The Korean Society of Surface Science and Engineering

The effect of PVdF on the electrochemical activity of composite electrodes for Li battery was analyzed using the PVdF-aqueous solution as a model system in terms of fractal dimension(D_f). To this end, specimens with different pore structures were prepared by controlling the electrode density and loading, and their electrochemical behavior under diffusion control was analyzed by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). The CV results showed a clear difference in D_f depending on the pore structure and confirmed that the electrochemical deactivation effect of PVdF is different for different pore structures. Particularly, its deactivation effect was larger at the macroscopic pore level, suggesting that it may be responsible for the inhomogeneous reaction across pore size regions. On the other hand, when EIS was applied, the overall D_f was similar to the value from CV, but the ability to distinguish differences in D_f according to pore structure was relatively low.

Keywords Lithium battery; Electrode; Pore structure; Fractal dimension; PVdF