bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the Electrochemical Kinetics of Aluminum Deposition from Ionic Liquids
Authors: Bottcher Rene , Mai Sebastian , Ispas Adriana , Bund Andreas 
Published: December 2020

Aluminum is one of the first metals that has been successfully deposited from ionic liquids (ILs) and has been in the focus of intense research. However, the electrochemical kinetics of the aluminum deposition from ILs is still not fully understood.
This paper will discuss recent results from the authors’ lab on the electrochemical kinetics of the deposition of aluminium from 1-ethyl-3-methyl-imidazolium based ILs. Overpotential measurements and electrochemical impedance spectroscopy (EIS) experiments were employed to extract kinetic data from potential-time transients (see Fig. 1). The transients were interpreted in terms of different contributions to the total overpotential. This includes a detailed discussion of the Ohmic drop, charge transfer, concentration and nucleation overpotential. The charge transfer mechanism of aluminum was investigated in terms of the anodic and cathodic rate-determining step (RDS) and oxidation and reduction mechanisms are suggested. Density Functional Theory (DFT) calculations were performed to evaluate if the suggested mechanism is thermodynamically reasonable.
Fig. 1 Potential-time transient for a constant-current step (j = 1.25 mA cm-2) at an aluminum electrode in [EMIm]Al2Cl7 at 300 K. The inset shows the first 500 ms of the potential-time transient.

Figure 1
Tuning Ionic Conductivity in Sodium Anti-Perovskite Ionic Conductors
Authors: Li Yiliang , Tsai Ping-Chun , Wang Fei , Kim Kwangnam , Halat David , Yin Liang , Lapidus Saul H. , Balsara Nitash P. , Reimer Jeffrey , Siegel Donald J , Chiang Yet-Ming 
Published: December 2020

Anti-perovskite materials have recently attracted great interest as a family of non-flammable solid state electrolytes with high ionic conduction.[1] Typical solid-state electrolyte materials have temperature dependent ionic conductivity following linear Arrhenius behavior over a substantial range of temperature, corresponding to a constant activation energy Ea. However, we have discovered several anti-perovskite materials that have strong positive deviations from Arrhenius behavior, leading to rapidly rising ionic conductivities with increasing temperature.
Na3OCl and Na3OBr are typical anti-perovskite compositions with atomic structure shown in Figure 1a. Strong deviations from Arrhenius (linear) behavior were observed in the temperature dependent conductivity measured by impedance spectroscopy, where Na3OCl0.5Br0.5 reaches the highest ionic conductivity with increasing temperature, as shown in Figure 1b. The structural origins of such behavior, such as change of octahedral tilt systems and order/disorder phase transition, has been investigated using multiple temperature-resolved characterization methods including synchrotron XRD, NMR, dielectric property measurements, and calorimetry, and modeled using AIMD and DFT. This work will give insight to tuning solid state electrolyte with high ionic conductivity.
This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.
Figure : Temperature dependent ionic conductivity and atomic model of Na-based anti-perovskites.

Figure 1
Temperature-Dependent Atomistic Dynamics Correlated to Cation Transport in Cluster-Ion Anti-Perovskites
Authors: Tsai Ping-Chun , Li Yiliang , Wang Fei , Kim Kwangnam , Halat David , Yin Liang , Lapidus Saul H. , Balsara Nitash P. , Reimer Jeffrey , Siegel Donald J , Chiang Yet-Ming 
Published: December 2020

As fast-ion conductors, cluster-ion anti-perovskites (APs) are attractive for potential new mechanisms of conduction whereby cation and anion motion is highly correlated [1,2]. Cluster-ion APs, like perovskites, have a framework that accommodates diverse atomic substitutions. Furthermore, the potential for cluster-ion substitution onto one or both anion sites (A and B in X3AB) provides additional compositional degrees of freedom. To identify model cluster-ion APs for understanding such conduction mechanism, we have synthesized and characterized ~20 cluster-ion APs compositions, from which Na3-x(NH2)xO1-x(BH4) has been identified as an ideal model system for understanding the correlation between cluster-ion rotation and cation transport as shown in Figure 1. Particularly, Na2(NH2)(BH4) exhibits an unusual positive deviation from ideal Arrhenius behavior indicative of a flattening of the energy landscape with increasing temperature. Concurrently, the sodium conductivity increases by 104 to 105, which is most likely due to some combination of the effects of Na vacancy introduction and NH2 and/or BH4 anion mobility. Herein, synthesis, property, and characterization of the cluster-ion APs, aimed at understanding the temperature-dependent atomistic dynamics and its effects on cation transport, will be discussed in the presentation.
This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.

