bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimizing and Improving the Sodium Ion Conductivity of Nasicon
Authors: Jolley Adam G , Taylor Daniel D , Wachsman Eric D. 
Published: February 2020

NASICON (Na3Zr2Si2PO12) has shown promise as a solid state electrolyte for a sodium battery due to its inherent safety and relatively high conductivity. Increasing the conductivity of NASICON to further improve the capability of a solid state electrolyte has come by way aliovalent substitution of the zirconium site in Na3Zr2Si2PO12. Both Na3.2Zr1.8M0.2Si2PO12 (M=Al3+, Fe3+, Y3+) and Na3.4Zr1.8M0.2Si2PO12 (M=Co2+, Ni2+, Zn2+) have exhibited greater bulk conductivity at room temperature than undoped NASICON. A decrease in low temperature activation energy as well as the lowered rhombohedral-monoclinic phase transformation temperature is responsible for the increased bulk conductivity of substituted NASICON. The Co, Zn, and Ni dopants were explored more extensively as they displayed the highest conductivity of 10% doped NASICON at room temperature. By adjusting the total substitution of Co, Zn, and Ni cations, the conductivity of NASICON was optimized further. Increasing the amount of Zn+2 dopant in Na3+2xZr2-xZnxSi2PO12 resulted in reduced distortion of the lattice as it transitioned from rhombohedral to monoclinic phase, and an increase in conductivity. Ultimately the bulk ionic conductivity of 20% Zn-doped NASICON is among the highest ever reported.
Solid State Li Ion Batteries with Monocarba-Closo-Decaborate Solid Electrolytes
Authors: Ware Nicholas , Tang Wang Si , Udovic Terrence John , El Gabaly Farid , Stavila Vitalie , Talin Albert Alec 
Published: February 2020

Solid state rechargeable batteries with high energy and power density as well as safety, reliability and long cycle life remain a long standing goal for the energy storage community. While many solid electrolytes have recently been demonstrated with ionic conductivities approaching those of liquid electrolytes at room, few have been integrated into full batteries with competitive power performance. Recently, we discovered a novel class of superionic solid electrolytes, whose facile cation conduction pathways are enabled by the spacious, vacancy-rich, interstitial network created by a sublattice of polyhedral, orientationally mobile, monocarba closo-borate anions and which form salts with alkali metals, LiCB11H12
and LiCB9H10 [1, 2]. These electrolytes exhibit conductivities of ~10-5 S/cm at room temperature and ~0.03 S/cm at 345 C. In this talk we will describe the fabrication and testing of complete batteries consisting of thick film LiCoO2 cathodes with theoretical capacity of ~1.5 mAhrs/cm2 and metallic Li anodes.
1. W. S. Tang, A. Unemoto, W. Zhou, V. Stavila, M. Matsuo, H. Wu, S. Orimo, and T. J.
Udovic, Energy Environ. Sci., 2015, doi: 10.1039/c5ee02941d.
2. W. S. Tang, M. Matsuo, H. Wu, V. Stavila, W. Zhou, A. A. Talin, A. V. Soloninin, R. V.
Skoryunov, O. A. Babanova, A. V. Skripov, A. Unemoto, S. Orimo, and T. J. Udovic, Adv.

Ener. Materials, in review.
(Invited) Can Basic Research in Academia Predict Battery Field Failures?
Authors: Jeevarajan Judith A 
Published: February 2020

Cell and battery field failures can occur in a number of ways. Cause of failures can vary from inadequate cell and battery safety controls to poor manufacturing quality. Oftentimes, basic research in academia is focused on improving materials to obtain higher specific capacity or power density. The practical issues of failure scenarios created due to scaling up from a lab scale to a large Mega or giga Watt energy storage application are seldom mimicked or studied. This paper will discuss the areas that have gaps in safety research with a focus on lithium-ion battery chemistry.
Structure and Electrochemical Properties of Na0.44MnO2 As Positive Electrode Material in Sodium Ion Battery
Authors: Man Tran Van , Huynh Nguyen Le Thanh , Nguyen Van Hoang , Phung LE My Loan 
Published: February 2020

