A team of scientists, including current and former members of the ICN2 Novel Energy-Oriented Materials Group, has developed an innovative triple hybrid material that significantly improves the efficiency of energy storage devices. Their approach, explained in an article published in Nanomaterials, is to combine three components exhibiting different properties to create a highly effective electrode.
A strategic approach for creating materials with desired properties involves combining various components, each possessing unique characteristics. The resulting material is expected to exhibit the combined traits and potentially introduce novel features. Scientists are extensively investigating this hybrid methodology across numerous technological domains. Among them is energy storage, a field in which the pursuit of materials that offer both electroactivity and exceptional conductivity is pivotal for fabricating efficient electrodes.
A group of researchers from the ICN2 Novel Energy-Oriented Materials Group –led by Prof. Pedro Gómez-Romero—, the Universitat Politecnica de Valencia (UPV, Spain), and the Utrecht University (The Netherlands) has developed a triple hybrid material that enhances the performance of supercapacitors, a type of energy storage devices characterised by high power density. The innovative material combines polyoxometalates (POMs), silver nanoparticles (Ag0 NPs), and activated carbon (AC) to create an improved electrode for supercapacitors. This study was described in a paper recently published in Nanomaterials, with Dr Sara Goberna-Ferrón, a former postdoctoral researcher in Prof. Gómez-Romero’s group at the ICN2 and currently at UPV, as corresponding author.
Polyoxometalates (POMs) are clusters of (early transition) metals with exceptional electrochemical behaviour. They can undergo fast, reversible redox reactions and are very stable, making them promising candidates for energy storage applications. However, they suffer from lack of electronic conductivity and show high solubility. In order to be used as electrode materials, POMs need to be anchored on a substrate and combined with a highly conductive component. This is precisely what the authors of this study pursued.
The researchers incorporated POMs onto the surface of silver nanoparticles (Ag0 NPs) to harness the high electrical (and thermal) conductivity showcased by silver. In addition, the use of nanostructures increases the overall surface-to-volume ratio, thereby reducing the amount of metal required. The third component is activated carbon (AC), which has excellent textural properties and is therefore used as a matrix for supporting the POM-Ag0 NPs. The combination of POMs, Ag0 NPs, and AC results in a nanohybrid material that exhibits remarkable electroactivity.
The research team fabricated the AC/POM-Ag0 NPs through a green electrochemical method, optimizing the size and homogeneity of the silver nanoparticles by varying reactant concentrations and redox potentials. Extensive characterization using various techniques confirmed the successful attachment of POMs to the Ag0 NP surface.
When tested as a hybrid electrode in a symmetric supercapacitor configuration, the nanohybrid material demonstrated notably improved performance compared to bare AC electrodes. It exhibited a moderately higher specific capacitance, indicating its potential for enhancing energy storage in supercapacitors.
This work not only showcases the effectiveness of the triple hybrid material in boosting supercapacitor performance but also paves the way for future studies to explore even more advanced combinations of materials for energy storage applications.
Reference article:
Sara Goberna-Ferrón*, Laia Cots, Marta Perxés Perich, Jun-Jie Zhu and Pedro Gómez-Romero, Polyoxometalate-Stabilized Silver Nanoparticles and Hybrid Electrode Assembly Using Activated Carbon. Nanomaterials 2023, 13(15), 2241. DOI: 10.3390/nano13152241