bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Thermal Nanoimprinting Process for the Fabrication of Tailored-Triboelectric Nanogenerator
Authors: Yoo Donghyeon , Choi Dongwhi , Kim Dong Sung 
Published: February 2020

Recently, triboelectric nanogenerator (TENG), working based on triboelectric effect and electrical induction, emerge as one kind of energy harvesting technology. The TENG is mainly composed of dielectric layer where frictional contact occurs and conductive layer where current flows. Because of the characteristic of triboelectric effect, strategies to make efficient TENG are focused on material selection and effective contact area increment. Given materials, micro/nanostructure fabrication corresponds to the latter strategy. Several fabrication methods are already reported such as surface etching with nanoparticle and surface replication, but they require high fabrication cost. Furthermore, they need additional process such as integration micro/nanotophographical layer with conductive layer, resulting in a multistep fabrication. The fabrication environment hinders high productivity and commercialization of TENG.
In this study, we used thermal nanoimprinting to fabricate a transparent and flexible TENG named a Pattern Assisted TriboElectric Replicable Nanogenerator (PATERN). From the method, we can achieve nanostructure replication and integration with conductive layer simultaneously, which are two essential steps to fabricate high performance TENG. The fabrication cycle was within 6 min. The PATERN has maximum transmittance about 88% at the 850-1600 nm range, and bending radius about 3.2 mm. From modifying the shape of electrode layer, we can also achieve a bi-directional mechanical energy harvesting ability, which is essential for efficiently harvest the energy from complex real mechanical motions. Given that TENG can be cost-effectively fabricated by utilizing conventionally available films (less than $1) with fast fabrication process, we believed the technology lead a new concept of disposable TENG and its accompanying application, such as hybrid energy harvester or biomechanical energy harvester.

Figure 1
Electrochemical UV Sensor Using Carbon Quantum Dot/Graphene Semiconductor
Authors: Wang Yuxuan , Myers Morgan , Staser John A. 
Published: February 2020

Skin cancer is a pressing public health issue, especially in rural communities like Appalachia.1 Increasing public awareness about the risk of exposure to UV radiation and its correlation to the prevalence of skin cancer could change public behavior in a positive way. Such behavioral changes could ultimately reduce the rate of skin cancer and directly address public health.
Wearable UV sensors that provide easy-to-understand, accurate and reproducible results is one possible avenue to impact public awareness and behavior. Our group has developed nitrogen-doped carbon quantum dot/graphene (N-CQD/graphene) photoactive electrodes that generate a sustained photocurrent upon illumination with UV radiation.

The sensor consists of the N-CQD/graphene photoactive electrode and a nonphotoactive graphene electrode sandwiching a Nafion® polymer electrolyte membrane. Critically, the magnitude of the photocurrent response is proportional to the intensity of the incident UV radiation.2

Incorporating the photoactive electrode into a sensor using a solid polymer electrode could lead to flexible UV sensors ideal for wearable applications by the general public.
This presentation will detail synthesis and evaluation procedures for the electrochemical UV sensor. We will discuss current limitations that must be overcome before such a wearable device can be made technically feasible.
[1]. Appalachia Community Cancer Network. Addressing the Cancer Burden in Appalachian Communities, 2010. Retrieved from http://www.accnweb.com/pages/cancer-burden-app.pdf
[2]. Y. Wang, M. Myers and J.A. Staser, J. Electrochem. Soc., 164: H3001-H3007 (2018).
(Invited) Electrical Energy Generation Via Reversible Chemical Doping on Carbon Nanotube Fibers – a Wearable All-Carbon Voltage Generator
Authors: Liu Albert Tianxiang , Kunai Yuichiro , Liu Pingwei , Kaplan Amir , Cottrill Anton , Strano Michael S 
Published: February 2020

Chemically modified carbon nanotube fibers enable unique power sources driven entirely by a chemical potential gradient. Electrical current (11.9 μA mg−1) and potential (525 mV) are reversibly produced by localized acetonitrile doping under ambient conditions. An inverse length-scaling of the maximum power as L−1.03 that creates specific powers as large as 30.0 kW kg−1 highlights the potential for microscale energy generation. We demonstrate that this Asymmetric Chemical Doping (ACD) electricity induction method can be scaled using a printing/patterning technique for the carbon nanotube fiber generators. This allows us to develop a conformable carbon based voltage generator that can be grafted onto human skin in a facile manner.
Reference: Advanced Materials, 2016, 28, 9752-9757
Slurry Model for Understanding Fabrication of Li-Ion Battery Electrodes
Authors: Nikpour Mojdeh , Cordon Joshua , Wheeler Dean R. , Mazzeo Brian 
Published: February 2020