Reference
s
:

[1] Hong Fang and Puru Jena. Li-rich antiperovskite superionic conductors based on cluster ions. Proceedings of the National Academy of Sciences, 2017, 114, 110461.
[2] Hong Fang and Puru Jena. Sodium Superionic Conductors Based on Clusters. ACS Appl. Mater. Interfaces. 2019, 11, 963-972.

Figure 1
Understanding the Structural Disorder Related to Ionic Conductivity Enhancement in Anti-Perovskite Ion Conductors
Authors: Wang Fei , Li Yiliang , Tsai Ping-Chun , Yin Liang , Evens Hayden , Kim Kwangnam , Lapidus Saul H. , Siegel Donald J , Chiang Yet-Ming 
Published: December 2020

Amongst known families of solid electrolytes of potential interest for solid-state batteries, the anti-perovskites (APs) have recently attracted great attention for the high ionic conductivities observed in certain compositions, and, like perovskites, the compositional flexibility provided by the possibility for ion substitution onto multiple lattice sites. [1] For example, variations in the extent of disorder, that are accompanied by changes in the distribution of lithium migration energies.[2] In surveying transport in this family of ion conductors, we observed a trend wherein numerous compositions show upwards curvature on an Arrhenius plot, indicating a non-constant activation energy. This is unusual as most solids exhibiting non-Arrhenius behavior exhibit a negative deviation. The structure origins of such deviations are not well understood.
Among the AP-structure SSEs, Li2OHCl and its variants are particularly interesting because of their relatively high conductivities at room temperature. Unlike Li3OCl, where six Li atoms occupy the vertices of the Li6O octahedral, in Li2OHX the vertices are occupied by four lithium atoms with two other sites vacant. H in Li2OHX sits at the oxygen atom in the center of the octahedron. The Li defects and the movement of H around the oxygen atom give rise to a change in the ionic conduction pathway as temperature varies (Figure 1).

Figure 1. The ionic conduction pathway of Li and H in Li2OHCl at different temperature
Herein, we explain the non-Arrhenius conduction behavior in relation to defect and H movement, and our attempts to understand the structural origin(s) of this behavior through temperature-dependent X-ray and neutron scattering, calorimetry, and other methods. Implications for the design of solid electrolytes for solid state batteries will be discussed.
This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.

Reference
s
:

[1] Zhao, Y.; Daemen, L. L. Superionic conductivity in Lithium-rich anti-perovskites. J. Am. Chem. Soc. 2012, 134, 15042−15047.
[2] Kwangnam Kim and Donald J. Siegel. "Correlating lattice distortions, ion migration barriers, and stability in solid electrolytes." Journal of Materials Chemistry A 7, no. 7 (2019): 3216-3227.

Figure 1
Direct Measurement of Nano-Sized Lithium Dendrite Growth Stress By in-Situ TEM
Authors: Aubin Megan , Kushima Akihiro 
Published: December 2020

