bluuebunny/crossref_metadata_2025_split huggingface dataset:
Icosahedral Cobalt Bis(dicarbollide) Ions with Bridge Linker and Their Electrochemistry in Aqueous Media
Authors: Fojt Lukáš , Grüner Bohumír 
Published: December 2020

Boron cluster compounds (BCC) proved recently promising properties for use in drug design and molecular probes. Their applications in medicine are inherently connected with use of water-based environments. Up to now, the BCC were predominantly characterized in non-aqueous milieus. Therefore, we decided to perform electrochemical research of BCC in water-based electrolytes. We have focused on several boron clusters with structures that follow our previous study on icosahedral cobalt bis(dicarbollide) ions with a central coordination Co(III) atom in phosphate buffers, where we have found the best response for bridge type of exo-skeletal substituent. Therefore, in present study, we decided to focus on the promising structures, in which two 11 vertexes C2B9 dicarbollide ligands are interconnected via short bridge. Such structures may contain side chains usable for bioconjugation experiments.
For our electrochemical experiments, we have used phosphate buffers of different pHs (2-10) and polished glassy carbon electrode. As the bridge structure served these exo-skeletal substituents: sulfur, amino group, tolylene, chlorpehenylene, phenylene, xylylene, byphenylene, phosphoric groups.
The effect of various exo-skeletally substituted cobaltacarboranes (differing in type and length of the side chain) on the electrochemical response was studied. The results show that all parameters, the peak shape, the potential position and the peak current density height are significantly altered by the endo- and exo- skeletal substituents. Within the range of studied substitution, we were able to detect the signals in a broad potential range from E = -1.38 V to E = 1.73 V. From this follows clear possibilities to tune the position of two potential types in the electrochemical window that alternatively correspond either to the oxidation of the core structure of boron polyhedra or the central Co(III). The results also show that the electrochemical methods represent another tool for fast tracking the aggregation phenomena connected with non-classical amphiphilic behavior of boron clusters in aqueous solutions
Observation of Interfacial Degradation of Solid Electrolytes Against Lithium Metal and Layered Transition Metal Oxides Via in Situ Electrochemical Raman Microscopy
Authors: Zhou Yundong , Hardwick Laurence J. 
Published: December 2020

Solid state batteries, utilizing ceramic solid-state electrolytes, are attracting intensive research for their improved safety and possible higher energy density. Solid-state electrolytes can have comparable ionic conductivities to the liquid carbonate electrolytes, for example, Li10GeP2S12 with an ionic conductivity at 1.2 × 10-2 S cm-1 at room temperature. However, the performance of solid state batteries requires improvement to enable long term cycling. The interface instability between the solid electrolytes and electrodes is one of the limiting factors for the utilization of solid state batteries. Traditionally, mostly ex situ surface characterisation techniques such as Raman or x-ray photoelectron spectroscopy can be used to study the buried interfaces within all-solid-state batteries. Raman microscopy, in particular, is a powerful surface characterisation technique and has been used to detect structural and chemical information on electrode interfaces primarily in liquid electrolyte cells. The ability to do in situ observation of the solid electrolyte – electrode interface is paramount for understanding the performance and design interfacial strategies for solid state batteries.
In this study, in situ Raman microscopy and ex situ Raman imaging were adopted to study the interfacial evolution during cycling covering β-Li3PS4, Li10GeP2S12, and Li6PS5Cl electrolytes against Li metal and LiCoO2 or LiNi0.6Mn0.2Co0.2O2. Degradation products at both Li metal side and cathode side were detected. For example, the degradation products of the interface Li6PS5Cl at both Li metal side and LiCoO2 side were resolved [1]. Li2S was formed by Li deposition onto Li6PS5Cl and there were polysulfides, and P2Sx species formation between Li6PS5Cl and LiCoO2 interface. In situ Raman results were correlated with ex situ Raman microscopy from cycled cells. The ex situ Raman imaging also directly visualised the distribution of degradation products. We will demonstrate that in situ Raman microscopy as a powerful tool in the study of electrode/electrolyte interfaces within the solid-state cell. The technique can be translated to alternative solid electrolyte – cathode combinations to understand the operando interfacial evolutions for designing improved all-solid-state batteries.

