bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Voltage Compatible Bi-Functional Electrolyte for Li Metal Batteries
Authors: Chang Won-seok , Sugimoto Toshinori , Mizumo Tomonobu , Lee Yong-Gun , Choi Hong Soo , Kang Hyorang , Yu Taehwan , Doo Seokgwang 
Published: February 2020

In a few decades, the huge advancement was achieved via successful commercialization of Li ion batteries. As the demand for more stable energy supply source grows, the necessity to replace the conventional carbon anode also is being increased. Lithium metal has been suggested as one of the candidates. However, it has few critical barriers regarding the safety which must be overcome to be successful alternative for the next generation batteries. Among diverse approaches, introducing a safe electrolyte to the system could be one step forward for Lithium metal to be used as the next generation batteries.
In this study, the glyme based electrolyte was formulated by simply making a solution with Lithium bis(fluorosulfonyl)imde (LiFSI), 1-2, dimethoxy ethane and the fluorinated ether. This mono-glyme has been known to be effective to restrain Lithium dendritic growth1. Also, it can dissolve LiFSI salt up to 9.6 mol. Since, highly concentrated electrolyte is able to put up with relatively high electrochemical stability2, thus, it could be a favorable solvent for the electrolyte. On the other hand, the fluorinated part of the electrolyte (1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether) could not dissolve the salt at all, but, it functions as an anti-oxidation agent and a viscosity lowering agent at the same time. In Figure 1(a), it was proven that the electrolyte comprising those two components is quite effective to maintain the stability within the practical voltage window ranged from 3.0 ~ 4.5 V (vs. Li/Li+) via cyclic voltammetry (CV).
Based on the stability, it also shows the full cell test results indicating outstanding cycle performance over 200 cycle even with highly packed cathode (c.a. 4g/cc) as illustrated in Fig. 1(b). The extended performance is attributed to the synergistic contribution from each component of the electrolyte.
Highly-Ordered Structural Deposition of Li2O2 in Li-O2 Battery
Authors: Hase Yoko , Seki Juntaro , Shiga Tohru , Nishikoori Hidetaka , Iba Hideki , Takechi Kensuke 
Published: February 2020

Non-aqueous Li-O2 battery is one of the possible alternatives to current lithium ion batteries due to its theoretical high energy density, however, it still presents unsolved fundamental issues related to poor cycle life and low current density. Li2O2, which has been accepted as a discharge product, shows inherently low electron conductivity and its deposition on cathodes leads the obstruction of continuing discharge reaction. Therefore, in many cases, nano-structural carbon materials with large surface area have widely been applied as cathode to obtain specific high discharge capacity.
Herein we present an alternative strategy to enhance the discharge capacity in the Li-O2 batteries with controlling the morphology of the deposition. We anticipated that the continuous steady discharging could be obtained if the reaction active sites on the cathode were not clogged with discharge products which were deposited in highly-order structure. In this study, we focused on the effect of the combination of cathode materials and electrolytes on the discharge capacity and the morphology of Li2O2. Figure 1. shows that relatively high current density (0.2 mA/cm2) and high discharge capacity (> 600 mAh/g) were obtained with the carbon paper cathode and the acetonitrile (AN) electrolyte (0.5 M LiTFSI in AN). In contrast, tetraethylene glycol dimethyl ether (TEGDME) or dimethyl sulfoxide (DMSO), which have higher viscosity and lower O2 solubility than acetonitrile, 1 resulted in the lower discharge capacity (< 30 mAh/g) when they were used as a solvent of the electrolyte under the same condition. We figured out the interesting correlation between the characteristic structure of Li2O2formed in the AN electrolyte and the discharge behavior that showed the oscillatory phenomena in the galvanostatic discharge process.
1) Laoire, C. O.; Mukerjee, S.; Abraham, K. M.; Plichta, E. J.; Hendrickson, M. A. J. Phys.Chem. C
2010, 114, 9178-9186.