At the present, most the electronic portables are operated by Li-ion batteries (LIB), moreover LIB have also been desired to apply in the large-scale as hydride electric vehicles, smart grid system because of its high density energy and high voltage. The development of LIB forecasts a growing demand for lithium supplies. In order to solve the problem of lithium raw resource, sodium is proposed as an alternative energy storage to replace the LIB in the future because of the several reason: abundance of sodium resource, low cost of sodium raw material and similar properties chemistry of lithium.
Na0.44MnO2 have been attracted as novel cathode materials for sodium-ion batteries due to low cost, high capacity and good performance. This work aimed to prepare the cathode material Na0.44MnO2 by solid state reaction form three different manganese precursors such as: MnCO3, Mn(AcO)2 and MnO2 (obtained by electrolysis of MnSO4 solution). The cyclic voltammetry curve presents the multi-peaks redox corresponding to the complex insertion/extraction of sodium ions. The sample Na0.44MnO2, prepared by Mn(AcO)2 precursor, exhibits both the excellent cycle stability (120 mAh/g at C/10) and high charge/discharge rate capability in the range 2-4 V (vs. Na+/Na). Furthermore, the ex-situ Raman Spectroscopy and Diffraction Rayon X studies are also reported the evolution of lattice parameters during discharge process that evidently confirmed the existence of transition-phases.

Keywords: cathode materials, Na0.44MnO2, sodium-ion batteries, Raman spectroscopy
Impact of Carbon Coating on the Electrochemical Property of Li2MnSiO4/C Cathode Material By Sol-Gel Method
Authors: Wang Pin-Han , Chang Chien-Min , Lee Ching-Feng , Chen Hwang-Sheng , Chen-Yang Yui Whei 
Published: February 2020

Lithium ion batteries have been widely used on the portable electronic devices due to its high energy density and long cycle life. In order to meets the market requests, various cathode materials such as lithium transition metal oxide (LiMO2, M=Mn、Co) and polyanion cathodes ( LiMPO4,Li2MSiO4, M=Mn、Co、Fe ) have been investigated. The lithium transition metal oxide is easily to be collapsed during the charge-discharge process because of the layer structure. The advantages of polyanion cathodes are the better stability than lithium transition metal oxides due to strong covalent bonds ( ex：P─O、Si─O) and environment more friendly, lower safety risk as well as lower cost. On the other hand, the lithium transition metal orthosilicates, Li2MSiO4 ( M=Fe, Co or Mn), which offers the possibility of two insertion/extraction lithium ions during charge-discharge, have higher theoretical capacity than the phosphate cathode materials and had been considering as promising cathode materials. Moreover, both Li2FeSiO4 and Li2MnSiO4 are more attractive cathode materials among the orthosilicates but Li2MnSiO4 can offer higher power density than Li2FeSiO4 because the Mn2+/Mn3+, Mn3+/Mn4+ redox potential is higher than Fe2+/Fe3+, Fe3+/Fe4+ redox potential.Nevertheless, Li2MnSiO4 also has some drawbacks that include poor electronic conductivity and Jahn-Teller distortion, resulting in collapse of the structure and formation of the amorphous Li2MnSiO4. To solve this problem, following methods have been suggested: 1) decreasing the particle size 2) coating a conductive carbon layer 3) doping transition metal. However, it is found that the characteristics, particle size, morphology etc., of the products are highly dependent on the synthesis method applied.
In this study, the sol-gel method is used with polyvinylpyrrolidone (PVP) as the in-situ carbon coating material to obtain the nanoscale primary particles with lower calcination temperature and without pressure that can lower the cost. Various amounts of PVP are used in Li2MnSiO4 solution for the sol-gel process to adjust the carbon content of the Li2MnSiO4/C cathode materials in the range of 3~6 wt%. The XRD spectra show that all the Li2MnSiO4/C materials synthesized are in Pmn21 structure. The TEM images indicate that a conducting amorphous carbon layer is deposited on the particle surface that improves the electronic conductivity of the Li2MnSiO4 cathode materials. In addition, it is found that the as –prepared LMS/C exhibits high capacity at 0.05C in the voltage of 1.5–4.8V and strong redox peaks in the cyclic-voltammetry curves. This is ascribed to the homogeneous carbon coating and nano-size primary particle that enhances the electronic conductivity and shortens the Li+ ion diffusion path, respectively.