Y Zhou, C Doerrer, J Kasemchainan, P.G. Bruce, M. Pasta, L.J. Hardwick, Batteries & Supercaps 3(2020)1-7.
Perspective on Cathode Composite Design: Revising Ceramic Processing Choices Toward Low Interfacial Impedance for Garnet-Based Solid-State Batteries
Authors: Kim Kun Joong , Rupp Jennifer L.M. 
Published: December 2020

The critical factors that determine the performance and lifetime of solid-state batteries (SSBs) are driven by the electrode–electrolyte interfaces.1,2 The main challenge in fabricating ceramic cathode composites for garnet-based SSBs has been lowering the thermal processing window in which both good contact and low interfacial resistance can be achieved.3 Here, we report an alternative ceramic processing strategy that enables the fabrication of all-solid composite cathodes at an unusually low processing temperature without the use of sintering additives or a fluid electrolyte (polymer-gel, liquid electrolyte). We present specific examples of LiFePO4 and LiCoO2 cathodes with a Li-garnet (Li7La3Zr2O12, LLZO) solid-electrolyte. An infiltration step is used to directly synthesize the LiCoO2 cathode from metal salts in a porous LLZO scaffold, resulting in the formation of the composite cathode (LiCoO2-LLZO) on top of a dense LLZO solid electrolyte. A promising discharge capacity of 118 mAhg−1 (3–4.05 V) with 62 Ohm·cm2 is realized for LiCoO2 with a lithium anode, whereas critical phase instabilities for LiFePO4 are uncovered. Our findings encourage a move away from synthesis techniques that employ particle mixing and sintering to fabricate composites. We provide guidelines on circumventing adverse interphase reactions according to chemistry and ceramic thermal processing budgets in the preparation of these ceramic interfaces as well as on increasing the number of reaction sites. Ultimately, this work provides key ceramic processing guidelines for the preparation of all-solid and high-performing composite cathodes for future Li-garnet SSBs for safe energy storage.
(1) van den Broek, J.; Afyon, S.; Rupp, J. L. M. Interface-Engineered All-Solid-State Li-Ion Batteries Based on Garnet-Type Fast Li+Conductors. Adv. Energy Mater.
2016, 6 (19), 1–11.
(2) Janek, J.; Zeier, W. G. A Solid Future for Battery Development. Nature Energy. 2016, 1–4.
(3) Samson, A. J.; Hofstetter, K.; Bag, S.; Thangadurai, V. A Bird’s-Eye View of Li-Stuffed Garnet-Type Li7La3Zr2O12 Ceramic Electrolytes for Advanced All-Solid-State Li Batteries. Environ. Sci.
2019, 12, 2957–2975.
Impact of Surface Conditioning on Bulk Conductivity of LLZO Garnet Electrolytes
Authors: Grissa Rabeb , Heinz Meike , Battaglia Corsin 
Published: December 2020

Li7La3Zr2O12 (LLZO) garnet ceramics are promising electrolytes for high-energy-density all-solid-state lithium-metal batteries. Unlike most ceramic electrolytes, LLZO is compatible with a lithium-metal anode and thus attracts extensive interest in the all-solid-state battery community.
A crucial parameter for a high performance lithium metal battery is a low anode/electrolyte interfacial resistance, which allows a homogeneous distribution of the local current density and thus prevents the undesired lithium dendritic growth during the charging process. Indeed, the lithium carbonate layer formed on the LLZO surface is found to be responsible for a surface lithiophobic character. Many studies reported and proved the possibility to achieve an ultralow lithium-metal/LLZO interfacial resistance <10 Ω·cm2 by different thermal, mechanical and/or chemical surface treatments in order to eliminate this carbonate layer 1–3 or by different coatings with lithiophilic materials4.
In this work, we study the impact of surface conditioning processes on the bulk properties of LLZO using a combination of different surface and bulk techniques including XPS, XRD, TGA and EIS5. We confirm that negligible interfacial resistance <10 Ω·cm2 is obtained after a thermal treatment at 400 °C. However, we demonstrate that thermal treatments >400 °C in argon atmosphere, even though efficient in eliminating the carbonate layer present on the surface, lead to the formation of an only partially lithiated LLZO layer with a resistance contribution of 10 Ω·cm2 at 500°C which increases to 120 Ω·cm2 at 600°C and almost doubles the pellet's resistance (dominated by grain boundaries).
We also show, by impedance spectroscopy, that chemical treatments with acid solutions lead to garnet protonation, by Li+/H+ exchange. An increase in pellet resistance higher than 50 Ω·cm2 is observed and attributed to the formation of the Li7-xHxLa3Zr2O12 phase, with mixed H+/Li+ conduction. This deteriorates the Li+ transference number of the material. Moreover, the degradation of the LLZO surface is also confirmed by XPS from La and Zr chemical shifts after only 30 s exposure to HCl in contrary to 30 s exposure to water. The presence of a protonated phase may favor dendrite formation.
Overall, this study provides a deep understanding of the impact of surface conditioning on garnets bulk properties. It shows that even though surface conditioning allows a low interfacial resistance between LLZO and lithium metal, it may influence the material's bulk electrochemical performance.
References:

A. Sharafi et al. Chem. Mater. 29, 7961–7968 (2017)

Y. Li et al. J. Am. Chem. Soc. 140, 6448–6455 (2018)

H. Huo et al. Nano Energy 61, 119–125 (2019)

W. Luo et al. Adv. Mater. 29, 1–7 (2017)

R. Grissa, M. Heinz, C. Battaglia, submitted
Sodium Niobium Sulfides As Active Materials for High Capacity Sodium Secondary Batteries
Authors: Nasu Akira , Sakuda Atsushi , Tatsumisago Masahiro , Hayashi Akitoshi 
Published: December 2020

All-solid-state sodium batteries with high safety and high energy density are expected as next generation rechargeable batteries. Active materials play the key role to develop the capacity and the reversibility of the batteries. We have focused on the transition metal sulfides as the active materials. We have reported that the all-solid-state cells using TiS2 operated reversibly[1]. In term of the practical use, the further increase of the capacity is important. One of the solutionsll is the application of sodium rich transition metal sulfides as active materials. In previous reports, the several new crystal polymorphs of Na2TiS3 were produced by melt quenching and mechanochemical reaction [2, 3]. P2-type layered Na2TiS3 obtained by melt quenching showed twice higher capacity than that of the stable phase of O3-type layered Na2TiS3. Cubic rocksalt phase Na2TiS3 prepared by mechanochemical process was also a metastable phase with high capacity. The metastable phases with high ionic conductivity are advantageous for insertion/extraction. Sodium niobium sulfides have sodium-rich compositions such as Na3NbS4. In lithium batteries, cubic rocksalt Li3NbS4 synthesized by mechanochemical process showed the reversible capacity of 400 mAh g-1 [4]. In this study, we have synthesized Na3NbS4 and optimized their crystal polymorphs by melt quenching and mechanochemical process for high capacity electrode.
Electrode materials with the composition of Na3NbS4 were prepared by solid phase reaction or mechanochemical reaction of Na2S, NbS2 and S. DTA curves of the mixture of Na2S, NbS2 and S with the Na3NbS4 composition suggested that phase transition occurred at 630oC. XRD patterns of Na3NbS4 prepared by melt quenching from 700oC showed that O3-type layered phase were obtained. The all-solid-state cells using the layered Na3NbS4 as active materials showed 80 mAh g-1, suggesting that the O3-type sturucture was not suitable for sodium extraction/insertion. On the other hand, the mechanochemical process produced the new metastable phase of Na3NbS4. The all-solid-state cells using the new phase showed the increment on the capacity of 240 mAh g-1. The new crystal polymorph of Na3NbS4 has also been profitable for sodium extraction/insertion. The newly developed Na3NbS4 is a promising active material with high capacity for all-solid-state sodium secondary batteries.

Reference
s
:

[1] A. Hayashi, K. Noi, A. Sakuda and M. Tatsumisago, Nat. Commun., 3 (2012) 856.
[2] A. Nasu, M. Otoyama, A. Sakuda, A. Hayashi, and M. Tatsumisago, Chem. Lett., 48 (2019) 288.
[3] A. Nasu, M. Otoyama, A. Sakuda, A. Hayashi, and M. Tatsumisago, J. Ceram. Soc. Jpn., 127 (2019) 514.
[4] A. Sakuda, T. Takeuchi, K. Okamura, H. Kobayashi, H. Sakaebe, K. Tatsumi and Z. Ogumi, Sci. Rep., 4 (2014) 2.
Particle Size Effects of the Ni-Rich Cathode Material in All-Solid-State Li-Ion Batteries
Authors: Heo Kookjin , Lee Jongkwan , Kim Min-Young , Im Dae-yeong , Gil Woo-ram , Park Won-seok , Lim Jinsub 
Published: December 2020

All-solid-state Li-ion batteries (ASLBs) may be promising candidate to solve the problem because it uses non-flammable inorganic solid electrolytes as an electrolyte and separator. However, ASLBs has serious drawback such as low ionic conductivity compared to liquid electrolyte and have a large interfacial resistance between positive electrode and solid electrolyte in positive electrode. In these regards, reducing particle size of the cathode material can be positive affect to increase the contact area between cathode material and solid electrolyte in the positive electrode to decrease the interfacial resistance. In addition, high capacity Ni-rich cathode material generally was used for high energy density in ASLBs.
In this work, we report on the particle size effects of the Ni-rich cathode material synthesized by co-precipitation method in all-solid-state Li-ion batteries. For comparison of the size effect, the physical, chemical, and electrochemical properties were evaluated by X-ray diffraction, field-emission scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS) and galvanostatic tests.
Bis(trifluoromethanesulfonyl)Amide-Based Room Temperature Ionic Liquid for Potassium-Ion Batteries
Authors: Yoshii Kazuki , Masese Titus , Shikano Masahiro 
Published: December 2020

