bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase Diagram Approach to Study Acid and Water Uptake of Polybenzimidazole -Type Membranes for Fuel Cells
Authors: Bertasi Federico , Conti Fosca , Wacker Jurgen , Lehnert Werner , Korte Carsten , Di Noto Vito 
Published: February 2020

Polybenzimidazole (PBI) membranes doped with phosphoric acid are the most commonly used materials for high-temperature polymer electrolyte fuel cells. Despite this fact, the thermodynamics of the adsorption process over the completely accessible doping range is still a hot topic and only little is known on the chemical equilibria of the species inside the membrane as a function of the composition of the ternary system PBI - H3PO4 - H2O. This includes details on the condensation equilibria, leading to the formation of diphosphoric acid and higher homologues species and on the proton transfer processes, i.e. on the dominant conduction mechanisms. As a first step to understand the thermodynamic equilibria in the ternary system PBI - H3PO4 - H2O the phase diagrams for two different polymers, uncross-linked poly(2,2’-(m-phenylene)-5,5’-bibenzimidazole) (m-PBI) and a cross-linked commercial PBI derivate (Fumapem AM-55), were evaluated from own and from experimental data found in literature. In this study, miscibility gaps are identified and equilibrium lines separating one- and two-phase fields in the diagrams are estimated. In conclusion, we present new evidences on the interactions between H3PO4 and polymer chains, the polycondensation equilibria of H3PO4 and the implications on proton conductivity.

References:

[1] Uptake of protic electrolytes by polybenzimidazole-type polymers – adsorption isotherm and electrolyte/polymer interactions
C. Korte, F. Conti, J. Wackerl, P. Damms, A. Majerus, W. Lehnert J. Appl. Electrochem., 2015, 45, 857-871
[2] A vibrational spectroscopic and DFT study of poly(2,5-benzimidazole) (ABPBI) –phosphoric acid interactions in HT-PEFC membranes
G. A. Giffin, F. Conti, S. Lavina, A. Majerus, G. Pace, C. Korte, W. Lehnert, V. Di Noto Int. J. Hydrogen Energy, 2014, 39, 2776-2784
[3] Carbon NMR investigation of the polybenzimidazole-dimethylacetamide interactions in membranes for fuel cells.
F. Conti, S. Willbold, S. Mammi, C. Korte, W. Lehnert, D. Stolten, New J. Chem., 2013, 37, 152-156.
[4] Thermogravimetric and Spectroscopic Investigation of the Interaction between Polybenzimidazole and Phosphoric Acid
A. Majerus, F. Conti, C. Korte, W. Lehnert, D. Stolten ECS Trans., 2012, 50(2), 1155-1165.
[5] Raman study of the interactions polybenzimidazole – phosphoric acid in membranes for fuel cells
F. Conti, A. Majerus, V. Di Noto, C. Korte, W. Lehnert, D. Stolten Phys. Chem. Chem. Phys., 2012, 14, 10022-10026.
Electrode Mapping; Effects of Porosity and Thickness on NMC Full Cells
Authors: Freigang Alexander 
Published: February 2020

While performance of a lithium ion battery is primarily determined by the materials used within, the cell design variables also play a significant role. Parameters such as electrode thickness and porosity can influence overall cell energy density, power/rate performance, and lifetime. Ideally, a cell design needs to include the effects from all relevant design variables and the interactions between these parameters. For example, increasing the electrode loading is a very effective method to improve overall cell energy density as decreasing the number of layers in the cell will improve the ratio of active/inactive components. However, the thicker electrodes can result in poorer rate or power performance. Porosity of the electrodes is also a key variable affecting both energy and power performance.
Cell based models are effective tools to estimate overall cell energy density as the electrode loading and porosity varies. However, these models are less adequate to predict power or rate effects as the electrode parameters are changed. Capacity and power fade during cycling are not well described by current models or calculations. Therefore, experimental evaluation of a wide range of electrode designs is necessary to appreciate the complex variable space of electrode composition, loading, and porosity.
In this poster, we will show the effects of cathode formulation, thickness, and porosity on key performance metrics for automotive applications. Results from these experiments were used to identify benefits and limits of high loading electrode designs in high energy and power automotive cells. The data were also inputted into automotive pack models to predict effects on system level performance. Furthermore the importance of a holistic approach to bridge the gap between lab scale experiments and a full scale application is discussed.
Annealing Effect on ORR Activity of Carbon Black-Based Electrocatalysts
Authors: Asih Wentika Putri Kusuma , Oktaviano Haryo Satriya , Waki Keiko 
Published: February 2020

