bluuebunny/crossref_metadata_2025 huggingface dataset:
High Temperature Primary Batteries for Venus Surface Missions
Authors: Glass Dean , Jones John-Paul , Shevade Abhijit V. , Sim Richard , Ratnakumar Bugga V. , Bhakta Dharmesh , Raub Eric
Published: February 2020

Because of the hostile environments of high temperature and pressure, previous Venus probes survived for just two hours. Future Venus surface missions need to survive for much longer durations of several days, in order to return useful science. NASA’s LISSE lander concept has been proposed to operate on the surface of Venus for 60 days. Operating at a temperature of 465 °C and an ambient (CO2) pressure of 92 bar for up to 60 days is a significant challenge and requires new battery chemistries and cell designs. With this objective, we have been investigating high temperature lithium primary batteries with lithium alloy anodes, transition metal sulfide cathodes and molten salt electrolytes. Various cathode materials were screened for thermal stability at high temperature, in contact with the molten salt. Among these cathodes, FeS exhibited the highest stability and laboratory cells were fabricated and tested at 475 OC at various discharge rates to demonstrate long-term operational capability. Initial single cell designs have been shown to be operational for up to 15 days, with the cathode utilization decreasing at the low rates of discharge. Factors determining selection of cathode material, electrolyte composition, separator, etc. will be discussed, along with plans to achieve a full 60 day discharge.
K0.54[Co0.5Mn0.5]O2: New Cathode with High Power Capability for Potassium-Ion Batteries
Authors: Choi Ji Ung , Kim Jongsoon , Myung Seung-Taek
Published: February 2020

Results and Discussion

We propose P3-K0.54[Co0.5Mn0.5]O2, which is rationally designed as a promising cathode material for high-performance potassium-ion batteries (KIBs). Its composition adopts the use of the valence state of Mn above 3.5+ to minimize the disruptive effect of Jahn–Teller distortion in the MnO6 octahedra during the electrochemical reaction. Unlike other types of layered materials that suffer from the sluggish diffusion of large potassium ions accompanying multi-step voltage profiles, P3-K0.54[Co0.5Mn0.5]O2 delivers a high specific discharge capacity of 120.4 mAh (g-oxide)-1 with smooth charge and discharge curves. First-principles calculations predict an activation barrier energy of ~260 meV for a large K+ diffusion, which is comparable to those observed in conventional layered cathode materials for lithium-ion batteries. As a result, even at 500 mA g-1, P3-K0.54[Co0.5Mn0.5]O2 is able to deliver a high discharge capacity of 78 mAh g-1, which is a retention of 65% versus the capacity obtained at 20 mA g-1. Combination studies using operando X-ray diffraction, the ex-situ X-ray absorption near-edge structure, and first-principles calculations elucidate the nature of the excellent potassium storage mechanism of K0.54[Co0.5Mn0.5]O2. This work provides a new insight for the development of efficient cathode materials for KIBs.

Experimental

The P3-K0.54[Co0.5Mn0.5]O2 powder was synthesized using a typical combustion method. An aqueous solution was stoichiometrically prepared by dissolving KNO3, Co(NO3)6H2O, Mn(NO3)26H2O, and citric acid as a chelating agent in distilled water. The starting solution was evaporated overnight on a hot plate at 110 °C under constant stirring. Then, the dried powders were further heated to 200 °C for the auto-combustion of the citric acid. The as-received powders were calcined at 500 °C for 3 h to decompose the nitrates, and then re-calcined at 800 °C for 5 h under an air atmosphere at a heating rate of 2 °C min-1. This was followed by slow cooling at a cooling rate of 1 °C min-1. The X-ray diffraction (XRD) with Cu kα radiation were conducted and structural crystallinity analyzed by Rietveld refinement. The particle morphologies and surface of the powders were observed using SEM and TEM. Galvanostatic charge/discharge test was performed using a R2032-type coin cell. The K-storage mechanisms in the charge and discharge processes were examined by means of ex-situ XRD, in
operando XRD, and ex-situ X-ray absorption spectroscopy (XAS). Also, the structural variation of P3-K
x
[Co0.5Mn0.5]O2 was predicted as a function of the K+ content in the structure based on the first-principles calculation.

Figure 1
A Coupled Tank-in-Series Electrochemical Engineering and Thermal Model for Lithium Sulfur Batteries
Authors: Parke Caitlin D. , Subramaniam Akshay , Kolluri Suryanarayana , Pathak Manan , Subramanian Venkat R.
Published: February 2020

Lithium sulfur (LiS) batteries are a promising option for next-generation energy storage due to their high energy density. Applications where weight is especially important like electric flight and electric vehicles have driven the study of this chemistry because lithium ion batteries are approaching their practical limits. For these applications, the demand for packing more energy into a battery can lead to higher resistive batteries. For lithium sulfur batteries in particular, the resistance is seen to increase with higher capacities per cell (1). As the required energy and subsequently battery packs increase, the importance of heat dissipation for safety and performance also grows, which requires an accurate thermal model for design and control.