Rechargeable potassium-ion batteries are promising candidates for low-cost largescale energy storage systems due to their cost-effectiveness, sustainability and comparable energy density. With an increasing number of publications related to electrolytes for potassium-ion batteries, (1) room temperature ionic liquids (RTILs) have also been suggested as feasible electrolytes owing to their superior properties, such as non-flammability and wide electrochemical window.(2)In our research group, we reported bis(trifluoromethanesulfonyl) amide (TFSA)-based RTILs as suitable for the operation of potassium-ion battery when coupled to high voltage cathode materials.(3) In this study, we evaluate the physicochemical properties of TFSA-based RTILs with KTFSA, in addition to assessing their application for high-voltage potassium-ion battery with honeycomb layered cathode oxides. (4)

N-methyl-N-propylpyrrolidinium (Pyr13) TFSA and 1-ethyl-3-methylimidazolium (EMI) TFSA were selected as RTILs in this study. A comparison of their physicochemical properties with same concentration of KTFSA, LiTFSA, and NaTFSA reveal RTILs containing KTFSA to show relatively high ionic conductivity and wide electrochemical window. When a symmetrical cell of potassium was constructed using Pyr13TFSA with 0.5 M of KTFSA, deposition and dissolution reaction could be performed repeatedly without increase in overvoltage. Finally, we evaluated the charge/discharge performance of K2Ni2-x
Co
x
TeO6 (where x=0.25, 0.5 and 0.75) high-voltage cathode materials using Pyr13TFSA with 0.5 M of KTFSA as an electrolyte. Results show that each positive electrode has good cycle performance, and the average voltage changed depending on the Co content in the cathode. We conclude that TFSA-based RTILs are potential candidates for high-voltage potassium-ion battery.
References
1. T. Hosaka, K. Kubota, A. S. Hameed and S. Komaba, Chem. Rev. (2020).
2. T. Yamamoto, K. Matsumoto, R. Hagiwara and T. Nohira, J. Phys. Chem. C, 121, 18450 (2017).
3. T. Masese, K. Yoshii, Y. Yamaguchi, T. Okumura, Z.-D. Huang, M. Kato, K. Kubota, J. Furutani, Y. Orikasa, H. Senoh, H. Sakaebe and M. Shikano, Nat. Commun., 9, 3823 (2018).
4. K. Yoshii, T. Masese, M. Kato, K. Kubota, H. Senoh and M. Shikano, ChemElectroChem, 6, 3901 (2019).
Acknowledgement
This work was conducted in part under the auspices of the Japan Society for the Promotion of Science (JSPS KAKENHI Grant Numbers 19K15686).
Electrodeposition of Tantalum Coatings on Nitinol Stents
Authors: Kuznetsov Sergey , Makarova Olga , Dubrovskiy Anton 
Published: December 2020

The Ni-Ti shape memory alloys are currently a topic of notable interest in medicine. They provide a unique opportunity to make novel surgical implants and instruments for vascular and orthopedic surgery. However, a high nickel content in these alloys could cause the problem of biocompatibility because of nickel toxic effect. In turn, a tantalum is successfully used in medicine as a wire or sheet. It does not irritate the living tissue and does not harm the functioning of the organism, but it has a high specific weight. Therefore, using of tantalum coatings on various materials is more appropriate than utilization of a bulk metal. Thus, it is necessary to improve a corrosion resistance of nickel-titanium alloys (nitinol) that can be achieved with applying of protective porousless tantalum coating.
For obtaining of tantalum coatings the NaCl-KCl-NaF(10 wt%)-K2TaF7(10 wt%) melt was used at a temperature 1023 K. Direct (DC), unsteady state (USC) and pulsed current (PC) were supplied for electrodeposition. A cathodic current density was changed from 5 to 200 mA/cm2 at the galvanostatic mode. The same cathodic current densities and the time of electrolysis (tel
= 0.5-5.0 s) with pauses (tp
= 1-5 s) were used at unsteady state and pulsed electrolysis. It was found that a pulsed electrolysis allow to produce coatings with lower roughness than galvanostatic electrolysis.
Electroreduction of tantalum complexes in chloride-fluoride melt at a nitinol electrode was investigated. A voltammetric curve registered at a nitinol electrode except of the electroreduction peak of tantalum fluoride complexes to tantalum has several peaks corresponding to the formation of intermetallic compounds of nickel and tantalum.
In the case of formation intermetallic compounds between a substrate and coating is an important aspect of the coating adhesion to substrate. The adhesion was measured by cross-sections method using a tester of adhesion Elcometer 107. The measurements showed that coatings obtained by DC and USC could be classified as adhesion to international standards ISO (1) and ASTM (4B). At the same time, coatings deposited on nitinol by PC have a maximum class of adhesion ISO (0) and ASTM (5B). These results were obtained for intermetallic compounds with a thickness around 1-2 μm.
Additional experiments were carried out for obtaining of thick layers of intermetallics and study their composition by SEM and EDX.
The porosity of tantalum coatings was determined by Erhard’s technique based on measuring a current dissolution at a certain potential, in which dissolves a substrate material and coatings remain passive.
Corrosion resistance of the composition tantalum coating-nitinol was studied in different corrosion media.
Ammonium·18-crown-6 bis(trifluoromethylsulfonyl)amide
Authors: Kawata Kio , Kitada Atsushi , Fukami Kazuhiro , Murase Kuniaki 
Published: December 2020