Acknowledgements : The authors gratefully acknowledge the Ministry of Science and Technology, Taiwan, R. O. C. and Chung Yuan Christian University for supporting this research work.
An Overview of Carbon Nanomaterials in Solid Acid Fuel Cell Electrodes
Authors: Varga Aron , Abel Bernd , Naumov Olga , Xubin Lu , Lohmann Felix , Schulze Patricia , Wagner Maximilian 
Published: February 2020

Micro- and nanometer sized carbon materials play an important role as components in low and intermediate temperature fuel cell electrodes. Vulcan carbon, active carbon, etc. have been used as catalyst substrates and electronic interconnect materials. As such, they reduce agglomeration of nanoparticulate catalyst and thus increase long-term stability. The catalyst utilization can be also increased significantly by improving the geometrical distribution of the catalyst. Recently, the drive towards ever smaller electrode structures has shifted attention towards carbon nanotubes (CNTs) and graphene. Their excellent electronic conductivity, extremely high specific surface area, and relatively good stability makes them suitable candidates as fuel cell electrode components. Both the catalyst distribution and utilization have been successfully improved, lowering costs and bringing the technology closer to market application. Importantly, numerous studies have recently shown functionalized CNTs and graphene, without precious metals, to be an effective catalyst for the oxygen reduction reaction. Especially nitrogen doped CNTs and graphene flakes show tremendous potential.1

Solid acid fuel cells based on CsH2PO4 as the solid state electrolyte operate at ca. 240°C and are currently performance limited at the cathode. Here, vulcan carbon has been mainly used as an electronic interconnect and catalyst support.2 Recently, carbon nanotubes have been employed, increasing the mass normalized activity of the Pt catalyst up to 61 S/mgPt.3,4

Here we combine the benefits of recent findings and present new fabrication routes based on spraydrying, metal-organic chemical vapor deposition to create highly active, nanostructured composite electrode materials, based on Pt decorated CNTs and graphene. In addition, we evaluate the suitability of surface functionalized carbon nanomaterials as precious metal free catalyst in solid acid fuel cell cathodes. Functionalization includes plasma treatment and electron beam irradiation under controlled atmospheres. Raman and XPS analysis is used before and after electrochemical measurements to evaluate structural and chemical changes. Data from impedance spectroscopy of symmetric electrochemical cells suggest effective electrochemical activity of CNTs and graphene in solid acid fuel cell cathodes.
(1) Gong, K.; Du, F.; Xia, Z.; Durstock, M.; Dai, L. Science
2009, 323, 760.
(2) Chisholm, C. R. I.; Boysen, D. A.; Papandrew, A. B.; Zecevic, S. K.; Cha, S.; Sasaki, K. A.; Varga, Á.; Giapis, K. P.; Haile, S. M. Interface Magazine
2009, 18, 53.
(3) Varga, Á.; Pfohl, M.; Brunelli, N. A.; Schreier, M.; Giapis, K. P.; Haile, S. M. Physical chemistry chemical physics : PCCP
2013, 15, 15470.
(4) Thoi, V. S.; Usiskin, R. E.; Haile, S. M. Chem. Sci.
2015, 6, 1570.
Evaluation of Pt-Au/MWCNT Electrocatalyst Performance As Cathode of a Proton Exchange Membrane Fuel Cell
Authors: Beltrán-Gastélum Mara , Salazar-Gastelum Moises Israel , Félix-Navarro Rosa María , Pérez-Sicairos Sergio , Reynoso-Soto Edgar Alonso , Lin-Ho Shui Wai , Flores-Hernández Roberto , Romero-Castañón Tatiana , Albarrán-Sánchez Irma Lorena , Paraguay-Delgado Francisco 
Published: February 2020

