bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Controlled Synthesis of the Ultra-Low-Platinum Electrocatalysts for High-Performance Polymer Electrolyte Membrane Fuel Cell (PEMFC) Cathode
Authors: Zhang Junliang , Luo Liuxuan , Tian Renxiu , Wang Chao , Cheng Xiaojing , Wei Guanghua , Shen Shuiyun
Published: February 2020

Controlled synthesis of the ultra-low-platinum electrocatalysts for high-performance polymer electrolyte membrane fuel cell (PEMFC) cathode Junliang Zhang*, Liuxuan Luo, Renxiu Tian, Chao Wang, Xiaojing Chen, Guanghua Wei, Shuiyun Shen

Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China

Abstract: A drastic reduction in the Pt loading of cathodes is urgently desired for the commercialization of polymer electrolyte membrane fuel cells (PEMFCs). The application of ultra-low Pt loading (≦0.1 gPt/kW) cathode comes up with two challenging research topics, one deals with the exploration on the local mass transport surrounding Pt particles in the catalyst layer, and the other involves in controlled synthesis of ultra-low Pt electrocatalysts. Herein, effective strategies have been developed to synthesize a series of ultra-low Pt electrocatalysts with both controlled compositions and structures, and investigated as the oxygen reduction reaction (ORR) electrocatalyst. The corresponding synthetic mechanisms and key influences on the catalytic activity, electrochemical stability as well as utilization toward the ORR are comprehensively elucidated. It is believed that the discussion will provide a solid scientific guideline for the development of ultra-low Pt PEMFCs.

Acknowledgements

This work was supported in part by National Natural Science Foundation of China (Grant No. 21533005 and 21373135) and the National Key Research and Development Program of China (2016YFB0101201 and 2016YFB0101312).

*Corresponding author. Tel.: (+86) 213420 7439; fax: (+86) 21 3420 6249.

E-mail: junliang.zhang@sjtu.edu.cn
Electrochemical Reduction of CO2 to CO or Ethylene: Status of Electrocatalysis and Technoeconomic Insights
Authors: Kenis Paul J.A.
Published: February 2020

One strategy to reduce anthropogenic CO2 emissions is the use of CO2 as a feedstock for the production of useful chemicals such as formic acid, carbon monoxide, ethylene, ethanol, or methanol via the electrochemical reduction of CO2. Over the past decade, significant advances have been made in the development of electrocatalysts for the efficient and selective conversion of CO2 to some of the aforementioned products. Scale up and commercialization activities are already ongoing for the conversion of CO2 to formic acid or CO. These electrolysis processes have the promise to be executed in a cost effective and sustainable manner, especially if otherwise-wasted renewable energy (produced in excess of grid demand) is used.

This presentation will summarize our efforts to perform electrolysis of CO2 to CO at high efficiency and selectivity using Ag, Au, and N-doped carbon based catalysts. Furthermore it will cover our recent advances in developing ever more active and especially selective catalysts for the production of ethylene and ethanol. Many researchers are pursuing Cu-based catalysts for this task. While reasonable conversion rates can be achieved (overall current densities exceeding 100 mA/cm2), the main challenge has been achieving selectivity for the desired products of ethylene and ethanol. We have developed Cu-based catalysts that produce 70-80% ethylene and ethanol, at a combined rate exceeding 170 mA/cm2. The presentation will also include an analysis of economic feasibility for the production of ethylene and ethanol from CO2, which highlights the importance of low electrical energy cost (as expected) as well as the need for high energy efficiency (low cell potential, low overpotentials) in the electrolysis process itself. This insight has led us to explore alternative reactions to the oxygen evolution reaction on the anode which typically represents >85% of the energy needs to drive a CO2 electrolysis process. For example performing the electro-oxidation of glycerol, a large byproduct of biomass conversion, can reduce the overall energy needs by 50%.
A Cost-Effective Lithium-Ion Battery Direct Recycling Process
Authors: Li Zheng
Published: February 2020

Lithium-ion batteries have dominated the power source market for consumer electronics (W⋅h scale) and are becoming the dominant battery technology for electrified vehicles (EV, kW⋅h scale) and grid-scale electrochemical energy storage systems (MW⋅h scale) [1,2]. The growing ubiquity of lithium-ion batteries also brings a rapid growth in hazardous battery waste from manufacturing processes and end-of-life (EOL) disposal [3,4]. In the EV sector alone, approximately 50-100 million lithium-ion cells in the US and China will reach their EOL by 2020, thus generating large amounts of hazardous waste [5]. However, conventional pyrometallurgical and hydrometallurgical battery recycling processes require high temperature, strong acid leaching and extensive gas treatment, which lead to prohibitive cost, high energy consumption, water contamination and recycled materials with low resale value [6,7]. Since the cathode materials account for 30-40% of the overall battery cost, a cost-effective and eco-friendly
direct recycling

process
that yields reusable battery-grade cathode materials can lower the energy consumption and battery materials cost. In this talk, we will demonstrate a scalable and cost-effective direct recycling process for EOL lithium-ion batteries to yield battery-grade cathodes. The recycled cathodes retain the microstructure and show equivalent electrochemical performance compared to the pristine cathode materials. We will also present life cycle analysis for several cathode materials widely used in current state-of-the-art electrified vehicles and compare the energy consumptions of different recycling approaches.

Reference

[1] M.S. Whittingham, Lithium Batteries and Cathode Materials, Chem. Rev. 104 (2004) 4271–4302. doi:10.1021/cr020731c.

[2] M.S. Whittingham, Ultimate Limits to Intercalation Reactions for Lithium Batteries, Chem. Rev. 114 (2014) 11414–11443. doi:10.1021/cr5003003.

