bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Discovery of New Capacity Fade Mechanism in Lixsn Batteries with Derivativeoperando (dOp) NMR Spectroscopy
Authors: Grandinetti Philip John , Lorie Lopez Jose , Co Anne C. 
Published: November 2022

Tin, silicon and other intermetallic forming electrodes have large volumetric lithium capacities—nearly 10 times that of graphite. Such a high capacity combined with their low cost make intermetallics promising materials for the next generation of rechargeable batteries. Unfortunately, severe capacity fade remains the greatest obstacle in their commercial use. For example, in 2005 Sony introduced their NEXELION battery technology using nanostructured SnCo electrodes but eventually had to pull these batteries from the market due to substantial capacity loss with cycling. While a major reason for capacity fade in these electrodes is thought to be cracking from large volume changes during transitions between intermetallic phases, little evidence for cracking in nanostructured electrodes has been found; and the mechanism for capacity fade in nanostructured intermetallic electrodes has remained a mystery.
Using derivative operando (dOp) 7Li NMR we have discovered a mechanism for capacity fade in LixSn nanoparticle electrodes that may solve this mystery. In short, the capacity fade in nanoparticle electrodes is the result of nanoparticles losing contact with the carbon/PVDF binder. Yet, it occurs in a peculiar way which causes the cell to reach full capacity at the end of every cycle on lithiation. In other words, capacity fade only occurs during delithiation. We present clear NMR evidence showing that particle disconnection occurs during the delithiation (volume contraction of the electrode particles) process. During lithiation (volume expansion of the electrode particles) our NMR data further reveals that connected particles are surprisingly pushed back into contact with the disconnected particles which then rejoin the circuit and allow the cell to reach full capacity on lithiation. Our dOp 7Li NMR spectra also reveal the structural transformation pathways between Li-Sn intermetallics during lithiation and delithiation of Sn nanoparticles. The disconnecting particles are associated with LixSn phases undergoing large decreases in diameters on delithiation, i.e., Sn, Li2Sn5, LiSn, and Li7Sn3. The Li–Sn phases observed are somewhat consistent with the structural evolution expected from the equilibrium binary phase diagram, but there are some notable exceptions with the observation of a metastable phase Li2Sn3, and two vacancy rich metastable phases, Li7−ζSn3, and Li13−δSn5 during delithiation.
Although this new capacity fade mechanism is simple, we know no in-situ microscopy method capable of detecting and following such a disconnection-connection mechanism. Our approach clearly show the power of operando NMR spectroscopy for revealing such fundamental processes. These results point the way for future efforts in both industrial and academic research labs to reduce capacity fade in a wider range of nano-structured intermetallic electrodes, involving Si, Ge and Sb.

Figure 1
(Invited) Insights of Electrochemical Degradation Enabled By Correlated in-Situ Electrochemical Diagnostics and Spatially Resolved Diffraction Mapping
Authors: Cheng Lei , Rezaei Talarposhti Morteza , Khedekar Kaustubh , Braaton Jonathan , Zenyuk Iryna V. , Craig Nathan , Johnston Christina 
Published: November 2022

One of the top priorities of human society is addressing climate change. Clean electrochemical technology is a vital part of the transformation necessary to meet climate goals and net-zero CO2 emissions by 2050. Electrochemical technology of high interest includes water electrolysis for green hydrogen generation, fuel cells for emission free transportation, and electrochemical CO2 reduction for achieving net-zero CO2 emissions. One critical challenge for wide-scale adoption of these electrochemical technologies is the long-term device durability. Comprehensive understanding the degradation phenomenon and underlying mechanism is of critical importance for technology and product development. In this regard, in-operando and in-situ techniques, providing unique and direct insight into the degradation process in these electrochemical devices, play important roles for advancing such understanding and ultimately increasing long-term durability.
Such techniques often rely on combined electrochemical diagnostics with advanced spectroscopy or other imaging capable of temporal and spatial resolution. In-operando techniques are often challenging due to the need for unique electrochemical cell configurations that fulfill the requirements of the technique while at the same time delivering electrochemical behavior similar to a commercial device.
The talk will first discuss a mapping methodology based on synchrotron X-ray micro-diffraction to study the heterogeneous degradation. Information obtained from the method and examples of application to study platinum catalyst degradation in accelerated stress tests will be discussed. The utility of correlating large datasets of in-situ electrochemical diagnostics from a variety of accelerated aging tests with the spatially resolved diffraction mapping will also be presented.
In-Situ/Operando Bragg Coherent X-Ray Diffraction Imaging for Nanoscale Imaging of Strain and Defect
Authors: Cha Wonsuk 
Published: November 2022