Figure 1
Monte-Carlo Simulation of the Ionic Transport of Electrolyte Solutions at High Concentrations Based on the Pseudo-Lattice Model
Authors: Kiyobayashi Tetsu , Kuratani Kentaro , Ozaki Hiroyuki 
Published: February 2020

The theoretical understanding of the ionic transport in electrolyte solutions is not yet well-established at high concentrations, such as at C/M > 1. In our present study, two transport phenomena---self-diffusion and ionic conduction---of the electrolyte solution at high concentrations (roughly 0.05 ≤ C/M ≤ 3) are computationally simulated by a kinetic Monte-Carlo scheme. A swap mechanism in the three-dimensional pseudo-lattice is proposed to model the movement of ions and solvent, in which only the nearest-neighbor interaction is considered. The energy difference between the before- and after-swap states, based on which the stochastic Monte-Carlo process occurs, is found to be expressed in only two energetic terms; the coulombic repulsion between ions with the identical sign, +εii, and the heat of dissolution of the ionic crystal, Δdiss
H. The self-diffusion coefficients of both ions and solvent decrease with the increase in the ionic concentration, which qualitatively agree with the experimental observation. The asymmetric bell-shape of the specific conductivity, σ, principally originates from the coulombic repulsion. The ionic concentration at which the maximum σ occurs well coincides with that of the experimentally observed results. The Δdiss
H-dependency reveals that, ceteris paribus, σ marks the highest at around -2kT < Δdiss
H< 0, out of the range of which σ is attenuated by either the ion-ion or ion-solvent interaction. Finally, the limitations in the model are addressed.
The detail of the study is in press at the date of 15 April 2016 in J. Electrochem. Soc.

Figure 1
Applications of Solution Process for Li4SnS4-Based Solid Electrolytes to All-Solid-State Lithium-Ion Batteries
Authors: Kim Dong Hyeon , Park Kern Ho , Choi Young Eun , Oh Dae Yang , Jung Sung Hoo , Jung Yoon Seok 
Published: February 2020

As the application of lithium-ion batteries (LIBs) has been expanded to large-scale systems such as electric vehicles and energy storage systems, their safety becomes the most important characteristic. However, conventional LIBs contain flammable liquid electrolyte which can cause serious safety concerns. In this regard, all-solid-state lithium-ion batteries (ASLBs) using inorganic solid electrolytes (SEs) are the most promising candidate to compete with the conventional LIBs. Especially, bulk-type ASLBs are considered to be highly competitive in terms of their potential for large-scale manufacturing, which is contrasted by high cost in vacuum-deposition-based fabrication for thin-film-type ASLBs. For the bulk-type ASLBs, inorganic sulfide SEs such as Li10GeP2S12 and glass-ceramic Li2S-P2S5 are appropriate because they show high ionic conductivity and deformability. The bulk-type ASLBs employing these sulfide SEs have demonstrated promising electrochemical performances.1

However, the severe discrepancy between the obtained performances and the expected ones from the extremely high conductivity values of sulfide SEs has been overlooked. The governing origin for this discrepancy is the poor ionic contacts in the composite electrode structures. As all components in bulk-type ASLB are solid, the surfaces of active materials are not fully covered by the SEs as far as the electrodes are fabricated by the mixing process.2 As efforts to circumvent this problem, direct coating of SEs by laser vapor deposition3 was reported. The laser vapor deposition technique should be, however, ruled out for scale-up because of the high cost. In this regard, development of the wet SE-coating process can be thus more attractive. However, the wet process for sulfide SEs has been hindered by instability of sulfide materials with solvents, which leads to too low ionic conductivity of the resulting precipitated materials. Also, the most sulfide SE with various solutions did not form coatable homogeneous solutions and the used solvents were not environmentally friendly. Recently, our group reported new solution processable SE, LiI-Li4SnS4, which was prepared from methanol-based solution. The resulting glass phase LiI-Li4SnS4 showed the high ionic conductivity of 0.41 mS cm-1 and the excellent dry-air stability.2

In this presentation, we will report facile electrode fabrication procedure employing the solution process of Li4SnS4, and its electrochemical performances will be presented.

References

Y. S. Jung, D. Y. Oh, Y. J. Nam, K. H. Park, Israel J. Chem.
55, 472 (2015).

K. H. Park, D. Y. Oh, Y. E. Choi, Y. J. Nam, L. Han, J.-Y. Kim, H. Xin, F. Lin, S. M. Oh, Y. S. Jung, Adv. Mater.
28, 1874 (2016).