[3] E. Gies, Recycling: Lazarus batteries, Nature. 526 (2015) 526S100a. doi:10.1038/526S100a.

[4] L. Gaines, To recycle, or not to recycle, that is the question: Insights from life-cycle analysis, MRS Bull. 37 (2012) 333–338. doi:10.1557/mrs.2012.40.

[5] Estimated based on the EV sales volume of US and China from 2011-2015, n.d.

[6] J.B. Dunn, L. Gaines, J.C. Kelly, K.G. Gallagher, Life Cycle Analysis Summary for Automotive Lithiumion Battery Production and Recycling, in: Rewas 2016 Mater. Resour. Sustain., John Wiley & Sons, Inc., 2016: pp. 73–79. doi:10.1002/9781119275039.ch11.

[7] L. Gaines, The future of automotive lithium-ion battery recycling: Charting a sustainable course, Sustain. Mater. Technol. 1–2 (2014) 2–7. doi:10.1016/j.susmat.2014.10.001.
Electrolytic Recycling of Primary Alkaline Batteries
Authors: Mustain William E , Soucie Hanna , Nguyen Christiane , Petracca Paul , Nguon Helen , Zhang Fan , Wangstrom Abbey
Published: February 2020

Approximately 4 billion alkaline batteries are sold annually in the United States, which amounts to nearly 150,000 tons of alkaline batteries. Alkaline batteries are not considered hazardous materials and are therefore safe to be landfilled; however, nearly $100 million of metals from the spent alkaline batteries are being wasted per year in the United States instead of being recycled (Battery Care and Disposal). Therefore, it would be beneficial to establish a viable alkaline battery recycling process to reuse materials and to reduce the tonnage of alkaline batteries that are landfilled. This problem represents a significant financial opportunity as well as the opportunity for the major alkaline battery manufacturers to reduce their environmental footprint.

Black mass, the powder product of crushing discharged alkaline batteries, consists of a mix of over twelve components and metals. The metals can be recycled, recovered individually, and resold. Currently, a very small percentage of black mass is used as fertilization for crop fields. Not reusing the remaining material wastes millions of dollars of metals per year. In this presentation, we will discuss one method to process and separate this black mass into two particularly useful components, electrolytic manganese dioxide (EMD) and zinc (Zn), which respectively make up the cathode and anode active material in their alkaline batteries – with an overall goal of designing an engineered system that can achieve > 95% purity of ingot zinc and EMD. In this talk, we will outline not only the overall process, but also discuss industrially-relevant parameters including scale and cost.
Perovskite Oxide Nanoparticles As High Performance Bifunctional Catalyst
Authors: Xu Weichuan , Yan Litao , Zhou Meng , Luo Hongmei
Published: February 2020

Developing efficient electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are vital to the new generation of electrochemical storage and conversion devices such as electrolyzer, metal-air batteries, and fuel cells. For the demand of reversible fuel cells and rechargeable metal-air batteries, the bifunctional catalyst that can be used for both ORR and OER is gathering attention. In order to address the longstanding problems with high cost and poor stability of noble metal electrocatalysts, perovskite (ABO3 formula, where A is rare-earth or alkaline metal and B is transition metal) with low cost, high versatility in structure and potential as bifunctional catalyst is of special interest. Applying our successful and novel polymer-assisted chemical solution (PACS) method, we will present the controlled synthesis of (La0.8Sr0.2)x(Mn1-yBy)O3 (B: Ir and Co, x=0-0.1, y=0-0.2) nanoparticles with different particle sizes, A-site nonstoichiometry, B-site doping, and oxygen vacancy, and epitaxial thin films with different crystal orientations. Stuctural characterizations and electrochemical analysis are utilized to investigate the correlation between their compositions, structures, and electrochemical properties.
Holistic Study of Doped Layered Titanate Nanofibers
Authors: Heath Caleb , Cole Parker , Kaloni Thaneshwor , Barraza-Lopez Salvador , Tian Ryan
Published: February 2020

Layered titanate nanostructures are uniquely suited to large-scale application in energy science due to their inexpensive processing, ease of synthesis, and their versatility to be ion-exchanged with specific elements. The quantity and scope of experimental literature that exists for these porous, ion-exchangeable nanostructures is not matched in the computational studies available; we have expanded the boundaries of both by combining the experiment and the computation to answer questions about how dopant atoms are integrated into the layered titanate nanofiber crystal lattice during synthesis. We simulated doped hydrogen trititanate (H2Ti3O7) with and without magnetic substitutional doping for a variety of dopant sites. Predicted structural energies, band structure, charge distribution, and magnetic properties were examined. Simulated XRD patterns are comparable to experimental results from synthesized doped nanofibers. Finally, EDX scans confirmed the presence of dopants in the titanates. We found that this combined computational/experimental collaboration provided strong evidence for one interpretation of the dopant integration, and we expect to generalize this work on different dopants.
Engineering Plasmonic Lattice Structures for Lab-on-Chip Sensing Platforms
Authors: Smith Kyle , Norville Casey , Dawson Jeremy
Published: February 2020

The study of plasmonics has increased in the past decades due to the benefits they offer to a wide range of application areas including optics, point-of-care sensing, spectroscopy, imaging, etc. The fabrication of plasmonic devices has relied on sub-micron to nanoscale fabrication techniques that are typically low throughput, and often result in transducers that are challenging to integrate with other lab-on-chip components. Methods based on a combination of bottom-up self-assembly and top-down nanosphere lithography based provided solutions to these fabrication challenges. This paper will discuss the design and fabrication of nanosphere-based plasmonic lattices that directly utilize nanosphere deposition to create resonant plasmonic transducers capable of resonant enhancement of quantum dot and fluorescent labels with visible-spectrum emission. Parametric simulations of critical plasmonic lattice dimensions using finite-difference time-domain (FDTD) software will be presented to offer insight into design optimization for maximum emission enhancement for a given range of commercially-available nanobeads. Fabrication of the sub-micron lattice using nanobeads sized in the 100-500 nm range in an evaporative deposition process will be described, along with an evaluation of variations in ‘as-drawn’ and fabricated lattice dimensions. Characterization results indicating 10-fold+ enhancement of photonic emission from labeled analyte in suspension will be provided.