Battery performance in part relies on the microstructure of each electrode, which is determined by the electrode composition and fabrication process. Accurate and direct experimental measurement of electrode properties is challenging due to the thickness of electrode films (30-80 µm), yet those properties are needed to generate cell-level performance models and to improve manufacturing processes. Therefore, a realistic microstructure prediction model is necessary for designing and manufacturing better batteries. In our model, we consider all the fabrication steps that would determine the final electrode microstructure in a predictive fashion.
We are not aware of any prior slurry models that can simulate the multi-phase nature of the Li-ion electrode fabrication process. We have been developing a series of particle-based microstructure models using LAMMPS (a particle simulator) [1]. In the most recent model, the governing equations are based on the smooth particle hydrodynamics (SPH) method. The major benefit of SPH is its Lagrangian formulation of the Navier-Stokes equations that would eliminate the need for mesh in our simulation.
We propose a model that imitates the microstructure of a commercial electrode like Toda NMC 523 in terms of composition and active material particle shapes (based on SEM images). We consider each component as a clump of a certain number of particles with a certain size; we also assign density, smoothing length and viscosity as the factors that would affect the interaction between particles.
In this presentation we will discuss the new model, including validation efforts. We use fluid viscosity, interactions between particles, and interfacial behavior as some indicators of our model accuracy. We also will show how the model predicts coating behavior in a slot die coating process. Our hope is to also use the model later to predict behavior during the drying and calendering steps, leading to the final microstructure of the film. The completed model will be used to explore the factors that create such microstructure and how we can control them to manufacture better batteries.

Figure 1: Simulation box model of slurry containing Toda 523; carbon domain is red, active material is yellow, and solvent particles are blue.
Reference

[1]
M. Forouzan et al., J. Power Sources 312, 172-183 (2016).

Figure 1
A Binder-Free Snowflake Grown Microcube Prussian Blue Particles As Possible Electrode for Supercapacitor and Sodium Ion Battery Applications
Authors: vijaya Sankar Kalimuthu , Seo Youngho , Jun Seong Chan 
Published: February 2020

For constructing high energy storage devices, designing of electrode materials with high performance is a great challenge for the past decades. So far, various materials were employed as suitable electrode for supercapacitor and sodium ion batteries. Such as nickel, cobalt, tin, vanadium, ferrite and bismuth oxides/hydroxides/sulfides/phosphide/nitrides, conducting polymers, 2D-materials and its composites are subjected as possible electrode materials. However, limited reports are available for anode materials for energy storage applications. Recently, the Prussian Blue has received more attention because of its wide applications in various fields. Herein, a binder-free Prussian blue is synthesized by a facile hydrothermal method and employed as anode, for the first time to our knowledge. The x-ray diffraction and Fourier transform infrared spectroscopy results reveals that the single and phase purity of the sample. The microscopic image reveals that the snowflake grows from microcupe, which more favor for large energy storage. The Prussian Blue exhibited the maximum specific capacitance (166 mF cm-2 at 5 mV s-1) and good lifespan over 5000 cycles in 1MKOH electrolyte. Likewise, the Prussian Blue tested as anode for sodium ion battery and delivered the specific capacity of 250 mAh g-1 (first cycle) at a current of 1 mA. Our results suggest the novel design of materials holds a great promise for potential application toward next-generation energy storage.
Figs. 1 represent the FESEM images of Prussian Blue at different magnifications.

