bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Stable Organic Redox Shuttles for Applications in Lithium Ion Batteries
Authors: Guarr Thomas F. , Mortimer Nicholas , Prins Amber J. , Polik Robert
Published: February 2020

The inclusion of a “redox shuttle” in a battery electrolyte can provide passive cell balancing as well as overcharge protection by functioning as a molecular shunt when the desired maximum charge voltage is reached.  There are many requirements for effective shuttle operation; chief among these are: 1) compatibility with other electrolyte components; 2) high oxidation potential (generally > 4.0 V vs Li/Li+); and 3) high stability in both reduced and oxidized forms (leading to long cycle life).

The most common traditional strategy for designing organic compounds that possess such high oxidation potentials involves the incorporation of electron withdrawing substituents; however, the resultant lack of electron density in the ring system often leads to undesirable side reactions and/or decomposition.  We have developed an alternative approach that exploits the change in molecular geometry that often accompanies the oxidation of heterocyclic compounds.  Specifically, by introducing bulky groups to sterically impede this reorganization, computer models suggest that oxidation potentials can be shifted to more positive values without sacrificing stability.  Preliminary results employing this strategy on various substituted carbazoles and phenothiazines will be presented.
New Iron-Based Polyanion Compounds As Low-Cost Cathode Materials for Rechargeable Alkali-Ion Batteries
Authors: Choudhury Amitava , Yaghoobnejad Asl Hooman
Published: February 2020

Polyanion compounds (Phosphates, sulfates, borates, and silicates) of transition metals are receiving an ever increasing attention as potential positive electrode in the secondary alkali ion batteries. They possess certain advantages over the traditional transition metal oxides due to their higher inherent safety and structural stability granted by the covalent bonding in the polyanion. In this context iron compounds are especially attractive, thanks to the natural abundance of iron resources and its environmental friendliness. Most importantly polyanion-based compounds of iron get big boost in Li-ion insertion voltage compared to pure oxide because of the inductive effect of the polyanions. Thus far the search for polyanion compound of iron yielded promising results, among which the Olivine LiFePO4 (3.45 V) and Triplite LiFeSO4F (3.9 V) are currently being considered for replacing the existing transition metal oxides. The vast possibilities of creating diverse 2D layered and 3D framework crystal structures through the incorporation of different secondary anion/polyanion into the primary polyanion compounds and subsequent tuning of the cell voltage has not been explored much.

In this paper we are presenting scalable fabrication of new mixed polyanionic compounds of iron and will demonstrate their ability to function as the cathode materials for low-cost alkali-ion batteries with good current capabilities and cycle-life. This work will introduce three recently discovered iron polyanion compounds containing mixed anions: Li3Fe(HPO3)3Cl, LixFe(H2O)2B(PO4)2∙H2O, and LiFePO4NO3; a report on their electrochemical activities with respect to Li- and Na-ion cells. The last compound, LiFePO4NO3, is a newly discovered family of mixed polyanionic compounds akin to Lix
MPO4CO3 (where M = Fe and Mn) where it allows the study of the effect of variation of ligand groups on the cell voltage and performance. Moreover for the same compound reversible Na+ intercalation proved to be effective which makes it a possible candidate for Na-ion battery cathode material. The presentation will cover the crystal structure of the respective compounds as solved through single-crystal or synchrotron powder X-ray diffraction as well as chemical, compositional and electrochemical studies including Mӧssbauer spectroscopy and galvanostatic charge/discharge tests.
Aqueous Carbon Suspensions for Electrochemical Applications
Authors: Muller Guillaume , Petrissans Xavier , Giaume Domitille , Laberty-Robert Christel , Barboux Philippe
Published: February 2020

We report the transport properties and mechanical behaviors of carbon inks as a conductive component in semi-solid electrodes. Commonly, the suspensions show a gel-like behavior implying the percolation of the solid network. Our work shows the dependency of rheological and conductivities properties on the carbon concentration, morphology, as a function of shear rate. Different percolating thresholds are found as a function of pH and ionic strength that act on the surface charge of the particles and their coulombic interaction. Under shear flow, the suspensions commonly exhibit a three-regime flow curve: shear-thinning at low and high shear rates separated by a small increasing-viscosity region over intermediate rates. These results are strongly dependent of the nature of the carbon slurry and measurement conditions. The highest conductivity can be obtained by tuning these parameters. The rheo-electrical behavior of aqueous carbon suspension shows the possibilities and limitations of semi-solid aqueous inks as flowable electrodes for two different technological applications such as redox flow batteries and electrowinning.

            First, semi-solid aqueous redox flow batteries are discussed in this work for safety, toxicity, cost and reliability. Such as flow-cell concept was recently described by Yet-Ming Chiang’s group at MIT in 2010 [1]. They proposed using typical intercalation electrode materials as active materials for a lithium rechargeable battery, but providing the active material in a slurry that can be mechanically pumped into and out of a reaction chamber. A redox flow batteries (RFBs) using intercalation electrode materials as active materials for a lithium rechargeable battery (such as “MIT suspension redox flow” batteries).

            Second, we discuss the use of such conductive pastes for extraction of various metals such as copper from various mineral ores. The conductive inks can be mixed with powdered ores and permit an electrical percolation that allow electrochemical dissolution of the materials. We analyze the electrochemical yield as a function of the copper concentration and formulation of the carbon paste before we discuss the applications.