Physics-based models enable a look into the internal states of the battery, which correspond to physical phenomena that can contribute to decreased performance under certain conditions. The mathematical model for lithium sulfur batteries developed by Kumaresan et al (2) was the first one-dimensional physics-based model for lithium sulfur batteries. This discharge model was developed with porous electrode theory and considers transport, kinetics, thermodynamics, and morphological changes. The LiS chemistry includes a reduction of solid sulfur to different order polysulfides and finally a precipitation of Li2S, which leads to complexity due to multiple charge carriers and dynamic electrode morphology. The corresponding physics-based model results in a numerically stiff set of equations with variables evolving across many orders of magnitude. To alleviate the computational footprint and still maintain a high degree of accuracy, we have previously developed a mass-conserving lumped model through volume-averaging, called the Lithium Sulfur Tank-in-Series Model. This model, with average quantities in each region, eliminates the spatial dependence for increased computational efficiency and fewer model parameters that expedites model use in estimation, control, and optimization.

In this work, the LiS tank-in-series model is coupled with a thermal model (3). The thermal model includes heat generation due to internal resistance and entropic contributions, and Stroe et al. used the thermal model predictions with a simple empirical model. Coupling the thermal model with a more accurate predictive model allows further insight into battery performance. The model predictions are compared with experimental data from 19.5 Ah pouch cells.

Acknowledgments

The authors are thankful for financial support from the Battery500 Consortium, BAE Systems, and the Joint Center for Aerospace Technology Innovation.

References

J. Offer and M. Wild, Lithium Sulfur Batteries, p. 149, John Wiley & Sons, New Jersey (2019).

Kumaresan, Y. Mikhaylik, and R. E. White, J. Electrochem. Soc., 155, A576 (2008).

I. Stroe, V. Knap, M. Swierczynski, and E. Schaltz, ECS Trans., 77, 467–476 (2017).
(Amazon Catalyst at ECS Grant Winner) Investigations of Magnesium Polysulfide Flow Batteries
Authors: He Peng , Ford Hunter O. , Gonzalez Seancarlos , Doyle Emily , Schaefer Jennifer L.
Published: February 2020

Magnesium-sulfur batteries are currently researched for their potential as beyond Li-ion electrochemical energy storage devices. Despite the theoretical high volumetric energy capacity of magnesium metal anodes, sulfur is not very dense and many reports on magnesium-sulfur batteries use configurations with low active material loading and high carbon content at the cathode and high electrolyte content. Thus, the overall energy density of demonstrated magnesium-sulfur batteries is not very high. However, there may be potential for magnesium-sulfur batteries to be competitive in grid scale storage applications. In this presentation, we will report on our investigations related to magnesium polysulfide flow batteries as supported by an Amazon Catalyst at ECS award.
(Invited) Understanding the Properties That Affect the Reversibility of Sodium Titanate Anodes
Authors: Alvarado Judith , Doeff Marca
Published: February 2020

Sodium-ion batteries have the potential to meet large-scale energy storage demands due to their low cost and abundance. In recent years, several breakthroughs have been made on cathode materials for sodium-ion batteries, including the recognition of oxygen redox activity. However, finding suitable anode materials for sodium ion batteries remains one of the major challenges given that few materials can reversibly intercalate sodium ions. Of these anode materials, sodium titanates are promising candidates due to their ultra-low voltages, high theoretical capacities, and low cost. However, their intrinsic insulating properties and poor conductivity lead to low initial Coulombic efficiencies and unstable solid electrolyte interphases. Herein, we explore a series of sodium titanates which include sodium nonatitanate, lepidocrocite-structured titanates, and Na2Ti3O7, by using a series of synchrotron characterization techniques to further understand the reduction mechanism. Furthermore, we investigate methods to improve the electrode/electrolyte interfaces in these low potential anodes. We hope to shed light on key factors that affect the reversibility of sodium titanate anodes.
Pre-Lithiation Method with Span-CNT Cathode in Li-S Batteries
Authors: Ye Donghao , Shen Chao , Zheng Jim P.
Published: February 2020

Lithium-sulfur (Li-S) batteries with a theoretical specific energy density up to 2,600 Wh·kg-1 is regarded as one of the most promising energy chemical power systems. However, the development of Li-S batteries still faces numerous technical challenges. Both sulfur and Li2S is electrically insulating, leading to a low power capability; the polysulfide generated during charging and discharging processes is highly soluble in electrolytes, resulting in loss of active material and severe redox shuttle effect. To address above issues, sulfurized polyacrylonitrile (SPAN) has been developed as a novel composite cathode material. The strong bonding between sulfur and polyacrylonitrile enables SPAN cathode to operate in commercial carbonate-based electrolyte with an exceptional cycle ability, inhibiting the shuttle effect and self-discharge phenomenon observed in conventional Li-S batteries. In this study, a freestanding SPAN/CNT composite is developed as the cathode material for Li-S batteries, which is capable to deliver a high specific capacity of 1303 mAh g-1 at 0.2 C and a desirable high-rate performance of 1085 mAh g-1 at 2.0 C. Furthermore, Li-ion sulfur full batteries based on SPAN/CNT cathode and graphite anode was assembled using pre-lithiation method. Both the cathode and anode pre-lithiation method was investigated for optimization of system performance. With a high specific capacity and good cycle life, the proposed Li-ion sulfur full battery system provides an alternative approach to fabricate safe and low cost metal-free Li-ion batteries.
Improvement of Electrochemical Stability of Layered Oxide Electrodes in Na-Ion Batteries Via Control of Chemical Composition in the Interlayer Region
Authors: Pomerantseva Ekaterina
Published: February 2020

