Solid oxide fuel cell (SOFC) technical challenges and solutions from nano-aspects

Abstract

SUMMARYThe classical (over 100 years) oxygen ion conductor and theory for solid oxide fuel cells (SOFCs) have met critical challenges, which are caused by the electrolyte material, the heart of the SOFC. Ionic conductivity of 0.1 S cm À1 as a basic requirement limits conventional SOFC electrolyte material, yttrium stabilized zirconia (YSZ) functioning at ca. 10001C. Such high temperature prevents SOFC technology from commercialization. Design and development of materials functioning at low temperatures are therefore a critical challenge. State of the art of the nanotechnology remarks a great potential for SOFCs. Through a review of typical SOFC electrolyte materials and analysis of the ionic conduction theory as well as constrains and disadvantages in single-phase materials, the need for design, development and theory of new materials are obvious. Our approach is to design and develop two-phase materials and functionalities at interfaces between the constituent phases in nanotech-based composites, that is nanocomposites. The nano-and composite technologies can realize superionic conduction by constructing the interfaces as 'ion highways'. Manipulation of the interphases of the nanocomposites can overcome SOFC challenges and thus enhance and improve material conductivity and FC performance at significantly lower temperatures (300-6001C).

Development of methanol-fueled low-temperature solid oxide fuel cells

“…These results indicate that the anode material of tri-phase oxides with lithiation is highly efficient for the application of SOFCs fueled by methanol [6]. Novel nanocomposite electrode materials are proposed for the catalytic enhancement of the anode [19]. After the fuel cell measurement, no carbon formation was observed on the anode surface, which agreed well with the thermodynamic calculations.…”

Breakthrough fuel cell technology using ceria-based multi-functional nanocomposites

“…The conventional SOFC using yttrium stabilized Zirconia (YSZ) reaches this conductivity at $1000°C. Designing and developing super oxygen ion conductors for advanced applications at low enough temperatures to be technically useful, especially for LT (<600°C) SOFCs, is a challenge for Material Science and Physics [87,88]. Oxygen ionic conduction through the structural vacancy mechanism has been known and dominated SOFC science and technology since the first SOFC was created [89].…”

An Electrolyte‐Free Fuel Cell Constructed from One Homogenous Layer with Mixed Conductivity

“…In our latest work on nanocomposites in low-temperature (300 ° C-600 ° C) SOFCs, [ 7 ] we have made substantial progress towards this goal. By using one homogenous layer of a mixture of ionic conductors (e.g., Gd 3 + or Sm 3 + doped ceria, GDC or SDC) and semiconductors, (e.g., LiNiZn-based oxides), we discovered that it was possible to realize a fuel-cell function of continuously converting H 2 for electricity generation (more details on the material are supplied in the Experimental Section).…”