In the last two decades, Bragg Coherent X-ray Diffraction Imaging (BCDI) has become a powerful nanoscale characterization technique [1]. Its extreme sensitivity to lattice displacements enables to image three-dimensional morphology as well as internal deformation field distribution of nano- or micro-scaled various materials. In-situ and operando capabilities have been combined to BCDI to address scientific questions on materials under realistic conditions. Nowadays, in-situ/operando BCDI on electrochemistry successfully shows strain evolution and dislocation dynamics inside materials.
In this talk, I will introduce current state-of-the-art of BCDI and the 34-ID-C beamline in the Advanced Photon Source which is dedicated to BCDI. This talk will also cover recent experimental results on in-situ/operando BCDI, for example, electrochemical dissolution/deposition [2] and battery materials during charging/discharging cycles [3,4].
[1] M. A. Pfeifer, et al., Nature 442, 63 (2006).
[2] Y. Liu, et al., Nano Lett. 17, 1595 (2017).
[3] A. Ulvestad, et al., Science 348, 1344 (2015).
[4] A. Singer, et al., Nat. Energy 3, 641 (2018).
Field-Effect Tuning of Electrochemistry at 2D Semiconductor Electrodes: Charge Transfer Kinetics Can be Modulated with a Back Gate Voltage
Authors: Wang Yuxin , Frisbie C.Daniel 
Published: November 2022

Semiconductor electrodes are widely used in electrocatalytic reactions. The ability to improve and modulate the heterogeneous charge transfer kinetics on semiconducting electrodes is a major challenge for the electrochemical application of these materials. Instead of changing the electronic occupation of the semiconductor by chemical doping, we adopt an electronic method to modulate band edge alignment and solution electrochemistry at 2D ZnO working electrodes.
In our approach, a field-effect transistor with ultrathin ZnO semiconductor (3-5 nm) is fabricated, the heart of which is a metal-insulator-semiconductor (MIS) stack. A high-dielectric-constant material (HfO2) is used as the insulator to realize low-voltage tunability of the device. The ZnO layer of the device functions as the working electrode (WE) for electrochemical reactions. By applying a back gate voltage to this MIS field-effect transistor, charge carriers are electrostatically induced and the ZnO band edges shift at the front face of the ZnO in contact with electrolyte. These effects can be exploited to manipulate the charge transfer kinetics on the ZnO electrode at a given electrode potential. We demonstrate this by focusing on outer-sphere redox chemistry. In order to eliminate mass transfer effects, microfluidic flow cells are coupled to the ZnO devices. Steady state kinetic analysis is carried out to extract the electron transfer rate constant of the redox process as a function of both electrochemical and back gate potentials. The heterogeneous electron transfer rate can be tuned by over an order of magnitude using the back gate voltage. The work demonstrates that a back gate provides another degree of freedom in determining electrochemical reaction kinetics at ultrathin semiconductor working electrodes. The method also opens possibilities for control over a wider range of semiconductor electrochemistry, such as electrocatalytic reactions.

Figure 1
(Invited) NMR Investigation of Proton Transport in Concentrated Aqueous and Polymer Electrolytes Based on Polyphosphoric Acid
Authors: Garaga Mounesha N , Greenbaum Steven 
Published: November 2022