Layered transition metal compounds with expanded interlayer region, stabilized by structural water, often show high initial capacities but suffer from rapid capacity decay and poor rate capability in Na-ion batteries. High-temperature annealing, accompanied by phase transformation with the formation of more dense atomic structures, has been shown to improve electrochemical stability. However, the capacity of annealed materials decreases compared to their original forms. Here, we for the first time demonstrate that low-temperature annealing (260oC under vacuum) can be used to achieve enhanced electrochemical stability of high capacity Na-preintercalated bilayered vanadium oxide (δ-NaxV2O5·nH2O) nanobelts, while preserving its open layered structure with expanded interlayer region available for insertion and diffusion of a large number of electrochemically cycled Na+ ions. The mechanism of the thermally induced interlayer water loss is discussed. The improved capacity retention exhibited by low-temperature vacuum annealed δ-NaxV2O5·nH2O nanobelts is attributed to the partial removal of the structural water from the interlayer region, formation of additional bonds within the V-O bilayers, and increased stacking order of V-O bilayers. Additionally, we will show the effect of the chemical pre-intercalation of alkali (Li+, Na+, K+) and alkali-earth (Mg2+ and Ca2+) ions in the interlayer region of the bilayered vanadium oxide on electrochemical stability in Na-ion batteries. By altering the nature of the chemically preintercalated ion, interlayer spacing of the synthesized δ-MxV2O5 (M = Li, Na, K, Mg, Ca) materials was varied between 9.62 and 13.40 Å. We show that the interlayer spacing increases with the increase of the hydrated ion radius. The ion (Li+, K+, Mg2+, Ca2+) stabilization effect was investigated in Na-ion cells, with Na-preintercalated phase, δ-NaxV2O5, serving as a reference material. Our analyses indicate that cyclability and rate performance of the δ-MxV2O5 improves with increasing interlayer spacing and decreasing the ionic radius of chemically preintercalated ion. The highest initial capacity, greatest capacity retention, and highest capacity retention at higher current rates were exhibited by Mg- and Li-stabilized δ-V2O5. Low-temperature vacuum annealing ion stabilization achieved via chemical pre-intercalation synthesis approach are proposed as efficient strategies to advance electrochemical stability of the growing family of hydrated transition metal compounds used as electrodes in beyond lithium-ion batteries.
Lithium-Mediated Ammonia Synthesis from Water and Nitrogen Based on a Membrane-Free Immiscible Aqueous/Organic Hybrid Electrolyte System
Authors: Kim Kwiyong , Chen Yifu , Li Wenzhen
Published: February 2020

Lithium-mediated pathway provides a promising way for facile and selective dissociation of nitrogen for ammonia synthesis [1,2]. However, the prevailing electro-deposition of lithium, especially when coupled to the anodic oxygen evolution from water or hydroxide, presents disadvantages including the use of expensive Li-ion conducting ceramics[3] or high temperature operation of molten salts[1]. Herein, we reported a membrane-free electrochemical system for Li deposition which relies on the immiscibility of aqueous/organic electrolytes and demonstrated the applicability of the biphasic system for the realization of Li-mediated ammonia synthesis. The behavior of this system is not different from a LISICON-based cell,[1] especially thanks to the stability of the biphasic system. Rather, this system requires lower cell voltage (5.3 V in this study vs. 6.2 V in LISICON-based cell[3] at 5 mA cm-2), even without the need of expensive membrane, rendering it more economically favorable. The fairly decent FE and NH3 synthesis rate (57.2 % and 1.21 × 10-9 mol cm-2s-1, respectively) have been realized merely using one hybrid model electrolytes system (LiClO4 and PC-H2O) without any optimization. Judicious selection of immiscible electrolytes with better biphasic stability, higher conductivity, higher stability against Li (lower SEI formation), and applicability to a continuous, integrated process will achieve further improvements in the novel Li-mediated NH3 synthesis approach.

References:

[1] J. M. McEnaney, A. R. Singh, J. A. Schwalbe, J. Kibsgaard, J. C. Lin, M. Cargnello, T. F. Jaramillo and J. K. Nørskov, Energy & Environmental Science, 2017, 10, 1621–1630.

[2] N. Lazouski, Z. J. Schiffer, K. Williams and K. Manthiram, Joule, 2019, 3, 1127–1139.

[3] K. Kim, S. J. Lee, D.-Y. Kim, C.-Y. Yoo, J. W. Choi, J.-N. Kim, Y. Woo, H. C. Yoon and J.-I. Han, ChemSusChem, 2018, 11, 120–124.
(Invited) Exploiting Surface Reactivity to Prepare Electrode Materials in a Single Step
Authors: Veith Gabriel M. , Armstrong Beth , Burdette Mary Kathyrn , Hoelzer David
Published: February 2020

Crushing rock has been an effective approach to make tools and materials for thousands of years. In this presentation this approach will be expanded to making electrode materials with tailored surface functionalities that facilitate electrode formation, SEI formation, and lifetime. Specific examples will be given with respect to the functionalization of silicon anode materials and how this functionalization influences electrode formation processes.