[1] M. Duduta, B. Ho, V.C. Wood, P. Limthongkul, V.E. Brunini, W.C. Carter, Y. Chiang, Semi- Solid lithium rechargeable flow battery, Advanced Energy Materials 1 (4) (2011) 511.
Discharge Behavior of Si-Air Batteries with Aqueous Electrolyte
Authors: Durmus Y. Emre , Kayser Steffen Alexander , Aslanbas Özgür , Tempel Hermann , de Haart L.G.J. , Granwehr Josef , Kungl Hans , Eichel Rüdiger-Albrecht
Published: February 2020

A recent concept of metal-air batteries, Si-air, has a good potential to play a major role in the primary battery market due to possessing the second most abundant element in Earth’s crust as an anode. The main drawback of this system is the low practical discharge capacities both in aqueous alkaline and room temperature ionic liquids. In the previous studies, limitation of discharge is suggested to originate from a formation of an oxide layer on the Si surface, which prevents further oxidation of the active material.1,2,3 Additionally, there is a high corrosion rate of Si in aqueous systems that results in low anodic mass utilization efficiencies.

The main objective of current work is to find an approach to overcome the discharge limitations in aqueous alkaline systems. Electrochemical characterizations of Si-air cells were carried out by galvanostatic discharge experiments with Si wafers under controlled ambient conditions. The complete consumption of the active Si in the cell was achieved when a suitable setup, i.e. sufficient electrolyte, was employed. Discharge behavior of the Si-air cells was also investigated along with variations of temperature and molarity of alkaline electrolyte.

Since large amounts of the Si mass were consumed in the corrosion reaction during the experiments, the current work focuses also on corrosion studies. From the data on Si anode mass and discharge capacities, the corrosion rate and anodic mass utilization efficiencies were calculated. To have a better insight into the corrosion mechanism, nuclear magnetic resonance experiments were performed on the Si dissolution in alkaline electrolyte. From these experiments, formation of different Si-O-H silicate species as products of the corrosion reaction was identified. Moreover, the effect of corrosion products on the discharge performance and corrosion rate was studied as well. Based on the experimental results, specific discharge capacities of Si-air batteries are discussed while taking the corrosion process into account.

In summary, in spite of the corrosion process, the main goal to overcome the discharge limitations was accomplished by complete consumption of the active Si during the discharge. The effect of corrosion products on the discharge performance was investigated and the results will be reported.

References

1. Cohn, G., Eichel, Rüdiger-A., Ein-Eli, Y. Phys. Chem. Chem. Phys. 15, 3256–63 (2013).

2. Zhong, X., Zhang, H., Liu, Y., Bai, J., Liao, L., Huang, Y., Duan, X. ChemSusChem 5, 177–80 (2012).

3. Park, DW., Kim, S., Ocon, JD., Abrenica, GHA., Lee, JK., Lee, J. ACS Applied Materials & Interfaces 7, 3126–3132 (2015).
Novel Inorganic Coatings for Li2s Cathodes
Authors: Medina Ulises
Published: February 2020

While Li2S cathodes are extremely attractive due to their high theoretical capacity (1166 mAh/g), low cost, and compatibility with non-lithium metal anodes, the lithiation/delithiation reaction pathway between Li2S and S includes the formation of soluble polysulfides, which leads to poor cycle life.  One strategy to improve cycle life is to coat Li2S particles with a protective layer, preventing polysulfide dissolution.

Leveraging a proprietary high-throughput synthesis workflow, Wildcat Discovery Technologies has demonstrated the reactive deposition of an inorganic coating onto Li2S particles.  The coating method, based on the reaction of precursors with Li2S, is shown to be a general method and used to deposit coatings with different compositions on the surface of Li2S. Galvanostatic cycling of coated cathodes shows reduced formation of soluble polysulfides which in turn increases cycle life with 95% capacity retention between cycles 1-3 and also improves long term cycle life. This coating also improves conductivity thus improving cycle 1 discharge capacity. The approach described in this presentation is unique in: 1) it focuses on the charged state of the cathode versus the uncharged state (Li2S vs S) which would enable cell chemistries that do not rely on a Li metal anode, 2) it is a novel type of coating for the active material which is compatible with any base Li2S, and 3) demonstrates the power of high-throughput screening in developing new chemistries for next generation batteries.
Improvement of Zinc Anode for Flexible Printed Zinc Air Batteries with High Energy Density
Authors: Kheawhom Soorathep , Suren Sira
Published: February 2020

Zinc-air batteries are potential energy storage devices because of their cost-effectiveness and high energy density. In this work, flexible zinc-air batteries were fabricated using an inexpensive screen-printing technique. The anode and cathode current collectors were printed using commercial nanosilver conductive ink on a polyethylene terephthalate (PET) substrate and a polypropylene (PP) membrane, respectively. Air cathode made of blended activated carbon with MnO2, was fabricated. Anode electrodes were fabricated by using formulations consisting of zinc and activated carbon in sodium silicate. The effects of the micro-structure of the anode electrodes and their electrochemical characterizations were investigated. In addition, the effects of composition of the activated carbon and zinc on the performances of the battery were also investigated. The optimal formulation was identified. The results also showed that highly porous anode electrode leads to the batteries with high power density. Moreover, silicate binders performed better than other binders. Finally, the batteries were tested for their flexibility by bending them so that their length decreased from 100% to 50%. The results showed that the bending did not affect characteristics on potential voltage and discharging time of the batteries.
Preparation of High Loading Pt Nanoparticles on Multiwalled Carbon Nanotubes By Electrodeposition Method Applied for the Anode of Proton Exchange Membrane Fuel Cells
Authors: Hu Sin Yi , Yeh Tsung-Kuang , Wang Mei-Ya
Published: February 2020

In this study, platinum nanoparticle catalysts grown on carbon nanotubes (CNTs) as the anode of Proton Exchange Membrane Fuel Cell (PEMFC) were prepared by electrodeposition method. In three-electrode electrochemical cell, high electrochemical activity catalysts were obtained by changing the redox potential, time, stirring rate and the concentration of the precursor. After assembling MEA using the high electrochemical activity catalysts as the anode of PEMFC, the single cell test performed high power density by changing hot pressing temperature and time.

