bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Nanotubes for DNA Conformation Sensing
Authors: Rotkin Slava V. 
Published: February 2020

The talk is focused on applying single-wall nanotubes (SWNT) as optical reporters of DNA structure. SWNT photoluminescence (PL) was used to explore photo-physics of pi-pi* transitions in the photoexcited DNA. The ssDNA wrapped CoMoCat SWNTs, water suspended, commonly produce a strong and stable PL under visible excitation[1]. Recently we demonstrated that under two-color excitation (visible plus UV) such a system shows rich behavior: normal double-band excitonic photogeneration resulting in UV-enhanced PL emission could be one type of response. The other behavior was found in a certain band of excitation wavelength: reversible PL quenching followed the cw-UV illumination, different from photobleaching or photochemical modification of pristine material. The explanation of this intriguing behavior was found and presented in Ref.[2].
By combination of optical spectroscopy, rate equation analysis for excited states, and semi-empirical quantum mechanical calculation the source of the PL quenching was identified to be free charge carriers introduced by the photoexcited DNA. It is known that the DNA in the course of biological evolution developed mechanisms of recovery after UV irradiation, as well as relaxation mechanisms for photoexcited states. One of those mechanisms, namely, the DNA autoionization (AI) mechanism has been detected experimentally using SWNT as a nanoscale reporter. Theoretical analysis of the effect showed existence of the AI rates shorter than 20 fs and dominated by a hole charge transfer from the ssDNA to the SWNT. The capability to detect a fundamental relaxation mechanism of UV-excited DNA by using two-color spectroscopy proves potential of a DNA-SWNT complex, as a model optical system, for detecting charge transfer from DNA. Furthermore, the model demonstrated that the AI rate is a function of the conformation of the DNA thus opening further avenues for biosensing of DNA architecture in these complexes.
Significant contributions to this work by Dr. T. Ignatova (UC Irvine), Dr. A. Balaeff (University of Central Florida), Dr. M. Zheng (NIST), Mr. M. Blades (LU), and Mr. P. Stoeckl (University of Rochester) are kindly acknowledged; special thinks to Dr. J. Fagan (NIST) for help with instrumentation. Research was partially supported by National Science Foundation (ECCS-1509786).
References:
[1] Carbon Nanotubes and Related Structures, ed. DM Guldi, N Martin.Weinheim:Wiley-VCH. (2010)
[2] T. Ignatova, A. Balaeff, M. Zheng, M. Blades, P. Stoeckl and SV. Rotkin, “Two-color spectroscopy of UV excited ssDNA complex with a single-wall nanotube probe: Fast nucleobase autoionization mechanism”, Nano Research, (2015).
(Invited) Evidence for Strong Electronic Correlations and Band-Gap Renormalization in Doped Single-Wall Carbon Nanotubes
Authors: Hertel Tobias , Hartleb Holger , Spaeth Florian , Eckstein Klaus , Achsnich Melanie , Schoeppler Friedrich 
Published: February 2020

We have investigated the photophysical properties of chemically and gate-doped semiconducting single-wall carbon nanotubes (s-SWNTs). The first subband exciton oscillator strengths as obtained from a global analysis of absorption spectra are used for assessment of carrier densities and provide evidence for band-gap renormalisation (BGR) in (6,5) SWNTs. We predict that BGR of one-dimensional gate doped semiconductors is accompanied by a stepwise increase of the carrier density by Δn=32meff
b/(πℏ)
2once the electrochemical potential reaches the valence or conduction band offset with b = (0.15 ± 0.05) eV nm (meff - effective carrier mass). Moreover, we show that the width of the spectroelectrochemical window of the first subband exciton of (1.55±0.05) eV corresponds to the fundamental band gap of the undoped (6,5) SWNTs in our samples and not to the renormalized band gap of the doped system. We also compare spectral changes in gate doped with those of chemically doped SWNTs. Femtosecond time-resolved pump-probe spectroscopy of chemically doped SWNTs provides evidence of exciton-trion coupling. These observations as well as a previously unidentified absorption band emerging at high doping levels in the Pauli-blocked region of the single-particle Hartree band structure, provide clear evidence for strong electronic correlations in the optical spectra of SWNTs.
Automated Silver-Zinc Fiber Battery Fabrication
Authors: Raj Abhishek , Kim Andrew , Steingart Daniel A 
Published: February 2020