Acknowledgement: This work was supported by the US Department of Energy’s Office of Energy Efficiency and Renewable Energy through the Vehicle Technology Office (Brian Cunningham Program Manager).
Investigating the Promise of Incorporating a Redox Mediator in Li–O2/CO2 batteries
Authors: Marques Mota Filipe , Byon Hye Ryung , KIM Dong Ha
Published: February 2020

In recent years, continuous studies have highlighted the languished research state of Li–O2, and the impelling development of energy storage devices with analogously high theoretical energy density [1]. In preliminary studies, we established that fed O2 and CO2 mixtures (Li–O2/CO­2) swiftly shift the reaction mechanism toward an exclusive formation of Li2CO3 in a TEGDME-based electrolyte. The proposed O2-assisted pathway is initiated by an electron transfer from the cathode, with subsequent CO4
– formation and complete Li2O2 suppression. Compared with O2-driven counterparts, the CO2-based Li–air cell suffers, however, from higher overcharges during the decomposition of Li2CO3 at ~4.5 V, rendering impracticable a commercialization of these technologies [2]. Here we propose for the first time the incorporation of a redox mediator (RM) toward facile Li2CO3 oxidation in Li–O2/CO­2 devices. Lithium bromide (LiBr) possessing two redox couples (Br−/Br3
− and Br3
−/Br2) has gathered increasing attention in conventional Li–air cells and was considered a suitable candidate in this study. All galvanostatic measurements were carried out under 30% CO2. At optimized concentrations, hindered recharge potentials (~0.5 V) at similarly sustained cyclability were demonstrated. Further dissection of the significance of involved Br−/Br3
−/Br2 species inferred, however, an additional role of the RM in the stabilization of intermediate discharge species and in the undesirable formation of side-products. In this context, drawn conclusions reinforced the need to consider a deeper evaluation of the effects of a RM inclusion beyond an overcharge decrease and the urge to stabilize RM/RM+ species participating in deleterious side-reactions with neighboring species and cell components.

References

[1] Grande, E. Paillard, J. Hassoun, J.-B. Park, Y.-J. Lee, Y.-K. Sun, S. Passerini and B. Scrosati, Adv. Mater.
2015, 27, 784.

[2] Qiao, J. Yi, S. Guo, Y. Sun, S. Wu, X. Liu, S. Yang, P. Hec and H. Zhou, Energy Environ. Sci.
2018, 5, 1211.
Atomic Layer Deposition of Ultrathin Glassy Lithium Borate-Carbonate Solid Electrolytes
Authors: Kazyak Eric , Davis Andrew L. , Yu Seungho , Chen Kuan-Hung , Sanchez Adrian J. , Lasso Jose , Thompson Travis , Sakamoto Jeff , Siegel Donald J , Dasgupta Neil P.
Published: February 2020

Solid state electrolytes could enable significant improvements in energy density, cycle life, and safety of next-generation battery chemistries. The ability to fabricate thin electrolyte films with high ionic conductivity and excellent stability on complex architectures has been a bottleneck to realizing a wide range of 3D structured thin film and bulk batteries. Recent progress in ALD for solid state electrolytes has shown great promise, and enabling even higher conductivities and stability with Li metal anodes could dramatically enhance the energy and power density of ALD-based batteries. In addition, ALD films with high conductivity and good stability could be used for interfacial engineering of bulk-type solid and liquid based batteries to improve stability and safety.

This work demonstrates a novel ALD process for glassy lithium borate-carbonate thin films with ionic conductivities above 10-6 S/cm at 298K. This represents a 6x improvement over the previous best reported value for an ALD solid electrolyte.1 The composition, structure, and stability of the films are characterized with X-ray photoelectron spectroscopy and a range of electrochemical measurements. These experiments are compared with those calculated with Density Functional Theory and Molecular Dynamics to elucidate the origins of the high ionic conductivity and excellent stability. The properties are studied as a function of deposition temperature showing tradeoffs between process conditions and performance, and demonstrating the precise control afforded by the ALD process.2 The optimized film remains an ionic conductor when in contact with metallic Li, with no measurable changes even over several weeks, and displays stable cycling when paired with a thin-film cathode and Li metal anode.

References

(1) Pearse, A. J.; Schmitt, T. E.; Fuller, E. J.; El-Gabaly, F.; Lin, C. F.; Gerasopoulos, K.; Kozen, A. C.; Talin, A. A.; Rubloff, G.; Gregorczyk, K. E.; Chem. Mater.
2017, 29, 3740–3753.

(2) Kazyak, E.; Chen, K. H.; Davis, A. L.; Yu, S.; Sanchez, A. J.; Lasso, J.; Bielinski, A. R.; Thompson, T.; Sakamoto, J.; Siegel, D. J.; Dasgupta, N. P.; J. Mater. Chem. A
2018, 6, 19425–19437.
Elastic Single-Ion Conducting Polymer Electrolyte
Authors: Cao Pengfei , Yang Guang , Nanda Jagjit , Sokolov Alexei P. , Saito Tomonori
Published: February 2020

Single-ion conducting polymer electrolytes (SCPEs) are well recognized being the advanced electrolyte system with increased energy efficiency and prolonged cell lifetime due to their capability to mitigate electrode polarization and reduce electrolyte loss. Fabrication of stretchable SCPEs will definitely benefit the future stretchable batteries/electronics considering the advantageous electrolyte performance of the SCPE based systems, while no one report the SCPEs with specific mechanical performance. Herein, we will report the fabrication of a series of single-ion conducting polymer electrolyte membranes with high flexibility and stretchability. Polydimethylsiloxane (PDMS) network and polyethylene glycol (PEG) side chains are critical in retaining their satisfied mechanical and electrochemical performance. The investigation revealed that the incorporation of poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) plays a significant role in forming the stretchable polymer membranes, which can not only lower the glass transition temperature but also provide additional reactivity. The obtained membranes exhibited 88%-252% elongation before breaks, and the mechanical properties, including Young’s modulus, toughness and tensile strength, are well adjustable by tuning the crosslinking density. Galvanostatic test of the assembled cells using the obtained SCPE member exhibited satisfied cycling performance with capacity retention up to 81.5% after 100 cycles.

