Developing the Fast Ionic Transport in the Semiconductor Ionic Heterostructure Composed of La0.8Sr0.2Co0.8Fe0.2-Gd0.1Ce0.9O2 for the Electrolyte Application in Ceramic Fuel Cells

Abstract

The challenging research topic for developing low-temperature ceramic fuel cells (LT-CFCs) is to design electrolytes with sufficient ionic conductivity either via doping or composite semiconductors with ionic conductors. Following this challenging topic, we have developed and synthesized a novel semiconductor ionic heterostructure La0.8Sr0.2Co0.8Fe0.2O3-Gd0.1Ce0.9O2 (LSCF-GDC) with different compositions and deployed it as an electrolyte to realize the functionality of the fuel cell. The developed LSCF-GDC electrolyte with mixed conduction of ions and protons possesses high ionic conductivity with only 0.06 Ohm·cm2 of ohmic area-specific resistance for the electrolyte component. The fuel cell using 3LSCF-7GDC as the electrolyte exhibits the best fuel cell performance of 1060 mW·cm−2 and an open circuit voltage (OCV) of 1.11 V at a low operating temperature of 550 °C among individual GDC, LSCF, and different heterostructures of LSCF and GDC. The attained performance and ionic conductivity are specially accredited to constructing heterostructures and massively deficient structures at the interface of the LSCF and GDC. The advanced semiconductor ionic heterostructure of LSCF-GDC provides new insight into designing new electrolytes with high ionic conductivity for LT-CFC applications.