Layered Vanadium Phosphates as Electrodes for Electrochemical Capacitors Part II: The Case of VOPO 4 •CTAB and K 0.5 VOPO 4 •1.5H 2 O

Jorge Alexis Zúñiga Martínez (1) , Sara Elena González Náñez (1) , Etienne Le Calvez (2, 3) , Raúl Lucio Porto (1) , Iván Eleazar Moreno Cortez (1) , Thierry Brousse (2, 3) , Luis Alberto López Pavón (1)

1 UANL - Universidad Autonoma de Nuevo Leon [Mexique]
2 IMN - Institut des Matériaux Jean Rouxel
3 RS2E - Réseau sur le stockage électrochimique de l'énergie

In the present work two layered vanadium phosphates were prepared, VOPO4 • CTAB and K0.5VOPO4 • 1.5H2O as electrode materials for electrochemical capacitors. These materials contain different molecular species in their interlayer space leading to an electrochemical behavior that drastically differs from the crystalline phase VOPO4 • 2H2O, with water molecules in the interlayer space. In the case of VOPO4 • CTAB, it was found that CTAB molecules block the pathway of electrolyte ions into the crystalline structure avoiding an intercalation/deintercalation process. In the case of K0.5VOPO4• 1.5H2O, the K+ ions from the crystalline structure hinder the intercalation/deintercalation process leading around 73 and 71 percent of the charge arise from a capacitive process in 3 M LiOH and 3 M KOH, respectively.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Jorge Alexis Zúñiga Martínez, Sara Elena González Náñez, Etienne Le Calvez, Raúl Lucio Porto, Iván Eleazar Moreno Cortez, et al.. Layered Vanadium Phosphates as Electrodes for Electrochemical Capacitors Part II: The Case of VOPO 4 •CTAB and K 0.5 VOPO 4 •1.5H 2 O. Journal of The Electrochemical Society, 2021, 168 (9), pp.090520. ⟨10.1149/1945-7111/ac23a0⟩. ⟨hal-03355965⟩