bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon Nanotube- and Nanoporous Carbon-Based Pt and Non-Pt Fuel Cell Catalysts with High Performance and Durability
Authors: Yang Jun , Tao Jie , Fujigaya Tsuyohiko , Nakashima Naotoshi 
Published: February 2020

Development of Pt-based and non-Pt-based electrocatalyst for fuel cells and batteries with high performance, durablity, and scalability is a strong social demand for the next-generation eco-friendly energy society[1].
In this meeting, we summarize our recent studies on i) development of a carbon nanotube (CNT)-based almost “immortal” fuel cell catalyst prepared by a double-polymer wrapping method [2], ii) pristine carbon nanotube/iron phthalocyanine hybrids with a well-defined nanostructure that show excellent efficiency and durability for oxygen reduction reaction[3], iii) decorating unoxidized-carbon nanotubes with homogeneous Ni-Co spinel nanocrystals that show superior performance for oxygen evolution/reduction reactions[4], and iv) a highly-durable CO-torelant poly(vinylphosphoric acid)-coated electrocatalysy supported on a nanoporous carbon[5].

References

[1] T. Fujigaya, N. Nakashima, Adv. Mater., 2013, 25, 1666-1681.
[2] M. R. Berber, I. H. Hafez, T. Fujigaya, N. Nakashima, Sci. Rep.,
2015, 5, art no. 16711.
[3] J. Yang, F. Toshimitsu, T. Fujigaya, N. Nakashima, J. Mater. Chem. A, 2017, 5, 1184-1191
[4] J. Yang, T. Fujigaya, N. Nakashima, Sci. Rep., 2017, 7, art.no.45384.
[5] Z. Yang, I. Moriguchi, N. Nakashima, ACS Appl. Mater. Interfaces, 2016,
8, 9030–9036.
X-Ray Absorption Study of Sputtered Pt-CeO2 Catalyst Used in PEM-FC
Authors: Fiala Roman , Drnec Jakub , Vaclavu Michal , Matolin Vladimir 
Published: February 2020

The proton exchange membrane fuel cell (PEMFC) is supposed to be an environmentally friendly near-future power source for mobile devices. The crucial problem in the fuel cell technology field is the finding of a stable, efficient and economical catalyst for hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) at working conditions of PEMFC. The Pt catalyst, which is widely used due to fact that this catalyst is only really functional enough, is an expensive material. Moreover, unfortunately all of the less expensive Platinum bimetallic alloys as ORR catalysts enhancing the activity rapidly degrade in acidic environment and ORR condition [1].
We have already shown that Pt-CeO2sputtered catalyst exhibits high specific power (thousand-times higher power per mg of platinum and only few times lower power density in comparison with Pt reference catalyst) so such material could be an appropriate for PEMFC anode (HOR) [2,3,4].
Presented work is aimed for understanding the role of Pt and Ce chemical states and Pt-Ce interactions in HOR and ORR catalytic activity investigated in-situ using X-ray Absorption Near Edge Structure (XANES). Additionally, the performance and endurance of this catalyst obtained through direct testing in fuel cell test station are presented. Then, morphology determined by scanning electron microscopy and photoelectron spectroscopy results is shown.
[1] G.-F. Wei et al., Energy Environ. Sci.,4(2011) 1268
[2] R. Fiala et al., J. Nanosci. Nanotechnol.,11 (2011) 5062–5067
[3] V. Matolin et al., Langmuir, 26 (2010) 12824–12831
[4] V. Matolin et al., Int. J. Nanotechnol., 9 (2012) 680–694

Figure 1
Titanium Oxide Nanosheets for Proton-Exchange Membrane Oxygen Evolution Electrocatalysts
Authors: Archer Randall , Godinez-Salomon Fernando , Rhodes Christopher 
Published: February 2020