Ammonium (NH4
+) ion has some unique properties as a charge carrier, i.e., natural abundance and lightweight properties. In addition, compared with metal cations (such as Li+, Na+, and K+), NH4
+ ion shows the highest intercalation potential and comparable cycling performance for Prussian blue-type positive electrode materials, KM[Fe(CN)6] (M = Ni and Cu).[1] More recently, the first rocking-chair-type NH4
+ ion battery has been proposed.[2] The electrolytes for NH4
+ ion batteries, however, have rarely been investigated except for aqueous solutions and solid state electrolytes [2,3]. Therefore, electrolytes which enable fast NH4
+ ion transport at medium temperatures, i.e. 100–200 °C, have been of great interest.
Molten salts, especially ionic liquids (ILs), have received considerable attention as novel electrolyte materials for future electrochemical devices owing to their various characteristics such as negligible volatility, low flammability, high thermal and electronic stability, and high ionic conductivity. We have lately reported a series of studies on a hydronium (H3O+) solvate IL, which is described as [H3O+·18C6]Tf2N (18C6 = 18-crown-6-ether; Tf2N = bis(trifluoromethylsulfonyl)-amide, Tf = SO2CF3).[4–6] In [H3O+·18C6]Tf2N, protic H3O+ ion (i.e., solute) is solvated by 18C6 ligand (i.e., solvent) to form a [H3O+·18C6] complex cation (i.e., solvate), and the counter anion is the Tf2N– anion.
It is well known that 18C6 features a six-oxygen cavity and matches well a C3v coordination with NH4
+ as well as H3O+, while the degree of off-center of [NH4
+·18C6] is larger than that of [H3O+·18C6]. As far as we know, however, NH4
+-based molten salts or ILs for electrolytes have never been reported, while alkyl ammonium-based ones have already been studied.[7]
Herein, we report synthesis and physicochemical properties of [NH4
+·18C6]Tf2N (Figure 1). We synthesized NH4Tf2N by neutralization of HTf2N with NH3 before adding equimolar amount of NH4Tf2N to 18C6 to obtain [NH4
+·18C6]Tf2N. A differential scanning calorimetry revealed that [NH4
+·18C6]Tf2N melts at around 100 °C (Figure 2). The ether-coordinated ammonium amide has potential applications as electrolyte materials toward a new class of ammonium ion batteries.
This work was supported financially by Grants-in-Aid for Scientific Research (B) (No.19H02490: A. K.) from the Japan Society for the Promotion of Science. A. K. also thanks the Joint Usage/Research Program on Zero-Emission Energy Research, Institute of Advanced Energy, Kyoto University (ZE2020A-09).
[1] C. D. Wessells et al., J. Electrochem. Soc., 159, A98 (2012).
[2] X. Wu et al., Angew.
Chem. Int. Ed., 56, 13026 (2017).
[3] R. C. T. Slade et al., J. Solid State Chem., 32, 87 (1980).
[4] A. Kitada et al., J. Electrochem. Soc., 165, H121 (2018).
[5] A. Kitada et al., J. Electrochem. Soc., 165, H496 (2018).
[6] K. Kawata et al., J. Electrochem. Soc., 167, 046508 (2020).
[7] J. Qu et al., Tribol.
Lett., 22, 207 (2006).

Figure 1