Beyond surface area

enhanced pseudocapacitive properties of cobalt layered double hydroxide through structural modifications

Anja Siher (Author), Ksenija Maver (Author), Uroš Luin (Author), Albin Pintar (Author), Iztok Arčon (Author), Andraž Mavrič (Author)

Abstract

Cobalt hydroxide and other first-row transition metal hydroxides have gained significant attention as pseudocapacitor materials due to their rapid and reversible redox processes. Their layered structures facilitate interactions between electrolyte anions and cobalt cation sites within the bulk of the material, enabling higher charge density and extending redox activity beyond the particle surface. By controlled precipitation under hydrothermal conditions, the structure and morphology of cobalt hydroxides can be optimized to enhance electrochemical performance. Challenging conventional assumptions, surface area alone is not the primary factor driving increased pseudocapacitive performance. The hexagonal hydrotalcite-like structure, characterized by lower skeletal density and larger basal plane spacing, outperforms the monoclinic cobalt carbonate hydroxide structure, achieving an order of magnitude higher capacitance. In situ X-ray absorption spectroscopy provides critical insights into the pseudocapacitive behavior, revealing enhanced accessibility of Co2+ sites for electrochemical oxidation. While monoclinic cobalt carbonate hydroxide exhibits minimal changes in the Co2+ oxidation state, indicative of surface-limited redox activity, the hydrotalcite-like cobalt hydroxides show substantial shifts in the Co K-edge position, highlighting oxidation of Co2+ sites throughout the bulk.

Keywords

pseudocapacitors;layered-double hydroxides;cobalt hydroxide;redox processes;in situ x-ray absorption spectroscopy;

Data

Language:	English
Year of publishing:	2025
Typology:	1.01 - Original Scientific Article
Organization:	UNG - University of Nova Gorica
UDC:	53
COBISS:	228947715
ISSN:	2468-0230
Views:	559
Downloads:	7
Average score:	0 (0 votes)
Metadata:

Other data

Secondary title:	Beyond surface area: enhanced pseudocapacitive properties of cobalt layered double hydroxide through structural modifications
Pages:	8 str.
Volume:	ǂVol. ǂ62
Issue:	ǂ[article no.] ǂ106174
Chronology:	2025
DOI:	10.1016/j.surfin.2025.106174
ID:	26057655