Non-precious metal electrocatalysts for ORR have been regarded as one of promising candidates for cutting the cost of fuel cell. It has been early considered that combination of transition metals, nitrogen doping together with carbon as support material is essential to have outstanding performance of this class of electrocatalyst.1 It is reported that in alkaline condition, combination of cobalt oxides (CoOx) nanocrystal-carbon nanotubes could also exhibit a high ORR activity.2 However, not only utilizing a large amount of transition metal oxides (~12-20 at. % Co) but also the annealing process in NH3 atmosphere are undesirable in the application. On the other hand, recently, it is reported that annealing in the inert atmosphere could also affect the ORR activity for carbon-based catalysts3. However, the understanding of the annealing effect in the inert atmosphere is still limited. Here, we showed that even by annealing the oxidized carbon black (CB) in Ar atmosphere at 900 oC and containing less amount of CoOx, we could achieve high ORR activity in 0.1 M KOH, suggesting that annealing process is essential to enhance the catalytic activity.
As precursor, we used raw CB from Tokai Carbon Co. Ltd (Tokablack #5500). To oxidize CB, raw CB was purified by using acid treatment as reported elsewhere3 and followed by solid-stated oxidation using CoOx as carbon oxidation catalyst. At first, purified CB was impregnated with 10 wt. % (~2.2 at. % Co), followed with heat treatment under Ar atmosphere at 300 °C for 3 hours and finalized by annealing in air at 230 °C for 25 minutes. Afterward, CoOx was removed by acid washing in 2M sulfuric acid, resulting in oxidized CB. To study the effect of annealing and removing the functional groups, samples were later treated at 900 oC in Ar atmosphere. Effect of the annealing toward ORR activity is shown in Fig. 1. It can be seen that without annealing in the Ar at 900 oC, oxidized CB showed lower reduction current than the annealed one. This suggests the important role of annealing to the enhancement of ORR activity. Annealing effect in the different temperatures together with the role of CoOx-oxidation catalysts on the ORR activity will be further discussed through the detailed characterization of the samples (e.g. RRDE, XPS, TPD and TEM) in the presentation.

References

[1] H. Tang, H. Yin, J. Wang, N. Yang, D. Wang and Z. Tang, Angew. Chem. Int. Ed., 52, 5585 (2013)
[2] Y. Liang, H. Wang, P. Diao, W. Chang, G. Hong, Y. Li, M. Gong, L. Xie, J. Zhou, J. Wang, T. Z. Regier, F. Wei, and H. Dai, J. Am. Chem. Soc., 134, 15849 (2012)
[3] K. Waki, R. A. Wong, H. S. Oktaviano, T. Fujio, T. Nagai, K. Kimoto, and K. Yamada, Energy Environ. Sci., 7, 1950 (2014)

Figure 1
Hybrid Electrolytes Composed of Garnet-Structured Inorganic Electrolyte and Polymer Binder for Lithium-Ion Battery with Enhanced Safety
Authors: Jung Yun-Chae , Kim Seul-Ki , Han Man-Seok , Kim Duck-Hyun , Shin Woo-Cheol , Ue Makoto , Kim Dong-Won 
Published: February 2020

Lithium-ion batteries (LIBs) have been extended their application from mobile devices to large-sized battery market such as electric vehicles and energy storage system.[1] Recently, safety issues have become a significant concern for full utilization of these batteries especially in large capacity applications. However, organic liquid electrolytes used in LIBs are problematic due to their high flammability and solvent leakage. In this respect, many Li-ion conducting electrolyte materials for improving battery safety have been investigated as alternative electrolytes for lithium-ion batteries. Among these electrolytes, solid inorganic electrolytes present potential advantages, such as absence of electrolyte leakage, high electrochemical stability, non-flammability, high thermal stability and absence of problems relating to vaporization of organic solvents.[2] However, sheet manufacturing using thin-film technologies for making large-scale lithium-ion batteries, is considered to be very difficult. In addition, a lack of flexibility results in poor interfacial contacts between inorganic solid electrolyte and solid electrodes in the cell during charge and discharge cycling. In this work, we prepared the flexible hybrid electrolytes composed of lithium lanthanum zirconium oxide (Li7La3Zr2O12) as a Li+-conducting solid electrolyte and poly(vinylidene fluoride-co-hexafluoropropylene) as a polymer binder, and their characteristics and electrochemical properties were investigated. The hybrid electrolyte was employed to assemble lithium-ion battery composed of graphite negative electrode and LiCoO2 positive electrode.