Figure 1
Design of High Voltage All-Solid-State Batteries Based on Sulfide Electrolytes
Authors: Li Xin
Published: February 2020

Ceramic sulfide solid-electrolytes are amongst the most promising materials for enabling solid-state lithium ion batteries. The ionic conductivities can meet or exceed liquid-electrolytes for such ceramic sulfides, however, there is a theoretical concern about the narrow electrochemical stability window of approximately 1.7-2.1 V vs Lithium metal. In addition, ceramic sulfides are frequently plagued by interfacial reactions when combined with common electrode active materials. In this talk, methods for the stabilization of both the bulk electrochemical decompositions and the interfacial reactions will be discussed. Solid-state cells stable up to 5V, including layered Li-Co-O and spinel Li-Mn-Ni-O, will be presented and the stabilization mechanisms will be discussed.

Ceramic sulfides are known substantially swell during electrochemical decay. Such swelling has been shown to provide a viable means by which to stabilize electrochemical decomposition in lithium ion batteries[1]. Evidence and theoretical understanding of stability window expansion as the result of mechanical constriction will be discussed for both Li10GeP2S12 and Li10SiP2S12 systems. Further discussion on the impact of interfaces will focus on our novel high-throughput computational schema[2], which has enabled the evaluation of nearly 70,000 material DFT calculation for interfacial chemical and electrochemical stability with Li10SiP2S12. These new computational methods found over 2,000 high-voltage coating materials that are electrochemically inert against Li10SiP2S12 at standard cathode voltages.

[1] Fan Wu, William Fitzhugh, Luhan Ye, Jiaxin Ning, Xin Li. Advanced Sulfide Solid Electrolyte by Core-Shell Structural Design. Nature Communications, (9), 4037 (2018).

[2] William Fitzhugh, Fan Wu, Wenye Deng, Pengfei Qi, Luhan Ye, Xin Li. A High-Throughput Search for Functionally Stable Interfaces in Sulfide Solid-State Lithium Ion Conductors. Advanced Energy Materials. In press.
(Battery Division Student Research Award sponsored by Mercedes-Benz Research & Development) Solution-processable closo-borate Electrolyte for all-solid-state Sodium–ion Batteries
Authors: Duchêne Léo , Kim Dong Hyeon , Moury Romain , Remhof Arndt , Hagemann Hans , Jung Yoon Seok , Battaglia Corsin
Published: February 2020

All-solid-state batteries promise to simultaneously yield higher energy and power density, and improved safety as compared to state-of-the-art lithium-ion technologies based on organic liquid electrolytes. A competitive all-solid-state battery requires a solid-state electrolyte with high ionic conductivity near room temperature, combined with high thermal and electro-chemical stability as well as ease of processing into a device. Meeting these requirements simultaneously represents a major challenge.

Here we present a sodium-ion conductor in the closo-borate family, namely Na2(B12H12)0.5(B10H10)0.5, that simultaneously offers high sodium-ion conductivity of 0.9 mS/cm at 20 °C, excellent thermal stability up to 450 °C, and importantly a large electro-chemical stability window of 3 V including stability versus metallic sodium enabling the use of a sodium metal anode.[1-2] Using a solution-based impregnation method to create intimate contact between cathode material and solid-state electrolyte, we demonstrate that Na2(B12H12)0.5(B10H10)0.5, can be implemented in a 3 V all-solid-state sodium-ion battery consisting of a sodium metal anode and a NaCrO2 cathode. The cell shows high cycling stability and good rate performance with more than 85% capacity retention after 250 cycles at C/5. [3]

We further extend this approach to the use of slurry-based composite electrodes as used in conventional batteries.[4] We show that Na2(B12H12)0.5(B10H10)0.5 can be prepared and infiltrated in its highly conductive phase inside porous sheet-type electrodes using the appropriate solvent. The infiltrated electrodes can be cycled in all-solid-state half cells at room temperature with remarkable stability and rate capability. The method is demonstrated for both NaCrO2 cathode and Sn metal anodes including demonstration of operation in an all-solid-state full cell based on the closo-borate electrolyte.[4,5]

[1] L. Duchêne et al., Chem. Commun., 2017, 53, 4195.

[2] L. Duchêne et al., Chem. Mater., 2019, 10.1021/acs.chemmater.9b00610

[3] L. Duchêne et al., Energy Environ. Sci., 2017, 10, 2609

[4] D. H. Kim et al., Nano Lett. 2017, 17, 3013.