The all-solid-state Li-ion battery is attracting attention because it enables the use of a high capacity Li metal anode while easing safety concerns by employing a stable solid electrolyte. It is expected that the use of a solid electrolyte with a high shear modulus would prevent the growth and propagation of destructive lithium dendrites. However, dendrites still penetrate solid electrolytes, causing the cell to short, and the exact mechanism is still under debate. Additionally, a large compressive stress is generally applied to the cell to maintain good contact between the electrode and the solid electrolyte, which may affect the lithium deposition process and the stability of the solid electrolyte. Therefore, understanding the relationship between the mechanical stress and lithium dendrite growth is key in decoding the dendrite penetration process.
We developed an in-situ transmission electron microscopy (TEM) technique to directly observe the early stages of the lithium dendrite growth process and obtain the initial force on a Li dendrite. Setup involved a sharp conductive cantilever tip contacting a relatively flat lithium metal surface and applying a potential bias initiating lithium plating at the tip. The in-situ TEM observation, as schematically illustrated in the figure below, commenced with dendrite nucleation (A) and progressed as a nano-sized lithium pillar growing vertically causing increasing stress (B). The dendrite continued its vertical growth until the force reached a critical value (C). The pillar then started to expand horizontally (D). The measured critical stress is much higher than the yield stress of bulk lithium, showing lithium can locally introduce high stresses on solid electrolytes without yielding. It is suggested that horizontal lithium growth helped to release dendritic stress buildup, unveiling a promising strategy to implement in future investigations of how to mitigate penetration through the solid electrolyte, preventing the dendrite from reaching the cathode and causing a catastrophic short. The information obtained in this work is useful for constructing a constitutive model of a lithium plating process in an all-solid-state system and understanding the mechanical stability of solid electrolytes particularly at the early stage of lithium deposition.

Figure 1
Crosslinked Single-Ion-Conductor Polymer Electrolytes
Authors: Jeanne-Brou Roselyne , Issa Sébastien , Devaux Didier , Grosso David , Phan Trang N. T. , Gigmes Didier , Bouchet Renaud 
Published: December 2020

Liquid based electrolytes used in conventional Li-ion batteries are made of a mixture of Li salt and flammable alkyl carbonate solvents. In addition, their transference number (t
+) is low, typically 0.3, which limits the battery power performance because of the formation of strong gradient of concentration during operation.[1] To increase both safety of energy density a solution is to develop a Li metal based battery comprising a single-ion-conductor solid polymer electrolyte.[2]
Poly(ethylene oxide) (PEO) doped with a Li salt is the fundamental solid polymer electrolyte due to its high ionic conductivity (> 10-4 S/cm) above its melting temperature (> 60°C), and, chemical and electrochemical stability towards Li metal. However, its t
+ is low, about 0.15.[3] A strategy is then to develop a single-ion-conductor polymer electrolyte comprising PEO to ensure Li metal stability and battery operation at room temperature.[4]
In this study, we report on the facile synthesis and the physico-chemical and electrochemical characterizations of series of crosslinked single-ion electrolytes based on a PEO matrix. These materials are shown to be single-ion-conductors with interesting Li dendrite resistance. In addition, for these electrolytes a thorough study by impedance spectroscopy using symmetrical cells with either Li reversible electrodes or stainless steel blocking electrodes reveals a complex electrolyte resistance response composed of two contributions as encountered in materials with bulk and grains boundaries (Figure 1). We thus proposed a methodology to extract the grain and grain boundary contributions, which is essential to correctly determine in turn the electrolyte transport properties (transference number, diffusion coefficient). Furthermore, a discussion on the origin of this phenomena is proposed.

References

[1] K. Xu, Chem.
Rev., 104 (2004) 4303.
[2] R. Bouchet et al., Nat. Mater., 487 (2012) 1
[3] K. Pozyczka et al., Electrochim. Acta., 227 (2017) 127
[4] L. Long et al., J. Mater. Chem. A, 4 (2016) 10038

Figure 1
Ceramic Composite Cathodes for All-Solid-State Lithium Batteries
Authors: Ihrig Martin , Tsai Chih Long , Finsterbusch Martin , Fattakhova-Rohlfing Dina , Guillon Olivier 
Published: December 2020

