bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soft Electrochemical/Electronic Devices and Their Applications in Point-of-Care Testing
Authors: Li Fei 
Published: May 2020

Using soft materials (e.g., paper, hydrogel) to replace the traditional hard materials (e.g., glass, silicon) as substrates have become a recent trend in developing point-of-care testing (POCT) platforms. And through integration of the soft materials with electrochemical or electric devices can further extend the applications of POCT. In our recent work, we used four kinds of soft materials, including paper, PDMS, hydrogel and liquid marble, as the new soft substrates of POCT platforms and realized their new applications in POCT. For example, by integration of the electrodes and hydrophobic channels on paper through simply writing method using home-made pens, the fabricated paper-based electrochemical devices have been successfully applied to detect glucose in artificial urine and melamine in sample solutions. By fabrication of MWNTs/PDMS fibers as multifunctional sensors and integration them on a glove, the measurement of gesture recognition and temperature have been realized by the “smart” glove. Through injection of liquid metal into the 3D helical structure of hydrogel and combination the hydrogel with electronic sensing device, the temperature, UV sensing and EMG signal detections have been performed by the wearable, multifunctional hydrogel device. By using liquid marble as a separator and small device for isoelectric focusing, the POCT separation and analysis of proteins have been realized. The proposed new soft platforms show wide application potential in POCT.
References
[1] H. Liu, M. X. Li, S. B. Liu, P. P. Jia, X. J. Guo, S. S. Feng, T. J. Lu, H. Y. Yang, F. Li, F. Xu, Spatially Modulated Stiffness on Hydrogel for Soft and Stretchable Integrated Electronics, Material Horizons. 2019, DOI: 10.1039/C9MH01211G.
[2] Z. D. Li, H. Liu, X. C. He, F. Xu, F. Li, Pen-on-Paper Strategies for Point-of-Care Testing of Human Health, Trac-Trends Anal. Chem. 108 (2018) 50-64. doi.org/10.1016/j.trac.2018.08.010
[3] H. Liu, M. X. Li, C. Ouyang, T. J. Lu, F. Li, F. Xu, Bio-friendly, Stretchable, and Reusable Hydrogel Electronics as Wearable Force Sensors, Small. 14 (2018) 1801711. doi: 10.1002/smll.201801711
Tailored Syngas Production Via High Temperature H2o-CO2 Co-Electrolysis
Authors: Marina Olga A. , Coyle Christopher A , Meinhardt Kerry D , Holladay Jamelyn 
Published: May 2020

Solid oxide electrolysis cells (SOEC) operating at 600 – 850°C are used to split water using excess renewable or nuclear electrical energy and convert it to chemical energy which is stored in H2 and O2. SOECs can also be used as electrochemical reactors for the co-electrolysis of steam and carbon dioxide. The two reactants, typically waste products in an industrial plant, could be turned into syngas (CO+H2), a valuable and very commonly used reagent in the chemical industry. Syngas is subsequently used to produce synthetic fuels, olefins or other liquid hydrocarbons via Fischer-Tropsch synthesis or for methanol synthesis and hydroformylation.
In this presentation we focus on CO2-H2O co-electrolysis, the simultaneous electrochemical reduction of carbon dioxide and steam, carried out on the porous Ni-based electrodes in high temperature SOECs. Experiments were conducted using multiple button cells. The rate of the electrochemical reactions was measured in the temperature range 700-850oC for varied reactant compositions: 10-98% CO2 and 5-50% H2O, also in the presence of some H2 and CO. Kinetics of electrochemical CO2 reduction were evaluated for different CO2/H2O ratios and compared to steam electrolysis. Product analysis was completed using gas chromatography. Long term electrochemical performance of multiple cells was recorded simultaneously for over 500 hours of continuous testing with occasional interruptions to obtain current-voltage characteristics and collect the impedance spectra. The ability to control H2 :CO ratios in generated syngas by varying the inlet H2O/CO2 ratios and cell potential was demonstrated. Thus, precise control of the H2 to CO ratios, a unique feature of electrochemical conversion can be used to optimize selectivity of the desired byproduct.
Advanced Electrochemical System for Energy Storage through CO2 conversion
Authors: Zhang Jiawei , Li Wenping , Zhang Bowen , Gao Minrui , Xu Chenyu , Duan Nanqi , Luo Jing-Li 
Published: May 2020

