Charge transfer kinetics at the solid-solid interface in porous electrodes

Interfacial charge transfer is widely assumed to obey the Butler-Volmer kinetics. For certain liquid-solid interfaces, the Marcus-Hush-Chidsey theory is more accurate and predictive, but it has not been applied to porous electrodes. Here we report a simple method to extract the charge transfer rates...

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Bibliographic Details
Main Authors: Bai, Peng (Contributor), Bazant, Martin Z. (Contributor)
Other Authors: Massachusetts Institute of Technology. Department of Chemical Engineering (Contributor), Massachusetts Institute of Technology. Department of Mathematics (Contributor)
Format: Article
Language:English
Published: Nature Publishing Group, 2014-10-29T18:49:04Z.
Subjects:
Online Access:Get fulltext
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100 1 0 |a Bai, Peng  |e author 
100 1 0 |a Massachusetts Institute of Technology. Department of Chemical Engineering  |e contributor 
100 1 0 |a Massachusetts Institute of Technology. Department of Mathematics  |e contributor 
100 1 0 |a Bazant, Martin Z.  |e contributor 
100 1 0 |a Bai, Peng  |e contributor 
700 1 0 |a Bazant, Martin Z.  |e author 
245 0 0 |a Charge transfer kinetics at the solid-solid interface in porous electrodes 
260 |b Nature Publishing Group,   |c 2014-10-29T18:49:04Z. 
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520 |a Interfacial charge transfer is widely assumed to obey the Butler-Volmer kinetics. For certain liquid-solid interfaces, the Marcus-Hush-Chidsey theory is more accurate and predictive, but it has not been applied to porous electrodes. Here we report a simple method to extract the charge transfer rates in carbon-coated LiFePO4 porous electrodes from chronoamperometry experiments, obtaining curved Tafel plots that contradict the Butler-Volmer equation but fit the Marcus-Hush-Chidsey prediction over a range of temperatures. The fitted reorganization energy matches the Born solvation energy for electron transfer from carbon to the iron redox site. The kinetics are thus limited by electron transfer at the solid-solid (carbon-LixFePO4) interface rather than by ion transfer at the liquid-solid interface, as previously assumed. The proposed experimental method generalizes Chidsey's method for phase-transforming particles and porous electrodes, and the results show the need to incorporate Marcus kinetics in modelling batteries and other electrochemical systems. 
546 |a en_US 
655 7 |a Article 
773 |t Nature Communications