Flexible electronics play host to a wide array of applications, ranging from wearable devices to large scale systems. Improvements in battery energy density while maintaining safe and stable operation under mechanical deformation is key in advancing the success of these flexible electronic systems. Currently, the majority of flexible batteries are fabricated as planar devices in which the electrodes and separator are stacked in sheets. These devices are limited due to their ability to only bend biaxially and the fact that repeated biaxial bending stresses often result in delamination or cracking of the battery components which is impractical for wearable devices. Batteries in a cable configuration have been proposed as an alternative to planar architectures; this form factor offers the ability for multi-directional bending and promises applications in woven textiles and washable electronics. The current process for fabricating such batteries as described in literature involves separate manual stages of plating the anode on a wire substrate, synthesizing an electrolyte and coating it around the anode, wrapping the cathode and packaging the final device with shrink tubing. This handmade approach to fabrication can vary between research groups and is not suitable for scaling to meet industry production levels; accordingly, such a process would be greatly benefitted by high throughput automation.
In the current work, we demonstrate a modular automated system for the fabrication of a secondary Ag/Zn wire battery; such automation enables rapid prototyping in a roll to roll compatible process for the testing and fabrication of new chemistries for flexible battery systems. Moreover, pipeline fabrication ensures repeatability of fabricated devices and offers a more streamlined approach to manufacturing. In our work, 3D printed parts are used with low-cost Arduino microcontrollers to feed a carbon fiber wire through a sequence of dip coating baths in order to synthesize the Zn anode and coat it in a polymer electrolyte which is safer for wearable applications than organic electrolyte alternatives. The next stage encases the cable with the Ag cathode before the device is packaged in chemically resistive tubing and passed through the final dip coating bath of a liquid electrolyte. The desired length of cable is then cut and sealed. Characterization of the wire batteries is reported based on SEM analysis, strain cycling, charge cycling, cyclic voltammetry, and electrochemical impedance spectroscopy in order to demonstrate the successful realization of a fiber battery based on our automated process. Performance metrics from these analyses such as discharge capacity and capacity retention is also compared to performance reported in literature for similar cable architectures.
Rapid Processing of Multi-Layered Iron Electrodes for Low-Cost Alkaline Batteries
Authors: Barnes Alistair David , Glover Carol Frances , Subramanian Raman , Sullivan James , Marinaccio Jordan Domonic , Williams Geraint , Elvins Jonathon 
Published: February 2020

Iron electrodes are known for their long cycle life and long term stability, yet have received little attention in recent years[1]. Modern electrode manufacture techniques are investigated in order to produce a low-cost iron electrode capable of scale up. Cyclic voltammetry and scanning electrochemical techniques are used to characterise the electrodes.
In this study, Near Infrared (NIR) radiative heating is used to cure screen-printable iron containing inks in seconds as opposed to 10’s of minutes via traditional convection heating routes. This reduction in processing time is vital to enable rapid roll-to-roll manufacture of large-scale electrodes. This development allows production of a modular device with inherent safety, exceptional lifetime yet at a low cost.
Additionally, performance of these electrodes is improved through novel layering of active material[2]. A compact layer of active material adjacent to the current collector allows for capacity, whilst a diffuse layer surrounds this in order to improve high power performance through increased accessible surface area. Efficiency of the electrodes is improved through use of additives previously reported by Manohar et al to combat the parasitic hydrogen evolution reaction which occurs upon charge[3], [4].
Performance is analysed using traditional physical and electrochemical techniques, including full cell cycling with commercial Ni cathodes. Scanning electrochemical techniques, more typical in corrosion studies, have been employed in a novel manner to investigate surface current densities in order to identify how regions of varying thickness and density effect rate capability.
References:
[1] T. Reddy, Linden’s Handbook of Batteries, 4th ed. McGraw-Hill Professional, 2010.
[2] V. I. Chani, Q. Yang, D. S. Wilkinson, and G. C. Weatherly, “Effect of substrate pre-coating on adhesion of sintered nickel plaques for electrode application in rechargeable batteries,” J. Power Sources, vol. 142, no. 1–2, pp. 370–381, Mar. 2005.
[3] A. K. Manohar, S. Malkhandi, B. Yang, C. Yang, G. K. S. Prakash, and S. R. Narayanan, “A High-Performance Rechargeable Iron Electrode for Large-Scale Battery-Based Energy Storage,” J. Electrochem. Soc., vol. 159, no. 8, pp. A1209–A1214, Jan. 2012.
[4] A. K. Manohar, C. Yang, S. Malkhandi, G. K. S. Prakash, and S. R. Narayanan, “Enhancing the Performance of the Rechargeable Iron Electrode in Alkaline Batteries with Bismuth Oxide and Iron Sulfide Additives,” J. Electrochem. Soc., vol. 160, no. 11, pp. A2078–A2084, Jan. 2013.
Unscented Kalman Filter-Based Online State-of-Charge Estimation in LiFePO4 Battery-Powered Electric Vehicles
Authors: Huang Boyan , Wang Chenxi , Zhu Zheng , Xiao Yegui 
Published: February 2020

