bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding Electrocatalytic Hydrogenation of Phenol and Benzaldehyde on Platinum Group Metals for Fuel Production
Authors: Singh Nirala , Sanyal Udishnu , Ruehl Griffin , Fulton John , Camaioni Donald , Gutiérrez Tinoco Oliver Y , Campbell Charles , Lercher Johannes A 
Published: February 2020

Despite the ability of aqueous-phase electrocatalytic reduction (hydrogenation) to produce fuels,1 pharmaceuticals, food and other commodity chemicals, the mechanisms of the metal-catalyzed reactions are not always well-understood. Understanding these reactions would allow us to develop improved electrocatalysts and processes to enable sustainable production of important fuels and chemicals. One major challenge in understanding the surface electrochemistry is that the characterization of the electrocatalyst surface is difficult in the presence of water. There are several techniques that can be used to understand the reactant coverages (under reacting conditions), and in this talk a brief overview will be given of spectroscopic techniques (including infrared, Raman, X-ray absorption) and cyclic voltammetry as ways to probe the electrocatalyst surface. In this talk, phenol and benzaldehyde hydrogenation (to cyclohexanol and benzyl alcohol, respectively) on Pt/C and Pd/C will be analyzed using i) experimental and theoretical X-ray absorption spectroscopy and ii) cyclic voltammetry to understand reactant coverages and explain observed reaction rates. Understanding these two models reactants will lead to improved electrocatalysis for not only phenol and benzaldehyde, but also similar compounds that exist in in waste bio-oil, which can be converted to transportation fuel-grade hydrocarbons. The effect of applied potential, reactant and product concentration, and pH on both electrocatalyst surface (including adsorbates) and reaction rate will be discussed. A brief discussion of these results with respect to gas-phase hydrogenation will also be included.
References
(1) Song, Y.; Gutiérrez, O. Y.; Herranz, J.; Lercher, J. A. Appl. Catal. B Environ.
2016, 182, 236.
(Invited) Operando X-Ray Absorption Investigations into the Oxygen Evolution Activity, Stability, and pH Dependency of NixFe1-XOy Nanoparticles
Authors: Abbott Daniel F. , Fabbri Emiliana , Borlaf Mario , Bozza Francesco , Graule Thomas , Schmidt Thomas J. 
Published: February 2020

Mixed Ni-Fe metal oxides currently represent some of the most attractive anode catalysts for the electrochemical splitting of water due to their low overpotentials for the oxygen evolution reaction (OER) in alkaline electrolytes. The concentrated potassium hydroxide solutions and anion exchange membranes that are typically employed in alkaline water electrolyzers, however, are prone to carbonation which can lead to significant shifts in the electrolyte pH from alkaline to quasi-neutral conditions (pH = 7-10). So far a fundamental understanding of how changes in the local pH environment induced via carbonation affect the catalyst electronic and surface structure, and ultimately the catalyst stability and electrochemical OER activity, is lacking. The importance of understanding this behavior is further highlighted by the potential application of Ni-Fe oxides as anode catalysts in co-electrolysis, where the electrochemical reduction of CO2 and the anodic evolution of oxygen occur in a carbonated, quasi-neutral pH environment.
Here we demonstrate a practical and scalable flame-spray pyrolysis synthesis capable of producing highly crystalline Ni-Fe oxide (Ni1-xFexOy) nanoparticles with high surface areas (SABET ≈ 20 - 75 m2/g). The research presented herein focuses on expanding the current understanding of the influence of the local electronic and surface structures on the OER activity and electrochemical stability in both alkaline (pH = 13) and carbonated, quasi-neutral (pH = 9) electrolyte. The resulting operando XANES and EXAFS analyses of the Ni and Fe K-edges permit useful insight into the nature of the valence states and rearrangements in local structure that occur under operating conditions representative of alkaline water electrolysis and co-electrolysis. Combined with a broad range of ex situ physical characterization techniques, we then relate the structural, electronic, and morphological changes to the observed electrochemical OER activity and stability.
Chemical Imaging Analysis of Solid-Electrolyte Interphase Layer in Li-S Battery
Authors: Murugesan Vijayakumar , Han Kee Sung , Shutthanandan Vaithiyalingam , Thevuthasan Suntharampillai , Mueller Karl T 
Published: February 2020

