Fe₂O₃ powder modified with Ce_0.6Mn_0.3Fe_0.1O₂ and Cr₂O₃ prepared by spray pyrolysis method for rechargeable Fe–air cell

Abstract

Highly porous and uniform sphere shape Fe powder with a nano-porous structure can be prepared successfully with a spray pyrolysis method and applied for solid oxide Fe-air rechargeable battery, which is consisted of solid oxide reversible cells using an H 2 O/H 2 redox mediator. The prepared Fe powder modified with both Cr 2 O 3 and Ce 0.6 Mn 0.3 Fe 0.1 O 2 shows a high redox reaction rate as well as cycle stability by uniform distribution. A discharge capacity of 1100 mAh⋅g -Fe −1 with almost 100% coulombic efficiency was achieved at initial cycles and that larger than 800 mAh⋅g -Fe −1 was sustained over 20 cycles at 873 K. After the reduction of Fe powder with H 2 flow so-called chemical charge, a discharge capacity of 900 mAh⋅g -Fe −1 was recovered and stably sustained for the following 20 cycles (40 total cycles), and discharge capacity may be sustained further longer cycles at 823 K. The round-trip efficiency for charge and discharge was about 90%, which can be assigned to the high reversibility of Fe redox with nano-porous structure prepared by spray pyrolysis method.

Nanoporous oxide electrodes for energy conversion and storage devices

“…Spray pyrolysis is another adaptable synthesis process that is commonly used to produce nanoporous oxides ( e.g. , aluminum oxide, 170 iron oxide, 171–173 tin oxide, 174,175 titanium oxide, 176 ruthenium oxide, 177 vanadium oxide, 178 copper-bismuth oxide, 179 cerium oxide 180 ) based on thermal degradation of a liquid sample. In typical spray pyrolysis shown in Fig.…”