Carbon nanotubes by chemical vapor deposition (CVD) were directly grown on the carbon cloth to increase the surface area where the catalysts were deposited. And then, the catalysts were deposited on CNT by the electrochemical method, and finally did test and analyzed. The electrochemical characterizations were obtained by cyclic voltammetry (CV) in argon saturated 0.5M H2SO4, 0.5M H2SO4 + 1M CH3OH solution, respectively. The morphology of Pt/CNT/Carbon Cloth was observed by scanning electron microscope (SEM). The Pt loading was obtained by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the pulsed electrodeposition provided uniform distribution of catalysts ,and the peak power density of homemade Pt/CNT/CC as the anode of PEMFC increased by about 300 mW/cm2 compared to commercial Pt/CB/CC under the same conditions because of carbon nanotubes offering high surface area and having excellent electron conductivity.
Electrocatalytic Activity of Graphene Oxide: Mediating Electron Transfer Between Two Redox Couples
Authors: Kamat Prashant V , Bridewell Victoria
Published: February 2020

Graphene based materials have been extensively employed to improve the performance of electrochemical storage devices as well as solar cells. Graphene oxide has also been extensively used to improve the performance of electrocatalysts in fuel cells and sensing devices. We have now probed the electron storage and electron shuttling property of graphene oxide by anchoring two redox couples (methyl viologen and ferrocene).  During the cathodic scan, we see a quasi-reversible reduction of MV2+ indicating the loss of electrons in charging of reduced graphene oxide. The electrons stored in reduced graphene oxide are then utilized to regenerate ferrocene during the anodic scan. The property of reduced graphene oxide film to store and shuttle electrons shows its ability to act as an electrocatalyst.
(Invited) A Carbon-Carbon Hybrid Immobilizing Carbon Nanodots and Carbon Nanotubes
Authors: Gudi Dirk M.
Published: February 2020

The thrust of this work is to integrate small and uniformly sized carbon nanodots (CND) with single-walled carbon nanotubes of different diameters as electron acceptors and electron donors, respectively, and to test their synergetic interactions in terms of optoelectronic devices. CNDs  were prepared by pressure-controlled microwave decomposition of citric acid and urea. CNDs were immobilized on single-walled carbon nanotubes by wrapping the latter with poly(4-vinylbenzyl trimethylamine) (PVBTA), which features positively charged ammonium groups in the backbone. Negatively charged surface groups on the CNDs lead to attractive electrostatic interactions. Ground state interactions between CNDs and SWCNTs were confirmed by a full-fledged photophysical investigation based on steady-state and time-resolved techniques. As a complement charge injection into the SWCNTs upon photoexcitation was investigated by ultra-short time-resolved spectroscopy.
(Invited) Completely Organic Carbon Nanostructured Thermoelectric Thin Films with Power Factors Exceeding Bismuth Telluride
Authors: Grunlan Jaime , Yu Choongho , Cho Chungyeon , Moriarty Gregory
Published: February 2020

Low electrical conductivity (s) and thermopower (S) have long excluded polymers from thermoelectric applications.  Adding carbon nanotubes produces polymer nanocomposites that exhibit thermoelectric behavior (i.e., generate electricity via a thermal gradient).  These nanocomposites exhibit electrical conductivity as high as 200,000 S/m, with a reasonable S (35 – 70 mV/K).1,2  This high electrical conductivity is paired with low thermal conductivity (k ~ 0.3 W m-1 K-1).  Power factors (PF = S2s) are as high as 500 mW m-1 K-2) for these composites, containing carbon nanotubes stabilized by porphines and poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), making them competitive with inorganic semiconductors (e.g., lead telluride) in terms of conversion efficiency. These composites are lightweight and relatively flexible when compared with traditional semiconductor thermoelectrics (e.g., bismuth telluride).  Very recent work using layer-by-layer (LbL) assembly will also be described.  Sequential layering of PANi, graphene, and double walled carbon nanotubes (DWNT) produces films with increased carrier mobility, originating from strong π-π interactions between PANi and DWNT and the higher electrical conductivity of graphene. In this investigation of the thermoelectric behavior of an LbL-assembled film, the resulting multilayer thin films exhibit a remarkable power factor (1825 mW m-1 K-2) that exceeds lead telluride and is more than half the value of bulk bismuth telluride.3  Additionally, these water-based systems can be applied like ink or paint, which should further improve their usefulness in harnessing waste heat from a variety of sources (e.g., exhaust manifolds or the human body through clothing).  For more information about the Polymer Nanocomposites Lab visit: http://nanocomposites.tamu.edu.

