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Abstract Long duration energy storage (LDES) is an economically attractive approach to accelerating clean renewable energy deployment. The newly emerged solid oxide iron–air battery (SOIAB) is intrinsically suited for LDES applications due to its excellent low‐rate performance (high‐capacity with high efficiency) and use of low‐cost and sustainable materials. However, rechargeability and durability of SOIAB are critically limited by the slow kinetics in iron/iron‐oxide redox couples. Here the use of combined proton‐conducting BaZr0.4Ce0.4Y0.1Yb0.1O3(BZC4YYb) and reduction‐promoting catalyst Ir to address the kinetic issues, is reported. It is shown that, benefiting from the facilitated H+diffusion and boosted FeOx‐reduction kinetics, the battery operated under 550 °C, 50% Fe‐utilization and 0.2 C, exhibits a discharge specific energy density of 601.9 Wh kg–1‐Fe with a round‐trip efficiency (RTE) of 82.9% for 250 h of a cycle duration of 2.5 h. Under 500 °C, 50% Fe‐utilization and 0.2 C, the same battery exhibits 520 Wh kg–1‐Fe discharge energy density with an RTE of 61.8% for 500 h. This level of energy storage performance promises that SOIAB is a strong candidate for LDES applications.
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A Kinetic Study on H 2 Reduction of Fe 3 O 4 for Long-Duration Energy-Storage-Compatible Solid Oxide Iron Air Batteries
Long duration energy storage (LDES) is economically attractive to accelerate widespread renewable energy deployment. But none of the existing energy storage technologies can meet LDES cost requirements. The newly emerged solid oxide iron air battery (SOIAB) with energy-dense solid Fe as an energy storage material is a competitive LDES-suitable technology compared to conventional counterparts. However, the performance of SOIAB is critically limited by the kinetics of Fe3O4reduction (equivalent to charging process) and the understanding of this kinetic bottleneck is significantly lacking in the literature. Here, we report a systematic kinetic study of Fe3O4-to-Fe reduction in H2/H2O environment, particularly the effect of catalyst (iridium) and supporting oxides (ZrO2and BaZr0.4Ce0.4Y0.1Yb0.1O3). With in situ created Fe3O4, the degree of reduction is measured by the change of H2O and H2concentrations in the effluent using a mass spectrometer, from which the kinetic rate constant is extracted as a function of inlet H2concentration and temperature. We find that kinetics can be nicely described by Johson-Mehl-Avrami (JMA) model. We also discuss the stepwise reduction mechanisms and activation energy for the reduction process.
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- Award ID(s):
- 1801284
- PAR ID:
- 10468369
- Publisher / Repository:
- The Electrochemical Society
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 170
- Issue:
- 10
- ISSN:
- 0013-4651
- Format(s):
- Medium: X Size: Article No. 104504
- Size(s):
- Article No. 104504
- Sponsoring Org:
- National Science Foundation
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