Investigation On Electrode Material Electrochemical Properties Of High Temperature SOEC

Solid oxide cells(SOCs)are the future of hydrogen and electricity production as the world needs clean energy sources with no carbon emissions.They offer high efficiency at high-temperature operations(600℃ to 800℃)and fuel flexibility.SOCs have two kinds according to the operation mode:solid oxide fuel cells(SOFC)which generate electricity and solid oxide electrolysis cell(SOEC)which produce hydrogen.Other renewable resources,such as wind and solar power,can be coupled with solid oxide cells for a sustainable source of energy.A lot of research is going on in solid oxide cells:(a)to lower the operating temperature for avoiding material degradation issue,(b)new cheap materials that are also easy to manufacture,(c)commercialization of fuel cells for different industries,and(d)hydrogen economy and storage issues.Hydrogen and synthesis gas are promising sources of clean energy in the future.High-temperature electrolysis of steam/CO2 mixtures using SOEC is an efficient hydrogen or Syngas production method.In this study,SOC has been discussed in detail from the following aspects:(a)Introduction in general,(b)Challenges for Commercialization of SOCs,and(c)Recent Advances in SOC materials.The high quality and efficiency of H2O and CO2 co-electrolysis via SOECs have been validated.However,there are still significant challenges to overcome for the commercialization of this technology.In order to fully adopt this technology,materials degradation issues,operating temperature,triple-phase boundary,cell fabrication,and integration with other renewable resources are all crucial factors.This study discusses the research challenge related to these crucial factors in detail.Mixed ionic and electronic conductors are very popular as electrode materials in solid oxide cells.The electrochemical kinetic properties of these materials are of great importance for improving the electrochemical efficiency of the cells,but they can’t be measured directly through experiments.The electrical conductivity relaxation technique plays an important role to determine surface exchange and bulk diffusion coefficients of MIECs,because of its reduced costs and simplified experiments.This study builds up a general and accurate method to determine the k and D from electrical conductivity relaxation measurement for MIECs.A new model is established to describe the coupled multi-physical processes involved in the real experiment system.The direct numerical approach is then logically embedded into the inverse algorithm to find out the values of k and D.A comparison between the new method and traditional method is carried out,and the results show the new model established is more accurate and compatible with more complex conductivity curves.