lithium in Li3V2(PO4)3

Abstract The chemical diffusion of lithium ion in Li 3 V 2 (PO 4 ) 3 were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. The CV results show that there exists a linear relationship between the peak current ( i p ) and the square root of the scan rate ( ν 1/2 ). The impedance spectrum exhibits a single semicircle and a straight line in a very low frequency region. A linear behavior was observed for every curve of the real resistance as a function of the inverse square root of the angular frequency in a very low frequency region. The obtained chemical diffusion coefficient from EIS measurements varies within 10 − 9 to 10 − 8  cm 2 ·s − 1 , in good agreement with those from CV results.