The synthesis and characterization of bimetallic electrocatalyst was synthesized and evaluated as cathode in fuel cells to ascertain their performance. The main reactions that take place during the operation of fuel cell are the fuel oxidation reaction at the anodic compartment and the oxygen reduction reaction (ORR) at the cathodic compartment. Although, Pt-based materials have been widely reported as catalysts in both processes, their high cost and low availability has been a strain on the commercialization of fuel cells.
The strategy employed in this work is to synthesize and compare the performance of nanoparticles based on Pt-Au (reduced platinum loading) supported on multiwall carbon nanotubes (MWCNT) materials using reverse microemulsion method (Pt-Au/MWCNT). To effectively compare the performance of the synthesized catalyst material, the catalytic activity of the electrocatalyst was compared to commercial electrocatalyst based on platinum on carbon vulcan (Pt/C).
MWCNT used as support material for the catalysts used in this study were synthesized using spray-pyrolysis. Different characterization techniques were used to determine physicochemical and electrochemical properties of the materials, such as particles size, thermal stability, morphology, composition, active area, catalytic activity, and thermodynamic parameters.
Assemblies were prepared using both the Diffuser Electrode Assembly (DEA), where the catalyst is dispersed onto the diffuser. In spite of the lower Pt loading in the Pt-Au/MWCNT catalyst, the fuel cell assembly results clearly shows that the Pt-Au/MWCNT assembly has approximately twice the power density of the Pt/C assembly, showing the remarkable catalytic ability of the Pt-Au/MWCNT catalyst (Figure 1), in addition to the lower catalyst cost enabled by reduced Pt loading.

Figure 1
(Invited) Application of Carbon Nanotubes in CdTe Photovoltaics
Authors: Khanal Rajendra R. , Phillips Adam B. , Liyanage Geethika K. , Wathage Suneth C. , Song Zhaoning , Stone Jonathan M. , Heben Michael J. 
Published: February 2020

Single-wall carbon nanotube (SWCNT) films formed by spray deposition and membrane transfer processes are finding application in a wide variety of different solar cell device architectures. With a 1.45 eV band gap, a high absorption coefficient, high solar to electric conversion efficiency, and proven low-cost, high-volume manufacturing, CdTe-based photovoltaics are a fast growing technology. For CdTe photovoltaics, single-wall carbon nanotubes have been shown to provide a low-barrier back contact without the addition of Cu,1 protection against shunts and weak diodes,2 as well as the ability to grow devices in the substrate configuration.3 From a technology point of view, processes to form SWCNTs layers can be readily integrated with conventional CdTe manufacturing processes to provide both cost and performance advantages. Scientifically, the electronic properties of the interface between CdTe and SWCNTs are unusual and allow tunneling contacts to be formed. This allows flexibility in device design and offers the potential for monolithically integrated thin-film tandems. We will discuss the use of SWCNT layers in CdTe and other PV devices from both scientific and technology perspectives.
(1) “Wiring-up Carbon Single Wall Nanotubes to Polycrystalline Inorganic Semiconductor Thin Films: Low-Barrier, Copper-Free Back Contact to CdTe Solar Cells”, Phillips, et al., Nano Lett., 2013, 13, pp 5224–5232.
(2) “Simultaneous Shunt Protection and Back Contact Formation for CdTe Solar Cells with Single Wall Carbon Nanotube Layers”, Phillips, et al. Applied Physics Letters, in press.
(3) “CdTe/CdS Thin Film Solar Cells in the Substrate Configuration on a Single-wall Carbon Nanotube Back Contact”, Khanal, et al., Proceedings of the 39th IEEE Photovoltaics Specialist Conference, pgs. 2013, pp. 1126–1130.
Hybrid Nanomaterials Composed of N-Doped Fullerene/Transition Metal Complex Polymer and P-Doped Conjugated Organic Polymers
Authors: Winkler Krzysztof , Brancewicz Ewa , Wysocka-Zolopa Monika 
Published: February 2020

