Investigation of Ba 0.5 Sr 0.5 Co x Fe 1-x O 3-δ as a pseudocapacitive electrode material with high volumetric capacitance

Pierre Lannelongue (1, 2) , Steven Le Vot (1, 2) , Olivier Fontaine (1, 2) , Moulay Tahar Sougrati (1, 2) , Olivier Crosnier (3, 2) , Thierry Brousse (3, 2) , Frédéric Favier (1, 2)

1 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 IMN - Institut des Matériaux Jean Rouxel

Ba0.5Sr0.5CoxFe1-xO3-d phases, with 0.75 < x < 0.90, so-called BSCFs, were investigated as pseudocapacitive electrode materials. These polycationic oxide phases were prepared by a modified glycine-nitrate process and show the same perovskite structural arrangement and similar morphological characteristics in the whole series. The electrochemical performance was evaluated in aqueous electrolytes at room temperature. BSCF powders showed promising pseudocapacitive behavior as electrode materials with high volumetric capacitances which depend on the Co/Fe ratio. A volumetric capacitance of 500 F cm-3 , i.e. five times higher than that of a standard activated carbon electrode, was measured in 5.0 M LiNO3 for the electrode based on Ba0.5Sr0.5Co0.8Fe0.2O3-d material composition (x = 0.80). The electrode also exhibited moderate self-discharge and 90% of capacitance retention over 2000 cycles. The charge storage mechanism seems to be dependent upon the nature of the ions in the electrolyte and on the Co/Fe ratio.

Mots clés: High density polycationic oxides; Pseudocapacitive electrode material; Fe/Co ratio; Neutral aqueous electrolyte; High volumetric capacitance

Domaines: Chimie

Pierre Lannelongue, Steven Le Vot, Olivier Fontaine, Moulay Tahar Sougrati, Olivier Crosnier, et al.. Investigation of Ba 0.5 Sr 0.5 Co x Fe 1-x O 3-δ as a pseudocapacitive electrode material with high volumetric capacitance. Electrochimica Acta, 2018, 271, pp.677 - 684. ⟨10.1016/j.electacta.2018.03.173⟩. ⟨hal-01785106⟩