A. Sakuda, A. Hayashi, M. Tatsumisago, Sci. Rep.
3
, 2261 (2013).
Ion-Conductive Properties of Novel Polymer Electrolytes Based on Ethylene Oxide/Ethylene Carbonate Copolymers
Authors: Morioka Takashi , Nakano Koji , Tominaga Yoichi 
Published: February 2020

Solid polymer electrolytes (SPE) are expected to be useful as an electrolyte for batteries because of its safety, flexibility and lightweight. Many attempts for polyether type SPE have since been made to improve their electrochemical and physicochemical properties. Poly(ethylene oxide) (PEO) and its derivatives have usually low glass transition temperatures (T
g) and those electrolytes exhibit relatively high ionic conductivity. However, PEO-based electrolytes suffer from low Li transference numbers (t
+), less than 0.3. In PEO-based electrolytes, a cross-linking structure based on strong ion-dipole interactions between cations and polar ether oxygen is usually formed. Ionic conduction in PEO-based electrolytes therefore strongly depends on the migration of anions, which is known to occur in materials unsuitable for practical batteries. To overcome these problems we recently suggested polycarbonates, such as poly(ethylene carbonate) (PEC), as a new polymer matrix for SPE. However, PEC-based electrolytes have a issue with low ionic conductivity relative to PEO-based electrolytes at low salt concentrations, because of the high T
g of the original polymer. In this study, we focus on the copolymerization of ether and carbonate units as novel candidates for the electrolytes. The ether/carbonate copolymers can be obtained with suitable ratio by the optimization of the polymerization condition. We investigated the influence of the ether units on the ion-conductive properties of poy(ethylene oxide/ethylene carbonate) (P(EO/EC))-based electrolytes. The electrolytes were prepared with lithium bis(fluorosulfonyl)imide (LiFSI). The LiFSI content in the electrolyte varied from 5 to 160 mol% to an average monomer unit of each EO and EC unit. We found that the T
g of neat copolymers and the electrolytes decreased with increasing the contents of EO unit, while the conductivity for the electrolytes increased with increasing both EO unit and salt concentration. The t
+ of P(EO/EC) electrolyte having EO unit of 53% and 80mol% of LiFSI had high t
+ 0.65 at 60 oC. This value was very high and comparable with that of the PEC-based electrolytes. The dissociation states of Li ions is essential to reveal ion-conductive properties of P(EO/EC) electrolytes, so the measurement of FT-IR was carried out. The results of characterization of FT-IR spectra suggest that Li ions interact preferentially with carbonate groups but hardly with ether groups in P(EO/EC). Thus, the P(EO/EC) electrolytes showed novel ion-conductive behavior which has advantages of both EO and EC-based electrolytes. The optimization of the copolymerization ratio for EO and EC units in the copolymers are expected to further improvement in the conductivity.
This work was supported financially by a Grant-in-Aid for Scientific Research (B) (No. 25288095, 16H04199) of JSPS KAKENHI ,Japan.
Thin Film Processing of Amorphous Lithium Lanthanum Titanate Based Solid-State Microbatteries
Authors: Lee Jungwoo Zema , Wang Ziying , Rustomji Cyrus Sam , Wynn Thomas Andrew , Meng Ying Shirley 
Published: February 2020

Next generation batteries will require a broad range of energies to meet the challenges of portable electronic storage from electric vehicles to microelectromechanical systems (MEMS). Solid state electrolytes are researched heavily because they have the potential to improve capacity loss, cycle lifetime, operation temperature, and safety [1]. Lithium lanthanum titanate (LLTO), with the perovskite structure (ABO3), has gained interest due to its high bulk conductivity (10-3 S cm-1) at room temperature [2]. LLTO has many advantages including negligible electronic conductivity, high voltage stability (> 8 V), atmospheric stability, and temperature stability [3]. Furthermore, LLTO is transferable to thin film structures for fabricating microbatteries for powering portable electronics on-chip [4].
However, crystalline LLTO has a relatively low grain boundary conductivity (<10-5 S cm-1), lowering the overall material conductivity [3]. Therefore, in this work, we investigate amorphous LLTO thin films grown by pulsed laser deposition (PLD). By controlling the laser fluence, background pressure, and temperature we are able to grow dense films with an ionic conductivity of 8x10-4 S/cm and electronic conductivity of 5x10-11 S/cm. Secondly, we explore LiNi0.5Mn1.5O4 (LNMO) spinel thin films deposited via PLD as a potential high voltage cathode for our battery. We report on LNMO/LLTO half cells and novel full LLTO based thin film microbatteries.
[1] A. Hayashi et. al.“ Superionic glass-ceramic electrolytes for room-temperature rechargeable sodium batteries,” Nature Communications. 3 (2012) 856–860.
[2] O. Bohnke. “The fast lithium-ion conducting oxides Li3xLa2/3 − xTiO3from fundamentals to application,” Solid State Ionics. 179 (2008) 9-15.
[3] C. Cao et. al.“Recent advances in inorganic solid electrolytes for lithium batteries,” Frontiers in Energy Research. 2 (2014) 1-10.
[4] A. Furusawa et. al. “Ionic conductivity of amorphous lithium lanthanum titanate thin film,” Solid State Ionics. 176 (2005) 553-558.
(Invited) Electrochemical Reduction of CO2 to Value-Added Chemicals: Status and Remaining Challenges
Authors: Kenis Paul J.A. 
Published: February 2020