Elemental sulfur, an abundant and low toxicity material, is emerging as a promising cathode material due to higher theoretical specific capacity compared with traditional metal oxides used in Li-ion batteries. Lithium-Sulfur (Li-S) batteries rely on the reduction of sulfur (S8) to lithium sulfide (Li2S) through gradual evolution of polysulfide (Li2S
n
) during the discharge process. Many of the intermediate polysulfide species (Li2S
n
; 4 ≤ n ≤ 8) are highly soluble in electrolyte solvents, leading to cathode corrosion and capacity loss. The dissolved polysulfide species shuttle towards the reactive Li-anode, and accelerates Li anode poisoning through highly a complex solid-electrolyte interphase (SEI) layer formation. The SEI layer is generated by complex interfacial reactions involving transient species/structures; the challenge is to detect, identify and quantify these reactions, which typically span a wide spatial and temporal region and are inaccessible by any single spectroscopic and/or classical computational method. Traditional ex-situ spectroscopic capabilities1-4 often fail to capture critical transient and metastable species which dictate the SEI layer evolution. Hence, it is critical to develop in situ multimodal approaches that can provide unprecedented chemical imaging of these complex interfaces5. In this presentation, we will discuss our recent in-situ X-ray photoelectron spectroscopy (XPS) analysis which yielded an unparalleled view of the chemical speciation and microscopic evolution of the SEI layer (see Figure 1). In combination with computational modeling these data provided a method to establish quantitative understanding of complex interfacial interactions in Li-S batteries.
References:

J. Chen, K. S. Han, W. A. Henderson, K. C. Lau, M. Vijayakumar, T. Dzwiniel, H. Pan, L. A. Curtiss, J. Xiao and K. T. Mueller, Advanced Energy Materials 6 (11) (2016).

H. Pan, K. S. Han, M. Vijayakumar, J. Xiao, R. Cao, J. Chen, J. Zhang, K. T. Mueller, Y. Shao and J. Liu, ACS Applied Materials & Interfaces 9 (5), 4290-4295 (2017).

N. N. Rajput, V. Murugesan, Y. Shin, K. S. Han, K. C. Lau, J. Chen, J. Liu, L. A. Curtiss, K. T. Mueller and K. A. Persson, Chemistry of Materials 29 (8), 3375-3379 (2017).

M. Vijayakumar, N. Govind, E. Walter, S. D. Burton, A. Shukla, A. Devaraj, J. Xiao, J. Liu, C. Wang, A. Karim and S. Thevuthasan, Physical Chemistry Chemical Physics 16 (22), 10923-10932 (2014).

M. I. Nandasiri, L. E. Camacho-Forero, A. M. Schwarz, V. Shutthanandan, S. Thevuthasan, P. B. Balbuena, K. T. Mueller and V. Murugesan, Chemistry of Materials 29 (11), 4728-4737 (2017).

Figure 1
Role of Structural Dynamics on Lithium Diffusion in Li10GeP2S12 (LGPS) and Li3PS4 (LPS) Solid Electrolytes
Authors: Hall Alex Thomas , Adelstein Nicole 
Published: February 2020

The search for an ideal solid electrolyte for a safe, long-lasting all-solid battery has been extenstive, but the fundamentals of lithium diffusion are still not completely understood. One of the fastest electrolyte that has been found in lithium germanium thiophosphate, though is electrolyte cannot be used in batteries due to instability with the electrodes. While significant computational research has been done on LGPS, nuances of the mechanisms are still unknown. Insight into the extraordinary conductivity of LGPS, will enable the engineering and search for new electrolyte materials.
Polarization of anions and tetrahedral moieties and rotation analysis were studied in order to elucidate the conductivity difference in LGPS and LPS solid electrolytes. LPS has orders of magnitude lower conductivity than LGPS, but a very similar composition and structure. These analyses allow quantification of the effect of electronic structure and correlated motion on lithium diffusion. Polarization and rotation events were extracted from Density Functional Theory Molecular Dynamics (DFT-MD) simulations. Detailed analysis of the MD simulations revealed that the interaction of lithium with the lattice affects diffusion through the polarization and rotation of the tetrahedral anions. The GeS4 behaves differently than the PS4, which increases the diffisivity in LGPS compared to LPS.
Exfoliated Transition Metal Dichalcogenide Nanosheets for Sodium Ion Batteries and Supercapacitors
Authors: David Lamuel , Mukherjee Santanu , Abass Monsur , Singh Gurpreet 
Published: February 2020