Figure 1
(Invited) Functionalization of Low Dimensional Carbons for Highly Efficient Energy Storage
Authors: Wang Hsing-Lin
Published: February 2020

Herein, we report synthesis of a series of 2D and 3D nanographenes with various functional groups attached to the edge of the nanographene basil planes. Among other potential applications, these high-surface area nanographenes have an excellent cyclic durability and a much enhanced charge capacity (> 1000 mAh/g) as novel anode materials for LIBs. Moreover, theoretical charge capacity of these nanographenes exceeds 2000 mAh/g due to an increased edge to surface ratio and oxygen containing functional groups. These exceptional performance characteristics are primarily due to the robust structure along and optimal d-spacing between nanographene layers which allowing for facilitated Li adsorpiton/desorption and diffusion.

Our study reveals insights on how control synthesis of nanographenes and their self-assemblies with optimized electronic structure and facilitated electron transfer has led to superior energy storage properties, there time the capacity of graphite, suggesting that the optimal design of conjugated nanographenes are promising for next generation LIBs.
Facile Synthesis of Highly-Graphitic Carbon By the Reaction of Calcium Carbide with Sulfur and the Application in Lithium-Ion Batteries
Authors: Li T. , Bai X. , Gulzar U. , Zaccaria R. P.
Published: February 2020

The design and preparation of new carbon materials (CMs) has long been of interest in the field of materials science. Various novel nanostructured CMs with unique structure and morphology usually exhibit a variety of potential applications owing to their outstanding chemical and physical properties.1
−
3

Recently, CMs were synthesized through the chemical reactions between calcium carbide (CaC2) and halogenated hydrocarbons or chlorine gas, which demonstrated promising applications for energy storage like supercapacitors.4 The as-prepared porous CMs with low degree of graphitization and high specific surface area are somehow different from the highly-graphitic carbon nanospheres prepared by the reaction of CaC2 with aluminum chloride hexahydrate or copper dichloride hydrate in sealed stainless steel autoclaves.5,6 The onion-like carbon nanospheres exhibited good cycling performance as anode materials for lithium-ion batteries (LIBs), delivering a high reversible capacity of 391 mAh/g after 60 cycles at a current density of 37.2 mA/g.6

In this work, we report, for the first time, a new one-step approach to prepare CMs by selective thermo-chemical etching the calcium from CaC2 by sulfur at 550 oC. By the comprehensive analysis on structure and morphology by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), N2 adsorption−desorption isotherm analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the prepared CMs reveal a mesoporous structure with high graphitization degree and a specific surface area of 159.5 m2/g. Most of the carbon product displays micron-scale mesoporous frameworks (4–20 um) with distinct layered structure, and the others are the agglomerates of highly-graphitic carbon nanosheets with thickness about 10 nm and lateral size of 1–10 μm (Figure 1a). When tested as anode materials for LIBs, the as-prepared CMs exhibit an excellent cycling performance and rate capabilities, delivering a high reversible capacity of 561.3 mAh/g at 0.1C (1C = 372 mA/g) after 120 cycles (Figure 1b), thus demonstrating intensive potential in electrochemical energy storage. The present study provides a perspective approach to fabricate CMs by the simple, cost-effective, and efficient synthetic route using CaC2 and sulfur as reactants.

References:

Georgakilas,J.A. Perman, J. Tucek, R. Zboril, Chem. Rev., 2015, 115, 4744–4822.

Gogotsi, V. Presser, eds., Carbon nanomaterials, CRC press, 2013.

Gu, G. Yushin, WIREs Energy Environ.,2014, 3, 424–473.

Li, Q. Liu, W. Li, H. Meng, Y. Lu, C. Li, ACS Appl. Mater. Interfaces, 2017, 9, 3895–3901.

L. Zhu, Y.J. Bai, Y.X. Qi, N. Lun, Y. Zhu, Carbon, 2012, 50, 1871–1878.

D. Han, B. Yao, Y.J. Bai, J. Phys. Chem. C, 2011, 115, 8923–8927.

Figure 1
(Invited) Nanoscale Imaging of Brain Tissue Features with Carbon Nanotubes
Authors: Cognet Laurent
Published: February 2020

Sub-wavelength localization of single molecules allows super-resolution imaging and a subtle probing of spatio temporal nano-environments [1]. Recently, we demonstrated that by using super-localization imaging of luminescent biocompatible single wall carbon nanotubes in the near-IR [2,3], we can unravel the local structure and rheology of the extracellular space in live brain slices. Because of the interplay between the nanotube geometry and the extracellular space local environment, we can indeed extract information about the extracellular space dimension and local viscosity [4]. In this presentation, I will show our recent results about the extracellular space properties near identified brain structures [5] (e.g synapses) and in neurodegenerative disease animal models [6].

References

[1] Godin et al , Biophys. J, (2014).

[2] Gao, et al, Biomater. Sci. (2016).

[3] Danné et al Nanomaterials (2017).

[4] Godin et al Nat. Nanotechnol. (2016).

