Oxyanion doping strategies for Solid Oxide Fuel Cell Materials

Lead Research Organisation: University of Birmingham
Department Name: School of Chemistry

Abstract

The drive for increasing energy efficiency and reducing greenhouse gas emissions has garnered increasing support for the use of fuel cell technology, which offers the potential for applications ranging from transport to stationary power generation. A number of different fuel cell systems have been investigated, with the electrolyte being crucial in dictating the temperature of operation. In terms of high temperature systems (>500C), a ceramic electrolyte is employed, and such solid oxide fuel cells (SOFCs) offer many benefits in terms of fuel flexibility and efficiency. A key requirement for an SOFC is a good ionic (oxide ion or proton) conductor as the electrolyte, and this has driven considerable research into the development of new oxide ion and proton conducting systems, along with accompanying electrode materials. In terms of the electrode materials, typically perovskite-related transition metal containing systems are targeted for the cathode. Research in this area has shown that in addition to the bulk characteristics of the material, the microstructure of the electrode is vitally important in ensuring optimum performance. This has led to considerable research into the design of nano-scale electrode structures, utilising low temperature synthesis techniques and carbon-based pore-formers. However, a feature that has not been considered is the fact that these strategies are likely to introduce residual carbonate into the electrode. This feature has been mostly overlooked due to the assumption that C is too small to be accommodated in the crystal structure of the electrode material. However, this is not necessarily the case, and indeed research from the high temperature cuprate superconductor area has shown that the perovskite structure will accommodate carbonate and a range of other oxyanions (sulphate, phosphate, borate). There is therefore a clear need to investigate the carbonate content of low temperature synthesised SOFC electrode materials, and examine how this affects the performance. In addition there is the potential to develop new materials with improved properties through the incorporation of carbonate or other oxyanions, as shown by recent work from our group on phosphate-doped electrolyte materials. In this project therefore, the possibility of oxyanion doping into a range of SOFC electrode and electrolyte materials will be examined, starting with perovskite systems, and then extending to investigate fluorite materials. In the case of carbonate incorporation, this will be achieved through low temperature synthesis from organic precursors, while in the case of sulphate and phosphate, both low and high temperature synthesis strategies will be employed (phosphate in particular is more thermally stable, allowing higher temperature synthesis strategies).

Planned Impact

In terms of the four factors comprising economic impact: knowledge, people, economy, society, this research project will have the following substantial impact. Knowledge The research is aimed at a novel strategy for controlling the performance of solid oxide fuel cell materials, both electrolyte and electrode. The work offers an important new dimension for introducing ionic conductivity into electrode systems, which along with their electronic conductivity, is key to their optimum performance. In addition, in the current SOFC literature there is a growing emphasis on low temperature routes, use of carbon pore-formers, for the production of electrode architectures raising the prospect that such electrodes contain carbonate. Therefore this project will highlight what effect this carbonate has on the performance. People The PhD student and PDRA will gain experience in a number of techniques, leading to two highly qualified researchers for the UK R&D effort in the commercially and politically important area of energy materials. They will have opportunities to present their work at collaborative departments and international conferences, thus aiding in their interpersonal skills, and further promoting the scientific knowledge from the project. In addition, they will be actively involved in public engagement events, improving their skills at interacting with a non-scientific audience. Economy This project will result in the development of a number of new materials, with potential applications as electrolytes or electrodes in solid state electrochemical devices. Examples of such devices include solid oxide fuel cells, electrolysers, hydrogen sensors and separation membranes. The work therefore has significant potential for IP generation. The work will be of interest to industrial R & D labs working in the area of solid state ionics, offering wealth creation at the Universities (through licensing of the IP) and the companies (through exploiting the IP). Society Fuel cells offer tremendous potential for improving energy efficiency and reducing greenhouse gas emissions, with potential applications ranging from transport to stationary power generation. The development of new materials, with improved properties, for use in such applications will result in these systems coming to commercial fruition sooner. As well as leading to wealth generation, as highlighted above, this will help to reduce greenhouse gas emissions, fuel usage, and so has substantial benefits for the environment and hence society in general. Fuel cell devices are also part of the Government's policy towards a low carbon economy, and hence the work is of relevance to the implementation of that policy. The public engagement work performed by the research consortium members will help to promote science to society, helping to highlight the benefits to society of this science, and encourage younger people into scientific study. The research team have demonstrated strong output in this respect from previous research, and has a number of contacts with science centres/museums, such as the Thinktank (Birmingham), where they have held previous demonstrations of fuel cell technology.