Electrocatalysts used for the oxygen evolution reaction (OER) within the acidic environment of proton-exchange membrane (PEM) electrolyzers typically use precious metal oxides, IrOx and RuOx, which are extremely expensive and have a very limited supply. Approaches that can significantly reduce or eliminate the precious metal content of acidic OER catalysts and that provide high activity and stability are of significant interest. Toward this end, we have investigated using titanium dioxide nanosheets for acidic OER electrocatalysts. Expressing TiO2 within a nanosheet morphology allows expression of specific facets that may allow increasing the activity. Further, the OER activity may be enhanced through substitution of different transition metals within the structure to tune the surface electronic structure as well as increase the electronic conductivity. The TiO2 and substituted TiO2 nanosheets were prepared using solution-phase synthesis routes. The structure of the nanosheets was determined using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. The OER activity and stability substituted TiO2 nanosheets were determined using a rotating disk electrode configuration and will be presented. The ability to create precious metal-free OER catalysts that provide high activity and stability provides the potential for significant reduction of the cost of PEM electrolyzers used for important applications including automotive hydrogen fueling stations and on-demand hydrogen production for industrial applications.
(Invited) Role of Ion-Conducting Membranes in Synthesis and Use of Sustainable Fuels
Authors: Soloveichik Grigorii L. 
Published: February 2020

Replacement of conventional catalytic technologies for synthesis of sustainable, carbon-neutral fuels with direct electrochemical synthesis has a potential for big energy savings due to reduction of number of process steps and pressure/temperature. In addition, electrochemical technologies are easily scaled down to allow for low capital, modular plants that match the scale of renewable energy production. The use of these fuels in electrochemical devices opens a path to cost-effective long-term energy storage and distributed energy generation. Development of low cost, ion-selective membranes with low area specific resistance is, along with electrocatalyst development, critical for the success of such technologies. Not less important is development of membrane manufacturing methods at a practical scale.
This presentation will review prospective technologies using ion-selective membranes for synthesis of carbon-neutral fuels for chemical energy storage and their use for generation of electricity (using fuel cells) and hydrogen. Advantages of electrochemical synthesis of ammonia from nitrogen and hydrogen or water compared to the conventional Haber-Bosch process will be discussed. Other processes include direct electrochemical synthesis of alcohols from CO2. The requirements to ion-selective membranes for these processes and fuel cells will be presented.
The Advanced Research Projects Agency (ARPA-E) funds high risk, high reward transformational research to reduce energy related emissions, reduce imports of energy from foreign sources, improve energy efficiency across all economic sectors, and ensure US technological lead in advanced energy technologies, including electrochemical energy storage and transformation for grid scale and automotive applications. The Renewable Electricity to Fuels through Utilization of Energy-dense Liquids (REFUEL) program funds the development of transformational technologies to reduce the barriers to widespread adoption of intermittent renewable energy sources by enabling the conversion of energy from these sources, water and air to energy-dense zero-carbon liquid fuels and their use for electricity or hydrogen generation. REFUEL projects targeting various ion conducting membranes as well as related projects supported by ARPA-E through OPEN program will be highlighted.
(Invited) Review of Progress in Solid Oxide Fuel Cell at FuelCell Energy
Authors: Ghezel-Ayagh Hossein , Borglum Brian P 
Published: February 2020

Significant progress has been made towards the development of Solid Oxide Fuel Cell (SOFC) at FuelCell Energy Inc. (FCE). The genesis of the advances in the technology is rooted in scale-up of the Company’s anode-support technology made by the TSC (Tape Casting-Screen Printing-Sintering) Process. The anode supported thin electrolyte planar cell platform was adopted for its higher power density at reduced operating temperature (600-800°C). Traditional materials, such as Ni/YSZ anodes, YSZ electrolytes and perovskite cathodes have been utilized in a basic cell structure. Research and development has been successful in developing better electrochemical functional areas at both cathode/electrolyte and anode/electrolyte interfaces. This was achieved through materials advancement, microstructure optimization, and manufacturing process integration. Cell materials development advancements have been made in performance, endurance, cell size (area) scale-up and cost reduction. These advancements led to an enhanced cell performance by reducing cell ASR (Area Specific Resistance) while reducing cell cost through cell design changes and materials reduction. Scaled-up cell size of up to 1000 cm2 have been made and tested with the current baseline cell size of 550 cm2 as the standard unit size for building SOFC stacks. The baseline stack design has been successfully scaled-up from 120-cell 550 cm2 cell area (16 kW nominal) stack. Using standardized manifolds and gas-electrical interconnects, these stacks have been successfully integrated into stack towers and arrays.
FCE recently designed, built, and tested a 50 kW fully automated SOFC system under a Co-operative Agreement with Department of Energy. In a follow-on DOE supported project, currently, FCE is engaged in design and construction of larger 200kW units that utilize baseline factory-built stack blocks representative of the future MW-scale power plants.
Improved Electrocatalytic Activity and Durability of NiMn2O4-CNTs as Reversible Oxygen Reaction Electrocatalysts in Zinc-air Batteries
Authors: Li Xuemei , Li Haoran , Nie Qi , Zhang Lei , Qiao Jinli 
Published: February 2020