The electron donor/acceptor approach is an effective way to convert solar energy into electrical energy in organic photovoltaic solar cells. The organic conjugated polymers have been widely used as donor constituents. The polymers of C60 and transition metals are good candidates for the electron-accepting components. In the coordination fullerene polymers, C60 moieties are bounded with transition metal atoms or complexes into three-dimensional polymeric network. The most intensively investigated polymer of C60 and palladium atoms, poly-Pd3C60, exhibits an ordered body centered cubic (bcc) structure of fullerene units with a slight rombohedral distortion. The fullerene cage is octohedrally coordinated by six palladium atoms. Each palladium atom is bounded to two C60units.
Hybrid materials composed of n-doped fullerene/transition metal complex polymers and polypyrrole were formed under electrochemical or chemical conditions. The electrochemically synthesis, bilayers of both materials exhibit rectifying characteristics and can serve as a charge trapping system.
The core shell nanoparticles, i.e., poly-Pd3C60@polypyrrole (Figure 1), were prepared by sequential chemical polymerization of both components. These systems can be used for the modeling of the charge transfer processes in bulk-heterojunction solar devices. The outer polypyrrole layer is easily oxidized at potentials corresponding to the potentials of pure polypyrrole oxidation. The poly-Pd3C60 core reduction is shifted toward more negative potentials in comparison to the potential of reduction of pure poly-Pd3C60. The electrochemical measurements reveal that poly-Pd3C60@polypyrrole with outer polypyrrole layer doped with light harvesting molecules and thinner than about 20 nm can be potentially used in solar energy conversion electrochemical devices. The small thickness of the outer layer prevents free charge carriers recombination. The large area of p-n nanojunction in nanostructured material should increase efficiency of solar energy conversion. The electric charge formed at the p-n nanojunction can be also transferred from poly-Pd3C60inner sphere to the metallic collector.

Figure 1
(Invited) Insight into Carbon Nanotube Surface Structures for PV Applications
Authors: Doorn Stephen K. , Hartmann Nicolai F. , Subbaiyan Navaneetha K , Pramanik Rajib , Mallajosyula Arun Tej , Mohite Aditya , Dowgiallo Anne-Marie , Blackburn Jeffrey L. 
Published: February 2020

Carbon nanotube (CNT) surface chemistry and surface structures impact their potential roles in photovoltaics in a number of ways. These include defining chirality-specific segregation behaviors that enable isolation of the required pure chiralities. Surface structures also define film morphologies and ordering that ultimately determine how intertube interactions facilitate or inhibit charge and energy flow. We present photoluminescence imaging results as a direct probe of these relevant surface structures. A demonstration of phase-dependent segregation in surfactant compositions at the nanotube surface will be shown as a determining factor in the mechanism of new aqueous two-phase separations approaches. We will also show how variations in polyfluorene polymer structures impact their surface morphologies, ultimately determining the ability to transport excitation energy and charge within thin-film nanotube-based PV devices.
Supercapacitors
Authors: Chowdhury Tazima , Grebel Haim 
Published: February 2020