[5] L. Duchêne et al., submitted
Investigation of the Stabilization Mechanism of Air Stable n-Type Single-Walled Carbon Nanotubes Sheets Based on Adsorption Isotherm Measurements
Authors: Yamaguchi Ryohei , Nakashima Yuki , Fujigaya Tsuyohiko
Published: February 2020

In spite of the remarkable growth of microelectronics such as wearable devices, remote sensors, etc. On the market in recent years, almost all of them are still powered by batteries that are required to be recharged or replaced at stated periods. If these electronic devices can run continuously for an extended time without any external interference, the benefits would be further enhanced. One such solution is to produce energy from the human body heat, where the thermoelectric (TE) generation mechanism is used to generate electricity from temperature difference. The principle behind TE generation is the Seebeck effect. It is a phenomenon to produce potential difference from the temperature difference between the ends of a TE generator. The efficiency of this TE conversion can be evaluated by the figure of merit, ZT = S2σT/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the thermal conductivity. TE generators with a high Seebeck coefficient, high electrical conductivity, and low thermal conductivity are expected to have good TE properties. To fabricate the TE devices, p- and n-type materials are necessary and the research of TE materials using inorganic semiconductors such as Bi2Te3 have been done for a long time as they illustrate high performance more than ZT = 1. However, these materials contain rare and toxic elements and they are difficult to process. Therefore, among the several candidates including conducting polymers, single-walled carbon nanotubes (SWNTs) are emerged as the promising candidate due to their non-toxicity, processability, remarkable electrical and thermal conductivity, potentially large Seebeck coefficient and light weight. However, due to air oxidation, SWNTs show only p-type semiconducting property in air. In the development of the SWNTs-based TE devices, instability of the n-type SWNTs has been a crucial issue, since n-type SWNT are easily oxidized due to an electrophilic chemisorption of oxygen on the charge polarization.1 Under such background, we have reported that air-stable n-type SWNTs can be formed by adsorbing 2-(2-methoxyphenyl)-1,3-dimethyl-2,3-dihydro-1H-benzo [d] imidazole (o-MeO-DMBI). However, the stabilization mechanism is not clear. herefore, in this research we studied the stabilization mechanism based on the adsorption isotherm measurements, where the SWNT sheets were dipped in the ethanol solution of o-MeO-DMBI in different concentrations at 25 ºC. From the adsorption isotherm, we revealed that SWNTs sheets adsorbed below monolayer of o-MeO-DMBI showed unstable in n-type, while SWNT sheets adsorption of o-MeO-DMBI showed stable n-type property over full coverage3.

1) Zhu, X.-Q.; Zhang, M.-T.; Yu, A.; Wang, C.-H.; Cheng, J.-P. J. Am. Chem. Soc. 2008, 130, 2501.

2) Nakashima, Y.; Nakashima, N.; Fujigaya, T. Synthetic. Metals. 2017, 76, 225.

3) Nakashima, Y.; Yamaguchi, R.; Fujigaya, T. submitted.
Real-Time Cross-Sectional Surface Observation of Brass to Investigate Dezincification Corrosion
Authors: Hoshi Yoshinao , Uchisawa Yukihiro , Nishihara Yoshihiro , Shitanda Isao , Itagaki Masayuki
Published: February 2020

The dezincification corrosion of brass (Cu-Zn alloy) is a serious problem in the plumbing system because it may cause the leakage accident. When the dezincification corrosion occurs on the brass surface, a porous copper rich layer is formed on the brass surface due to the selective dissolution of zinc1,2. In order to understand the dissolution mechanisms, it is important to explore the relationship between the dissolution behavior of zinc and the growth of the copper rich layer. Our group3-5 developed the real-time surface observation system with channel flow double electrode to investigate localized corrosion of copper and magnesium. In the present study, a real-time cross-sectional surface observation system combined with electrochemical measurement was developed for the investigation of the dezincification corrosion of brass.

A video of the cross-sectional surface morphology of brass was taken by an optical microscope combined with a charge-coupled device (CCD) camera during the anodic polarization. The electrochemical cell was constructed using transparent acrylic plates. The electrochemical measurement was carried out by a three-electrode cell. The working electrode and the counter electrode were a brass plate and a platinum wire, respectively. A KCl-saturated silver/silver chloride electrode (SSE) was used as a reference electrode. The electrolyte solution was 0.5 M NaCl containing 5 mM NaHCO3 and kept at 60 oC. The surface of brass plate was covered with the transparent resin except the active surface area (0.393 cm2). The brass plate was fixed at wall surface to record the video of the active surface area.

The galvanostatic polarization was performed for 24 h to observe the dissolution behavior of brass. After 3 hours, the copper rich layer was formed on the brass surface due to the selective dissolution of zinc. The localized dissolution was observed after 6 hours, and the dissolution was then observed on the whole surface. The selective dissolution of zinc and simultaneous dissolution of zinc and copper from brass surface were discussed based on the video images and the potential changes of brass during the measurement.

References:

1) H.W. Pickering, C. Wagner, J. Electrochem. Soc., 7, 114 (1967).

2) Yoshinao Hoshi et al., J Solid State Electrochem, 19, 3551 (2015).

3) Yoshinao Hoshi et al., J. Electrochem. Soc., 164, C450 (2017).

4) Yoshinao Hoshi et al., Surf. Finish. Soc. Jpn., 69, 34 (2018).

5) Yoshinao Hoshi et al., J. Electrochem. Soc., 165, C243 (2018).
Cavitation Corrosion of Cast Al-Alloy in an Ethylene Glycol-Water Solution
Authors: Zhou Lin , Chen Zhenning , Wang Xindi , Shi Yanan , Yong Xingyue
Published: February 2020

As a heat media, an ethylene glycol-water solution is widely used as a key component in a cooling liquid for the cooling systems of motors and electric equipment or devices. Therefore, cast Al alloy pumps are often used to circulate the ethylene glycol-water solution in the cooling systems. Thus, cast Al alloy are often subjected to cavitation corrosion.