References

1. Moriarty, G. P.; Briggs, K.; Stevens, B.; Yu, C.; Grunlan J. C. Energy Technology
2013, 1, 265-272.

2. Kim, D.; Kim, Y. S.; Choi, K.; Grunlan J. C.; Yu, C. ACS Nano
2010, 4, 513-523.

3. Cho, C.; Stevens, B.; Hsu, J.-H.; Bureau, R.; Hagen, D. A.; Regev, O.; Yu, C.; Grunlan J. C. Advanced Materials
2015, 27, 2996-3001.
Physical Entrainment Versus Chemical Binding: Carbon Nanofoam, Metal Nanoparticles, and the Role of Thiophene Linkers
Authors: Parker Joseph F. , Wallace Jean Marie , Brandell Natalie L. , Rolison Debra R.
Published: February 2020

Porous carbon electrodes provide structure and function for energy storage and conversion devices such as batteries, electrochemical capacitors, and fuel cells. Ultraporous, high-surface-area carbon nanofoams with submicrometer pore networks interconnected in three dimensions (3D) offer increased versatility as conductive scaffolds, particularly because the surface of the carbon network can be readily modified with energy-storing or catalytic moieties. We modify the surfaces of our carbon nanofoams with thiophene-like "hooks" to anchor pre-formed Pd or Au nanoparticles, yielding electroactive carbon nanostructures containing less than 1 wt% of well-dispersed precious metal colloids. Gold, formerly regarded as a poor catalytic noble metal, now well known for its use as a gas-phase oxidation catalyst when sized on the nanoscale, has recently come into interest for its potential in fuel-cell technology and sensors. The nanoparticle-functionalized nanofoams are characterized in terms of their electrochemical accessibility for the ethanol oxidation reaction and the role of the thiophene linker. We observe that colloidal gold nanoparticles adsorb at both the boundary surface and interior walls of thiophenylated carbon nanofoams, allowing us to probe whether the metal nanoparticles chemically bind at the heterocyclic sulfur moieties in the carbon walls or if they are physically entrained within the nanometric pores, voids, nooks, and crannies of the composite.
Heteroatom Doped-Carbon Nanospheres for Energy Storage Systems
Authors: Ferrari Stefania , Pappas George , Huang Xiaobin , Bhagat Rohit , Haddleton Dave , Wan Chaoying
Published: February 2020

Graphite-based lithium batteries hold a significant position in the market since graphite is the only material to combine low cost, performance and easy processability, three factors which are crucial for industrial production and realization in true applications. Much effort is now being expended in attempts to advancing anode materials (silicon, transition metal oxides, various alloys etc.) for Li-ion batteries driven by the ongoing development of high power demanding applications and tools [1]. Novel materials have larger theoretical capacity than graphite (372 mAh g-1) but often suffer from low electrical conductivity and large volume expansion which lead to poor cycling performance. Also, new promising technologies are emerging like Na-ion batteries that can be key as an alternative energy storage system [2] and require the exploration of different carbonaceous materials.

Here we investigate the performance of a novel type of heteroatom co-doped (nitrogen, phosphorous and sulfur) carbon nanospheres (CNSs) with high specific surface area as anode materials for lithium and sodium ion batteries. The one-step synthesis of highly cross-linked hybrid organo(cyclotriphosphazenes) (OPZs) is an excellent and high efficient method to prepare various nanostructured materials like nanospheres, nanotubes, core-shell and hollow particles. The CNSs were obtained from carbonization of OPZs with 300 nm in diameter. Irreversible capacity loss due solid-electrolyte interface (SEI) layer formation is a common issue for carbonaceous materials used in electrodes for Lithium cells and studying the correlation of the capacity loss with multiple atom doping is essential. Work to be discussed here will present results of the investigation of the effect of the carbonization temperature on the microstructural and elemental composition and ultimately the electrochemical behaviour of the CNSs. The as prepared CNSs showed remarkable cycling stability for more than 1000 cycles delivering a capacity of about 130 mAhg-1 at a current rate of 1C. In addition a significant coulombic efficiency as high as 99.99% was maintained during the long cycling thereby showing great promise for application in Lithium batteries. The high specific surface area, porous structure and multi-heteroatom doping all contributed to the electrochemical performance of the CNSs. Heteroatom doped CNSs are potential materials for a set of different important applications in catalysis, supercapacitors and hydrogen storage and synergistic effects of dopant atoms could be key for advancing technology.

[1] N. Nitta, F. Wu, J. T. Lee, G. Yushin, Mater. Today, 18 (2015) 252

[2] B. L. Ellis, L. F. Nazar, Curr. Opin. Solid State Mater. Sci. 16 (2012) 168
Preparation of Graphene/N-Doped Carbon Nanowire Composites for an Effective Electrocatalyst for the Oxygen Reduction Reaction
Authors: Kadumudi Firoz Babu , Choi Won Mook
Published: February 2020

Platinum (Pt) and its alloys have long been recognized as the best electrocatalyst for ORR in fuel cells. However, high cost due to the scarcity of Pt and its insufficient durability limited the mass production and commercialization of electrocatalysts.Thus, doped carbon materials with various heteroatoms, such as sulfur (S), nitrogen (N), boron (B), and phosphorous (P), has attracted intense attention due to its reportedly high catalytic activity, high long-term durability and tolerance to poisoning as a metal-free ORR electrocatalyst. In this work, we report the facile preparation of graphene decorated with N-doped carbon nanowires for an efficient ORR electrocatalyst. The proposed method here involves the formation of polypyrrole (PPy) nanowires decorated on reduced graphene oxide (rGO-PPy) by in situ polymerization of pyrrole monomer in the presence of rGO. Subsequently, the synthesized rGO-PPy is annealed at 800 oC in an argon atmosphere to afford the N-doped carbon nanowires decorated on rGO (rGO-CN) by the carbonization of PPy nanowires. The prepared rGO-CN exhibits the high nitrogen content and a unique nanostructure afforded by the integration of carbon nanowires and graphene sheets, which facilitate the efficient adsorption of oxygen molecules for improved electron transfer efficiency and increased electrocatalytic activity for ORR. The morphology of rGO-CN is confirmed by TEM analysis and the chemical composition and interaction of the prepared samples are analyzed by XPS and FT-IR analysis. The electrocatalytic activity of rGO-CN toward ORR is also evaluated by the cyclic voltammetry. It is found that the rGO-CN electrode shows superior electrocatalytic performance toward ORR, compared to rGO and rGO-PPy, which demonstrates the promising potential of rGO-CN as a carbon-based, metal-free electrocatalyst for enhancing the electrocatalytic property towards ORR.
Three-Dimensional Porous Carbon Materials with High Surface Area for Electrochemical Energy Storage
Authors: Han Jae Hee , Kim Tae-Ho , Kim Byoung Gak , Hong Young Taik
Published: February 2020