Figure 1
Tailoring the Kinetics of Sn Anodes for High Power Energy Storage Devices
Authors: Cui Jiang , Yao Shanshan , Kim Jang-Kyo 
Published: February 2020

Alkali ion batteries, such as Li-ion batteries (LIBs) and Na-ion batteries (NIBs), have recently drawn much attention due to their high energy densities, high Coulombic efficiencies and low self-discharge rates, making them useful in electronics, electric vehicles and grid-scale energy storage. One of the major obstacles to widespread applications of these rechargeable batteries, however, is their poor electrochemical performance under high power densities. The obstacle is attributed to the sluggish electrochemical kinetics, including slow diffusion rate of alkali ions in solid electrodes, low electrical conductivity and undesired phase transformation. Sn-based anodes having both high gravimetric and volumetric capacities are considered a promising candidate for next-generation LIBs and NIBs, but they also face the same challenge. Herein, we demonstrate that the electrochemical kinetics of Sn-based anodes, such as SnO2 and SnS2, can be largely enhanced by amorphization, doping of heteroatoms and facilitating the pseudocapacitive charge storage. The mechanistic insight of the enhanced kinetics is revealed by combining the electrochemical measurements with in situ TEM characterization and the first-principles calculations. Thanks to the new findings, we successfully fabricate Sb-doped SnO2/graphene-CNT aerogel anodes which deliver a high areal capacity of 2.6 mAh cm-2 at a high current density of 8 mA cm-2 in LIBs. The Na hybrid capacitor consisting of an activated carbon cathode and a SnS2/graphene-CNT aerogel anode is further developed for applications requiring high power densities and low costs. The as-assembled hybrid capacitor delivers an exceptional energy density of 26.9 Wh kg−1 at an ultrahigh power density of 6053 W kg−1. The implications of these discoveries for both fundamental understanding and practical applications are discussed.
References:
[1] J. Cui, S. Yao, J.K. Kim, Energy Storage Mater. 7 (2017) 64-114.
[2] J. Cui, Z.L. Xu, S. Yao, J. Huang, J.Q. Huang, S. Abouali, M. Akbari Garakani, X. Ning, J.K. Kim, J. Mater. Chem. A 4 (2016) 10964–10973.
[3] J. Cui, S. Yao, J.Q. Huang, L. Qin, W.G. Chong, Z. Sadighi, J. Huang, Z. Wang, J.K. Kim, Energy Storage Mater. 9 (2017) 85-95.
[4] J. Cui, S. Yao, Z. Lu, J.Q. Huang, W.G. Chong, F. Ciucci, J.K. Kim, Adv. Energy Mater. (2017) 201702488.
Flame Made Nanopowder Processing Results in Low Temperature Sintering of β'’-Al2O3 Thin Films (50 µm) with TiO2 and ZrO2 Addition
Authors: Laine Richard , Yi Eongyu , Temeche Eleni 
Published: February 2020

β’’-Al2O3 is used commercially as a Na+ conducting ceramic electrolyte for its high ionic conductivity (0.2-0.3 S cm-1 at 300°C) and low materials’ costs. However, for batteries using β'’-Al2O3, about half of the cell resistance arises from the electrolyte itself because traditionally processed electrolyte materials are 1-2 mm thick. One can anticipate dramatic drops in cell resistance at <100 µm. However, traditional high sintering temperatures of 1600 °C/0-4 h cause rapid and excessive Na2O loss driving formation of the β- rather than β'’-Al2O3 phase lowering ionic conductivities limiting final properties. Known methods of β'’-Al2O3 sintering commonly involve covering the sample with the same powder to reduce Na2O loss. The quality (phase, particle size, particle morphology, etc.) of the starting powder has been shown to have a strong effect on β’’-Al2O3 sintering behavior.
In line with our latest success of using flame made nanopowders (NPs) to minimize the external energy input for sintering Li7La3Zr2O12, Li+ conducting ceramic electrolyte known for its difficulty in sintering, we show that the same can be achieved for β’’-Al2O3. In this study, β’’-Al2O3, TiO2 and ZrO2 NPs were produced by liquid-feed flame spray pyrolysis (LF-FSP). The NPs were then processed to green films (80 µm) by tape casting such that β'’-Al2O3 with 0, 1, 2, and 3 wt.% of TiO2 addition is produced. TiO2 was selected to aid sintering as Al3+ vacancies generated by Ti4+
doping promote the sintering process. Furthermore, low melting point (1050-1150 °C) Na2O-TiO­2 line compounds form inducing liquid phase sintering.
As expected, superior densification of β'’-Al2O3 films occurs with increasing TiO2 wt. %. Near full densities are reached at ≥ 1360 °C/2 h with 2 and 3 wt. % added TiO2. However β’’-Al2O3 content reaches only ~65 wt.% and the orientation of the c-axis is perpendicular to the film surface per XRD. The preferred conduction plane is perpendicular to the c-axis reducing net conductivity. Also, the large grain sizes seen in the 2 and 3 wt. % TiO2 samples suggest liquid phase sintering. To perturb grain reorientation during liquid phase sintering, and also pin grain boundaries to reduce grain growth, we introduced 10 wt. % of ZrO2 with 2 and 3 wt.% TiO2. The added ZrO2 may also reduce Na2O loss rate by reducing surface exposure of β’’-Al2O3.
Sintering of the aforementioned samples both reduces final grain sizes and degrees of c-axis orientation. Furthermore, nearly full densities could be accessed at 1320 °C/2 h with 85 wt.% β'’-Al2O3. Ionic conductivities obtained equal those reported by others. Our approach is scalable and economical for mass producing β'’-Al2O3 films. Furthermore, the combination of nanopowders with selected additives allows sintering β'’-Al2O3 at 1320 °C, the lowest ever reported.
Work supported on NSF subcontract from Na4B to University of Michigan and by a give from Mercedes-Daimler.
Development of Transparent Secondary Zinc Air Batteries with Extreme Mechanical Robustness
Authors: Kwon Oh Chan , Hwang Ho Jung , Ji Yunseong , Jeon Oksung , Kim Jeong Pil , Lee Chan Min , Shul Yong Gun 
Published: February 2020

