Copper Electroactivity in Prussian Blue-Based Cathode Disclosed by Operando XAS

Angelo Mullaliu (1) , Giuliana Aquilanti (2) , Paolo Conti (3) , Jasper Plaisier (2) , Marcus Fehse (4) , Lorenzo Stievano (4, 5) , Marco Giorgetti (1)

1 UNIBO - Alma Mater Studiorum Università di Bologna = University of Bologna
2 Elettra Sincrotrone Trieste
3 UNICAM - Università degli Studi di Camerino = University of Camerino
4 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
5 RS2E - Réseau sur le stockage électrochimique de l'énergie

The electronic and structural evolution of copper hexacyanoferrate (CuHCF) cathode material was studied by operando X-ray absorption spectroscopy (XAS) simultaneously at both Fe and Cu K edges during a full galvanostatic cycle. The full set of XAS data collected during the electrochemical process was analyzed by a combined chemometric approach using the multicurve resolution analysis with the alternate least squares algorithm. Using this joint approach and by applying a simultaneous multiple-edge fitting procedure, it was possible to clarify the participation of both copper and iron centers to the redox processes and to analyze their local environment. The structural modifications occurring in CuHCF along with the redox processes are entirely reversible, with the steady multiplicity of Fe–C–N–Cu linear chains evidencing the structural stability of the material during cycling.

Domaines: Matériaux

Angelo Mullaliu, Giuliana Aquilanti, Paolo Conti, Jasper Plaisier, Marcus Fehse, et al.. Copper Electroactivity in Prussian Blue-Based Cathode Disclosed by Operando XAS. Journal of Physical Chemistry C, 2018, 122 (28), pp.15868 - 15877. ⟨10.1021/acs.jpcc.8b03429⟩. ⟨hal-01845342⟩