[5] Paviolo et al

[6] Soria et al
(Invited) Utilization of Single Wall Carbon Nanotube Sensors for Detection of Disease Development
Authors: Iverson Nicole M , Stapleton Joseph A , Hofferber Eric M , Adams Janelle J
Published: February 2020

Single walled carbon nanotubes (SWNT) are unique in the field of sensors due to their extremely small size and longevity. Through the use of SWNT sensors information about the development of diseases can be elucidated, providing researchers and clinicians with a detailed explanation of how and why a disease is progressing in a specific fashion. With improved understanding of disease development, both early detection and improved disease treatment can occur. This talk will focus on the initial steps towards the goal of improved disease characterization.
Learning DNA/SWCNT Recognition Sequences
Authors: Yang Yoona , Zheng Ming , Jagota Anand
Published: February 2020

DNA/single walled carbon nanotube (SWCNT) hybrids have attracted significant attention for their ability to disperse and sort SWCNTs according to their chirality. Much effort has been expended in recent years to discover the special short DNA sequences, called ‘recognition sequences’, which recognize specific corresponding partner SWCNTs from mixtures. Several computational molecular modeling studies have established our understanding of the structural basis for sequence-specific recognition. Although some sequence patterns have emerged from a directed and limited search of the DNA library, our ability to predict recognition sequences remains weak. In this research, we proposed a new approach to prediction of recognition sequences using machine learning techniques. We used two different ways to represent the DNA sequences: Position Specific Vector and Term Frequency Vector. The Position Specific Vector method conserves the position information of each nucleotide in a sequence but is only applicable for sets of sequences with the same length. The Term Frequency Vector method does not contain position information but can be used for sets of sequences with variable length. We have applied these feature extraction methods to experimental data sets, using them to train several classifier algorithms (logistic regression, support vector machine and multilayer perceptron). We add a further iteration loop by tested experimentally new sets of predicted sequences, re-evaluating and retraining models each time. We report significantly improved ability to predict recognition sequences.
(Invited) Carbon Nanotube Photoluminescence Spectroscopy for Applications in Cancer Research
Authors: Heller Daniel A , Budhathoki-Uprety Januka , Galassi Thomas Vito , Frederiksen Rune , Harvey Jackson , Horoszko Christopher Peter , Jena Prakrit Vaibhav , Langenbacher Rachel E , Roxbury Daniel , Shah Janki , Shamay Yosef , Williams Ryan M. , Baker Hanan
Published: February 2020

The detection of biomarkers and drugs in live cells and animals would allow for more effective studies of the dynamics of cancer and treatment. Toward these ends, single-walled carbon nanotube photoluminescence is suitable for measurements in live cells and in vivo, and nanotube near-infrared emission exhibits sensitivity to the local environment via solvatochromic responses. We developed new optical instrumentation to image carbon nanotubes and to measure spectral changes of carbon nanotube photoluminescence in live cells and animals. Concomitantly, we developed new methods to exacerbate the nanotube emission response to produce large spectral shifts (> 14 nm) upon the binding of cancer biomarkers and chemotherapeutic drugs. The ability to improve measurements and control of carbon nanotube solvatochromism may improve sensitivity and selectivity of nanosensors and potentially expand the application of nanotube-based optical measurements to new classes of bioanalytes.
DFT Study on the Adsorption of Organic and Organometallic Sensitizers on Nanocrystalline TiO2 for DSSC Applications
Authors: Chitumalla Ramesh Kumar , Jang Joonkyung
Published: February 2020

Computational simulations are performed to understand the structure and the electronic properties of dye@TiO2 interfaces and thus complement experimental work. A common computational approach is to perform calculations of adsorbate-nanocrystalline TiO2 surface systems using periodic boundary conditions. With a relatively small periodic TiO2 slab model, the electronic structure of TiO2 can be described and a density of states (DOS) with a bandgap close to the bulk value can be obtained. As the interaction between dye and TiO2 can strongly influence the electronic coupling between dye and TiO2, we have focused our research on the adsorption of dyes on TiO2 by employing periodic-DFT methods. We have studied different possible adsorption configurations of organic d-π-A dyes on extended anatase TiO2 (101) surface and evaluated their adsorption strengths with the TiO2. The calculated adsorption energies are in proportion to the experimental short-circuit photocurrent densities (
Jsc

).1 The electronic structure of the dye sensitized TiO2 is explained from the calculated DOS which shows an overlap of the unoccupied molecular orbitals of the dye and the TiO2 conduction band.2 We also used alternative cluster models, which enable studies of the interaction of large adsorbates with nanostructured TiO2 substrates.3 We have studied the adsorption geometry and optical absorption spectra of thiocyanate free cyclometalated ruthenium dyes on (TiO2)38 cluster which allowed us to understand the electron injection (direct/indirect) mechanism and the electronic structure of the dye@TiO2 assemblies.4

References

Srinivas, K.; Kumar, C. R.; Reddy, M. A.; Bhanuprakash, K.; Rao, V. J.; Giribabu, L., D-π-A organic dyes with carbazole as donor for dye-sensitized solar cells. Met. 2011, 161, 96-105.

Srinivas, K.; Sivakumar, G.; Ramesh Kumar, C.; Ananth Reddy, M.; Bhanuprakash, K.; Rao, V. J.; Chen, C.-W.; Hsu, Y.-C.; Lin, J. T., Novel 1,3,4-oxadiazole derivatives as efficient sensitizers for dye-sensitized solar cells: A combined experimental and computational study. Met. 2011, 161, 1671-1681.

Chitumalla, R. K.; Gupta, K. S. V.; Malapaka, C.; Fallahpour, R.; Islam, A.; Han, L.; Kotamarthi, B.; Singh, S. P., Thiocyanate-free cyclometalated ruthenium(ii) sensitizers for DSSC: A combined experimental and theoretical investigation. Chem. Chem. Phys. 2014, 16, 2630-2640.

