LiNiFe-based layered structure oxide and composite for advanced single layer fuel cells

A layered structure metal oxide, LiNi0.1Fe0.9O2-delta (LNF), is explored for the advanced single layer fuel cells (SLFCs). The temperature dependent impedance profiles and concentration cells (hydrogen concentration, oxygen concentration, and H-2/air atmospheres) tests prove LNF to be an intrinsically electronic conductor in air while mixed electronic and proton conductor in H-2/air environment. SLFCs constructed by pure LNF materials show significant short circuiting reflected by a low device OCV and power output (175 mW cm(-2) at 500 degrees C) due to high intrinsic electronic conduction. The power output is improved up to 640 and 760 mW cm(-2), respectively at 500 and 550 degrees C by compositing LNF with ion conducting material, e.g., samarium doped ceria (SDC), to balance the electronic and ionic conductivity; both reached at 0.1 S cm(-1) level. Such an SLFC gives super-performance and simplicity over the conventional 3-layer (anode, electrolyte and cathode) FCs, suggesting strong scientific and commercial impacts. (C) 2016 Elsevier B.V. All rights reserved.