Fast electrochemical storage process in sputtered Nb₂O₅ porous thin films

Cassandra Arico (1) , Saliha Ouendi (1, 2) , Pierre-Louis Taberna (3) , Pascal Roussel (4) , Patrice Simon (3) , Christophe Lethien (1, 5, 6)

1 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
2 CMNF - IEMN - Centrale de Micro Nano Fabrication - IEMN
3 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
4 UCCS - Unité de Catalyse et Chimie du Solide - UMR 8181
5 CSAM - IEMN - Circuits Systèmes Applications des Micro-ondes - IEMN
6 RS2E - Réseau sur le stockage électrochimique de l'énergie

The formation of a thin film electrode exhibiting high capacity and high rate capabilities is challenging in the field of miniaturized electrochemical energy storage. Here, we present an elegant strategy to tune the morphology and the properties of sputtered porous Nb₂O₅ thin films deposited on Si-based substrates via the magnetron sputtering deposition technique. Kinetic analysis of the redox reactions is studied to qualify the charge storage process, where we observe a non-diffusion-controlled mechanism within the porous niobium pentoxide thin film. To improve the surface capacity of the Nb₂O₅ porous electrode, the thickness is progressively increased up to 0.94 μm, providing a surface capacity close to 60 μAh.cm^-2 at 1 mV.s^-1. The fabrication of high energy density miniaturized power sources based on the optimized T-Nb₂O₅ films could be achieved for Internet of Things applications requiring high rate capability.

Mots clés: Nb2O5; Sputtering; Thin film; Lithium intercalation; Fast kinetics

Domaines: Matériaux; Energie électrique; Micro et nanotechnologies/Microélectronique

Cassandra Arico, Saliha Ouendi, Pierre-Louis Taberna, Pascal Roussel, Patrice Simon, et al.. Fast electrochemical storage process in sputtered Nb₂O₅ porous thin films. ACS Nano, 2019, 13 (5), pp.5826-5832. ⟨10.1021/acsnano.9b01457⟩. ⟨hal-02263481⟩