The extensive usage of fossil fuel as energy source has led to the increased atmospheric concentration of CO2, which is mainly responsible for the negatively intensified greenhouse effect upon our living habitat. Various pathways have been studied in order to alleviate the negative effects of CO2 emission; electrochemical reduction of CO2 is considered as one of the promising method to effectively reduce CO2 emission. The process involves the conversion of CO2 to useful chemicals and fuels using high temperature solid oxide electrolysis cells (SOECs), these devices can run in the opposite direction in solid oxide fuel cells but utilize similar concepts, and involve materials challenges and operating conditions to achieve ‘Power to Fuels’. It is well known that CO2 molecules are very stable so that high energy input is required for cathodic reaction to proceed. The cathodic reaction, therefore, plays a vital role in the overall cell performance and so far, extensive investigations have been conducted to develop the advanced cathode materials with high catalytic activity and stability.
Among various types of catalysts for SOECs, perovskite-based materials have attracted world wide research efforts as the mixed ionic and electronic conductors through introducing proper doping elements into perovskite lattice during synthesis process. Nonetheless, the cathodic material thus developed still suffer from relatively lower catalytic activity compared to conventional nickel-based cermets. In this work, three strategies are adopted to improve their performance of CO2 electrochemical reduction. It has been demonstrated that the perovskites with exsolved nanoparticles anchored on the surface of matrix exhibit excellent catalytic activity in comparison with the conventional ones. As a facile in-situ process, exsolution can significantly increase the number of reaction sites by forming uniformly dispersed active nanoparticles and at the same time, can efficiently impede agglomeration of nanoparticles under high temperature. Therefore, the perovskite with exsolved nanoparticles is a promising cathode material that can enhance the overall performance of CO2 reduction in an electrochemical cell.
Introduction of Disruptive Gas Flow Via Fluidic Oscillation to Improve Solid Oxide Cell Performance
Authors: Rothman Rachael H , Call Ann V , Holmes Thomas D , Desai Pratik D , Zimmerman William B 
Published: May 2020

An increased focus on renewable technologies is necessary to meet the level of carbon emission reduction required to achieve the 2°C scenario (2DS). Carbon containing materials are at the root of most industrial value chains and currently 90% of organic chemicals are made from fossil fuels and 5-10% of global crude oil demand is for the manufacture of chemicals. By providing a process to convert waste CO2 into high value CO we can take steps towards the goal of reducing emissions and provide an important link between various sectors to turn waste materials into new products, improving resource efficiencies, and reducing negative environmental factors. This presents a significant opportunity to leverage CO2 as a feedstock while supporting global goals in green energy, manufacturing, etc.
Solid oxide cells (SOCs) provide an effective mode of simultaneously reducing CO2 and separating O2, however, over 80% of the cost to co-electrolyse CO2 and H2O comes from electrical input necessary to drive a SOEC. While changes in cell geometry and composition have been used to improve performance, energy inputs need to be reduced to increase overall device efficiency for widespread commercialisation to be realised.
In this work we focus on the use of oscillating the gas flow into an SOC to create a highly efficient energy conversion device to facilitate the reduction of CO2 to CO. Fluidic oscillation is known to cause disruptive flow which promotes turbulence in small flow fields, thereby increasing the overall efficiency – key to furthering their commercialisation.
Fluidic oscillators are one of a variety of fluidic switching devices developed in the field of microfluidics. A single gas supply inlet guides an incoming gas flow into a destabilising microfluidic feature, generating the necessary disruption that results in jet diversion between two identical channels. This switching results in a pulsed flow in each of the outlet channels, alternating between full forward flow, and very slight backflow. The flow in the forward regime bears similarity to laminar flow, whereas the slight backflow regime more closely resembles turbulence. This effect can be observed even in extremely small channel diameters and causes a disruptive effect which interrupts the formation of a boundary layer of stagnant gas flow along flow field chamber walls. While conventional oscillators require high flow rates on the order of 50-80 L/min, for this particular work we are utilising a novel fluidic oscillator capable of producing an oscillatory flow at low onset flow rates of as low as 50 ml/min, which is necessary for operation with lab scale SOCs.
Experimental results show improved performance with the addition of oscillating gas flow and no other changes to cell geometry, materials composition, or gas composition. The magnitude of improvement in polarization resistance was dependent on operating conditions, the reasons for which will be discussed in the paper.
Development of Protonic Ceramic Fuel Cells Using Yb-Doped BaZrO3 Electrolytes
Authors: Kuroha Tomohiro 
Published: May 2020