Chitumalla, R. K.; Jang, J., Density functional theory study on ruthenium dyes and dye@TiO2 assemblies for dye sensitized solar cell applications. Sol. Energy. 2018, 159, 283-290.

Figure 1
(Invited) Redox-Active Carbon Positive Electrodes for High-Performance Hybrid Supercapacitors
Authors: Liu Tianyuan , Lee Byeongyong , Lee Michael J , Lee Seung Woo
Published: February 2020

Hybrid supercapacitors combine the advantages of lithium-ion batteries and electrochemical capacitors to achieve both high energy density and power density. However, the overall energy density is limited by the low capacity of the carbon-based positive electrodes. We have been trying to improve the energy density of the carbon-based positive electrodes by incorporating surface reactions into nanocarbon materials, including carbon nanotube and graphene. Recently, we have demonstrated the redox-active carbon positive electrodes by coating functional polymers on the surface of carbon nanotubes.1
,2 This presentation introduces shape-controlled carbon materials with significantly enhanced charge storage performance. We also demonstrate high-performance hybrid supercapacitors by combining the redox-active carbon positive electrode with the battery-type negative electrode.

References

J. C. Bachman, R. Kavian, D. J. Graham, D. Y. Kim, S. Noda, D. G. Nocera, Y. Shao-Horn and S. W. Lee, Nature Communications, 6:7040 (2015).

T. Liu, K. C. Kim, B. Lee, Z. Chen, S. Noda, S. S. Jang and S. W. Lee, Energy & Environmental Science, 10, 205 (2017).
Understanding Catalytic Behavior of Co-Sn Alloy/Graphene Counter Electrode Electrocatalysts in Liquid-Junction Photovoltaic Devices
Authors: Oh Hyo-Jun , Dao Van-Duong , Choi Ho-Suk
Published: February 2020

Understanding the electrocatalytic activity of counter electrode (CE) favors to tune the sluggish triiodide reduction kinetics and to compare their catalytic activities. We present here the synthesis of CoXSn1-X alloys (0 ≤ X ≤ 1) on reduced graphene oxide (RGO) under atmospheric pressure plasma without using any toxic chemical reagents. The developed materials are then applied as catalysts for the reduction of triiodide ions to iodide ions in CE of dye-sensitized solar cells (DSCs). It should be noted that the triiodide reduction reaction is one of the utmost significances in the advanced electrochemical energy conversion of DSCs. Therefore, insights into the relationship between alloy composition, electronic structure and catalytic activity should be carefully determined in this study. As the TEM measurements, CoSn nanoparticles with size in the range of 1-5 nm is successfully immobilized on the surface of RGO. Electrochemical catalytic activity performances indicate that the Co0.9Sn0.1/RGO gave the highest catalytic activity compared other electrodes which were determined by the lowest charge-transfer resistance and diffusion impedance values. Thus, the highest power conversion efficiency was obtained for the device using Co0.9Sn0.1/RGO CE. The strategy has a great promise in developing high-performance DSCs and the launched reduction rate constant having commonality in comparing the catalytic activity of CE electrocatalysts.
Cost-Effective Mo Fe Alloy/Reduced Graphene Oxide Counter Electrodes As a New Avenue for High-Efficiency Dye-Sensitized Solar Cells
Authors: Shin Sangho , Dao Van-Duong , Choi Ho-Suk
Published: February 2020

MoxFe1-x/reduced graphene oxide (RGO) (0 ≤ x ≤ 1) is successfully synthesized using atmospheric pressure plasma under near room temperature and without using any toxic reagents. HRSEM, TEM, XRD and XPS measurements are conducted to analyze the morphology and chemical composition of the developed materials. Then, the developed materials are applied as Pt-free CEs in DSCs. To obtain efficient CEs, the chemical composition of the MoxFe1-x/RGO is controlled through optimizing the volume ratio of the Mo and Fe precursors during the synthesizing process. The catalytic activity of the developed CEs is carefully evaluated through EIS, CV and Tafel measurements. Finally, the effect of CEs on the efficiency of DSCs is further confirmed by J-V and IPCE performances. As the result, the high conductivity and excellent catalytic activity toward triiodide reduction in CEs of DSCs are obtained for MoxFe1-x/RGO CEs.
Synthesis, Isolation and Characterization of Two Isomers of Dy2O@C82
Authors: Yang Wei , Zhuang Jiaxin , Shi Yue , Chen Ning
Published: February 2020

Recent theoretical studies predicted that the magnetic properties of Dy2O@C82 may be superior than any other clusterfullerenes decovered so far, but the synthesis and characterization have never been reported. Here, we report that the clusterfullerenes Dy2O@C82 have been synthesized by arc-discharging method with graphite rods packed with graphite powder and metal oxide(Dy2O3) under a He/CO2(8:1) atmosphere. Two isomers of Dy2O@C82 endohedral fullerene have been isolated and purified by high performance liquid chromatography by multistage separation on different columns. The purified Dy2O@C82 were characterized by mass spectrometry, UV-Vis-NIR absorption spectroscopy. One isomer shows large resemblance to those of previously reported metallic fullerenes, such as Er2@C
s-C82, Sc2O@C
s-C82, and another one is similar to Y2C2@C
3v-C82. This work will lead to the detailed study of the unique molecule magnetic properties of dysprosium-based oxide cluster fullerenes and their potential of application in high density information storage, quantum calculation and spintronics.
(Invited) Molecular Structures and Unique Bindings of Actinide Endohedral Fullerenes
Authors: Chen Ning , Echegoyen Luis , Feng Lai , Wang Yaofeng , Zhang Xingxing
Published: February 2020