The dynamics and trends of the portable electronics market drives researches to develop energy sources with newer properties. The advancement of augmented reality has opened windows of opportunities for optical modification of batteries to be implemented in transparent devices similar to the heads-up display. While realization of products is still in its infant ages, it is without question that technology will pursue such directions. Zinc air batteries hold numerous strongholds that advertise itself as the post lithium ion technology. The system’s abundant energy density along with advantages such as cheaper materials cost and environmentally friendliness has prompted this study to further investigate its potentials.
In this presented work, we report the first ever fabrication of transparent secondary zinc air batteries. The system utilizes a commercial transparent stainless-steel mesh as the current collectors. Owning to the unique structure of the battery, the cell exhibits extreme mechanical versatility as free bending without tariffing the cell performance is possible. The average transparency in the visible light region was recorded at 48.8%. Electrochemical analysis revealed stable galvanostatic discharge-charge cycle operations, exceeding more than 100 turnovers for every bended angle. Electrochemical Impedance Spectroscopy results observed minimal deviation between the conformational states.
This research’s potential lies in the simple technique to achieve optical properties in power sources that can be extended to further areas. Mass scale production is also opportunistic as the process utilized are favorable enough for large productions.
Initial Formation of the Solid Electrolyte Interphase in Li Metal Batteries
Authors: Kasse Robert M , Geise Natalie R , Toney Michael F 
Published: February 2020

Advances in energy storage technology beyond traditional lithium ion battery (LIB) materials are necessary to meet future energy demands. These include the growing number of electric vehicles and grid storage applications. Next generation technologies such as Li-S and Li-O2 batteries employ metallic lithium as an anode material due to its high specific capacity and low electrochemical potential. However, lithium presents a number of challenges including uncontrolled electrolyte consumption, formation of dendrites and “dead” lithium, as well as formation of a non-passivating and inhomogeneous solid electrolyte interphase (SEI). The composition, morphology, and electrical properties of the SEI are critical to overall battery performance and lifetime. Nevertheless, there exists a lack of fundamental understanding regarding its initial formation and how these early processes relate to cell performance after many cycles.
In this work, we use soft X-ray absorption spectroscopy (XAS) and electrochemical measurements to study the initial stages of SEI formation in Li-Cu cells as a function of cycling parameters in different electrolytes. Using these methods, the potential and rate dependence of electrolyte decomposition and the corresponding SEI formation is illuminated and the effects on initial Li metal plating are investigated. Further, the continued evolution of the SEI during the first several plating and stripping half cycles is studied. Controlled formation of the SEI during the first several half cycles may lead to large effects on the long-term composition and structure of the SEI and determine overall battery performance and cycle life.
DFT Analysis of N2 Electroreduction Kinetics at the Electrode-Electrolyte Interface
Authors: Janik Michael John , Rostamikia Gholamreza , Li Yawei , Maheshwari Sharad 
Published: February 2020