Lithium iron phosphate (LiFePO4) battery has gained popularity due to its desirable characteristics such as low pollution, long cycling life, large power density, high safety and relatively low production costs. The estimation precision of State of Charge (SoC) of lithium iron phosphate (LiFePO4) battery determines the life and working efficiency of energy storage system. In practical applications, the battery capacity deteriorates with temperature drift and charge/discharge cycles, which make the accurate estimation of SoC a challenging issue.
In this paper, a novel online estimation technique for SoC has been developed. Based on a simplified RC model, the Open Circuit Voltage (OCV) of the battery is calculated through two adaptive filtering stage, which is then used to determine the SoC via a dynamic OCV–SoC curve. In the first stage a variable step-size Least Mean Square (VSS-LMS) algorithm is employed to adaptively estimate the model parameters in real-time; in the second stage, an Unscented Kalman Filter (UKF) is used to estimate the OCV from the parameters. UKF can provide a more accurate and stable performance compared to Extended Kalman Filter at an equal computational complexity by utilizing deterministic sample points to calculate mean and covariance terms which are propagated through the true nonlinearity, without approximation. Further, the influence of polarization potential on OCV parameter measurement is analyzed and the averaged battery terminal voltage and current are introduced to avoid the large error of OCV estimate causing by the inconsistency of batteries. The impact of polarization over potential variation in battery capacity is eliminated through a smooth filter so as to achieve a stable online estimation process. Plenty of experiments under data acquisition systems with different precisions were carried out in order to confirm the effectiveness of the proposed system. The errors in estimating the battery’s SoC were below 2% compared to more than 5% and 9% in the case of using an extended Kalman filter and ordinary Kalman filter. The proposed SOC estimation method with its simplified model was transferred to DSP system also to verify the accuracy, simplicity and feasibility of SoC estimation for real-time application.
Enhancement of Cycle Stability and Durability in Secondary Zinc-Air Batteries By Optional Ion-Transporting Separator
Authors: Hwang Ho Jung , Kwon Oh Chan , Shul Yong Gun 
Published: February 2020

Highly durable secondary zinc air batteries were developed using polypropylene (PP) membrane (Celguard 5550) coated with polymerized ionic liquid as separators. The anionic exchange polymer was synthesized copolymerizing 1-[(4-ethenylphenyl)methyl]-3-butyl-imidazolium hydroxide (EBIH) and butyl methacrylate (BMA) monomers by free radical polymerization for both functionality and structural integrity. The ionic liquid induced copolymer was coated on a commercially available PP membrane. The coat allows anionic transfer through the separator and minimizes the migration of zincate ions, which causes the loss of active sites by the formation of zinc oxide on the surface of the catalyst layer. Electrochemical Impedance Spectroscopy (EIS) during the cycle process elucidated the premature failure of cells due to the zinc cross over for the untreated cell and revealed a substantial importance must be placed in zincate control. Scanning electron microscopy (SEM) revealed significant decrease in the porosity of the coated film without large cell performance sacrifice. Energy dispersive x-ray spectroscopy (EDS) data revealed the copolymer coated separator showed less zinc element in the cathode electrolyte, indicating lower zinc permeation through the membrane. Ion Coupled Plasma Optical Emission Spectroscopy (ICP-OES) analysis confirmed over 96% of zinc ion cross over was reduced. In our charge/discharge setup, the constructed cell with the ionic liquid induced copolymer casted separator exhibited drastically improved durability as the battery life increased more than 281% compared to the pure commercial PP membrane.
Ultrasonic Sonochemical Synthesis and Electrochemical Study of Na-Li-Ti-O Quaternary Anode Materials for Secondary Batteries
Authors: Ghosh Swatilekha , Barpanda Prabeer 
Published: February 2020