Faced with the increasingly serious energy crisis, fuel cells, as a clean and efficient power source, have become the most promising energy conversion devices and attracted significant attention during the last decades. Oxygen reduction reaction (ORR) at the cathode of fuel cells plays a decisive role in determination of the performance, and electrocatalysts with high-performance ORR are essential for practical applications. However, some big technical challenges are still encountered due to their inherently sluggish of cathodic ORR, which usually requires a significant number of noble metal catalyst [1, 2]. To overcome these bottlenecks, great attention has been paid to pursue non-precious metal or metal-free carbonaceous materials. Mesoporous carbon materials have been used for ORR due to their preeminent textural characteristics, high surface area, mechanical stability and mesoporous structure. However, the properties of mesoporous carbon materials base on not only the sizes and loction of the pore, but the heteroatoms doped into the carbon framework. It is believed that the quantity of N-doped and S-doped in carbon will be vastly different, if it was annealed at various reaction temperatures [3]. Herein, we use N and S co-doped mesoporous carbon which is prepared by polyquaternium-7 as a starting material to investigate the reaction with N2 at various temperatures.
Nitrogen and sulfur co-doped mesoporous carbons were prepared by homogeneously mixing polyquaternium-7 and ferrous sulphate and silica. After drying overnight, the resulting solid was ground to a fine powder and then calcined at 600, 700, 800, 900 and 1000 for 1 hour in a nitrogen atmosphere. The silica was washed off in excess sodium hydroxide and dried. The excess metal Fe was removed in sulfuric acid at 85 ℃. Finally, the resulting catalytic graphite was pyrolyzed at 600 to 1000 ℃ for 1 hour again. Results of electrochemical characterizations for ORR were studied by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) employing rotating disk electrode (RDE) technique. It is found that the temperature of the heat treatment is a significant parameter in synthesizing the high performance ORR catalysts.
References
[1] M.J. Wu, J.L. Qiao, K.X. Li, X.J. Zhou, Y.Y. Liu and J.J. Zhang, Green Chem. Vol., 18,2699 (2016)
[2] M. Arenz, K.J. Mayrhofer, V. Stamenkovic, B.B. Blizanac, T.Tomoyuki, P.N. Ross and N.M. Markovic, J. Am. Chem. Soc. Vol., 127,6819 (2005)
[3] S.B.Yang, L.J. Zhi, K. Tang, X.L. Feng, J. Maier, K. Müllen, Adv. Funct. Mater. 22, 3634 (2012).
Optimizing the Thickness of Esb-GDC Bilayer Electrolytes for Efficient Low Temperature Operating SOFCs
Authors: Ren Yaoyu , Abdul Jabbar Mohammed Hussain , Huang Yi-Lin , Robinson Ian , Stanley Patrick , Pesaran Alireza , Wachsman Eric D. 
Published: February 2020

Bilayer electrolytes with high oxide ion conductive materials such as Er2O3-stabilized Bi2O3 (ESB) and Gd-doped CeO2-
δ (GDC) were developed to lower the operating temperature of solid oxide fuel cells (SOFCs) without compromising their efficiency[1]. In a bilayer electrolyte design, optimizing the thickness of ESB to GDC (r
ESB/GDC) and the total electrolyte thickness (h) can help to maximize the SOFC performance. However, such optimization of electrolyte thicknesses requires elaborate understanding on the voltage drop across SOFC components. In this work, efforts are made to study the voltage drop across various layers of SOFCs on a Ni-GDC based anode-supported cell. The anode-supports were deposited with ESB-GDC bilayer electrolytes with varying r
ESB/GDC and h. In particular, the voltage drop across ESB (V
ESB), GDC+anode (V
GDC+anode) and the whole cell (V
total) were determined at open circuit voltage and under load conditions. These measurements were performed by positioning the voltage probes between ESB/GDC and ESB/cathode. The behavior of V
ESB, V
GDC+anode, and V
total with a varying r
ESB/GDC and h were monitored and analyzed. Specific losses that could potentially limit the overall SOFC performance with reference to electrolyte thicknesses are addressed.
[1] E.D. Wachsman, K.T. Lee, Science, 334 (2011) 935-939.
(Invited) Cathodes for High Rate, Long Cycle Life Lithium Sulfur Batteries
Authors: Wixom Michael , Wu Qingliu , Zhang Pu , Aurora Peter 
Published: February 2020