Supercapacitors are widely recognized as an important class of energy storage devices because they can provide a high specific power and long cycle life. Electrical double-layer capacitors (EDLCs) store charge and release electric energy through the transfer of ions to and from the electrode/electrolyte interface without a Faradaic reaction. Therefore, the amount of energy stored by EDLCs is dependent on the surface area of the electrodes available for electrolyte ion access. However, for the use of the commercial carbon materials such as activated carbon and CNT etc., a poor energy density is observed due to the lack of porous structure which limits the active area for charge storage. Thus, great efforts have been focused on preparation of 3D-porous structure carbons for EDLCs to improve upon these factors.

In this work, a new type of advanced 3D macroporous carbon material derived from PIM-1 with a high surface area and electrical conductivity is proposed and anticipated for energy storage applications. PIM-1 (polymer of intrinsic microporosity) is a polymer with a large fractional free-volume with a high surface area of 760 m2/g and chosen as precursor material for carbonization. 3D macroporous PIM-1 films (NPIMs) with continuously interconnected structure were fabricated by applying the nonsolvent-induced phase inversion method. Finally the carbonized NPIMs (cNPIMs) were obtained through direct high temperature pyrolysis of NPIMs without any external activation agent. The cNPIMs presented a very large surface area (2101.1 m2/g) with narrow micropore size distribution (0.75 nm) as shown in Fig. 1. The SEM analysis revealed that cNPIMs also have a unique 3D macroporous structure having both dense skin layer and gradient pore structure, which is expected to grant a smooth and easy ion transfer capability as an electrode material. Consequently, the cNPIM exhibits a high capacitance (405.8 F/g) and long-term stability in aqueous electrolyte. We believe that our approach can provide a variety of new 3D macroporous carbon materials for the application in a electrochemical energy storage.

Figure 1
(Invited) Differential Sub-Cellular Processing of Single-Wall Carbon Nanotubes Via Interfacial Modification
Authors: Islam Mohammad F.
Published: February 2020

Strategies for cell-specific targeting and delivery of single-wall carbon nanotubes (SWCNTs) have made significant advancements over recent years. However, control of sub-cellular localization, an important criterion for many biomedical applications, remains largely unexplored. I will present our experimental work demonstrating how different molecules that are used to non-covalently suspend hydrophobic SWCNTs in aqueous conditions also influence cellular processing and localization. We utilized complementary imaging modalities including real-space fluorescence imaging, confocal Raman imaging, and fluorescence lifetime imaging microscopy to show that SWCNTs dispersed using the membrane active tri-block copolymer Pluronic® F-127 (PF127) were endocytosed into cells by the millions but eventually escaped endosomes and altered F-actin structures. In contrast, SWCNTs dispersed with the protein bovine serum albumin (BSA) were endocytosed into cells at similarly high levels but remained in the endosomal pathway, ultimately co-registering with endoplasmic reticulum and vesicles. Interestingly, cellular exposure to SWCNTs–BSA in the presence of the endosome disrupter, chloroquine, led to altered F-actin structures that were similar to the alterations induced by cellular exposure to SWCNTs–PF127. These results suggest that PF127 facilitated endosome escape and that SWCNTs might have an energetically favorable interaction with stiff, filamentous structures inside the cell. Thus, our results provide a design principle for non-covalent surface modifications of SWCNTs that do not degrade the desirable, intrinsic SWCNT properties but provide differential trafficking to intracellular compartments for sub-cellular biomedical applications.
(Invited) Single-Walled Carbon Nanotubes As Multimodal Agents for Biological Imaging and Drug Delivery
Authors: Naumov Anton V , Gliko Olga , Weiss Michelle , Weisman R. Bruce , Kirkpatrick Lynn
Published: February 2020

Due to their unique physical and chemical properties, carbon nanotubes have a number of applications in biomedical field as agents for photothermal therapy, drug transport vehicles and biological imaging agents. Single-walled carbon nanotubes (SWCNTs) provide a large platform for the transport of multiple drugs and target agents, while protecting human body from adverse effects of the drugs. SWCNTs also simultaneously serve as biological imaging agents via their intrinsic fluorescence in the near-infrared, where biological tissue is more transparent. In our work, SWCNTs were employed to successfully deliver several siRNA payloads in vitro and in vivo for the purposes of cancer therapeutics. They protected siRNA, non-covalently bound to SWCNT platform, from degradation in blood and facilitated successful transfection via enhanced cellular membrane penetration. Delivery pathways of siRNA were monitored through fluorescence imaging, verifying that SWCNTs could effectively deliver their payload in cancer cells and tumor tissues. SWCNT fluorescence spectroscopy allowed for quantitative assessment of their pharmacokinetics in blood and tissue biodistribution in animal models with human tumor xenografts. As a result, an apparent antitumor activity of siRNA/SWCNT complexes was observed, complimented by the evidence of SWCNT accumulation in tumor. This data suggests that carbon nanotubes can effectively serve as multimodal agents for image-guided therapy in biomedical applications. Due to the specificity of nanotube emission, SWCNTs also show a strong potential for simultaneous delivery and imaging of multiple biological agents at once.
Well-Defined Water-Soluble C60-PVP Conjugate
Authors: Tiu Elisha Gabrielle V. , Aroua Safwan , Yamakoshi Yoko
Published: February 2020