The successful isolation and characterization of Th@C82, U@C82, U@C74 have shown that actinide fullerenes have unique properties which are previously unknown to the endohedral fullerene world. Now, with the further exploration of actinide endohedral fullerenes based on U and Th, we found these endohedral fullerenes are unique for not only fullerene chemistry but also to actinide chemistry. U@C80 and U@C76 have been found to process Non-IPR cages, which are rare cases for the mono metallic endohedral fullerenes. Th@C86 and U@C86, on the other hand were found to share the same IPR cages, where have never been reported before. The crystallographic and computational studies of U2C@I
h-C80 reveal reveals a cage-stabilized, carbide-bridged, bent UCU cluster with unpreced­entedly short uranium-carbon distances (2.03 Å) of genuine U=C double-bond character. The isolation of U2C@C80 gives an unprecedented look into a long sought after but heretofore unknown U=C bond which lacks heteroatom support, allowing for detailed structural and electronic insights.
(Invited) Molecular Structures of La2C2@C90-C104: The Effect of Inserting a C2-Unit
Authors: Lu Xing , Cai Wenting , Zhao Shasha
Published: February 2020

Giant fullerenes (e.g. C>90) show clear connections with short carbon nanotubes. Herein we report the X-ray structures of eight EMFs containing a La2C2 cluster, namely, La2C2@C2(41)-C90, La2C2@D3(85)-C92, La2C2@C1(132)-C94, La2C2@C2(157)-C96, La2C2@C1(175)-C98, La2C2@D5(450)-C100, La2C2@Cs(574)-C102, and La2C2@C2(816)-C104. It is evident that the cage length increases roughly along with increasing of the carbon atom number, resulting in an increase of the La-La distance. This is a clear indication that giant fullerenes tend to grow along the long axis to achieve a tubular appearance. Encapsulation of a large La2C2 cluster inside D5(450)-C100 induces a 5% axial compression of the cage, as compared with the structure of La2@D5(450)-C100.[1] Moreover, it is demonstrated that the defective cage of C2(816)-C104 is a starting point to form the other tubular cages known so far, i.e., D5(450)-C100, Cs(574)-C102, and D3d(822)-C104, presenting evidence for the top-down formation mechanism of fullerenes.[2] Overall, our experimental results have unambiguously confirmed that insertion of a C2-unit exerts a synergistic effect in stabilizing these giant cages.
[3]

References
：

Cai, W.; Bao, L.; Zhao, S.; Xie, Y-P.; Akasaka, T.; Lu J. Am. Chem. Soc.
2015, 137, 10292-10296.

Cai, W.; Li, F-F.; Bao, L.; Xie, Y-P.; Lu J. Am. Chem. Soc. 2016, 138, 6670-6675.

Zhao, S.; Zhao, P. Cai, W.; Bao, L.; Chen, M.; Xie, Y-P.; Zhao, X.; Lu J. Am. Chem. Soc.
2017, 139, 4724–4728.
(Invited) Structures and Properties of Saturn-like Complexes Composed of Oligothiophene Macrocycle with Methano[60]Fullerene and [70]Fullerene
Authors: Aoyagi Shinobu , Iyoda Masahiko , Shimizu Hideyuki , Okada Hiroshi , Zhou Biao , Matsuo Yutaka
Published: February 2020

π-Expanded oligothienylene macrocycle with a large inner cavity incorporates fullerenes such as methano[60]fullerene (C61H2) and [70]fullerene (C70) inside to form Saturn-like complexes.[1] Although the oligothiophene macrocycle weakly interacts with fullerenes in solution, it forms stable Saturn-like fullerene complexes in the solid state. X-ray analysis of the Saturn-like complexes exhibited short contacts between the sulfur atoms of the oligothiophene macrocycle and fullerene carbons, which hinder the rotation of fullerenes. As a result, the non-covalent interaction between the oligothiophene macrocycle and fullerenes was employed in crystal structure determination of fullerenes. UV–vis–NIR spectra of the Saturn-like complexes showed weak donor–acceptor interaction between the oligothiophene macrocycle and fullerenes.

[1] M. Iyoda, H. Shimizu, S. Aoyagi, H. Okada, B. Zhou, Y. Matsuo, Can. J. Chem.
95 (2017) 315-319.
(Invited) Synthesis and Properties of Open-Cage Fullerene Derivatives
Authors: Murata Yasujiro
Published: February 2020

Endohedral fullerenes represent caged-clusters of carbon encapsulating metal ions, metal clusters, atoms, and molecules. Although their syntheses mainly rely on physical methods under harsh conditions, organic synthesis has been attracting interests to realize molecule-encapsulating fullerenes owing to high selectivity of fullerene cages and high yields of desired products. The "molecular surgery" was able to be applied to fullerene C70 in spite of difficulties in characterization of products due to the low symmetry compared with C60. Importantly, reflecting the larger inner space than C60, two small molecules were introduced inside open-cage C70 derivatives to afford the corresponding doubly-encapsulating C70 such as (H2O)2@C70[1] and (H2O-HF)@C70[2] in addition to mono-encapsulating H2O@C70 and HF@C70. On the other hand, applying combination of the molecular surgery and ion implantation, doubly-encapsulating (H2-N)@C70 was able to be generated, in which the atomic nitrogen interacts with the hydrogen molecule, without forming covalent bonds.[3]

References

1. Zhang, R.; Murata, M.; Aharen, T.; Wakamiya, A.; Shimoaka, T.; Hasegawa, T.; Murata, Y. Nat. Chem. 2016, 8, 435-441.

2. Zhang, R.; Murata, M.; Wakamiya, A.; Shimoaka, T.; Hasegawa, T.; Murata, Y. Sci. Adv. 2017, 3, e1602833 (6 pages).

3. Morinaka, Y.; Zhang, R.; Sato, S.; Nikawa, H.; Kato, T.; Furukawa, K.; Yamada, M.; Maeda, Y.; Murata, M.; Wakamiya, A.; Nagase, S.; Akasaka, T.; Murata, Y. Angew. Chem. Int. Ed. 2017, 56, 6488-6491.
(Invited) Changing the Conformation of Paramagnetic Endohedral Fullerenes with Magnetic Fields
Authors: Greber Thomas
Published: February 2020

The torque that is exerted by a magnetic field on a magnetic moment may lead to a change of the atomic conformation in a molecule. This effect has been demonstrated recently for a single Ho magnetic moment in the endohedral Fullerene HoLu2@C80 [1].