References

1. J. B. Goodenough, and Y. Kim, Chem. Mater. 22 (2010) 587.
2. J. W. Fergus, J. Power Sources 195 (2010) 4554.
Templated Non Precious Cathode Catalysts Prepared By Transition Metal and Chitosan for Oxygen Reduction Reaction in Alkaline Electrolyte
Authors: Qiao Jinli 
Published: February 2020

The oxygen reduction reaction (ORR) is an important energy conversion reaction, especially for fuel cells1 and metal–air batteries.2 Pt-based materials are widely recognized as superior ORR electrocatalysts , hindering this technology's commercialization because of their expensive and scarce nature;3 in addition, these catalysts are not sufficiently stable and exhibit unsatisfactory catalytic activity towards the oxygen reduction reaction (ORR). Certain types of N-containing transition metal catalysts have showed high activity for oxygen reduction in alkaline media,4 however, compared to Pt-based catalysts for practical application in fuel cells, both the ORR activity and stability of these catalysts have to be significantly improved.5,6

It is believed that the high surface area, high porosity and proper pore structure of catalyst usually lead to high catalytic activity for the ORR. Template method has drawn great attention to obtain the specified morphology and predetermined microstructure.7,8 In this paper, we choose template method to synthetize polyporous non precious metal catalysts. Nanoscale SiO2 was employed as sacrificial supports to create pores, while chitosan (CTS) as source of N and C.
The CTS-Fe catalysts were prepared by homogeneously dispersion of metal and CTS precursors onto the surface of SiO2. SiO2 was etched by 5M NaOH after dried at 85 oC for 48h, then the resultant powder was pyrolized in an N2 atmosphere at 800oC for 1h. The vacated SiO2 particles lead to creation of pore. The final powder was washed to be neutral by purified water and then dried overnight. Meanwhile, samples pyrolized in an N2 atmosphere respectively at 700oC, 900oC for 1h were prepared by the same procedure. Base on this method, we prepared CTS-Fe catalysts respectively at 700oC, 800oC, 900oC,with high porosity. The kinetics and electrocatalytic activity on the M-PEI catalysts have been measured using cyclic voltammetry (CV), linear sweep voltammetry (LSV) and rotating disk electrode (RDE). All these tests were carried out in a glass cell consisting of a three-electrode system in 0.1M KOH at the ambient solution temperature.
References
1. B. C. Steele and A. Heinzel, Nature
, 2001, 414, 345.
2. E. M. Erickson, M. S. Thorum, R. Vasic, N. S. Marinkovic, A. I. Frenkel, A. A. Gewirth and R. G. Nuzzo, J. Am. Chem. Soc., 2012, 134, 197.
3. M. Arenz, K. J. Mayrhofer, V. Stamenkovic, B. B. Blizanac, T. Tomoyuki, P. N. Ross and N. M. Markovic, J. Am. Chem. Soc., 2005, 127, 6819.
4. J.L. Qiao, L. Xu, L. Ding, L. Zhang, R. Baker, X. F. Dai, J. J. Zhang, Applied Catalysis B: Environmental
125, 197 (2012).
5. Y. Yang, Z. Shi, S. Holdcroft, Macromolecules
37 1678 (2004).
6. R.W. Kopitake, C.A. Linkours, H.R. Anderson, G.L. Nelson, J. Electrochem Soc
147, 1677 (2000).
7. K. Kamegawa, H. Yoshida. Carbon
35, 631(1997).
8. R. Ryoo, S.H. Joo, M. Kruk, M. Jaroniec. Adv. Mater.
13, 677(2001).

Figure 1
The Influence of Electrolyte Composition on the Electrochemical Properties of Li-Sulfur Dioxide Batteries
Authors: Yang Tae Hyeon , Yang Hye Jeong , Kang Ji Hoon , Kim Seok , Jung Yongju 
Published: February 2020

Primary lithium-sulfur dioxide (Li-SO2) batteries composed of a carbon cathode, a lithium anode and an organic electrolyte containing sulfur dioxide (SO2) in an organic solvent were presented in the late 1960s and are mainly used in defense applications.1 Recently, rechargeable Li-SO2 batteries with high energy density have been demonstrated.2-3 The technological breakthrough came from innovative electrolyte systems and nanostructured carbon cathodes. In general, a highly conductive liquid inorganic electrolyte such as LiAlCl4×xSO2 has been used.
To date, however, the influence of the electrolyte composition on the electrode reaction of SO2 has not been explored. In this study, the electrochemical properties of Li-SO2 rechargeable batteries are examined in various electrolyte solutions. In addition, the relation between carbon loading and SO2 utilization is intensively investigated.