Practical applications of lithium sulfur batteries remain limited by utilizing a limited fraction of the available sulfur and by fast capacity fading. The root causes are poor electronic conductivity of the cathode combined with high solubility of intermediate polysulfide products formed during cycling. Novel cathode materials based on conductive nanoporous ceramic host address these limitations. The promising electrochemical performance is achieved through high chemical affinity to both non-polar sulfur and polar polysulfide species. The features of Navitas’ ceramic cathode design to enhance LSB performance and life include: (1) nanoporous structure will better accommodate sulfur volume changes during cycling; (2) mechanical strength and conductivity will enable high utilization of sulfur; and (3) high affinity to both sulfur and polysulfides will minimize sulfur dissolution.
Structural and electrochemical properties will be presented. The host material possesses a surface area of 101 m2/g and porosity of 50% as designed. Melt-diffusion of sulfur has been used to impregnate sulfur into the porous ceramic host. Thermal gravimetric analysis (TGA) confirmed that controllable amount of sulfur (50% - 70%) sulfur could be impregnated into the porous host. The ceramic cathode exhibits promising electrochemical performance in lithium sulfur cells. The initial charge capacity of >900 mAh/g was higher than baseline cathodes based on mesoporous carbon. The ceramic cathode also shows improved rate capability, retaining 80% capacity at 1C and 73% capacity at 2C. Navitas’ ceramic cathode retains 82% capacity after 100 cycles. Based on the initial results, electrode design and projected performance of large format cells will be discussed.
Temperature Evolution As a Novel Indicator for State of Health Estimation of Lithium-Ion Cells
Authors: Wu Yao , Jossen Andreas 
Published: February 2020

Performance degradation of lithium-ion cells is inevitable during their application. Hence, state of health (SoH) estimation is crucial for battery management, especially in electric vehicles (EV), where the demands on the cell performance are more stringent. Conventional SoH estimation is often based on the cell capacity or impedance. Nevertheless, online capacity and impedance measurements are rarely achievable owing to the diverse and dynamic operation conditions. An alternative indicator should replace capacity and impedance to make SoH estimation more manageable.
In our work, an aging test matrix, including calendar and cycle life aging, is carried out on a commercial lithium-ion pouch cell. The stress factors are temperature (25 °C, 40 °C, 55 °C) and discharge rate (1C, 3C, 5C). Performance tests are conducted every two weeks to measure the actual capacity of the tested cells in a climate chamber at 25 °C. The performance test consists of two continuous constant current (CC) and then constant voltage (CV) charge/discharge cycles with 1C (5 A). The cut-off voltages are 2.7 V and 4.2 V with a cut-off current of C/20 (0.25 A). During the performance tests, a temperature sensor is attached to the surface center of each cell to monitor the surface temperature evolution.
During the analysis of the surface temperature evolution from the performance tests, a strong cooling effect is detected in the 1C CC charge process after about 0.4 h charging. The dT/dt curve of a new cell is shown in Fig. 1, along with its temperature evolution curve, to identify the position of the maximum cooling effect, i.e. the dT/dt minimum. Then, t0 is defined as the period from the charge beginning to the dT/dt minimum during 1C CC charging. In Fig. 2, a linear correlation between t0 and the cell actual capacity is noted with a coefficient of determination (R2) of 0.93. This correlation is analyzed for the aforementioned cells aged under both calendar and cycle life conditions. Furthermore, various stress factors have little influence on the linear correlation behavior of the cells. Accordingly, t0 could be employed as a new indicator for SoH estimation of lithium-ion cells.

Figure 1
LiPO2F2 As an Additive in Li[Ni0.5Mn0.3Co0.2]O2/Graphite Pouch Cells
Authors: Ma Lin , Liu Qianqian , Dahn Jeff R 
Published: February 2020