Oxide-ceramic based all-solid-state lithium batteries (ASSLB) can provide high intrinsic safety, extended operational temperature range, and high energy density. As the first two are intrinsic to the materials system, one prerequisite to obtain high energy densities with such ASSLBs is the manufacturing of composite cathodes. Preferably, cathode active material (CAM) and electrolyte should form an intertwined 3D-network with an intimate extended contact between two phases. The interface between the CAM and the electrolyte should feature high total surface area with a low impedance to enable an efficient charge transfer and transport and minimize the resistance losses in a battery.
Composite solid cathode microstructures can be formed via a co-sintering of solid electrolyte and CAM powders. However, many CAMs such as Li[Ni1-x-yCoxMny]O2 (NMC), Li[Ni1-x-yCoxAly]O2 (NCA) or Li2NiMn3O8 (LMO) cannot withstand sintering temperatures required, for oxide class solid electrolytes as Li7La3Zr2O12 (LLZ) or Li1+xAlxTi2-x(PO4)3, to obtain sintered composite cathodes. Furthermore, the thermodynamic stability of CAMs significantly decreases in the presence of solid electrolytes. Still, several groups have demonstrated that thermodynamic limitations can be significantly lessened via a kinetic control of the process such as reduction of reaction times and a careful control of powder morphology during ceramic sintering process.
Following this work, we now demonstrate that FAST/SPS enables fabrication of different solid-state battery components within minutes such as a dense LLZ separator layer with a high ionic conductivity, a dense dual LiCoCO2 (LCO)/LLZ composite cathode without any interfacial reactions, and an integrated cathode half-cell consisting of a composite cathode and a LLZ separator layer at temperatures as low as 675 – 800 °C. Analyzing the structure, morphology, and electrochemical performance of the obtained components, we conclude that the impurities (carbonates) on the surface of LLZ powder play a decisive role in the formation of high-quality interfaces and the minimization of porosity. Furthermore, these impurities decrease the ionic conductivity at low sintering temperature and deteriorate the cycling stability of an ASSLB. High areal capacity of up to 4.0 mA h/cm2 at 80 °C with a constant current of 50 µA/cm2 and a good utilization of LCO was achieved for ASSLB with LLZ powders free of surface impurities. FAST/SPS can therefore open new processing windows for ceramic-based ASSLBs to alleviate the problem of interphase formation.
Improvement of ORR Activity and Durability of Pt Electrocatalyst Nanoparticles Anchored on TiO2/Cup-Stacked Carbon Nanotube in Acidic Aqueous Media
Authors: Matsumoto Futoshi , Ando Fuma , Gunji Takao , Ohsaka Takeo 
Published: December 2020

Platinum nanoparticles (Pt NPs) have been selectively anchored by photodeposition on titanium oxide (TiO2) matrix which is formed by hydrolysis of titanium isopropoxide on cup–stacked carbon nanotubes (CSCNT) in isopropanol, producing the composite Pt catalyst useful for oxygen reduction reaction (ORR) in acidic media, i.e., Pt NPs/TiO2/CSCNT (Fig. 1). Using scanning transmission electron microscopy (STEM) with a high–angle annular–dark–field (HAADF) detector it has been clarified that Pt NPs are sunk into the TiO2 moieties and have the unique polyhedral shape surrounded mainly by the Pt (1 1 1) and Pt (1 0 0) facets. X–ray photoelectron spectroscopy (XPS) allowed us to confirm changes in electronic properties of both Pt NPs and TiO2 support, induced by the so-called strong metal–support interactions (SMSI) and the significantly increased ORR activity was attained in 0.1 M HClO4, compared with the Pt NPs deposited on CB (Vulcan carbon) and CSCNT. The surface structure of the Pt NPs was characterized by transmission electron microscopy (TEM), indicating the improved durability of the Pt NPs deposited on the TiO2/CSCNT, i.e., the only slight increase in the particle size after the durability test (typically 2000 times’ potential cycling at 10 mV s-1 in the potential ranges of 0.05 to 1.1 V and 1.0 to 1.5 V vs. RHE in 0.1 M HClO4). The results obtained demonstrate that the anchoring of Pt NPs on the TiO2 support material deposited on CSCNT is an effective way to enhance the ORR activity of Pt NPs by the SMSI as well as to prohibit Pt NPs from aggregating, i.e., the degradation of the ORR activity of Pt NPs.
Figure １ HAADF STEM images of Pt NPs/TiO2/CSCNT sample with (A) low- and (B) high-magnification. The high-magnification image in (B), which shows the assignment of the surface geometry of the Pt NPs deposited on TiO2/CSCNT, was collected from the selected area denoted by the dotted square in (A).