Publications

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Hancock CA (2015) Oxyanions in perovskites: from superconductors to solid oxide fuel cells. in Dalton transactions (Cambridge, England : 2003)

 
Description 1. Demonstration of enhanced conductivities in fuel cell electrolytes through oxyanion doping

2. Demonstration of improved performance in fuel cell electrode materials through oxyanion doping
Exploitation Route Talks/displays on fuel cells Potential applications in solid oxide fuel cells, and oxygen/hydrogen separation membranes
Sectors Energy

 
Description Our findings are rapidly gaining notice. There were some substantial advances noted, in particular related to Si doping. Si is traditionally viewed as a poison for fuel cell materials, whereas we have shown that it can be incorporated into perovskite materials, potentially improving properties. This unusual observation is persuading others to reevaluate their work on fuel cell electrode materials. In particular it is helping to explain why surfaces of perovskite electrodes tend to have less impurities than corresponding fluorite systems. The materials developed are gaining interest for other applications, including low temperature fuel cells and thermoelectric applications.
First Year Of Impact 2013
Sector Energy,Environment
Impact Types Societal

 
Description Exploring carbonate incorporation in "oxide" materials: the hidden dopant
Amount £84,760 (GBP)
Funding ID RPG-2017-011 
Organisation The Leverhulme Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 07/2017 
End 10/2020
 
Description Monitoring of charge diffusion in solids by null-point ellipsometry 
Organisation Weizmann Institute of Science
Country Israel 
Sector Academic/University 
PI Contribution A collaboration has been set up with I. Lubomirsky, Dept. Materials and Interfaces, Weizmann Institute of Science to investigate in more detail space charge layers in fuel cell electrolytes. The collaboration arose following a meeting after Dr. Slater presented a talk on the initial results of this EPSRC project at a conference in the US.
Start Year 2012
 
Description 'Chemistry at Work' at the Black Country Museum 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Chemistry at work event at the black country museum. Talk and demonstrations on energy technologies including fuel cells
Year(s) Of Engagement Activity 2017
 
Description Christmas Schools Lecture (16th Dec 2019) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Christmas lecture covering the chemistry of energy production.
Year(s) Of Engagement Activity 2019
 
Description Development of new Li ion battery and Fuel Cell Materials 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Participants in your research or patient groups
Results and Impact Presentation on work on garnet type li ion conductors, and oxyanion doped fuel cell materials.

Talk at the Weizmann Institute, Israel
Year(s) Of Engagement Activity 2013
 
Description Energy Materials Conference (Bath) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Presentation given on oxyanion doping in perovskites and other systems, covering work performed during the grant and follow up work since
Year(s) Of Engagement Activity 2016
 
Description Exploring Alternative "Realities" in Solid State Chemistry: Keynote Talk at Science Matters Conference, Loughborough Uni 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Talk highlighting current research on fuel cells and batteries, emphasising the importance of investigating new avenues of research
Year(s) Of Engagement Activity 2018
 
Description Fuel Cell Practical 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Fuel cell workshop at Wodensborough Ormiston Academy
Year(s) Of Engagement Activity 2017
 
Description Fuel Cell and Battery outreach activity for students with special educational needs 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact this was a day long event with Woodlands school which caters for pupils for special educational needs specifically social, emotional and mental health needs. Sessions on Fuel Cells and Batteries were run for a group of Year 11 (Final year GCSE) students.

The event included:
· Introducing our area of research (Fuel Cells and Battery materials)
· Discussing development of batteries e.g comparing mobile phones batteries from the past and present
· Helping students put together rudimentary batteries and fuel cells to demonstrate their principals
· Getting the group to think about the possible drawbacks of both technologies.
· Connecting those drawbacks discussed with current research conducted at Birmingham

The events was very enjoyable and the group seemed very engaged with the topic and they seem to really enjoy the practical experiments chosen for the session. The activity was designed to underpin the basic principles the students are taught inside the classroom for their science GCSE.
Year(s) Of Engagement Activity 2019
 
Description Fuel Cell demonstration 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? Yes
Primary Audience Schools
Results and Impact Fuel cell demonstration stand at the British Science Festival launch event, Bham library.
Year(s) Of Engagement Activity 2014
 
Description Introduction to Fuel Cells 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Date: 30/10/17
School: Lordswood Girls' School
Approximately 20 students.

