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SUMMARY:A rule that’s made to be broken? Reframing the Arrhenius law and
  the calculation of activation energies for ion transport in solid electro
 lytes. - Dr Vanessa Ward\, Durham University
DTSTART:20260225T143000Z
DTEND:20260225T153000Z
UID:TALK241081@talks.cam.ac.uk
CONTACT:Lisa Masters
DESCRIPTION:A broad variety of materials are currently the subject of rese
 arch for energy applications. For example\, in new battery technologies\, 
 a very topical issue and a key societal challenge [1]. Many different elec
 trolytes have been proposed for use in next-generation solid state batteri
 es\, with the potential to provide greener\, more efficient energy storage
 . A key stumbling block in proposed electrolytes is often low conductivity
 . Therefore\, when considering a new material\, the first step is to under
 stand ion transport. The Arrhenius law is ubiquitous in the physical scien
 ces. It describes how an observable property scales with temperature\, T\,
  as exp(±A/T) for a constant A\, interpreted as an activation energy. Oft
 en transport coefficients are well-described by an Arrhenius fit. However\
 , there are many exceptions\, making it difficult to extract an activation
  energy from macroscopic transport properties. One reason for non-Arrheniu
 s behaviour is correlated motion [2]. For example\, the diffusion of indiv
 idual ions depends upon the diffusion of neighbouring ions. Ions may also 
 become trapped due to local structure and undergo movement but in a back-a
 nd-forth motion that does not contribute to overall transport. Using metho
 ds developed for supercooled liquids [3]\, we identify ion ‘jumps’\, p
 articularly those that are productive for transport\, and correlated motio
 n. The method enables us to extract the true underlying activation energy 
 from diffusion data and recover the Arrhenius law. The methods can be demo
 nstrated for low-dimensional-networked Li-rich anti-perovskites\, potentia
 l solid electrolytes [4]. \nReferences\n[1] Faraday Insights – Solid-Sta
 te Batteries: The Technology of the 2030s but the Research Challenge of th
 e 2020s\, Issue 5: February 2020\n[2] NM Vargas-Barbosa and B Roling\, Che
 mElectroChem 7:367–385 (2020)\n[3] VK de Souza and DJ Wales\, J. Chem. P
 hys.\, 129:164507 (2008) \n[4] AC Coutinho Dutra et al\, Energy Adv. 2:653
 –666 (2023)
LOCATION:Unilever Lecture Theatre\, Yusuf Hamied Department of Chemistry
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