Based on their high photosensitivity, the potential medical application of fullerenes (C60 and C70) such as photodynamic therapy agents has been discussed for decades. Due to their high hydrophobicity, it is necessary to find a good method to solubilize fullerenes in water or water-miscible solvents for such application.  We have been using a biocompatible and water-soluble polymer, poly(vinylpyrrolidone) (PVP) to prepare water-soluble C60/ or C70/PVP complex1 and C60- or C70-PVP conjugates2. 3 with efficient reactive oxygen species (ROSs) generation under visible light.4,5 However, in the clinical use, well-defined compounds with narrower molecular weight distribution are favored.

In this study, we synthesized a RAFT reagent 1 for the preparation of well-defined PVP. The terminal moiety was converted to an amine 2 to connect to a C60 acid anhydride derivative 3 which was obtained through a Prato reaction.6 Obtained C60-PVP conjugate had a narrower molecular distribution, high water-solubility and photoinduced ROS generation.7

(1) Yamakoshi, Y.; Yagami, T.; Fukuhara, K.; Sueyoshi, S.; Miyata, N. J. Chem. Soc., Chem. Commun. 1994, 517. (2) Iwamoto, Y.; Yamakoshi, Y. Chem. Commun. 2006, 4805. (3) Oriana, S.; Aroua, S.; Söllner, J. O. B.; Ma, X.; Iwamoto, Y.; Yamakoshi, Y. Chem. Comm. 2013, 49, 9302. (4) Yamakoshi, Y.; Sueyoshi, S.; Fukuhara, K.; Miyata, N. J. Am. Chem. Soc. 1998, 120, 12367. (5) Yamakoshi, Y.; Umezawa, N.; Ryu, A.; Arakane, K.; Miyata, N.; Goda, Y.; Masumizu, T.; Nagano, T. J. Am. Chem. Soc. 2003, 125, 12803. (6) Aroua, S.; Schweizer, W. B.; Yamakoshi, Y. Org. Lett. 2014, 16, 1688. (7) Aroua, S.; Tiu, E. G. V.; Ayer, M.; Ishikawa, T.; Yamakoshi, Y. Polymer Chem. 2015, 6, 2616.

Figure 1
(Invited) Application of Aqueous Two-Phase Partitioning Towards Total Structure Control of Single-Wall Carbon Nanotube Dispersed Populations
Authors: Fagan Jeffrey A.
Published: February 2020

Scaled separation of single-wall carbon nanotube (SWCNT) populations with completely specified physical structures is a primary milestone necessary for enabling SWCNT-based technologies.  Aqueous two-phase extraction (ATPE), in which the spontaneous phase separation of an aqueous polymer mixture is utilized to spatially separate solutes on the basis of their chemical potential difference for the two phases, is a promising technology for achieving this milestone.  By implementing multistage iterative separations using surfactant composition gradients, either stepwise or through an automated process, many individual species of SWCNT have been isolated, with isolation for some species to the level of specific left, or right,-handed enantiomer.  Results on the improved processing methodologies, including on separation of metallic SWCNT species, will be addressed.  Additionally, combination of ATPE with separately developed methods for length separation and endohedral volume specification will demonstrate the progress towards the total structure control goal.
(Invited) Figure of Merit for Carbon Nanotube Photothermoelectric Detectors
Authors: Léonard François
Published: February 2020

Carbon nanotubes (CNTs) have emerged as promising materials for visible, infrared, and terahertz photodetectors. Further development of these photodetectors requires a fundamental understanding of the mechanisms that govern their behavior as well as the establishment of figures of merit for technology applications. Recently, a number of CNT detectors have been shown to operate based on the photothermoelectric effect. Here we present a figure of merit for these detectors, which includes the properties of the material and the device. In addition, we use a suite of experimental characterization methods for the thorough analysis of the electrical, thermoelectric, electrothermal, and photothermal properties of the CNT thin-film devices. Our measurements determine the quantities that enter the figure of merit, and allow us to establish a path towards future performance improvements.

Figure 1
Printed Carbon Nanotube Gas Sensor Arrays
Authors: Schwartz David Eric , Smith Clinton , Zhang Yong , Iftime Gabriel , Whiting Gregory , Matei Ion , Meyyappan Meyya , Kim Beomseok
Published: February 2020

PARC is developing extremely sensitive room-temperature printed gas sensors based on arrays of modified carbon nanotubes (CNTs). The sensors are combined with electronics to form distributed gas sensing networks for applications including natural gas leak detection, equipment failure, industrial safety, and indoor air quality monitoring. The sensing materials comprise CNTs modified with coatings, chemical functionalization, and nanoparticles, to achieve sensitivity to a wide selection of gases including CH4, NH3, CO, H2S, and others. Advanced machine learning techniques allow gas identification and sub-ppm sensitivity. Digital printing of sensor materials on printed electrodes enables low-cost, simple customization of sensor design, and electrode layout. An overview of the project and recent experimental results will be presented.
(Invited) A Carbon Nanotube Based Single Photon Source
Authors: Jeantet Adrien , Chassagneux Yannick , Lauret Jean-Sébastien , Reichel Jakob , Voisin Christophe
Published: February 2020

