Exploiting the giant electrocaloric effect

Lead Research Organisation: University of Cambridge
Department Name: Materials Science & Metallurgy

Abstract

This project has the capacity to deliver revolutionary technology for a wide range of refrigeration and/or power generation scenarios.Our discovery paper [AS Mischenko, Q Zhang, JF Scott, RW Whatmore & ND Mathur, Science 311 (2006) 1270] marks the rebirth of a field of research but it is only a materials development and we do not yet know whether any technology will actually result.The point of this grant application is to develop materials that function well near room temperature, and demonstrate refrigeration and electricity generation in devices. Moreover, this proposal contains a strong scientific component that will reveal new information about electrocaloric materials and the way they behave.The materials development is perfectly realistic because the electrocaloric effect is expected near any ferroelectric phase transition, and there are many suitable materials such as those we name explicitly. Moreover, the strategies we propose for improving properties of interest are well established.The device fabrication, which is relatively straightforward, is necessary since our promising simulation efforts [AS Mischenko & ND Mathur, GB Patent 2420662 (2006)] are no substitute for real data. Note that there are several aspects to device optimisation, e.g. film thickness and composition.

Publications

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Correia T (2011) PST thin films for electrocaloric coolers in Journal of Physics D: Applied Physics

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Crossley S (2016) Large electrocaloric effects in single-crystal ammonium sulfate. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

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Crossley S (2014) Finite-element optimisation of electrocaloric multilayer capacitors in Applied Physics Letters

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Defay E (2013) The electrocaloric efficiency of ceramic and polymer films. in Advanced materials (Deerfield Beach, Fla.)

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Fisher B (2010) Sliding charge-density waves in manganites in Nature Materials

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Kar-Narayan S (2014) Electrocaloric Materials

 
Description We showed that multilayer capacitors are the ideal devices for electrocaloric cooling. We investigated the cooling powers that they can develop in order to verify technological significance. And we introduced a new figure of merit to report the energy efficiency of electrocaloric materials: our "electrocaloric efficiency" shows that polymers slightly outperform ceramics, and will be useful in future for electrocaloric materials selection.



We also showed two new ways to measure electrically driven temperature change directly, and we showed giant electrocaloric strength in single-crystal barium titanate, i.e. very large thermal changes per unit applied electric field.
Exploitation Route The electrocaloric effect could form the basis of some future cooling technology.
Sectors Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Electronics,Energy

 
Description The work on multilayer capacitors has demonstrated the type of electrocaloric device that is required for applications of the electrocaloric effect. The thermal modelling allows cooling power to be predicted. Collaboration with the Japanese company Murata has led to devices for me to test, one published paper, and more papers to come.
Sector Electronics
Impact Types Cultural

 
Description CEA-LETI
Amount £25,000 (GBP)
Organisation CEA-Leti 
Sector Charity/Non Profit
Country France
Start  
 
Description CEA-LETI 
Organisation CEA-Leti
Country France 
Sector Charity/Non Profit 
PI Contribution We have supplied expertise to predict electrocaloric efficiency, and we have also performed experiments together.
Collaborator Contribution We have benefited from the infra-red camera and electronics expert at CEA-LETI.
Impact The electrocaloric efficiency of ceramic and polymer films Emmanuel Defay, Sam Crossley, Sohini Kar-Narayan, Xavier Moya and Neil D. Mathur Advanced Materials 25 (2013) 3337-3342 Direct electrocaloric measurements of a multilayer capacitor using scanning thermal microscopy and infra-red imaging S. Kar-Narayan, S. Crossley, X. Moya, V. Kovacova, J. Abergel, A. Bontempi, N. Baier, E. Defay, and N. D. Mathur Applied Physics Letters 102 (2013) 032903 pages 1-4 Too cool to work X. Moya, E. Defay, V. Heine and N. D. Mathur Nature Physics - commissioned Commentary
Start Year 2010
 
Description Murata 
Organisation Murata Manufacturing
Country Japan 
Sector Public 
PI Contribution We measure electrocaloric properties of samples supplied by Murata.
Collaborator Contribution Murata send us samples for testing
Impact None so far - the collaboration is new.
Start Year 2014