From the statistical model that describes the equilibrium orientation of a magnetic moment in an external magnetic field with the ratio between the Zeeman energy and the thermal energy kBT, for a given saturation magnetisation a freezing temperature may be determined. Below this freezing temperature the conformation does not change. For an applied field of 7 T and a cooling rate of 5 mK/s the freezing temperature is 55 K. For fields below 7 T the extra magnetisation due to the molecular orientation depends on the cooling rate, and quadratically on the external magnetic field during cool down. From the corresponding kinetics of the freezing temperature vs. cooling rate data we may infer an activation energy and the corresponding attempt frequency for the endohedral rotation. Since the magnetisation measurements are accurate, variations in the percent range of this activation energy can be detected for different endohedral units. With this molecular dynamics potentials may be tested and steric effects of the endohedral unit can be inferred. On a longer perspective this effect, mimicking the smallest compass, also opens avenues to orient endohedral units on surfaces by help of magnetic fields.

[1] Switching Molecular Conformation with the Torque on a Single Magnetic Moment, Kostanyan et al. Phys. Rev. Lett. accepted for publication.
Solid-State Batteries Enabling Electric Mobility and New Applications
Authors: Albano Fabio , Yi Eongyu , Chen Guoying , Sofie Stephen , Shen Hao , Doeff Marca
Published: February 2020

Fisker Inc. is an innovative American company designing, developing and manufacturing electric vehicles with long range and fast charging. Since 2016 we have taken a holistic approach to electric vehicle design based on innovative battery systems with extremely high energy density that will set new standards in matter of vehicle electrification. Our battery research in full solid-state systems is poised to deliver practical cells with specific energy in excess of 500Wh/kg. This presentation will share fundamental and applied aspects of bulk solid-state batteries manufactured via facile and scalable methods and their applicability to automotive applications and beyond. We will present new solid-state electrolyte materials and designs geared towards high performance, and demonstrate how these systems can enable electric vehicles of tomorrow, life changing medical devices and smart grid and energy storage. This work was done in collaboration with Lawrence Berkeley National Lab, Montana State University and Fisker Inc. as part of the Battery 500 Consortium.

Figure 1
A Stable 3 V All-Solid-State Sodium–Ion Battery Based on a Closo-Borate Electrolyte
Authors: Duchêne Léo , Remhof Arndt , Kühnel Ruben-Simon , Battaglia Corsin
Published: February 2020

We report on a particularly stable 3 V all-solid-state sodium–ion battery built using a closo-borate based electrolyte, namely Na4(B12H12)(B10H10). The battery employs a sodium metal anode and a NaCrO2 cathode. Battery performance is enhanced through the creation of an intimate cathode–electrolyte interface resulting in reversible and stable cycling with a capacity of 85 mAh/g at C/20 and 80 mAh/g at C/5 with more than 90% capacity retention after 20 cycles at C/20 and 85% after 250 cycles at C/5. We also discuss the effect of cycling outside the electrochemical stability window and show that electrolyte decomposition leads to faster though not critical capacity fading. Our results demonstrate that owing to their high stability and conductivity closo-borate based electrolytes could play a significant role in the development of a competitive all-solid-state sodium–ion battery technology.

L. Duchêne, R.-S. Kühnel, D. Rentsch, A. Remhof, H. Hagemann, C. Battaglia, Chem. Comm. 2017, 53, 4195

L. Duchêne, R.-S. Kühnel, E. Stilp, E. Cuervo Reyes, A. Remhof, H. Hagemann, C. Battaglia, Energy & Environmental Science 2017, 10, 2609
A Membrane-Free Redox Flow Battery with Two Immiscible Electrolytes
Authors: Navalpotro Paula , Palma Jesus , Anderson Marc Arlen , Marcilla Rebeca
Published: February 2020

Electrochemical energy storage devices are destined to be key technologies to alleviating the intermittent and fluctuating nature of renewable energy sources (1). In particular, Redox Flow Batteries (RFB) have been recognized as a viable technology for the integration and balancing electricity grids due to their ability to decouple power and energy. However, wide-spread implementation of conventional RFBs is limited by some obstacles related to low abundance, toxicity and high cost of vanadium redox compounds, and the poor-performing and expensive ion exchange membranes used to separate catholyte and anolyte compartments (2).

Here, we present an innovative concept of Membrane-Free Battery which proposes to eliminate any separator or membrane in the cell by using immiscible redox electrolytes (Fig. 1). Moreover, the metal-based redox species are replaced by cheap and abundant organic redox molecules that can be specifically designed to provide high solubility and adequate redox potentials. As result, this disruptive technology is hugely versatile with respect to the nature of the electrolytes (aqueous / non-aqueous) as well as the type of organic redox species dissolved in each electrolyte (Fig. 1). To demonstrate the feasibility of this concept, we report here a spontaneous biphasic system formed by an acidic solution and an ionic liquid both containing dissolved quinoyl species that behaves as a reversible battery without any membrane or separator (3). The electrochemical performance of this Membrane-Free battery and the new challenges and future opportunities of the technology will be discussed.