Lithium ion cells with longer lifetime, higher energy density and better rate capability are of interest for electric vehicle (EV) makers. The use of electrolyte additives is one of the most effective ways of improving cell performance1–3. In this work, LiPO2F2 was used as an electrolyte additive to promote the performance of Li[Ni0.5Co0.2Mn0.3]O2
(NMC532)/graphite pouch cells. LiPO2F2 was graciously provided by Guangzhou Tinci New Materials Technology Co. and Shenzhen Capchem Technology Co.
Experiments were performed using a high temperature (60°C) storage system, the ultra high precision charger (UHPC) at Dalhousie University, electrochemical impedance spectroscopy (EIS), in-situ gas evolution measurements and long term cycling tests (40°C and 20°C). LiPO2F2
containing cells demonstrated excellent capacity retention at both 40°C and 20°C, better impedance control, gas reduction and good rate capability at room temperature. The results of advanced characterization methods such as XPS and NMR to elucidate the impact of LiPO2F2 on the solid electrolyte interface layers will be reported, if available.
Figures 1a - 1c) show that LiPO2F2-containing NMC532/graphite pouch cells have better capacity retention, lower polarization growth and higher energy efficiency during long term cycling between 3.0 and 4.3 V at 40°C. Figures 1d - 1f) show that LiPO2F2-containing NMC532/graphite pouch cells have less voltage drop, less gas production and better impedance control during storage testing at high temperature (60°C). The results here suggest that LiPO2F2 is a very promising electrolyte additive for improving cell performance from many perspectives. The synergetic effect between LiPO2F2 and other useful electrolyte additives needs to be explored carefully.
References:
1. M. Nie, J. Xia, L. Ma, and J. R. Dahn, J. Electrochem. Soc., 162, A2066–A2074 (2015).
2. D. Aurbach, K. Gamolsky, B. Markovsky, Y. Gofer, M. Schmidt, and U. Heider, Electrochimica Acta, 47, 1423–1439 (2002).
3. K. Xu, Chem. Rev., 114, 11503–11618 (2014).
Figure 1(a-c) Normalized discharge capacity (a), the difference between average charge voltage and average discharge voltage (b) and energy efficiency versus cycle number for NMC532/graphite pouch cells with or without LiPO2F2 in 1.2M LiPF6 EC/EMC (3/7) during constant-voltage-constant-current (CCCV) cycling between 3.0 and 4.3 V at 40°C with a current corresponding to C/3 (cut-off current is C/20). Figures 1d – 1f show voltage versus time (d), gas production (e) and impedance change (f) during storage testing (500 hours) at 4.4 V for NMC532/graphite pouch cells with or without LiPO2F2 in 1.2M LiPF6 EC/DMC (3/7) at 60°C. In Figure 1f, the solid lines represent the results before storage and the dashed lines represent the results after storage.

Figure 1
(Invited) Oil and Water – the Challenge of Developing Separators for Ionic Liquid Electrolytes
Authors: Francis Candice , Sammut Karl , Lammas Andrew , Best Adam Samuel 
Published: February 2020

Ionic liquids are without doubt one of the most interesting materials for the replacement of organic solvent based electrolytes for both lithium-ion and lithium metal batteries [1]. Their improved physico-chemical properties, such as negligible vapour pressure, high thermal decomposition temperatures and wide electrochemical window, as compared to traditional battery electrolytes, make them attractive for these devices. However, their relatively high viscosities due to their elevated melting points and lower conductivity at sub-ambient temperatures have proven difficult to overcome without blending them with other organic-based materials.
A further challenge has appeared in recent times as researchers and companies try prototyping devices incorporating ionic liquid electrolytes – suitable separators [2, 3]. Due to the varying hydrophobic / hydrophilic nature and rapidly changing viscosity (as a function of temperature) of ionic liquid electrolytes, the choice of a suitable separator is extremely challenging. Traditional polyethylene and polypropylene separators are typically difficult to “wet” and as such, lead to relatively high internal resistance and low initial capacities as the cell components wet out. In most instances, researchers revert to Whatman glass fibre separators due to the ease of wetting because of the very open pores within the structure.
In this presentation, we will detail some of the approaches to developing separator materials specifically for ionic liquid electrolytes by previous workers and contrast and compare this with our own efforts. We will detail the impact of the choice of base separator material on wettability and device performance and then examine various methodologies used to enhance separator performance.

References

1. A. Lewandowski and A. Swiderska-Mocek, Journal of Power Sources
194: 601-609 (2009)
2. C. S. Stefan, D. Lemordant, B. Claude-Montigny and D. Violleau, Journal of Power Sources
189(2): 1174-1178 (2009)
3. M. Kirchhöfer, J. von Zamory, E. Paillard and S. Passerini, International Journal of Molecular Sciences
15(8): 14868-14890 (2014)

Acknowledgements

The authors acknowledge funding support provided by the ARC Research Training Centre for Naval Design and Manufacturing and the CSIRO Manufacturing High Performance Metal Industries Program.