Acknoledgments

This study was supported by the Energy Efficiency and Resources Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), the financial resources granted from the Ministry of Trade, Industry and Energy, Republic of Korea (No. 20132020000260).

References

1. W. F. Meyers, B. Bell, J. W. Simmons, U.S. Patent 3,423,242 (1969).
2. G. Jeong, H. Kim, J. H. Park, J. Jeon, X. Jin, J. Song, B.–R. Kim, M.-S. Park, J. M. Kim and Y.-J. Kim, Energy Environ. Sci., 8 (2015) 3173.
3. H.-D. Lim, H. Park, H. Kim, J. Kim, B. Lee, Y. Bae, H. Gwon and K. Kang, Angew. Chem., 127 (2015) 9799.
Noble Metal Nitride X Catalyst for H2-Br2 Redox Flow Batteries
Authors: Doan Huong , Alsudairi Amel , Ghoshal Shraboni , Bates Michael , Jia Qingying , Mukerjee Sanjeev 
Published: February 2020

Renewable energy such as wind and solar has grown exponentially resulting in a high demand for low-cost, modular and scalable energy storage. Redox Flow Batteries (RFBs) offer improved flexibility in energy capacity and power density for grid-scale energy as compared to NaS & Li-ion batteries which are currently in-use. In particular, H2-Br2 RFBs are known for their low-cost components such as electrolyte (HBr) and electrodes (Br-/Br2). However, the hydrogen electrode of H2-Br2 flow cells suffers from well-known stability issues as a result of halide adsorption on the catalyst surface and Pt dissolution. The shortcomings occur due to Br2 cross-over. Finding a catalyst that could overcome this would be a significant milestone in addressing energy needs. Northeastern University Center for Renewable Energy Technology (NUCRET) synthesized and tested several Pt & Ir nitride catalyst. These catalyst materials were screened for hydrogen evolution reaction and hydrogen oxidation reaction (HER-HOR) activity via a rotating disk electrode (RDE) cell. RDE studies of pure Ir/C and Pt/C catalysts showed that the Ir-component and Pt- component are active for both HER & HOR. However, Ir or Pt catalysts alone are not stable under stability testing conditions which involve high-voltage cycling or exposure to Br2. NUCRET successfully synthesized 40 wt% Pt-Ir-Nx/C sample that exhibited i0 well above the 0.6 A/ mg target. This Pt-Ir-Nx/C catalyst, along with commercial Pt-Ir/C and Pt/C, were also subjected to stability testing in 1M HBr with 1mM Br2 The Pt-Ir-N/C sample exhibited increased stability compared to the commercial Pt-Ir/C and Pt/C catalysts. Cyclic Voltammetry (CV) results suggest that the Pt-Ir-Nx/C sample suffered ~50% loss in HER/HOR activity (Figure 1 right). In addition, Pt-Ir-Nx/C sample lost about 30% of electrochemical active surface area (ECSA) (Figure 1 left), compared to 70% Pt-Ir/C and 100% Pt/C standard loss. This presentation will attempt to analyze the results from the point of view of the effect of nitrogen functionalization as distinct from other factors such as particle size, etc. Use of in situ synchrotron XAS spectroscopy and Raman in conjunction with electrochemical data both from single cell as well as RDE will be presented.

Acknowledgement

The authors gratefully acknowledge the financial support from Arpa-e, Department of Energy under grant no DE-AR0000262, lead by TVN systems, Kansas.

Figure 1
Intermetallic Li-Anode Systems: Cu-Li-Sn
Authors: Fuertauer Siegfried , Beutl Alexander , Li Dajian , Cupid Damian Marlon , Flandorfer Hans 
Published: February 2020