Figure
1
. a) Scheme of our Membrane-Free Battery concept. b) Versatility of this concept by using different combinations of immiscible electrolytes and their corresponding characteristics.

References:

Z. Yang et al., Chem. Rev.
111, 3577–3613 (2011).

a) H. Prifti, A. Parasuraman, S. Winardi, T. M. Lim, M. Skyllas-Kazacos, Membranes (Basel).
2, 275–306 (2012). b) W. Wang, V. Sprenkle, Nat. Chem.
8, 204–206 (2016). c) J. Winsberg, T. Hagemann, T. Janoschka, M. D. Hager, U. S. Schubert, Angew. Chemie - Int. Ed.
55, 2–28 (2016).

P. Navalpotro, J. Palma, M. Anderson, R. Marcilla. Angew.
Chem. Int. Ed. 56, 12460 –12465. 2017

Figure 1
Impact of Graphene Oxide and Carbon Nanotube Incorporation to TiO2 Bronzes over Its Performance As Anode in Na-Ion Batteries
Authors: Ramírez Guadalupe , Díaz-Lujan Alfredo , Cabrera René , Reguera Edilso , Acevedo-Peña Prospero
Published: February 2020

TiO2 is a welll known material for energy (batteries and supercapacitors) aplications. This have been widely used as anode in Li-ion batteries thanks to its easy processing, relatively abudance, reversibility and that storage Li-ion in a safe potential avoiding the reduction of the organic electrolyt to form the SEI. Among all the TiO2 polymorphs, the monoclininc TiO2(B) exhibit the best performance thanks to its larger interstitials to storage ions, largers ionic conductivity and the alignment of open chanels to transport the ions. Nevertheless, this polymorph have not been widely employed as anode in Na-ion batteries and its performance remain bellow to that of the TiO2 anatase. Furthermore, incorporing carbon nanoestructures to TiO2 based materials is a widely employed strategy to improve the performance of the material thanks to the increment of the conductivity of the composite and the larger surface area. For this reason, the effect of incorporing carbon nanoestructures (graphene oxide and carbon nanotubes) during the synthesis of TiO2(B) over their morphology and performance in the Na-ion storage process, is studied in the present work.

TiO2(B) was synthesized by hydrothermal treatment in 10 M NaOH followed by hydrolysis and thermal treatment at 400 °C during 4 h. Carbon nanoestructures were incorporated by previously forming a core@shell structure with amorphous TiO2 through controlled hydrolisis of Titanium isopropoxide under reflux, or by preparing a suspension of the carbon nanostructure and amorphous TiO2, and then the TiO2(B) was formed as indicated before. The materials were characterized by XRD, Raman, XPS, SEM, TEM and BET. A two-electrode swagelock cell was assembled by coating a copper foil with a ink of active material:carbon black:PVDF (80:10:10) in N-methyl-Pyrrolidone, and metallic Na as counter and reference electrode. A Whatman glass-fiber separator soaked in 1 mol L− 1 NaPF6 in 1:1 dimethyl carbonate/ethylene carbonate electrolyte was used as separator. The materials were characterized by Cyclic voltammetry, charge-discharge curves and electrochemical impedance spectroscopy. The impact of carbon nanostructure over the specific capacity of Na-ion storage and apparent Na-ion diffusion coeficient in the TiO2(B) willl be discussed in the presentation of the work.
Characterization of Effect of H2 Evolution in Aluminum Air Battery
Authors: Zhou Chong , Bhonge Kaustubh , Cho Kyu Taek
Published: February 2020

The demand of electrical energy system is increasing rapidly these days for diverse applications from portable electronics and electrical vehicles to grid-scale energy storage. Lithium-ion battery has been utilized for most of those applications, but due to high cost (about $600/ kWh) and lower energy density (0.38 kWh/kg) [1], the advent of low cost and high performing battery system is required. Metal-air system, which has metal as a reactant for the anode side and oxygen for the cathode side of the battery cell, is getting intense attention due to its benefits such as high energy density and low system cost. Especially, metals such as lithium, aluminum, magnesium, calcium, iron, and zinc whose reduction potential is substantially low are typically used for the negative electrode, while oxygen generally from air is used for the positive side.

The energy density of the metal-air battery systems is 3 to 10 times greater than that of the conventional lithium ion battery (i.e. specific energy of the metal-air system is in the range from 0.8 to 3.9 kWh/kg, while that of the conventional lithium ion battery is 0.38 kWh/kg) [2].

Especially, aluminum of which specific energy is roughly 10 times greater than lithium ion battery is abundant, low price, environmentally benign, and inertness to humid operating condition, preventing the catastrophic thermal failure which is the major safety issue of the conventional system. However those promising systems could not reach the commercialization stage due to the challenging issue associated with the redox reaction of metal electrode: self-corrosion reaction (i.e. hydrogen evolution)[3].

In this study, the effect of H2 evolution due to aluminum corrosion on the cell performance will be investigated through combined research of experiment (cell-based and component-based tests) and physics-based computational model. Especially, the coverage of H2 bubbles on the electrode surface, change of diffusion layer thickness affected by the H2 bubble rise, and change in the electrolyte conductivity will be analyzed with respect to various pH conditions, flow rate conditions, and currents. The results will be utilized to understand the underlying physics of H2 bubble issues and to define the key controlling parameters for the cell performance.

Reference

[1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J.-M. Tarascon, Nat Mater 2012, 11, 19-29.

[2] Q. Li, N. J. Bjerrum, J. Power Sources 2002, 110, 1-10.

[3] D. R. Egan, C. Ponce de León, R. Stokes, F. C. Walsh, J. Power Sources 2013, 236, 293-310.