In recent years, protonic ceramic fuel cells (PCFCs) have been widely studied and are expected to be used as intermediate temperature solid oxide fuel cells (SOFCs) [1]. PCFCs’ power generation efficiency will likely be higher and operating temperature lower than those of SOFCs using yttrium stabilized zirconia as an electrolyte [2]. However, PCFCs are at the research and development phase and many issues such as durability must be overcome for practical use. Therefore, we fabricated single-cells and evaluated their power generation performance and durability from a practical perspective.
Acceptor-doped barium zirconate was used as the electrolyte material because it has CO2 stability. Previous studies have shown that yttrium-doped barium zirconate (BZY) has the highest proton conductivity. However, cells using BZY crack in the conventional ceramic tape-casting and firing process used to fabricate laminated ceramic electronic devices. This is because the NiO used for the anode reacts with BZY to form BaY2NiO5.
The reactivity between the acceptor-doped barium zirconate and NiO was examined at the 1500 °C firing temperature. Ytterbium-doped barium zirconate (BZYb) did not form the complex oxide with NiO. Using BZYb revealed no problems such as cell cracking. In the cell using BZYb, the maximum power density at 700 °C and 600 °C were 0.70 Wcm-2 and 0.49 Wcm-2, respectively. Electrochemical impedance spectroscopy of the cell showed that the ohmic resistance was 0.28 Wcm2, approximately three times larger than the resistance value calculated using the bulk conductivity of BZYb and electrolyte thickness. It seems to be due to the solid solution of Ni in the electrolyte. To improve performance, techniques to prevent Ni solid solution diffusion are necessary.
References
[1] C. Duan, R. O’Hayre, Nature 557 (2018) 217–222.
[2] Y. Matsuzaki, K. Sasaki, Scientific Reports 5 (2015) 12640.
(Invited) Equivalent Circuit Analysis of Mass Transport of Proton- Oxide Ion- Electron Mixed Conductors for Fuel Cells and Electrolysis Cells
Authors: Yashiro Keiji , Okuyama Kotaro , Kawada Tatsuya 
Published: May 2020

Recently proton conducting ceramics have been intensively developed for proton ceramic cells (PCCs) for fuel cell and electrolyzer. There are potentially three conduction carriers (proton, oxide-ion, electron hole) in a proton conducting electrolyte, whose partial conductivities vary drastically with change in chemical potential and temperature. Therefore the complicated mass transport phenomena in proton conducting electrolyte must be fully understood to develop the fuel cell and electrolysis cell. While a couple of papers have reported the analysis results of behavior of proton, oxide-ion, and electron hole in the electrolyte [1, 2], the cell behavior including electrode materials are not yet fully understood. In this paper, we analyze complex impedance response of PCCs under the operation conditions of fuel cell and electrolysis cell by equivalent circuit analysis using universal circuit simulator.
[1] H. Zhu, R. J. Kee, Int. J. Hydrogen Energy, 41 (2016) 2931.
[2] D. Poetzsch, R. Merkle, J. Maier, Adv. Func. Mater., 25 (2015) 1542.
Electrochemical Analysis of Anode Supported Pcfc with Pseudo Symmetrical Cell
Authors: Yamauchi Kosuke , Kuroha Tomohiro , Goto Takehito , Terayama Takeshi , Mikami Yuichi , Asano Hiroshi , Tsuji Yoichiro , Shiraishi Seigo , Okuyama Yuji 
Published: May 2020