In this study, the cavitation behaviors of cast Al alloy in an ethylene glycol-water solution were studied using the ultrasonic cavitation corrosion apparatus which was made in accordance with ASTM G32. Then, the electrochemical kinetic of cavitation corrosion and the chemical structures of the corroded surface were investigated with EIS in conjunction with XPS analysis. The results showed that the synergistic effect between electrochemical corrosion and cavitation resulted in the increment of the cumulative weight loss of cast Al-alloy in an ethylene glycol-water solution with cavitation time. The calculation of the impacting efficient for cathodic and anodic processes demonstrated that the cavitation corrosion of cast Al-alloy was controlled by anodic process. In this case, the polarization resistance increased with cavitation time. In a stagnant ethylene glycol-water solution, EIS spectra of cast Al-alloy consisted of a deformed capacitance loop, but it had two time constants based on the Bode plot. Under cavitation, its EIS spectra consisted of a capacitance loop at high frequency zone and an inductive loop at a low frequency zone. It was indicated that the cavitation corrosion mechanism of cast Al alloy in an ethylene glycol-water solution under cavitation was changed obviously. Under cavitation, corroded morphology became rougher with cavitation time and many of pits and cracks existed after cavitation. At the same time, the volume of Al and Si compounds decreased, and that Si compound decreased much more compared with Al(OH)3. At the same time, the volume of OH- increased with cavitation time. This was shown that cavitation accelerated Si compound to peel off from the substrate, resulting in the changes of both the morphology and the chemical structures of surface film under cavitation. Finally, the cavitation corrosion model was proposed based on the above studies.
Investigation of Corrosion Behavior of Stainless Steels As a Function of Composition, Grain Size and Austenite to Martensite Phase Ratio
Authors: Kotan Hasan , Uzunoglu Aytekin
Published: February 2020

It is well established that the severe plastic deformation of metastable austenitic stainless steels causes martensitic transformation and the annealing of deformation induced martensitic phase induces reverse transformation from martensite to austenite the ratio of which has been found to be a factor of alloy compositions and annealing / sintering temperatures. In this study, nanocrystalline austenitic stainless steels of different compositions will be synthesized from elemental powders by using high energy mechanical milling. As-milled powders will be cold-consolidated and sintered at elevated temperatures up to 1100 ºC in order to facilitate a better densification for the subsequent experiments and alter the microstructure i.e., grain size and austenite to martensite phase ratio. Microstructural evolutions as a function of alloy compositions and sintering temperatures will be investigated using focused ion beam, transmission electron microscopy and in-situ / ex-situ x-ray diffraction techniques to determine the grain sizes and phases upon milling and sintering. The corrosion behavior of austenitic stainless steels will be determined using immersion and electrochemical tests at various temperatures. The electrochemical corrosion tests will be conducted using a flat corrosion test and a potentiostat. The relative importance of compositions, grain sizes and austenite to martensite phase ratios will be discussed with respect to corrosion behavior of the studied stainless steels.
Electrochemical Impedance Analysis on Hydrogen Penetration Mechanisms on Steel
Authors: Fukada Haruka , Hoshi Yoshinao , Shitanda Isao , Itagaki Masayuki
Published: February 2020

Environmental degradation of steels associated with the hydrogen embrittlement has been a serious problem worldwide. The hydrogen evolution reaction (HER) on steel has been studied by some electrochemical methods [1-3] in order to explore the hydrogen penetration behavior on steel. In the present study, the electrochemical impedance spectroscopy was applied to the investigation of the hydrogen reaction mechanisms on steel because the time constants observed in impedance spectrum can be discriminated.

The reaction scheme of HER on a metal were proposed to be a multistep as described below [4].

H+ + M + e- → MHads (1)

MHads + H3O+ + e- → H2 + H2O + M (2)

The reaction related to the hydrogen adsorption and absorption on steel was expressed by the following reaction [4].

MHads ↔ MHabs (3)

In these reactions, the M is metal, the MHad is the hydrogen adsorption, the MHab is the hydrogen absorption. The first step (Eq. (1)) and the second step (Eq. (2)) are Volmer reaction and Heyrovsky reaction, respectively. The third step is the hydrogen penetration reaction on steel. The reactions (2) and (3) are competition reactions when the MHad generated by the reaction (1). In order to investigate these competition reactions, the Faraday impedance simulations were carried out based on these reactions. When the reaction rate constant of hydrogen penetration reaction is small compared to the HER, the capacitive loop related to the electrode/solution interface was observed in the high frequency range and the capacitive loop appeared in the low frequency range. In the case of the large reaction rate constant of hydrogen penetration compared to the HER, the impedance spectrum described the capacitive loop related to the electrode/solution interface in the high frequency range and the inductive loop in the low frequency range, respectively. These results indicated that the low frequency impedance is related to the rate-determining step of the reactions (2) or (3). The electrochemical impedance measurement of steel was performed under potentiotatic polarization in order to discuss the HER and the hydrogen penetration mechanisms on steel based on the results of simulations.

References:

[1] M. A. Devanathan and Z. Stachurski, J. Electrochem. Soc., 111, 619 (1964).

[2] J. O'M. Bockris, J. McBreen, and L. Nanis, J. Electrochem. Soc, 112, 1025 (1965).

[3] E. Tada and A. Nishikata, ISJ internatonal, 56, 424 (2016).

