(284g) Electrochemical Porosimetry

Porous structure is omnipresent in Nature. It is the basic structure of life and universe, providing large surface area in a space-saving way. ?Porous? electrode is also a common denominator for the energy technology of the 21st century: batteries, fuel cells and supercapacitors. Microstructure of porous materials has been characterized by various analytical methods. Previous methods, however, are ex situ techniques for the electrochemical applications, so that measured structures may not be identical to those accessible to electrolyte ions in real applications. Therefore, it has been extremely difficult to correlate the microstructure of porous electrodes with electrochemical behavior of energy storage devices. Here, we present the electrochemical porosimetry (ECP) which gives microstructural information most meaningful in electrochemical systems. The methodology is based on the transmission line model with pore size distribution (TLM-PSD) that relates electrochemical impedance with microstructure such as pore size distribution (PSD) and pore length (lp). This geometric information was validated for the microporous, mesoporous and macroporous samples. Also, the ECP could be used as a nondestructive probe to investigate the construction of electrochemical devices. We anticipate that the ECP would take up a considerable room as a widely accepted porosimetry for general purpose.