Concentrated aqueous electrolytes have received much attention in recent years due to their high ionic conductivity and electrochemical window that usually exceeds that of the water electrolysis limitation. In collaboration with Ziyue Li and Fei Wang (Fudan University) we have investigated water/polyphosphoric acid solutions ranging in concentration from 1.25 to 16.6 molar being considered for proton-based batteries. Self-diffusion coefficients measured by pulsed field gradient NMR as well as spin-lattice time relaxation measurements were determined for 31P and 1H. The results shed light on the observed maximum in conductivity at the 5.9 molar concentration.
For polymer electrolyte membrane fuel cells (PEMFC), polybenzimidazole (PBI) membranes with high phosphoric acid content have been developed previously by collaborator Brian Benicewicz (University of South Carolina) using the so-called PPA process. Recently, a carefully controlled drying method has been discovered by Benicewicz and co-worker Laura Murdock in which a PBI membrane prepared by the PPA process is transformed into a dense PBI film. Though originally developed for flow battery applications, it was found that this dense film could be re-acidified to yield a mechanically robust PEM. Furthermore this method provides a synthetic route to PBI films without the use of any organic solvents. The re-doped PBI films display high ionic conductivity at elevated temperatures, similar to the starting PBI gel membranes prepared by the PPA process, while containing nearly a factor of two less acid than the latter and also exhibiting enhanced mechanical properties. NMR spectroscopy was used to characterize the structure and dynamics of the modified and the original PBI/PPA membranes. In addition to pulsed field gradient diffusion studies, we have performed solid state one-dimensional 31P, 13C and two-dimensional 31P{1H} and 13C{1H} HETCOR NMR measurements, which yield additional information on structural differences between the membranes and how these differences may affect transport properties.
(Invited, Digital Presentation) Charge Transfer at Heterogeneous Functional Interfaces in Energy Conversion and Storage Devices: A Quantum Chemical Perspective
Authors: Munoz Garcia Ana Belen 
Published: November 2022

Energy conversion and storage devices are triggering the ecological transition toward a sustainable economic and social development. In these technological devices, several constituent materials and their interfaces undergo charge/mass transport processes over different time/space scales, from local fast electron transfer to long-range slow ionic diffusion.
Often, experimental techniques cannot dissect such processes at the nanoscale, which hinders a rational design of new devices with better performances. Thus, the application of computational modeling tools with atomistic resolution represents an ongoing revolution in materials design and device development.
In this context, this contribution will display how cutting edge DFT-based approaches allow to unveil the charge transfer mechanisms in several different electrochemical environments: (i) at hybrid interfaces considering promising Cu-based molecular redox couples in dye sensitized solar cell photoanodes [1,2], (ii) at heterogeneous interface in last generation perovskite solar cells [3] and (iii) ion-electrode interfaces in the context of nanostructured electrodes in sodium-ion batteries [4,5,6].
The results will provide new insights on the structure-property-functional relationships of different functional materials/interfaces and will pave the basis of new design principles for further improvements of the corresponding devices.
[1] AB Muñoz-García, I Benesperi , G. Boschloo, JJ Concepcion, JH Delcamp, EA Gibson, GJ Meyer, M Pavone, H Pettersson, A Hagfeldt, M Freitag

Dy
e-sensitized Solar Cells strike back

2021 Chemical Society Reviews 50, 12450-12550
[2] I Benesperi, H Michaels, T Edvinsson, M Pavone, MR Probert, P Waddel, AB Muñoz-García*, M Freitag

Dynamic dimer copper coordination redox shuttles

2022 Chem 8, 439-449 (Cover Article)
[3] A Pecoraro, A De Maria, P Delli Veneri, M Pavone, AB Muñoz-García*

Interfacial electronic features in methyl-ammonium lead iodide and p-type oxide heterostructures: new insights for inverted perovskite solar cells

2020 Physical Chemistry Chemical Physics 22, 28401-28413
[4] A Massaro, AB Muñoz-García, PP Prosini, C Gerbaldi, M Pavone

Unveiling Oxygen Redox Activity in P2-Type NaxNi0.25Mn0.68O2 High-Energy Cathode for Na-Ion Batteries

2021 ACS Energy Letters 6, 2470-2480
[5] A Massaro, A. Langella, AB Muñoz-García, M Pavone

First-principles insights on anion redox activity in NaxFe1/8Ni1/8Mn3/4O2: Towards efficient high-energy cathodes for Na-ion batteries

2022 Journal of American Ceramic Society https://doi.org/10.1111/jace.18494

[6] A Massaro, AB Muñoz-García, P Maddalena, F Bella, G Meligrana, C Gerbaldi, M Pavone

First-principles study of Na insertion at TiO2 anatase surfaces: new hints for Na-ion battery design

2020 Nanoscale Advances 2, 2745-2751
Electrochemiluminescence: Digging into the Past and Illuminating the Future
Authors: Brown Kelly , Dennany Lynn 
Published: November 2022