Protonic Ceramic Fuel Cell (PCFC) is expected to be the next-generation fuel cell for its higher energy conversion efficiency and lower operation temperature. BaZrO3 based oxide are potential materials as PCFC electrolyte because they have a high chemical stability under CO2 condition and high proton conduction. [1] Recently, we have developed PCFC using BaZr0.8Yb0.2O3-δ (BZYb) as the electrolyte. The proton conductivity of the BZYb pellet was 1.1×10-2 S/cm at 600℃ and did not form the complex oxide with NiO. The power density of the developed cell (Ni-BaZr0.8Yb0.2O3-δ|BaZr0.8Yb0.2O3-δ|La0.6Sr0.4CoO3-δ) achieved 0.49 W/cm2 at 600℃.To improve the performance of anode supported PCFC, anode supported pseudo symmetrical cell:
Ni-BaZr0.8Yb0.2O3-δ|BaZr0.8Yb0.2O3-δ|Ni
was manufactured and analyzed by impedance spectroscopy under the various conditions and temperatures (Figure).The thickness dependence of the ohmic resistance was measured for three types of electrolyte (thickness: 8 μm, 16 μm and 25 μm) under 48%H2-49%N2-3%H2O gas condition at 300-700℃. The conductivity was calculated from the relation between electrolyte thickness and the ohmic resistance, which was 0.35×10-2 S/cm at 600℃. The degradation of proton conductivity occurs due to Ni dissolution. The performance of anode supported PCFC might be improved further if the Ni dissolution to electrolyte can be inhibited.
Reference
[1] K. D. Kreuer, Proton-conducting oxides, Annu. Rev. Mater. Res., 33 (2003) 333–359.

Figure 1
(Invited) A Full Carbon Balance Analysis on High Current Density Electrochemical CO2 Reduction Reactors with Cu Catalysts
Authors: Seger Brian , Ma Ming , Clark Ezra L , Therkildsen Kasper , Chorkendorff Ib 
Published: May 2020

CO2 emissions are significantly contributing to anthropogenic climate change, but at the same time the costs of sustainably based electricity has greatly been reduced in the last decade. This has provided a perfect economic and societal opportunity for electrochemical CO2 reduction into chemicals. However, this field is not technologically mature yet, and there are many engineering details that needs to be investigated. This talk will focus on understanding the complete carbon balance on low temperature electrochemical CO2 reduction reactors operating at industrial relevant current densities (100-500 mA/cm2). The focus will be primarily be on using a gas diffusion approach with a liquid catholyte using sputtered Cu as a catalyst.
By employing a post-reactor volumetric flow rate to measure outlet flow rates, highly accurate faradaic efficiency measurements were achieved. Furthermore, these results show that if one instead assumes inlet gas flowrates, this can overestimate faradaic efficiencies of gas products by up to 25%. By careful analysis of both gas and liquid products we show a near 100% faradaic efficiency as well as completely accounting for all the carbon in our reactor. Our liquid analysis showed glycoaldehyde and ethylene glycol, two products never seen before in high current density electrochemical CO2 reduction reactors
Using an anion exchange membrane, we show significant crossover to the anode of anionic species such as acetate, and formate, as well as carbonate crossover and subsequent CO2 evolution on the anode. We show that the ratio of CO2 to oxygen evolution on the anode is 2:1 throughout a current density range of 100-300 mA/cm2, however the time it takes to equilibrate at this ratio is both current dependent and dependent upon the catholyte and anolyte reservoirs. This talk will also discuss variations in pH at both the anode and cathode as a function of operating parameters and give insight into the potential advantages and pitfalls of various reactor designs.
This work was funded by the ECOEthylene project from Innovation Fund Denmark (Grant # 8057-00018B)
Microkinetic Modeling of the Oxygen Evolution Reaction (OER) on Hydrous Iridium Oxide during Dynamic Operation
Authors: Geppert Janis , Kubannek Fabian , Krewer Ulrike 
Published: May 2020