With the existing drawbacks of the Li ion batteries (LIBs) in terms of expenditure and safety, there is an increasing research focus on Na ion batteries (NIBs) as a viable replacement especially for large scale grid storage applications. Considering the rather bulky Na ion and the challenges it would pose for efficient reversibility, choice of optimum electrode materials is of significance. Among the various types of materials being considered for applications as the negative electrode, 2-dimensional (2D) transition metal dichalcogenides (TMDs) have elicited interest due to their layered structure and existing in a range of compositions. Among the various TMDs that have been studied, MoS2 has received the most focus due to its excellent cyclability as well as stability, however, others in the TMD family have not received as much focus.
In this work, we study the sodium recycling properties of exfoliated TMD (MoSe2, WSe2 and MoTe2)- reduced graphene oxide (rGO) composite. Electrochemical analysis was performed by using the TMDs in coin cells with Na foil being the counter electrode in organic electrolyte within a cycling window of 2.25 V – 10 mV. Cell cycling results have indicated that WSe2 electrode performed the best and provided a reversible capacity more than 250 mAhg-1 whereas pristine rGO demonstrated only about 80 mAhg-1.
Also, all the TMD/rGO composite electrodes demonstrated a first cycle efficiency greater than 50 %. Similarly, capacity retention results demonstrate a similar pattern, with WSe2 exhibiting about 80 % capacity retention followed by MoSe2 (∼60 %) and MoTe2 (∼45%). Results in aqueous media exhibit similar trends.
In conclusion, it can be said that different 2D layered TMDs have shown promise for application as negative electrodes in NIBs in organic and aqueous environment. This provides hope in their extensive application as stable, high reversible capacity negative electrode materials in NIBs.
Mechanically Milled Si-Mn-Fe Alloys as Negative Electrodes for Li-Ion Batteries
Authors: Cao Yidan , Scott Ben , Dunlap R. A. , Obrovac M. N. 
Published: February 2020

The theoretical volumetric capacity of silicon (2194 Ah/L) is much larger than that of graphite (756 Ah/L). However, the large volume expansion of silicon is still a main concern for practical utilization. One method of reducing the volume expansion of Si is to alloy it with an inactive element. Both iron and manganese are cheap and abundant transition metals and are therefore interesting candidate inactive alloying metals for silicon based anodes. The binary systems, including Si-Fe and Si-Mn, have been previously studied in our group and by others. It has been found that adding Mn or Fe to Si reduces volume expansion during lithiation by forming inactive phases with Si and by inhibiting Li15Si4 formation. The silicides of Fe and Mn are different in structure and stoichiometry. Ball milled alloys in the Si-Fe-Mn ternary system have not been previously reported. Therefore it is meaningful to investigate the Si-Fe-Mn ternary system.
Here, Si100-x-y
Mn
x
Fe
y
((x,y)=(0,15), (5,12), (10,9), (15,6), (20,3), (25,0)) alloys were prepared by ball milling and their phase composition, microstructure and electrochemistry in Li half cells were studied. The XRD results show that α-Si2Fe and β-Si2Fe are formed in low Mn content samples, i.e. Si85Fe15, Si83Mn5Fe12. As the Mn content is increased, only Si19Mn11 phase is detected. However, the continuous peak shifts in XRD profiles and Mossbauer spectroscopy, shown in Figure 1, demonstrate that Fe atoms are present in the Si19Mn11 structure, to form ternary solid solutions.
The potential and differential capacity curves of Si100-x-y
Mn
x
Fe
y
alloys are typical of alloys in which Si is the only active phase. The formation of Li15Si4 is successfully suppressed in all the samples in the initial cycles. However, Li15Si4 forms after about 10 cycles, as shown in Figure 2. The volumetric capacity and volume expansion of the materials increase with increasing silicon ratio, as shown in Figure 3. In this presentation the composition, microstructure and electrochemistry of alloys in the Si-Mn-Fe system will be thoroughly discussed.