Despite its discovery in the 1960’s electrochemiluminescence (ECL) has only in recent years seen an increased popularity within the wider analytical community. This can be largely correlated to the improvements in technology within the last decade which have facilitated the reduction in instrument size and complexity, so much so that today the technique can be performed through modification of a smartphone device. As such, ECL can now be considered a powerful addition to the analytical toolbox, with ever expanding reach of the technique into new areas of analytical science.
This research aims to further expand the understanding of potential utilisation of the technique by displaying its fundamental success for applications into previously underrepresented or unique fields. Through the combination of screen printed electrodes with different metal luminophores and modification strategies a number of sensing systems, building upon the traditional ruthenium based devices, has been achieved. Preliminary research has displayed, through the unique characteristics offered by ECL, successful application to the archeological, horticultural, and veterinary fields. Each sample type offered unique challenges, with the final outcome offering an in-field compatible and potentially non-destructive analysis method. Further attributes include minimal sample preparation procedures and volumes alongside simplistic operation and interpretation further enhancing its usability making it an ideal candidate for non-experts or indeed electrochemists.
Here we display exciting opportunities for the expansion of not only of ECL but electro-analytical devices toward a range of unusual and unique environments. Such areas have either minimal or no past experience in the utilisation of ECL for direct target analysis, and as such we hope to successfully demonstrate its capabilities. Through promotion of the versatility of the technique into new arenas we hope to drive forward the expansion of ECL both within the analytical community but also beyond, by sparking interesting in this fundamentally promising technique from outwith the electrochemical and ECL communities.
Influence of Ascorbic Acid Concentration on Photoelectrochemical Response of TiO2 and SnS2
Authors: Radic Gabrijela , Juric Kacunic Danijela , Perovic Klara , Kusic Hrvoje , Kraljic Rokovic Marijana 
Published: November 2022

TiO2 is already a well-studied photocatalytic material because of its excellent properties such as chemical stability, low price and non-toxicity. However, the fact that its band gap (3,2 eV) allows it to absorb only the UV light limits its use. On the other hand, the SnS2 (band gap ~2,2 eV) absorption range is well within the visible light spectrum, which is more suitable for solar harvesting. Both of these materials yield rapidly recombining electron-hole pairs upon photoexcitation. This recombination can be prevented by the addition of hole scavengers, which increase the survival probability of the electrons. Over the years there have been various efforts to improve such reaction efficiency using different hole scavengers. This work was focused on the influence of ascorbic acid (AA) on the photoelectrochemical response of TiO2 and SnS2 [1].
The obtained results indicated that by using an AA solution photocurrents response significantly increases confirming its good hole scavenging properties. Additionally, it was shown that by increasing AA concentration from 10 mM to 100 mM TiO2 photoactivity was not improved while SnS2 photoactivity significantly increased. The photoactivity was determined by using linear sweep voltammetry, electrochemical impedance spectroscopy and open circuit potential monitoring. The interaction of AA and metal oxide was studied by UV/Vis spectroscopy.

[1] A. Indra, R. Beltrán-Suito, M. Müller, R.P. Sivasankaran, M. Schwarze, A. Acharjya, B. Pradhan, J. Hofkens, Promoting Photocatalytic Hydrogen Evolution Activity of Graphitic Carbon Nitride with Hole-Transfer Agents, ChemSusChem, 14, (2020), 306-312, doi: https://doi.org/10.1002/cssc.202002500

This research
has
been
supported
by
European
Structural
and
Investment
Funds
,
Water
Purification
and
Energy
Conversion
using
Novel
Composite
Materials
and
Solar
Irradiation
, KK.01.1.1.04.0001 and Croatian
Science
Foundation
under
the
project NaSCEnT (IP-2018-01-1982).
Electrochemical Methodologies for the Detection of Traditional and Emerging Illicit Drugs
Authors: Blake Rowan Sirkka , Brown Kelly , Dennany Lynn 
Published: November 2022

