Diffusion characteristics of the LiFePO4/C composite in an electrolyte based on LiBOB

摘要

The behavior of a composite cathode material LiFePO4/C has been analyzed using the methods of chronopotentiometry, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacity of the LiFePO4, synthesized by the solid state method, changes from 110 to 40 mA·h/g with an increasing of the current density from 0.1 to 10C. The values of the diffusion coefficient for the lithium ions (D_(Li)) using the CV method are 2.06·10~(-14) and 1.07·10~(-14) cm~2/s for the anodic and cathodic processes, respectively. The diffusion coefficients, calculated by the impedance spectroscopy data.have been change in the range of 4·10~(-12) to 6·10~(-16) cm~2/s and are in a good agreement with the cyclic voltammetry data.