[4] C. Gabrielli, P. P. Grand, A. Lasia and H. Perrot, Electrochemical Society Proceedings, 16, 147 (2000).
Corrosion Protection of Mg Based Alloy in Neutral Sodium Chloride Solution By Electrodeposited Ni-TiO2 – Silane Composite Coating
Authors: BinSabt Mohammad , Al-Kharafi Faizah M , Abditon Maryam , Galal Ahmed
Published: February 2020

The electrochemical behavior of magnesium based alloy (composition Mg(93) Zn(1) Al(6) alloy) is studied in corrosive media of 3.5% NaCl aqueous electrolyte solution. Electrochemical techniques including D.C polarization and electrochemical impedance (EIS) measurements are used to characterize the behavior of the alloy. The data indicated the direct dissolution of the alloy as evidenced from ICP measurements and surface examination after exposure to the corrosive media. The alloy then was treated with a silane-polymer coating that proved effective protection to the surface of the alloy against corrosion.

Another approach is applied to improve the corrosion protection ability and film quality to the magnesium-based alloy based on the electro – deposition of another metal layer on top of the surface of the alloy. The Ni/TiO2 – silane composite layer was applied to the electrode to serve as a protective layer for the alloy. First the nickel and TiO2 nanoparticles was applied to the surface of the alloy followed by a protective silane film either by sequential spin-coating or layer-by-layer spin-coating. The protecting film is composed of 1,2bis(triethoxysilyl)ethanepoly(vinyl alcohol) hybrid (TESEPVA). Surface examination of the alloy or film-coated alloy was performed before and after exposure to the corroding electrolyte. The surface techniques used are field-emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray analysis, X-ray photoelectron spectroscopy (XPS) and surface enhanced Raman spectroscopy (SERS). The film thickness and surface wettability were also determined with the film displaying relative increase in the hydrophobic character.
Corrosion Behavior of Electrodeposited Znfe Sacrificial Coatings in Saline Solution: Alternative to Conventional Electrodeposited Sacrificial Coatings
Authors: Baissac Lucas , Arrighi Céline , Savall Catherine , Creus Juan , Rolet Jason
Published: February 2020

Surface treatment and especially metal plating is a key process in the mechanical industry. It allows to protect structural and mechanical parts from degradation and prolongs their service life. To protect steel against corrosion, sacrificial coatings are widely used, and zinc coatings are often applied in this scope. However, the kinetic of zinc galvanic corrosion is very important. To overcome this problem, more noble elements are codeposited, involving the use of harmful metal salts, for instance nickel (II) salts. The industrial use of these salts is more and more restricted and regulated all over the world. Many alternatives are proposed, the more promising consisting in zinc-iron alloy electrodeposition with high iron content. The Atlas project (Alternative TechnoLogies for improved Anticorrosion Solutions), which is a large industrial consortium, is born in order to develop the ZnFe coatings properties and the knowledge of its corrosion mechanism.

The corrosion behaviors of commercial ZnFe electrodeposited coatings were investigated in 3.5 % NaCl solution. Corrosion potential is shifted towards more positive values, limiting the risk of galvanic corrosion with the substrate compared with pure zinc coatings. Sacrificial protection is evaluated with potentiodynamic tests, and longtime open circuit potential immersion is performed in order to analyze corrosion products. Other industrial sacrificial coatings performances are evaluated as a reference for those new ZnFe sacrificial coatings.
(Invited) Electrolyte Design and Solution Mediation Processes in Lithium-Oxygen and Lithium-Sulfur Batteries
Authors: Lu Yi-Chun
Published: February 2020

Lithium-sulfur (Li-S) and lithium-Oxygen (Li-O2) batteries have attracted intensive research attentions owing to their potential to provide higher gravimetric energy density than conventional Li-ion batteries. However, Li-S and Li-O2 batteries have been suffering from poor cycle life, low round-trip efficiency and low practical energy density compared to conventional Li-ion batteries. Different from intercalation-based charge storage, Li-S and Li-O2 both operate based on solution-mediated redox processes. The development of stable and reversible Li-S and Li-O2 chemistries requires fundamental understanding on how solvent and salt affect the reaction mechanism and mediation processes. In this presentation, we apply in situ/operando spectroscopy/analytical techniques to study electrolyte structure-function relationship in Li-S and Li-O2 batteries. We exploit online electrochemical mass spectrometry, operando UV-Vis spectroscopy, rotating rink disk electrode and synchrotron-based X-ray absorption near edge structure spectroscopy to investigate the role of solvent and salt (e.g., donicity, electron-accepting ability, dielectric constant etc) on the reaction mechanism and solution mediation processes in sulfur and oxygen redox chemistries. We will discuss the interplay between solution mediation and solid phase precipitation and the synergistic effect of employing redox mediators and novel cell design in improving the rate and cycle life of Li-S and Li-O2 batteries.
(IBA Research Award) Crystal Chemistry of Nasicon-Type Electrodes and Solid Electroytes
Authors: Masquelier Christian
Published: February 2020

Polyanionic materials are of special interest as positive electrodes alkali-ion batteries since they offer competitive electrochemical performances in particular for long-term electrochemical operation. Phosphate-based polyanionic crystal structures of Na-containing compositions in particular are based upon stable 3D frameworks, which provide long-term structural stability and demonstrate a unique variety of atomic arrangements in their crystal structures. In particular, the NASICON structure offers unique playground for extensive transition metal substitution and lithium or sodium content monitoring, for the extensive exploration of new cathode materials for Li or Na batteries or of solid electrolytes for all solid state batteries.