Drug abuse and drug addiction is a multifaceted problem which has for a long time had far-reaching societal and physical consequences. In recent years, these negative effects have been further exacerbated by an increase in the production, trafficking and consumption of illicit drugs. Furthermore, the introduction of potent synthetic analogues and compounds known as New Psychoactive Substances (NPS) to the illicit drug market and their rapid proliferation has lead to an unprecedented threat to public health and safety. As such, the necessity has grown for the development of robust screening methodologies for these compounds within forensic and clinical research. Electroanalytical chemistry has quickly become a popular and powerful tool to address such demands. Electrochemical sensors evade many of the pitfalls associated with conventional detection methods, allowing for exceptionally good analytical performance at minimal cost.
Within this contribution we present the use of electrochemiluminescence (ECL) as a novel screening methodology for the detection of Synthetic Cannabinoids (SCs), which are the most prevalent group of NPS currently being monitored by the European Monitoring Centre for Drugs and Drug Addiction. AB-CHMICA, NE-CHMIMO, BB-22 and 5F-ADB-PINACA were all successfully detected at relevant concentrations using the developed screen-printed electrode ruthenium-based sensor. While in its infancy, these results show the potential of ECL as a screening methodology for SCs and leave much to be explored including its applicability to street and biological samples.
Moreover, we aim to highlight the diversity of electrochemical techniques toward illicit drug detection via investigation into the use of wearable electrochemical sensors for the detection of traditional cannabinoids and benzodiazepines.
Development and Improvement of an Electrochemical Cell for X-Ray Fluorescence and Absorption Spectroscopy
Authors: Lopez-Astacio Hiram J , Cunci Lisandro , Pollock Christopher 
Published: November 2022

The use of X-ray spectroscopy is an essential technique for the study of any material. Our research investigated the electrochemical cell design and improvement for X-ray absorption and fluorescence spectroscopy. Our objective was to improve the design capability of the current electrochemical cell design to perform absorption and fluorescence spectroscopy at once. By changing the geometry of the receiving window on the electrochemical cell, we could accomplish both fluorescence and absorption spectroscopy functions for CHEXS experiments. Our approach was a simple, inexpensive prototype cycle that anyone could use. Using a hobbyist Computer Numerical Control (CNC) and free 3D CAD software, anyone can develop a reliable electrochemical cell using our design. The electrochemical cell was fabricated using a small computer numerical control system, which allowed a fast turnaround for our project. Our work contributed to designing an open-source electrochemical cell that CHESS or any user could use, modify and share for future projects. Scientifically, we aimed to implement the ability to do both fluorescence and absorption spectroscopy, incorporate the ability to purge the cell with a gas, decrease ionic resistance in the cell to have all the electrodes within the same cell, and avoid leaks.
The development of a new electrochemical cell design was made to improve the reliability and performance of the cell for CHESS experiments. By re-arranging the positions of the working electrode (WE), counter electrode (CE), and reference electrode (RE), we accomplished low ionic resistance within the cell. In addition, creating a 45-degree angle slope on both sides of the X-ray receiving window will allow the design of the electrochemical cell to perform fluorescence and absorption spectroscopy simultaneously. Furthermore, an add-on to the top of the electrochemical cell was designed to perform gas purging of the cell successfully. Lastly, the change from an o-ring to a gasket addressed the leakage problem thoroughly.
(Invited) Developing Universal Sensing Strategies-Combining Functional Nucleic Acids with Photoelectrochemical and Electrochemical Signal Transduction
Authors: Soleymani Leyla , Pandey Richa , Victorious Amanda , Saha Sudip , Sakib Sadman , Zhang Zijie , Li Yingfu , Zhitomirsky Igor 
Published: November 2022

Biosensors combine biorecognition with signal transduction for analyzing biologically-relevant analytes. Nucleic acids are powerful building blocks for biosensors and are used both for biorecognition and facilitating signal transduction. In this talk, we will show that functional nucleic acids can be specifically engineered for electrochemical signal transduction. We develop both aptamers and DNAzymes that are designed for electrochemical signal transduction. Electrochemical biosensors relying on functional nucleic acids are used herein to detect bacterial and viral infectious diseases in native clinical samples such as saliva and urine.
In addition to electrochemical signal transduction, we show that nucleic acids serve as powerful tools in photoelectrochemical signal transduction. We use double stranded DNA for biorecognition and for serving as a nano-ruler for tuning the separation between a photoelectrochemical label and the electrode surface. This allows us to switch the signal transduction capability of the system between signal-on and signal-off. Additionally, engineering functional nucleic acids for photoelectrochemical signal transduction, enabled us to develop a new class of pathogen biosensors. These biosensors are used in direct analysis of bacteria in water.