Significant reduction in atmospheric CO2 emissions as well as in the development of alternative energy sources will be critical to curb the unwanted effects of climate change (e.g., global warming, erratic weather patterns) and to reduce our dependence on fossil fuels. A variety of strategies needs to be pursued to curb the increase in atmospheric CO2 level. One potential strategy that can be employed to overcome this challenge is the electrochemical reduction of CO2 into useful chemicals such as formic acid, carbon monoxide, hydrocarbons, or alcohols. To drive thus process in a cost effective manner otherwise-wasted renewable energy that is produced in excess of grid demand can be used. A key challenge is the development of catalyst materials that are active and selective for the electrochemical reduction of CO2, i.e., catalysts that can reduce CO2 at low overpotentials (and thus high energetic efficiency), produce desired products at high current densities over long periods of time, and do so selectively while suppressing unwanted reactions.
Most present efforts to re-energize spent CO2 via electrochemical methods struggle to achieve simultaneously high energetic efficiency, high product selectivity, and high throughput. This presentation will provide an overview of progress by us and others in (i) developing suitable cathode catalysts for CO2 reduction (primarily to CO) as well as suitable anode catalysts (typically for the oxygen evolution reaction) needed for a CO2 electrolysis cell; (ii) optimizing operation conditions for these catalysts (pH, electrolyte composition, …); and (iii) developing gas diffusion electrodes suitable for a CO2 electrolysis cells. A projection for the potential for further improvement of catalysts, electrodes, operation conditions, and electrolysis cell designs will be made. Also, a gross margin model to estimate economic feasibility, as well as the results of a techno-economic analysis of a process that converts the CO2 of a 0.5 MW power plant to fuel via electroreduction of CO2 to CO, followed by Fischer-Tropsch will be presented.
(Invited) Converting Petroleum Coke into Hydrogen
Authors: Tao Greg Gege 
Published: February 2020

Hydrogen has been long recognized as a potential chemical fuel to meet worldwide energy needs while reducing (and eventually eliminating) CO2 and other GHG emissions. It is widely used by petroleum refineries in upgrading processes, necessary to facilitate the hydrotreating/catalytic hydrocracking of heavy hydrocarbon molecules, and the reduction of sulfur content. Hydrogen, as a secondary energy carrier, doesn’t exist in an elemental form in the environment to an appreciable extent, but can be produced by reacting a variety of widely available primary energy carriers with water or by using renewable energy sources, either directly or indirectly. At an industrial scale, three major technologies are presently used to produce hydrogen, depending on the primary energy sources or available feedstock: coal gasification, natural gas steam reforming, and water electrolysis.
Petroleum coke (or petcoke), similar to coal, is a byproduct of refinery processes. The U.S. refineries produce more than 125,000 short tons petcoke per day (st/d). With a low heating value (LHV) of 6.024 MMBtu/barrel (equivalent to 8.826 MWhr/st), petcoke produced in the U.S. potentially is worth 17,689 MW electricity assuming 40% efficiency. However, due to larger activation energies, higher sulfur content and less volatile materials than coal, petcoke is not a desirable feedstock for the conventional coal-burnt power plant and more than 62% of petcoke was exported annually.
Instead of purchasing hydrogen over the fence, a refinery potentially can build on-site hydrogen production infrastructure directly utilizing its available resource (petcoke). Materials & Systems Research Inc. currently has been developing an advanced hydrogen production process built-upon the solid-oxide electrochemical technology with reduced energy consumption and low costs for CO2 separation & sequestration. In this talk, a scalable hydrogen production process will be discussed. Proof-of-concept demonstration of hydrogen production at a 200W stack level will also be presented.
Predictive Control of Catalyst Selectivity in the Electroreduction of Carbon Dioxide
Authors: Billy Joshua , Co Anne 
Published: February 2020