Activity: 2 hour session which started with a general introduction to energy as a topic. Discussed the benefits of green technologies such as fuel cells. Students then took part in an electrolysis experiment where the students generated hydrogen to then powder an LED. Full method here (half way down the page):

https://chembam.com/experiments/fuel-cells-for-future-energy/

After the experiment, we discussed with the students what were the pros and cons of the set up that they had just assembled and then briefly talked about everyday life working as a researcher. As there was still time in the session, we asked the students to have a go at the alginate experiment.
Year(s) Of Engagement Activity 2017
URL https://chembam.com/experiments/fuel-cells-for-future-energy/
 
Description Invited talk at international conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Prof. Slater gave an invited talk at MS&T14 (pittsburgh, UK)

Results disseminated to other research groups
Year(s) Of Engagement Activity 2014
 
Description Lecture and demonstrations for RSC Top of the bench competition (Jan 18, 2020) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Using resources developed to explain Li ion batteries and fuel cells, a lecture was given on the chemistry of energy production and storage
Year(s) Of Engagement Activity 2020
 
Description Meet the Scientist 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? Yes
Primary Audience Public/other audiences
Results and Impact Produced and manned a stand for the Meet the Scietist week at the Thinktank museum, Birmingham.

A wide ranging display was produced to highlight fuel cells and research from Birmingham on grants EPSRC: EP/I003932/1, EPSRC: EP/G009929/2 and EPSRC PPE grant EP/F065663/1
Year(s) Of Engagement Activity 2011
 
Description New Battery and fuel cell materials 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact The talk raised a lot of interest, with a number of questions and subsequent discussions

The undergraduate students who attended requested (and were given) copies of my slides
Year(s) Of Engagement Activity 2015
 
Description Radio broadcast 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact two hour phone in session on UnityFM birmingham (20000 listeners) covering the periodic table and clean energy (fuel cells, batteries)
Year(s) Of Engagement Activity 2019
 
Description Research talk at GE3C meeting, Bilbao, Spain 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Prof Slater gave a plenary talk at GE3C Bilbao

A participant has applied for funding to visit Prof Slaters lab for 3 months
Year(s) Of Engagement Activity 2014
 
Description STEM Ambassador Networking Meeting 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? Yes
Primary Audience Schools
Results and Impact We were invited to do a display on fuel cells to teachers/stem ambassadors.

We presented a display to promote fuel cells and the STEM ambassador scheme
Year(s) Of Engagement Activity 2011
 
Description School's lecture on energy 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact school's christmas lecture covering energy, including fuel cells and batteries
Year(s) Of Engagement Activity 2018
 
Description Talk for postgraduate conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Presentation "Exploring Alternative "realities" in Solid State Chemistry" to PG/UG audience highlighting the importance of considering alternative approaches in research
Year(s) Of Engagement Activity 2018
 
Description The flexibility of perovskite and related structures to accommodate oxyanion dopants, and the consequent influence on the structure and conductivity 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact talk given at the European Conference on Solid State Chemistry in Glasgow
Year(s) Of Engagement Activity 2017
 
Description battery workshop for primary school children 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Visit to Valley School to deliver two back to back sessions to 90 primary pupils (180 students in total). Following an intro, we did some short whole group activities and then each PhD ambassador took on a group of 30 students. They helped them to make and understand the potato batteries they made. The pupils enjoyed the sessions and there were lots of great questions which showed how well they understood the group intro.
We related batteries back to work of the our EPSRC projects on batteries and fuel cells. We also discussed more generally with students "what a scientist" looks like - a few were shocked that two of our scientist don't wear spectacles, which goes to show how important it is for them to meet real scientists and break down some of these ideas.

Teachers feedback indicated that we increased the students chemistry knowledge, linked the work to the curriculum and they are likely to organise a visit again. Their comments were "the kids loved it" and "the kids really enjoyed it".
Year(s) Of Engagement Activity 2019
 
Description hydrogen and fuel cell workshop 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Primary Audience Schools
Results and Impact School workshop on hydrogen and fuel cells.

Visit to the University of Birmingham by Kingsbury School and Sports College for a workshop on hydrogen and fuel cells
Year(s) Of Engagement Activity 2012
 
Description hydrogen and fuel cells workshop 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Primary Audience Schools
Results and Impact workshop on h2 and fuel cells held for 26 local schoolchildren.

workshop on H2 and fuel cells held at the Univ. of Birmingham
Year(s) Of Engagement Activity 2013
 
Description workshop on batteries and fuel cells 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact workshop for several groups of schoolchildren on batteries and fuel cells
Year(s) Of Engagement Activity 2019
 
Description workshops on batteries and fuel cells aimed at low ability school children 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact We ran workshops for low-ability Yr 10 students from Balaam Wood School.
This included:
• Introducing Li ion batteries and fuel cells
• Discussing batteries use with small groups e.g. use in everyday life
• Helping students doing a practical on batteries/fuel cells
• Demonstrating a simple fuel cell/battery in action
• Showing students real life fuel cell/battery
Year(s) Of Engagement Activity 2018