Carbon nanotubes have strong assets for future integrated single-photon sources since their working wavelength can easily be tuned to the telecom C band by choosing an appropriate diameter [1]. In addition, they show a pronounced antibunching both at low and room temperature[2,3]. Nevertheless, the practical implementation of such a single-photon source requires to embed the nanotube into a micro-cavity in order to funnel the emitted photons into a specific mode (and possibly to an optical fiber) and in order to beat the non-radiative recombination by means of Purcell brightening. In order to tackle the stringent spatial and spectral matching conditions, we developed a flexible micro-cavity design where the concave mirror is micro-engineered at the apex of a single mode optical fiber [4] that can be scanned at the surface of the back mirror where nanotubes has been deposited.

By doing so, we are able to observe, both by means of photon counting and time-resolved measurements a Purcell effect of the order of 6, which allows us to funnel 90% of the photons into the mode [5]. In addition, by exploiting the cavity feeding effect on the phonon side-bands, we are able to tune the source over a 5 THz spectral window while keeping a high spectral purity (80 GHz) and an anti-bunching rate better than 0.01.

[1] V. Ardizzone et al. Phys. Rev. B 91, 121410 (R) (2015)

[2] Hogele et al. Phys. Rev. Lett. 100, 217401 (2008)

[3] Ma et al. Nature nano. 10, 671 (2015)

[4] Hunger et al. N. J. Phys 12, 065038 (2010)

[5] Jeantet et al., arXiv1508:06297 (2015)
(Invited) Single Carbon Nanotube Tracking Reveal Nanoscale Dimensions of Living Tissue Structuration
Authors: Cognet Laurent
Published: February 2020

The optical microscopy of single molecules has recently been beneficial for many applications, in particular in biology. It allows a sub-wavelength localization of an isolated nano-object and a subtle probing of its spatio temporal nano-environment on cells [1].

For many bio-applications, near infrared nanoprobes and/or more photostable nanoprobes than conventional fluorescent molecules or quantum dots are desirable. In this context, the use of single walled carbon nanotube tubes (SWCNTs) is expected to be favorable. A prerequisite is however to understand and tune their physical properties/morphologies for applications in bio-environments as well as to optimize optical schemes to detect them in complex environments depending on nanotube lengths and foreseen applications [2]. Here we show that by tracking individual SWCNT for minutes, structural information of the living tissues are revealed at the nanoscale. These results, which could not be obtained by other approaches, are obtained by analysis of the structure-dependent diffusion properties of the anisotropic SWCNTs combined to super-resolution imaging strategies [3].

 

References

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

[2] Gao, et al, Sci. Rep. (2015); Gao, et al, Biomater. Sci. (2016);

[3] Godin et al submitted
(Invited) A Highly Efficient and Tumor Vascular-Targetingtherapeutic Technique with Size-Expansiblegadofullerene Nanocrystals
Authors: Wang Chunru
Published: February 2020

It has long been a dream to achieve tumor targeting therapy

that can efficiently reduce the toxicity and severe side effects of

conventional antitumor chemotherapeutic agents. Taking advantage

of the abnormalities of tumor vasculature, we demonstrate

here a new powerful tumor vascular-targeting therapeutic

technique for solid cancers that applies advanced nanotechnology

to cut off the nutrient supply of tumor cells by physically

destroying the abnormal tumor blood vessels. Water soluble

magnetic Gd@C82 nanocrystals of the chosen sizes are deliberately

designed with abilities to penetrate into the leaky tumor

blood vessels. By triggering the radiofrequency induced phase

transition of gadofullerene nanocrystals while extravasating the

tumor blood vessel, the explosive structural change of nanoparticles

generates a devastating impact on abnormal tumor blood

vessels, resulting in a rapid and extensive ischemia necrosis and

shrinkage of the tumors. This unprecedented target-specific

physiotherapy is found to work perfectly for advanced and refractory

solid tumors.
(Invited) Unprecedented Aromatic Ring Scissoring Observed in the Reaction of Sc3n@Ih
-C80 with Aryl Azides
Authors: Wang Guan-Wu
Published: February 2020

A number of reactions of endohedral metallofullerenes (EMFs) have been reported in the literature. Recently, we investigated the reaction of aryl azides with Sc3N@Ih
-C80. It was found that isomeric [5,6]- and [6,6]-azafulleroids can be obtained from the thermal reaction of Sc3N@Ih
-C80 with 4-isopropoxyphenyl azide, while photoirradiation leads exclusively to the [6,6]-azafulleroid.[1] Surprisingly, when the thermal reaction was conducted at a lower temperature and under the aerobic conditions, an EMF isoxazoline derivativehaving a hexa-2,4-dienal moiety was obtained. This unprecedented reaction involved the aromatic ring scissoring and participation of O2. The same phenomena were applied to the reaction of Sc3N@Ih
-C80 with other electro-rich aryl azides.