The direct electrocatalytic reduction of carbon dioxide to fuel-type chemicals remains a promising utilization pathway to mitigate rising carbon dioxide concentrations in the atmosphere. Copper metal is the most widely studied catalyst used in the reaction due to its unique ability to produce hydrocarbon species. While a lot of focus has been improving the catalysts, the experimental parameters that affect the reaction have not been fully understood.
A variety of factors have been shown to affect the activity and selectivity of the CO2 electroreduction reaction. Pre-electrolyzing the electrolyte is a common practice after Hori et al.

1
determined that trace impurities in the salts used to make the electrolyte solutions can deposit on the electrode surface and inhibit the reaction. High purity metal electrodes (ex. Cu 99.999+ %) are used for a similar reason. The identity of the electrolyte also has an effect, leading to different product distributions even by simply using a salt with a different alkali metal cation2. Electrolyte concentration has also been shown to alter the product selectivity3. Hori et al. concluded that the cationic species and electrolyte concentration affect the local pH at the electrode surface, which plays a major role in regulating the reaction.
Other researchers have also demonstrated the importance of local pH and its effect on the reaction. Gattrell et al.

4
calculated the surface concentrations of several important species in the electroreduction of CO2 in KHCO3 solutions, showing that local concentrations are drastically different from the bulk. Factors such as current density and boundary layer thickness play a role.
To optimize our electrochemical set-up, we investigated how the CO2 bubbling rate and the solution flow rate within an electrochemical flow cell affected the reaction. We found that the selectivity between CH4 and C2H4 can be predictively controlled by varying the bubbling rate and solution flow rate, and that the two are inversely related. A combination of mass transport processes and local pH affects can be used to explain our observations. This work highlights the importance of controlling parameters in the electroreduction of CO2 and demonstrates predictive control of hydrocarbon selectivity.

1. Y. Hori, H. Konishi, T. Futamura, A. Murata, O. Koga, H. Sakurai and K. Oguma, Electrochimica Acta, 2005, 50, 5354-5369.
2. A. Murata and Y. Hori, Bulletin of the Chemical Society of Japan, 1991, 64, 123-127.
3. Y. Hori, R. Takahashi, Y. Yoshinami and A. Murata, Journal of Physical Chemistry B, 1997, 101, 7075-7081.
4. N. Gupta, M. Gattrell and B. MacDougall, Journal of Applied Electrochemistry, 2006, 36, 161-172.
Influence of Anion-Exchange Ionomers on Electrocatalysts for Carbon Dioxide Reduction
Authors: Manthiram Karthish , Fenwick Aidan Q. , Edwards Julian P. , Grubbs Robert H. 
Published: February 2020

Electrochemical fixation of carbon dioxide may provide a sustainable path for generating both hydrocarbon fuels and commodity chemicals. By powering such electrochemical processes using sources of clean, direct electricity, it is possible to re-envision the carbon cycle and reduce the carbon footprint associated with producing these products.
Practical architectures for electrochemical carbon dioxide reduction devices are likely to involve membrane-electrode assemblies (MEAs) in order to minimize the ionic diffusion length scale and maximize energy efficiency. MEAs consist of sandwich structures in which cathodic and anodic gas diffusion layers (GDLs) are on either side of a membrane. Electrocatalysis occurs in the gas diffusion layers (GDLs), which must facilitate transport of reactants, products, ions, and electrons. As a result, GDLs contain nanoparticulate catalysts, carbon black for electronic conductivity, ionomers for ionic conductivity, and binders for structural stability. Although GDLs require contacting of catalytic nanoparticles with ionomers in order to deliver and remove ions from the catalyst surface, the effect of the ionomers on the underlying catalyst is poorly understood for carbon dioxide reduction.
This presentation will focus on the influence of anion-exchange ionomers on the activity and selectivity of transition-metal electrocatalysts for carbon dioxide reduction. Using electrochemical studies and vibrational spectroscopy, the interaction of the anion-exchange ionomers with the catalyst surface has been elucidated. Based on the results, insights for the design of ideal anion-exchange ionomers for incorporation into GDLs for electrochemical carbon dioxide reduction will be presented.