In an energy system which is based on intermittent renewable sources, efficient energy storage and conversion technologies are needed. Proton exchange membrane (PEM) electrolysis is a promising technology for the storage of electrical energy in the form of hydrogen. In PEM electrolyzers, the oxygen evolution reaction (OER) is seen as the bottleneck due to its high overpotential. To enhance the overall performance, highly active but stable OER catalysts are essential. Oxidized iridium shows good activity for the OER and is more stable compared to other materials such as ruthenium oxide[1]. It has been shown that electrochemically grown hydrous iridium oxide is particularly favorable[2]. A better understanding of the changes of its complex surface structure and chemistry during dynamic operations is crucial for practical applications and for obtaining deep insights in factors that affect its activity and stability.
In the present work we investigate the surface states of hydrous iridium during the OER. For this purpose, we implement a dynamic physical model to simulate the formation of different types of intermediate states. A complete set of microkinetic equations is derived, solved and validated with cyclovoltammetric data (see figure 1). By solving the surface species balances dynamically, the phenomena that are observable in cyclovoltammetric, chronoamperometric and impedance spectroscopic experiments can be interpreted quantitatively[3].
Applying this method onto hydrous iridium oxide we are able to study the degree of oxidation of the iridium atoms at the surface at various electrode potentials. In a wide potential region from 0.4 V vs RHE up to the OER potential range, the simulation predicts the amount of adsorbed -OH, -O, -OOH and -OO species, which determine the overall oxidation state of the iridium. The characteristic peaks and shoulders in the cyclovoltammogram are assigned to the single reaction steps. By comparing different mechanisms, a deep understanding of the predominant reaction pathway is gained. Furthermore, the quantification of microkinetic rate constants allows us to define rate determining reaction steps during the dynamic operation. With this study we confirm that the mechanism in figure 1, in which two parallel reaction pathways are present, can describe the experimental cyclovoltammogram quantitatively.
[1] S. Cherevko et al., Oxygen and hydrogen evolution reactions on Ru, RuO

2

, Ir, and IrO

2

thin film electrodes in acidic and alkaline electrolytes: A comparative study on activity and stability, Catalysis Today 262 (2016) 170–180
[2] S. Cherevko et al., Oxygen evolution activity and stability of iridium in acidic media. Part 2. –Electrochemically grown hydrous iridium oxide, Journal of Electroanalytical Chemistry 774 (2016) 102–110
[3] U. Krewer et al., Impedance spectroscopic analysis of the electrochemical methanol oxidation kinetics, Journal of Electroanalytical Chemistry, 589 (2006) 148–159

Figure 1
(Invited) In Situ Electrochemical TEM and XAS Studies in Oxygen Evolution Reaction
Authors: Balaghi S. Esmael , Sologubenko Alla S. , Najafpour Mohammad Mahdi , Patzke Greta Ricarda 
Published: May 2020

The design of a highly efficient, cost-friendly and the green water oxidation catalyst is one of the most challenging research areas in the field of sustainable energy. Despite the presence of promising research findings of active catalysts in OER, their stability during long-term water oxidation reactions remains unexplored. The almost infinite number of possible compositions of mixed oxides makes the latter a great challenge towards the improvement of the stability and activity of such OER catalysts for future applications in water splitting devices and batteries.[1] Modern advances in the fabrication of micro electrochemical cells for operando microscopy have opened new horizons to perform the real-time investigation of electrochemical dynamic behaviors at the electrode-electrolyte interface.[2,3]

In this study, an in situ electrochemical TEM approach was employed to directly visualize the early stages of OER and screening the morphological evolution of catalyst on the working electrode surface. The aforementioned method was applied on La0.6Sr0.4Co0.2Fe0.8O3 (LSCF), La0.8Sr0.2MnO3 (LSM) and LiNi0.33Mn0.33Co0.33O2 (LNMC) mixed oxides, respectively. Furthermore, electron atomic pair distribution function (ePDF) was used in order to obtain the quantitative insight into the structural changes of the electrode surface under operational conditions. The electrochemical stability and structural changes behavior of the catalysts during OER was studied using in situ electrochemical X-ray absorption spectroscopy (XAS). Moreover, this structural changing process was reinvestigated by several ex situ methods such as X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD), Raman spectroscopy, transmission electron microscopy, (TEM), scanning electron microscopy (SEM), cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Finally, we propose a novel mechanistic insight, which demonstrates that the ongoing quest for true catalysts design in OER is a dynamic and rapidly developing research area.

References:

[1] W. T. Hong, M. Risch, K. A. Stoerzinger, A. Grimaud, J. Suntivich, Y. Shao-Horn, Energy Environ.
Sci.
2015, 8, 1404.
[2] T. Li, O. Kasian, S. Cherevko, S. Zhang, S. Geiger, C. Scheu, P. Felfer, D. Raabe, B. Gault, K. J. J. Mayrhofer, Nat. Catal.
2018, 1, 300.
[3] Y. He, X. Ren, Y. Xu, M. H. Engelhard, X. Li, J. Xiao, J. Liu, J.-G. Zhang, W. Xu, C. Wang, Nat.
Nanotechnol.
2019, 14, 1042.