Figure 1
A Study on the Electrochemical Performance of Fe-V Chloric/Sulfuric Mixed Acid Redox Flow Battery Depending on Electrode Activation Temperature
Authors: Lee Han Eol , Kim Dae Eop , Kim Taekeun 
Published: December 2020

As the main component of the redox flow battery, the electrode has a great influence on the electrochemical performance of the redox flow battery. Among the several investigated electrodes, GFD 4EA was found to exhibit the highest capacity, coulomb efficiency, and energy efficiency when chloric/sulfuric mixed acid supporting electrolyte was used for Fe2+/Fe3+ and V2+/V3+ redox couple reactions. The selected electrode was further investigated for the effect of activation temperature.[1-3] Physical characteristics including the mass retention and surface functional oxygen group were analyzed for the samples obtained from the various activation temperature. For electrochemical analysis, electrochemical capacity, coulomb efficiency, and energy efficiency were evaluated depending on activation temperature.[4] The mass retention rates for the electrodes activated under 500 ℃ were over 99.0%, while 89.0 % and 58.3% for the samples activated at 600 ℃ and 700 ℃, respectively. The electrochemical capacity showed the increasing tendency as the increase of the activation temperature up to 400 ℃, then continuously decreased. The XPS analysis confirmed that the oxygen functional groups were sufficiently generated on the surface of the electrode during the high-temperature activation which results in the electrochemical performance. The energy efficiency showed maximum value at 500 ℃. It is considered that significant mass loss of the electrodes at high activation temperatures results in changes in the shape and structure of the electrode surfaces, thus decreased the electrochemical performances due to increased interfacial resistance.

References

[1]. B. Sun and M. Sykllaskazacos, Electrochim Acta, 37, 1253 (1992).
[2]. K. J. Kim, Y. J. Kim, J. H. Kim and M. S. Park, Mater Chem Phys, 131, 547 (2011).
[3]. A. M. Pezeshki, J. T. Clement, G. M. Veith, T. A. Zawodzinski and M. M. Mench, J Power Sources, 294, 333 (2015).
[4]. P. C. Ghimire, Nanyang technological university, 190 (2019).
An Improved High-Rate Discharging Performance of “Unbalanced” LiFePO4 Cathodes with Different LiFePO4 Loadingsby a Grid-Patterned Micrometer Size-Holed Electrode Structuring
Authors: Matsumoto Futoshi , Watanabe Tatsuya , Gunji Takao , Ohsaka Takeo , Nakamura Susumu , Soma Naohiko , Ando Nobuo , Hayashi Narumi 
Published: December 2020

The degradation of charging/discharging capacities in the rate-performance test of lithium iron phosphate (LFP) cathodes with different loading amounts of an active material on both sides of a current collector (i.e., “unbalanced” LFP/LFP cathodes) in a laminated cell (typically composed of anode/separator/unbalanced cathodes/separator/anode) was not observed actually at low C-rates (e.g., 0.1 C). However, the rate-performance data obtained at high C-rates (e.g., > 5 C) indicated that the imbalance of the loading amounts of an active cathode material on both sides of an Al current collector causes a significant capacity degradation. We have found that it is possible to prevent the capacity degradation observed at high C-rates by holing the unbalanced LFP/LFP cathodes in a micrometer-sized grid-patterned way (the percentages of the holed area are typically several %) using a pico-second pulsed laser: The non-holed unbalanced LFP/LFP cathodes exhibited a considerable capacity degradation at C-rates which are, for example, larger than 5C, while the holed ones showed no degradation in capacity even at high C-rates (e.g., 5-20 C). Forming micrometer-sized grid-patterned holes in the LFP/LFP cathodes leads to an improved capacity and high-rate performance of their charging/discharging processes. The improvement in the discharging performance at the holed cathodes at high C-rates can be considered to result from a facilitated transfer of Li+ ions in the discharging of the thick layer as well as the thin one through both the surface and the sidewalls (produced by forming the holes) of the LFP layer (or the LFP/current collector layers). In order to keep a high discharge capacity at high C-rates even in thick LFP layers, resulting in an improvement of the battery performance of LIBs, the optimization of the diameter of holes formed and the percentage of holed areas (i.e., opening rate) is examined now.
Fig. 1 Schematic description of high-rate discharging processes on (A) non-holed, (B) through-holed and (C) non-through-holed LFP/LFP cathodes with loading ratios of 3 at low- and high-rate discharging (e.g., at 0.1 and 10 C).

Figure 1