Active and selective nitrogen electroreduction is challenged by the need to activate the inert N-N triple bond and the competition with hydrogen evolution. Density functional theory has been used to argue that metal surfaces will inherently be non-selective and offer large overpotentials, due to scaling relationships that correlate all intermediate binding energies with a metal’s N adsorption energy [1-2]. In this talk, we will apply DFT to investigate the elementary kinetics of N2 reduction on metal and metal-oxide surfaces. We will consider elementary kinetics across late transition metal surfaces to examine how the inclusion of kinetic consideration alters the trade-offs between the ability to activate N2 and to reduce eventual NHx species to ammonia. We then consider how electrolyte composition, including proton-transfer co-catalysts, alter the kinetics of reduction of surface bound intermediates on metal surfaces. We apply ab initio thermodynamics to determine the stability of oxide surfaces under N2 reductions, then examine the elementary steps on the (partial reduced) oxide surfaces. We will present possible mechanistic avenues to using metal oxides and electrolyte/surface additives to alter the activity and selectivity of N2 reduction electrocatalysts.
[1] Skulason et al. Physical Chemistry Chemical Physics, 2012, 14, 1235.
[2] Montoya et al. ChemSusChem 2015, 8, 2180-2186.
(Invited) A Surface Enhanced Infrared Absorption Spectroscopy Study on the Nitrogen Electrochemical Reduction Reaction on Gold Surfaces
Authors: Yao Yao , Zhu Shangqian , Wang Haijiang , Li Hui , Shao Minhua 
Published: February 2020

Ammonia has received much attention as a potential energy storage medium and an alternative fuel for vehicles, in addition to its use as a kind of fertilizer. Recent studies showed that ammonia could be produced by N2 and H2O through an electrochemical method, with the advantages of zero CO2 emission and energy saving compared with the “Haber-Bosch” process.1-2 However, as the theoretical potentials of hydrogen evolution reaction (HER) and nitrogen reduction reaction (NRR) are very close, H2 is the dominant product due to the much fast reaction kinetics of the former. For this reason, the experimental studies on NRR mechanism are rather rare. In this study, the NRR mechanism on Au surfaces was first studied by surface enhanced infrared absorption spectroscopy (SEIRAS) technique. Au was selected as its excellent NRR activity but low HER activity.3-4

An Au nanofilm deposited on the Si prism by a chemical deposition method was used as the working electrode. Its cyclic voltammograms (CV) in a N2 saturated KOH solution is shown in Figure 1a. In the 1st segment (cathodic scan, solid red line), the reduction current resulting from the HER and NRR appeared at 0 V and arose sharply starting at -0.1 V. Figure 1b is the corresponding FTIR spectra of the 1st segment in Figure 1a. The bands at 3300 cm-1 and 1645 cm-1 attribute to the O-H stretching and H-O-H bending of water molecules. Those bands intensity increase significantly as a result of the change in the adsorption configuration of water molecules upon decreasing the potential. The bands at 1450 cm-1, 1298 cm-1 and 1109 cm-1 attribute to the H-N-H bending, -NH2 wagging and N-N stretching of adsorbed N2Hy species, respectively. Those bands started to appear at potentials below 0 V and increased with potential decreasing. This result indicates that the nitrogen reduction reaction on Au surfaces follows an associative mechanism, and the N≡N bonds in N2 tend to break simultaneously with the hydrogen addition. Similar spectroscopic studies on Pt surfaces will be also discussed.
Figure 1. a) Cyclic voltammograms of an Au film electrode deposited on the Si prism in a N2-saturated 0.1M KOH aqueous solution; potential scan rate: 2.5 mV s-1. b) FTIR spectra during the 1st segment from 0.4 V to -0.5 V on the Au film electrode in a N2-saturaed 0.1 M KOH solution. The reference spectrum was taken at 0.4 V.

References

Lan, R.; Irvine, J. T. S.; Tao, S. W. Sci Rep
2013,
3, 1145..

Renner, J. N., Greenlee, L. F., Ayres, K. E., Herring, A. M. The Electrochemical Society Interface
2015,
24, 7, 51-57.

Bao, D.; Zhang, Q.; Meng, F. L.; Zhong, H. X.; Shi, M. M.; Zhang, Y.; Yan, J. M.; Jiang, Q.; Zhang, X. B. Adv. Mater.
2017,
29, 1604799.

Shi, M. M.; Bao, D.; Wulan, B. R.; Li, Y. H.; Zhang, Y. F.; Yan, J. M.; Jiang, Q. Adv. Mater.
2017,
29, 1606550.

Figure 1