Rethinking Pseudocapacitance: A Way to Harness Charge Storage of Crystalline RuO2

Ankita Jadon (1) , Sagar Prabhudev (2) , Gaëtan Buvat (2) , Sai Gourang Patnaik (3) , Mehdi Djafari-Rouhani (1) , Alain Estève (1) , Daniel Guay (2) , David Pech (3)

1 LAAS-NEO - Équipe Nano-ingénierie et intégration des oxydes métalliques et de leurs interfaces
2 EMT-INRS - Énergie Matériaux Télécommunications - INRS
3 LAAS-ISGE - Équipe Intégration de Systèmes de Gestion de l'Énergie

With its huge pseudocapacitance and excellent stability, ruthenium dioxide (RuO2) is considered to be one of the best electrode materials for supercapacitors. However, such properties are only obtained with hydrous RuO2 in an amorphous phase, limiting the range of possible deposition techniques. Herein we report a detailed understanding of reactions of protons (H+) occurring in crystalline RuO2 with regard to its orientation using density functional theory. In particular, we show that migration pathways are energetically favorable along the [001] direction, leading to a deeper H+ penetration within the bulk of the active material and a much higher charge storage ability.

Mots clés: hydrogen diffusion; supercapacitor; ruthenium dioxide; cathodic polarization; charge storage; DFT

Domaines: Matériaux; Matériaux; Energie électrique; Physique Numérique [physics.comp-ph]; Chimie théorique et/ou physique

Ankita Jadon, Sagar Prabhudev, Gaëtan Buvat, Sai Gourang Patnaik, Mehdi Djafari-Rouhani, et al.. Rethinking Pseudocapacitance: A Way to Harness Charge Storage of Crystalline RuO2. ACS Applied Energy Materials, 2020, 3 (5), pp.4144-4148. ⟨10.1021/acsaem.0c00476⟩. ⟨hal-02600888⟩