Mauro Pasta
Associate Professor of Materials
+44 1865 283324
My research interests lie in electrochemical energy storage and conversion, with an emphasis on:
1) Energy storage: Li and Na-ion batteries, grid-scale energy storage.
2) Energy conversion: power from salinity gradients (blue energy), seawater desalination and delithiation.
3) Electrocatalysis: organic molecules electroxidation, ORR and HER reactions, carbon dioxide sequestration and electroreduction.
Research Group website https://www.pastagroup.org
New Postgraduate Research Projects Available
Selected Publications
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Electrochemo-Mechanical Properties of Red Phosphorus Anodes in Lithium, Sodium, and Potassium Ion Batteries
December 2020|Journal article|MATTER -
Outlook on K-Ion Batteries
October 2020|Journal article|Chem -
Paving the Way toward Highly Efficient, High-Energy Potassium-Ion Batteries with Ionic Liquid Electrolytes
September 2020|Journal article|Chemistry of Materials -
2020 roadmap on solid-state batteries
August 2020|Journal article|Journal of Physics: Energy -
Filling vacancies in a Prussian blue analogue using mechanochemical post-synthetic modification.
July 2020|Journal article|Chem Commun (Camb)Mechanochemical grinding of polycrystalline powders of the Prussian blue analogue (PBA) Mn[Co(CN)6]2/3□1/3·xH2O and K3Co(CN)6 consumes the latter and chemically modifies the former. A combination of inductively-coupled plasma and X-ray powder diffraction measurements suggests the hexacyanometallate vacancy fraction in this modified PBA is reduced by approximately one third under the specific conditions we explore. We infer the mechanochemically-driven incorporation of [Co(CN)6]3- ions onto the initially-vacant sites, coupled with intercalation of charge-balancing K+ ions within the PBA framework cavities. Our results offer a new methodology for the synthesis of low-vacancy PBAs. -
Understanding the conversion mechanism and performance of monodisperse FeF2 nanocrystal cathodes.
June 2020|Journal article|Nature materialsThe application of transition metal fluorides as energy-dense cathode materials for lithium ion batteries has been hindered by inadequate understanding of their electrochemical capabilities and limitations. Here, we present an ideal system for mechanistic study through the colloidal synthesis of single-crystalline, monodisperse iron(II) fluoride nanorods. Near theoretical capacity (570 mA h g<sup>-1</sup>) and extraordinary cycling stability (>90% capacity retention after 50 cycles at C/20) is achieved solely through the use of an ionic liquid electrolyte (1 m LiFSI/Pyr<sub>1,3</sub>FSI), which forms a stable solid electrolyte interphase and prevents the fusing of particles. This stability extends over 200 cycles at much higher rates (C/2) and temperatures (50 °C). High-resolution analytical transmission electron microscopy reveals intricate morphological features, lattice orientation relationships and oxidation state changes that comprehensively describe the conversion mechanism. Phase evolution, diffusion kinetics and cell failure are critically influenced by surface-specific reactions. The reversibility of the conversion reaction is governed by topotactic cation diffusion through an invariant lattice of fluoride anions and the nucleation of metallic particles on semicoherent interfaces. This new understanding is used to showcase the inherently high discharge rate capability of FeF<sub>2</sub>. -
Quantifying the Search for Solid Li-Ion Electrolyte Materials by Anion: A Data-Driven Perspective
April 2020|Journal article|JOURNAL OF PHYSICAL CHEMISTRY C -
Observation of Interfacial Degradation of Li6PS5Cl against Lithium Metal and LiCoO2 via In Situ Electrochemical Raman Microscopy
March 2020|Journal article|BATTERIES & SUPERCAPSelectrode-solid electrolyte interface, electrochemistry, in situ Raman microscopy, interfaces, solid-state batteries -
Single-Step Chemical Vapor Deposition Growth of Platinum Nanocrystal: Monolayer MoS
2 Dendrite Hybrid Materials for Efficient ElectrocatalysisJanuary 2020|Journal article|Chemistry of MaterialsCopyright © 2020 American Chemical Society. Two-dimensional (2D) molybdenum disulfide (MoS2) has excellent electrocatalytic behavior for the hydrogen evolution reaction (HER), where the catalysis of 2H phase originates from its edges, defects, and strains. Most synthetic methods to activate the electrochemically inert basal planes with catalytic active metals are completed by sequential steps. However, this is extremely time-consuming and lacks production scalability. Herein, we develop a one-step strategy to achieve efficient electrocatalyst of Pt:MoS2 hybrid utilizing atmospheric pressure chemical vapor deposition synthesis on a conductive glassy carbon (GC) plate that can be directly employed as the working electrode in the HER. The monolayer thickness ensures decreased interlayer electron hopping and increased efficiency of the charge transfer from the electrode. We tune the domain morphology by controlling the precursor flux to enter kinetic or thermodynamic growth regime, delivering dendritic or triangular shape. The materials chemistry undertaken provides fundamental insights into the instability of Pt as metal substitutional dopants in the MoS2 lattice, and instead the stable configuration observed is with Pt as highly dispersed small nanocrystals and single atoms bound to the MoS2 surface. The Pt functionalization at a reduced loading level modulates the favorable HER pathway and triggers synergies in the cocatalyst, which exhibits an onset potential of 48 mV, a Tafel slope of 46 mV dec-1, and an exchange current density of 110 μA cm-2. The enriched edges and defects of dendrite endow it superiority to the triangle, with regard to the density of catalytic sites and synergistic effects along with electrical resistance. These underpin the positive role of a large dendritic MoS2 monolayer as a Pt scaffold in water electrolysis. -
Increasing the electrochemical activity of basal plane sites in porous 3D edge rich MoS
2 thin films for the hydrogen evolution reactionSeptember 2019|Journal article|Materials Today Energy© 2019 Elsevier Ltd Molybdenum disulfide (MoS2)has been extensively utilized as an electrocatalyst for the hydrogen evolution reaction (HER)with edges as the primary active catalytic sites. Previous work on edge-rich MoS2 nanoplatelet 3D porous films (3D-ER-MoS2)shows they are promising catalysts, yet have basal planes that are inactive. Here we demonstrate how hydrogen annealing and oxygen plasma etching of 3D-ER-MoS2 generates defects and increases active site density within the basal plane, leading to dramatic improvements in HER catalytic activity. We also explore the critical processing parameters for electrocatalytic enhancement. Significantly enriched edge density was revealed for both routes. O2 plasma treatment was more effective in increasing the number of edges by creating micro-cracks and local surface damage on the basal planes as well as structuring saw-toothed edges; H2 etching mainly introduced irregular shaped basal surface nanopores and strips. By controlling processing parameters, optimum surface area/active sites density enhancement can be achieved, together with the robust 3D porous architecture and superaerophobic surface. The defect-rich MoS2 catalysts exhibit excellent HER activity: 700 °C – H2 – MoS2 shows Tafel slope of 94 mV/dec and low onset overpotential of 193 mV; 15 min – O2 – MoS2 performs amongst the best with excellent exchange current density of 57 μA/cmgeo−2. Our defect engineered 3D-ER MoS2 exhibits jgeo (η = 0.5 mV)of 6-fold and 38-fold compared to monolayer MoS2 subject to similar process, for O2 plasma and H2 etching approaches respectively. Our study demonstrates an effective way to realize high performance Pt-free electrocatalysts for hydrogen generation by dual enhancement via edge enrichment and basal surface activation.