In our studies, gate electrodes were placed in mid-position between the anode and the cathode of electrolytic capacitors. Ionic currents were made to flow through these gate electrodes. The gate was an electronic p-n junction and consisted of p-type and n-type functionalized carbon nanotubes (CNT). Chrono-potentiometry and electrochemical impedance spectroscopy revealed the effect of the gate electrode on the overall cell's capacitance. Current-Voltage measurements (I-V curves) were made on dry samples, which were consisted of p-type and n-type CNT layers. These data clearly exhibited an electronic diode-like gate characteristics. Cyclic voltammetry (CV) with two-electrode system configuration was carried out at room temperature and using 1 M NaCl as an electrolyte.
The electrolytic cell capacitance was assessed while biasing the gate voltage in the range of -15 mV to +15 mV. This small bias was enough to substantially increase the cell capacitance.
[1] Y. Zhang, H. Grebel, “Controlling Ionic Currents with Transistor-like Structure”, ECS Transactions 2 (18). 2007
[2] S. Sreevatsa, H. Grebel, “Carbon Nanotube Structures as Ionic Barriers: A New Corrosion Prevention Concept”, ECS Transactions 19 (29) 91-100. 2009
[3] T. Chowdhury and H. Grebel, "Effect of Gate Electrode in Electrochemical Cells", Session B01: Energy Storage: Batteries and Supercapacitors, Abstract MA2015-01 721, 227 ECS Annual Meeting, Chicago, IL, (May 2015).
One-Pot Electrochemical Exfoliation and Functionalization of Graphene Sheets
Authors: Ossonon Diby Benjamin , Bélanger Daniel 
Published: February 2020

Graphene is currently attracting a lot of interest because of their potential applications in several different fields. Various approaches are being developed to prepare it at large-scale, by green method and cost-effectively. To this end, graphene sheets can be prepared by electrochemical exfoliation of graphite in aqueous electrolyte. In this work, graphene was produced by electrochemical exfoliation of graphite in acidic and neutral electrolytes. With this procedure, graphene sheets with low oxygen content are produced. Graphene sheets were also functionalized during the electrochemical exfoliation process by using appropriate reagents and experimental conditions. The resulting materials were characterized by several techniques such as Fourier transform infrared, X-ray photoelectron and Raman spectroscopy, thermogravimetric analysis, elemental analysis, electronic conductivity measurements and electrochemical techniques.
Surface Electrochemical Degradation Characterization of Carbon Fibers in Aqueous Electrolytes
Authors: Heydarzadeh Sheykhangafsheh Zahra , Wang Yun 
Published: February 2020

Electrolysis of water is the decomposition of water (H2O) into oxygen (O2) and hydrogen gas (H2) due to an electric current being passed through the water. In pure water at the negatively charged cathode, a reduction reaction takes place, with electrons (e−) from the cathode being given to hydrogen cations to form hydrogen gas (the half reaction balanced with acid):
Reduction at cathode: 4H+(aq) + 4e-→ H2(g)
At the positively charged anode, an oxidation reaction occurs, generating oxygen gas and giving electrons to the anode to complete the circuit:
Oxidation at anode: 2H2O(l) → O2(g) + 4 H+(aq) + 4e-

Carbon is a widely used electrode material for electrolysis of water due to its excellent electric conductivity and electrochemical stability. Carbon material may also subject to degradation under severe electrochemical environments due to radical attack and electrolysis of carbon. The present work is to study the carbon electrode degradation during electrolysis of water with a focus on the surface characterization. The net reaction of electrochemical gasification of carbons during water electrolysis is:
Net Reaction: C(s) + 2H2O(l) → CO2 (g) +2H2 (g)
Experimental results show that the surface area of carbon cloth electrodes after water electrolysis changes by up to 50 times depends on the working condition.The experimental setup employed in this study is shown in Fig. 1. The effect of various parameters, including operating temperature, voltages and also time durations of water electrolysis, on the carbon surface cloth is investigated to determine the optimum working condition. The analysis was done using H2SO4 solution as an electrolyte with 25% concentration and a three-electrode cell was used to measure the capacitance of a single electrode by cyclic charge/discharge (CCD) technique.

Figure 1