Interfacial ionic transport in natural palygorskite-Na0.60CoO2 nanocomposite mineral materials

Natural clay minerals have been applied to various energy fields due to their low cost, good stability, and abundance of resources, but few of them have been investigated for fuel cell application. Proton ceramic fuel cell, one of the most promising sustainable-energy-conversion technologies, has attracted a lot of attentions because it possesses high ionic conductivity at relatively low temperatures (<600 °C). However, the characteristics of expensive construction cost and high temperature operation hinder the development and industrialization of fuel cell. In this paper, natural clay minerals palygorskite (PAL) and Na_0.60CoO₂ (NCO) nanosheets composite were synthesized via an electrostatic adsorption method, and used as the electrolyte of fuel cell. NCO/PAL demonstrated a high conductivity of 0.27 S?cm^?1 at 550 °C and the maximum power output of 641 mW cm^?2 was achieved for NCO/PAL cell. The mechanism of proton transport at the interface of NCO/PAL semiconductor-insulator composite was discussed.