Energy storage is a key sector propelling portable electronics, hybrid automobiles and grid storage sectors, where Li-ion and Na-ion batteries form the numero-uno devices. Design and development of new and robust anode (negative insertion) materials is crucial to realize safe and high-performance secondary batteries. While Fe/Mn/Co/Ni-based compositions rule the cathode chemistry, the anode materials are broadly based on carbon and Ti-based materials. For suitable Ti-based anodes, synthesis of nanostructured materials holds the key in realizing desirable electrochemical performance. The current work explores the Na-Li-Ti-O quaternary systems to study few Ti-based anode materials for rechargeable Li-ion and Na-ion batteries, namely Na2Li2Ti6O14 (1.3 V vs. Li+/Li), Li4Ti5O12 (1.5 V vs. Li+/Li), Na2Ti6O13 (2.5 V vs. Na/Na+) and Na2Ti3O7 (0.85 V vs. Na/Na+) prepared by energy-savvy ultrasonic sonochemical synthesis route.
The sonochemical synthesis of various Na-Li-Ti-O compounds was conducted at operating condition of 20 kHz-500 W by applying sonication for 10-30 min (at 25 °C) using various precursor ratios. The final products were obtained by thermal annealing of the obtained powder at 500-650 °C for short duration (ca. 1-2 h, in air). While conventional solid-state synthesis demands prolonged annealing (12-24 h), sonication-assisted method yielded desired phases with restricted annealing of 1-2 h. This energy-savvy synthesis route involving lower calcination temperature and duration delivers uniform, spherical and nanostructured products (ca. 50-200 nm) suitable for anode application in batteries. Near theoretical capacity was obtained with excellent cycling stability in all four Na-Li-Ti-O compounds. First principle DFT calculation was employed to determine the structural stability and diffusion barrier for Na-/Li-ion migration in these anode materials. The effect of various synthesis parameters on the structural, morphological and final electrochemical properties of these Ti-based anodes will be presented gauging their potential usage in Li-ion and Na-ion batteries.
Three-Dimensional Si-Based Composite Nanorods Array Applied in Energy Storage System
Authors: Li Jing , Yue Chuang , Yu Yingjian , Lin Wei , Zheng Mingsen , Kang Junyong 
Published: February 2020

The rapid development of the integrated circuit (IC) and Micro/Nano-Electro Mechanical System (M/NEMS) technologies are promoting the continued emergence or commercialization of the miniaturized autonomous devices such as wireless sensor networks (WSN) in smart grid.[1-4] In order to operate independently, the micro/nano autonomous electronic devices must have onboard power supply. However, the battery miniaturization still can not keep pace with the size scaling-down of the CMOS electronic technologies, due to the poor electrochemical performance of the micro/nano batteries or the un-compatible battery fabrication process with the IC technologies. Currently, the transition from two dimensional (2D) to 3D rechargeable LIBs with better electrochemical properties in a small areal footprint was found to cope well with state-of-the art semiconductor technologies conceptually providing new opportunities for micro/nano power systems in the future. [5-7]
In this work, the electrochemical performances of 3D Si-based composite nanorod (NR) arrays buffered by TiN/Ti interlayer, which were fabricated by a cost-effective, wafer scale and Si compatible process, were demonstrated and systematically investigated as the anode in rechargeable batteries. Lithium/Sodium ion storage behaviors were experimentally and theoretically studied.

References:

[1]. Scott E. Thompson and Srivatsan Parthasarathy, materialstoday, 2006, 9, 20-25.
[2]. Yunhao Liu, Yuan He, Mo Li, IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, 24, OCTOBER 2013.
[3]. Jeffrey W. Long, Bruce Dunn, Debra R. Rolison, and Henry S. White, Chem. Rev., 2004, 104, 4463-4492
[4]. Timothy S. Arthur, Daniel J. Bates, Nicolas Cirigliano, Derek C. Johnson , Peter Malati, James M. Mosby, Emilie Perre, Matthew T. Rawls, Amy L. Prieto, and Bruce Dunn, MRS Bull., 2011, 36, 523-531.
[5]. Loïc Baggetto, Harm C. M. Knoops, Rogier A. H. Niessen, Wilhelmus M. M. Kessels, and Peter H. L. Notten, J. Mater. Chem.,2010, 20, 3703-3708.
[6]. Alireza Kohandehghan, Peter Kalisvaart, Kai Cui, Martin Kupsta, Elmira Memarzadeha, and David Mitlin, J. Mater. Chem. A, 2013, 1, 12850-12861.
[7]. Peter H.L. Notten, Fred Roozeboom, Rogier A.H. Niessen, and Loïc Baggetto, Adv. Mater., 2007, 19, 4564-4567.
A Study on the Thermal Behavior of an Ultracapacitor Module Comprising 136 Cells
Authors: Park Sung June , Yi Jaeshin , Shin Chee Burm , Choi Jongrak , Lee Ha-Young 
Published: February 2020

Ultracapacitors, also known as supercapacitors, have the potential to meet the increasing power requirements of energy-storage systems for automotive applications. As compared to batteries, ultracapacitors offer a higher power density, higher efficiency, and longer shelf and cycle life. Because the performance of an ultracapacitor depends on temperature, it is important to calculate accurately the thermal behavior of a single ultracapacitor cell and the module composed of multiple ultracapacitor cells for the efficient and reliable systems integration of an ultracapacitor in automotive applications.
In this work, modeling is performed to study the thermal behavior of an ultracapacitor module. The ultracapacitor module is subject to the charge/discharge cycling with constant-current between 190V and 380V. The validation of the modeling approach is provided through the comparison of the modeling results with the experimental measurements.
Fig. 1 shows the schematic diagram of the ultracapacitor module composed of the 136 ultracapacitor cells (2.8V/350F) from LS Mtron Ltd. In Fig. 2, the variation of surface temperature with time from the experiment is compared with that from modeling during the charge-discharge cycles with the constant current of 10 A.

Figure 1
A Comparison of Potentiodynamic and Potentiostatic Electrochemical Test Methods for Resolving the Localized Corrosion Response of Heat Treated Al-Li-Cu Alloy 2099
Authors: Hanna Benjamin , Buchheit Rudolph , Yang Fan 
Published: February 2020

The corrosion mechanisms for 3rd generation Al-Li-Cu alloy AA2099 were characterized based on the localized attack on the microstructure. Samples were subjected to a series of artificial heat treatments conducted at temperatures ranging from 120°C to 180°C for times ranging from 12 to 168 hours. The varying microstructures were analyzed using transmission electron microscopy (TEM) and electron diffraction spectroscopy (EDS), which characterized the secondary phase precipitates grown during artificial aging. The formation of the strengthening phase T1 (Al2CuLi) is of particular note due to its anodic behavior relative to the alloy matrix. This particle is prone to selective dissolution and dealloying and can dictate the morphology of localized corrosion depending on how it is distributed within the alloy.
Localized corrosion was induced via individual immersion tests that utilized a highly oxidizing NaCl/H2O2 aqueous solution. The extent and morphology of the corrosion was assessed by optical microscopy. Results showed that pitting attack was apparent on samples aged at lower temperatures and/or for shorter times, when growth of secondary phase precipitates is hindered. Intergranular corrosion (IGC) was observed for the time-temperature combinations that promoted such precipitate growth. As revealed from TEM analysis, these samples showed T1 precipitates localized along grain boundaries. However, as samples continued to age and T1 formation became prevalent in the matrix, IGC was reduced. This is attributed to a smaller potential difference between grain boundary T1 and the surrounding area. Potentiodynamic experiments were then performed to identify any change in the localized breakdown potentials among the heat treated samples. It was shown that the specimens susceptible to IGC displayed a lower breakdown potential than those susceptible to only pitting.
Additional electrochemical tests were performed to capture the transition from pitting to IGC and determine whether the transition is potential-dependent, time-dependent or a combination of both. Unlike other Al-Cu alloys scanned potentiodynamically through the region of passivity breakdown, AA2099 did not display a double breakdown potential that would have indicated separate breakdown events for pitting and IGC. However, potentiostatic tests conducted after the onset of pitting showed that this transition can be captured based on the total charge imparted on the alloy. Samples that exhibited the most severe IGC via the immersion tests required the smaller amount of imparted charge to initiate IGC from pits. This demonstrates that the progression from pitting to IGC is marked by a distinct temporal component.