In addition to alternative modifications of carbon and organic composite materials, intermetallic alloys are promising candidates for new anode materials for lithium ion batteries (LIBs) because of the significantly increased theoretic capacities when compared to conventionally used graphite. However, the drastic volume changes during lithiation of pure metals such as Al or Sn lead to degradation of particle-to-particle contacts, resulting in very low cyclic stabilities. One of the various concepts to solve this problem is to use intermetallic alloys as new anode materials. For example, Cu6Sn5 and Cu3Sn are promising anode materials because Cu does not form intermetallic compounds with Li. A (Cu)-alloy matrix would act to buffer the strain induced by volume changes and simultaneously ensure electrical contact between lithiated regions.
Advanced materials design by computational methods rely significantly on experimentally determined thermodynamic and phase diagram data of the material systems to be able to simulate the electrochemical behaviour of new lithium ion batteries. Therefore comprehensive experimental investigations applying various methods like PXRD and SC-XRD studies, thermal analysis, and drop calorimetry were performed to gain a full understanding of the Cu-Li-Sn alloy system. The outcome of our comprehensive experimental work includes 4 isothermal sections, 8 isopleths, a liquidus projection and a reaction scheme as well as mixing and formation enthalpies. In addition, six new ternary intermetallic compounds could be found and their structure was described. Based on these results, the equilibrium lithiation reactions of Cu-Sn alloys could be proposed for the first time.
In this presentation we would like to briefly report about the special features and designs of our experimental methods. Subsequently, selected experimental results on Cu-Li-Sn will be shown and discussed. Our comprehensive experimental data together with literature data will lead to a very well founded CALPHAD assessment as an input for computational materials design.
This work has been funded by the FWF under the project I559-N19 and by the DFG under the projects FL-730/1-2 and CU 203/ 1-2, all within the DFG priority project SPP 1473 “WeNDeLIB”.
(Invited) Prisitine C60 and C70 fullerenes As Electron Transport Materials for Perovskite Solar Cells
Authors: Delgado Juan Luis 
Published: February 2020

The photovoltaic community is currently experiencing the revolution of the solar cells based on perovskite materials. Since the first reports based on a solid hole-transporting layer appeared, a great variety of organic molecules have been employed as electron or hole-selective contacts in regular and/or inverted perovskite-based solar cells (PSCs) (Figure 1 A and C, respectively). Fullerene and their derivatives are playing a very important role as electron-selective contact (ESC) in inverted solar cells as well as in self-assembled monolayers of fullerene derivatives on TiO2 in regular devices. Moreover, the interest of fullerenes in PSCs has been increased by the recent report of Snaith’s group, which describes the successful incorporation of [60]fullerene instead of the usual TiO2 as ESC in regular PSCs architectures (Figure 1B).
In the present comunication, careful photovoltaic studies following a well-described experimental protocol have been carried out with PSC fabricated with [70]fullerene, [60]fullerene and [60]fullerene derivatives as Electron Transport Material in regular perovskite solar cell architecture, in order to study their suitability as ETM for PSC. The obtained results indicate that the use of these materials as ET materials in PSC allow the obtention of highly efficient devices (≥10%), due to the introduction of the "fullerene saturation approach".

Figure 1
(Invited) Controlled Assembly of C60 Using Supramolecular Scaffolds
Authors: Fukushima Takanori 
Published: February 2020

Spontaneous molecular assembly in solution usually proceeds under thermodynamic control and thus provides a reliable approach to creating materials with high positional and/or orientational order of the constituent molecules. If supramolecular building blocks could be purposely designed, one may control the alignment of functional molecular units so that the resulting assembly can take full advantage of the inherent properties of the functional units. This presentation will focus on the controlled assembly of C60 using several supramolecular building blocks. When C60 is attached to a particular type of hexabenzocoronene capable of forming a nanotubular assembly, a coaxial nanotube results, where the wall consists of hole-transporting hexabenzocoronene arrays, while inner and outer surfaces are covered by an electron-transporting monolayer of C60 [1]. We have also shown that an amphiphilic design of an oligothiophene-C60 dyad provides a rational strategy for tailoring bicontinuous electron donor and acceptor arrays [2]. We recently found that a tripodal triptycene self-assembles into a 2D hexagonal structure by nested packing. The interpenetration of the triptycene part may suppress structural fluctuation, thus enabling the formation of organic films with a remarkably long-range structural order [3]. Using this tripodal triptycene as a supramolecular building block, a C60 unit can be assembled into a two-dimensional sheet-like structure. The synthesis and properties of these materials with controlled C60assemblies will be discussed.
References: [1] Y. Yamamoto, G. Zhang, W. Jin, T. Fukushima, N. Ishii, A. Saeki, S. Seki, S. Tagawa, T. Minari, K. Tsukagoshi, T. Aida, Proc. Natl. Acad. Sci. U.S.A.
2009, 106, 21051–21056. [2] W.-S. Li, Y. Yamamoto, T. Fukushima, A. Saeki, S. Seki, S. Tagawa, H. Masunaga, S. Sasaki, M. Takata, T. Aida, J. Am. Chem. Soc.
2008, 130, 8886­–8887. [3] N. Seiki, Y. Shoji, T. Kajitani, F. Ishiwari, A. Kosaka, T. Hikima, M. Takata, T. Someya, T. Fukushima, Science
2015, 348, 1122–1126.