Figure 1
State-of-Health Estimation of Lithium-Ion Batteries Based on Partial Charging Voltage Profiles
Authors: Stroe Daniel Ioan , Knap Vaclav , Schaltz Erik 
Published: February 2020

Lithium-ion batteries have developed as the key energy storage solutions for various applications from power tools and consumers’ applications to electric vehicles and a renewable energy storage applications. Besides offering better performance (e.g., high gravimetric and volumetric energy density, high power capability during both charging and discharging, long lifetime) in comparison to other energy storage devices, Lithium-ion batteries are non-linear systems with their performance and degradation behavior strongly dependent on the operating conditions [1]. Thus, knowledge about the battery state-of-health (SOH) has become mandatory for real-life applications. Consequently, the topic of Lithium-ion battery was brought at the forefront of the research.
Many battery SOH estimation methods were developed and are available in the literature [2]. Most of these methods, which show very good accuracy, are applicable and validated only for perfect laboratory testing conditions. However, in real-life applications, the batteries are subjected to various constraints imposed by the battery management system (BMS); the constraints refer among others to impossibility of applying high current peaks to measure the internal resistance, discharge the battery to measure the capacity by other means then driving the car and/or have access to the whole battery voltage window to measure the battery capacity.
Thus, in this paper we proposed a method for estimating the SOH of the battery, which focuses on the measurement of the battery capacity for a certain voltage interval (e.g., 10%-90% SOC), which is not the entire voltage window allowed by the manufacturer as presented in Figure 1 and Figure 2. The proposed SOH estimation method is applied and its accuracy is assessed to different Li-ion battery chemistries.
[1] M. Kassem, J. Bernard, R. Revel, S. Pelissier, F. Duclaud, C. Delacourt, J. of Power Sources, 208, 296-305, (2012)
[2] M. Berecibar et al., Renewable and Sustainable Energy Reviews, 56, 572-587 (2016).

Figure 1
New Artificial Interphase with Li-Ion Pathway between Li Metal and Electrolytes for Secure Lithium Metal Anodes
Authors: Lee Jung-In , Shin Myoungsoo , Park Soojin 
Published: February 2020

While Li-ion batteries were firstly studied with Li metal as anodes due to its high theoretical specific capacity (3860 mA h g-1) and lowest negative electrochemical potential (-3.040 V vs SHE), commercial Li-ion batteries since 1992 consisted of graphite as an anode because of critical safety issues. However, for several decades, many strategies have been developed to surmount difficulties like problems of dendrite growth using modifications of electrolytes with additives, a change of lithium metal morphology, and an introduction of chemical/physical coating layers on Li metal.
Herein, we report a simple approach to improve the electrochemical performance of Li metal anodes in Li-ion batteries with commercial carbonate-based electrolytes by utilizing a high Li-ion conductor, Li2TiO3, on Li metal anodes. Monoclinic Li2TiO3 is electrochemically inert in a wide voltage range with excellent structural stability in a liquid electrolyte. In addition, it structurally has a 3D path for Li-ion diffusions, leading to more uniform Li-ion flux. Li2TiO3 nanoparticles with a size of sub-100 nm were synthesized via a sol-gel method, and then the resulting particles were mixed with carbon as a conducting material and PVDF-HFP as a binder. A bright Li metal surface was covered with gray Li2TiO3 films in Figure 1a. From various Li plating and striping tests with pristine and modified Li metal as working electrodes, the modified Li metal exhibited outstanding electrochemical performances such as stable coulombic efficiency over 100th cycles at 1 mA/cm2 as shown in Figure 1c. Moreover, the modified Li metal was applied for practical lithium-ion batteries as a counter electrode to confirm the protective effects with LMO as a working electrode at a room temperature (25 oC) and high temperature (60 oC).