References

1. Liu, T.-X.; Tao, W.; Zhu, S.-E; Wang, G.-W.; Jiao, M.; Yang, S.; Bowles, F. L.; Olmstead, M. M.; Balch, A. L. J. Am. Chem. Soc.
2012, 134, 11956-11959.
(Invited) Entrapping a Group-VB Transition Metal, Vanadium, within an Endohedral Metallofullerene
Authors: Yang Shangfeng
Published: February 2020

So far the entrapped metals for the isolated endohedral metallofullerenes (EMFs) are primarily limited to rare earth metals, whereas except group-IVB metals whether or not it is possible to entrap other d-block transition metals remains unclear. In this talk, we report the successful entrapment of the group-VB transition metal vanadium (V) into fullerene cage, affording the heretofore unknown V-containing EMFs. Two novel V-containing EMFs — VxSc3-xN@C80 (x=1, 2) — were isolated, and their molecular structures were unambiguously determined by X-ray crystallography to be Ih
(7)-C80 cage entrapping the planar VSc2N/V2ScN clusters.  VxSc3-xN@Ih
(7)-C80 (x=1, 2) were further characterized by UV-vis-NIR and ESR spectroscopies and electrochemistry, revealing that the electronic and magnetic properties of VxSc3-xN@Ih
(7)-C80 (x=1, 2) are tunable upon varying the number of entrapped V atoms (i.e., x value). The molecular structures and electronic properties of VxSc3-xN@Ih
(7)-C80 (x=1, 2) were further compared with those of the reported analogous EMFs based on lanthanide metals and the adjacent group-IVB transition metal Ti, revealing the peculiarity of the group-VB transition metal V-based EMFs.
Numerical Modeling of Lithium Ion Battery Capacity Fading on Electric Vehicles
Authors: Yuan Chris
Published: February 2020

Electric vehicles are recognized as clean alternative to conventional vehicles and promoted globally for large fleet deployment. As predicted, the EV global fleet number will reach 2.6 million by 2016 and 230 million by 2030. Current EVs are all powered by lithium ion batteries due to its higher energy density and power density. There are two types of EVs on current market: Plug-in Hybrid EV, represented by Chevrolet Volt, and battery EV, represented by Nissan Leaf. The lithium ion batteries used on both Nissan Leaf and Chevrolet Volt are with the same chemistry: graphite anode and lithium manganese oxides (LMO) cathode. However, current EV lithium ion batteries have severe capacity fading issue which limits the market penetrations of EVs. For example, the Nissan Leaf battery pack, with 24 kWh capacity, can power the vehicle for 84 miles/charge and the battery performance is warranted for 5 years or 60,000 miles only.

In this research, we report our numerical modeling approach for predictive modeling of battery capacity fading on electric vehicle operations for both cycling capacity loss and calendar capacity loss. The capacity fading of a typical 24 kWh LMO-Graphite lithium ion battery during actual EV operations are mathematically modeled under state-level average driving conditions in the United States, considering the EV travel demand, driving range, hourly temperature, and driving pattern. The calculated annual cycling capacity losses are between 0.5% and 1.2% in first year, and slightly going up in following years. The calculated annual calendar capacity losses are between 4% and 8.9% in first year, and falling down quickly in following years. The results are validated by actually reported Nissan Leaf capacity fading data in several representative states of U.S.
Shape Memory Polymer-Based Self-Healing Triboelectric Nanogenerator
Authors: Lee Jeong Hwan , Hinchet Ronan , Kim Sung Kyun , Kim Sanghyun , Kim Sang-Woo
Published: February 2020

Recently, triboelectric nanogenerators (TENGs) have received increasing interest due to their large potential for mechanical energy harvesting. Important progress has been achieved in increasing the output power and efficiency while new structures have emerged. In particular, their robustness and endurance have increased, but some critical concerns still remain about the degradation and lifetime of TENGs. How will TENGs age under intensive use in our daily lives? To address this issue, we propose in this paper to use shape memory polymers (SMPs) to extend TENGs’ lifetimes and guarantee their performance. For this purpose we introduce a new smart SMP-based self-healing TENG which has the capacity to be healed and to recover good performance after degradation of its triboelectric layer. We studied the degradation and healing process of the SMP–TENG, and the improvement in its endurance and lifetime, and thus demonstrate the huge potential of self-healing SMP–TENGs.

Figure 1
Natural Polymer Derived Carbon Microsphere Anode for Alkali-Ion Batteries
Authors: Chen Chaoji , Huang Yunhui , Xie Jia
Published: February 2020

Rechargeable batteries are one of the most emerging energy storage techniques for the integration of renewable energy sources like solar energy and wind power. As the key members of rechargeable batteries, alkali-ion batteries have been investigated broadly due to their high safety, high energy density and environmental friendliness. Among them, lithium ion batteries (LIBs) represent one of the most mature and commercial technology in this field, however, the insufficiency of lithium resource and the growing cost become challenges to industry for large-scale energy storage applications. Recently, Na-ion batteries (NIBs) and K-ion batteries (KIBs) have been regarded as two of the most promising alternatives to LIBs, especially for large-scale energy storage, due to the abundant resource and low cost of sodium and potassium precursors. It is believed that the electrode materials are the key components in realizing high-performance batteries. For large-scale energy storage applications, electrode materials with low cost, high energy density and long cycling life are highly desired but also challenging.

Here we introduce a low-cost and high-performance carbon microsphere (CM) anode derived from natural polymer for high-capacity and long-life alkali-ion batteries. The CM electrode as anode for NIBs delivers a high capacity of ~250 mAh g-1 at 30 mA g-1 and long cycling life of more than 8000 cycles without obvious decay. More appealingly, as anode for KIBs, the CM electrode demonstrates a higher capacity of ~300 mAh g-1 at 30 mA g-1, superior rate capability of over 150 mAh g-1 at an extreme current rate of 20 A g-1 and long cycling life of more than 2000 cycles. The carbon microsphere electrode demonstrated here is highly promising for large-scale energy storage applications.