Figure 1
Approaches to Complex Electrolyte Formulation Optimization
Authors: Cheng Gang , Zhu Ye , Strand Dee 
Published: February 2020

Lithium ion battery electrolytes are complex formulations of solvents, salts, and additives. Each component can contribute to the battery performance in a unique way. For example, high dielectric constant solvents are necessary to dissolve the lithium salt, but are high viscosity. Therefore, low viscosity solvents are required to reduce the bulk electrolyte viscosity. Salt type and concentration can affect properties such as conductivity and thermal stability. Finally, many additives may be considered for use in formulations – with functions such as anode solid electrolyte interphase (SEI) formers, cathode SEI formers, acid scavengers, thermal stabilizers, and more. Development of optimized electrolyte formulations can require many experiments to find the best components and ratios/concentrations of components.
Using Wildcat’s high throughput battery workflow, we can apply combinatorial chemistry approaches to screen hundreds of new electrolyte components and study their interactions for electrolyte formulation development. Combining statistical models for formulation optimization, and component substitution, the function of a single component in a complex electrolyte and its interaction with other components can be elucidated. In this presentation, we will demonstrate the power of these tools to rapidly improve and optimize complex electrolyte formulations.
Improving the Performance of PEO-Based Electrolytes to Enable Metallic Li As an Anode
Authors: Gupta Arushi , Sakamoto Jeff 
Published: February 2020

Replacing carbon-based anodes with metallic Li can drastically improve the performance of Li-ion batteries. However, stabilizing the Li metal/liquid electrolyte interface has been difficult and it is critical to replace them with solid state electrolytes. Solid polymer electrolytes (eg. PEO-LiTFSI) are of particular interest as they are easy to fabricate and have superior ductility, leading to suitable mechanical properties. This work addresses two challenges in developing viable PEO-based electrolytes – 1) factors affecting the SPE/Li interface are not well understood and 2) these electrolytes inherently have low room temperature conductivity.
The first part of this work focuses on minimizing the interfacial impedance between PEO-LiTFSI (SPE) and lithium anode by controlling the external variables in a Li/PEO-LiTFSI symmetric cell. The stability and kinetics of the interface were correlated with temperature, stack pressure and electrode type using electrochemical impedance spectroscopy (EIS) and dc cycling in order minimize interfacial impedance and maximize the limiting current (j
lim). Second, a critical stack pressure was established for 60oC and 80oC as 400 kPa and 200 kPa respectively by relating the stack pressure with interfacial impedance, below which interfacial impedance was shown to be at least 50 times higher. The effects of increasing temperature on the kinetics and mechanics of the interface manifest as variations in the EIS and cycling profiles. Lastly, the PEO-LiTFSI/Li interfacial impedance was reduced by 67%, from 4000 Ohms.cm2 to 1675 Ohm.cm2 at 30oC by using vapor deposited Li over Li foil electrode, increasing the limiting current from 0.5 mA/cm2 to 1mA/cm2.
The second part of this work was dedicated towards increasing the room temperature conductivity of PEO-LiTFSI electrolytes by adding a filler material. LLZO (Lithium Lanthanum Zirconium Oxide) was chosen because of its high room temperature conductivity and good cycling capabilities. Low values of interfacial impedance calculated from EIS on a trilamilar PEO-LiTFSI and LLZO cell with blocking electrodes proved the viability of the composite electrolyte. A solvent casting method was developed for the fabrication of flexible composite electrolytes of 100-500 microns thickness. The flexibility of the composite electrolytes was comparable to that of nascent PEO-LiTFSI electrolyte membranes, while their ionic conductivity was an order of magnitude higher. EIS was also used to determine the temperature dependence of the composite electrolyte’s conductivity. Lastly, the variation in bulk impedance with increasing LLZO volume percent in the PEO-LiTFSI was studied to optimize conductivity, while maintaining its flexibility.
Overall, this study provides effective guidelines for improving the performance of PEO-based electrolytes towards enabling viable all-solid state batteries.