bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Thermoelectric Coefficient of Prussian Blue Analogues
Authors: Fukuzumi Yuya , Kobayashi Wataru , Niwa Hideharu , Moritomo Yutaka 
Published: February 2020

The electrochemical thermoelectric coefficient (S
EC = dV/dT, where V and T are the redox potential and temperature, respectively) is a significant material parameter, which enables thermal power generation with use of thermocell during heat cycles. Recently, the thermal power generation has been demonstrated using two kinds of Prussian blue analogues (PBAs) with different S
EC
[1]. To realize the thermocell with high efficiency, the S
EC values are systematically investigated for three PBAs, Na
x
Co[Fe(CN)6]0.71 (NCF71), Na
x
Co[Fe(CN)6]0.90 (NCF90), and Na
x
Mn[Fe(CN)6]0.83 (NMF83) against sodium concentration (x).
The figure shows the discharge curve (the black solid line) and S
EC against x (the orange closed circles) of NCF90. The discharge curve shows two plateaus regions (plateaus II and III) around 3.8 and 3.2 V. Plateau II is ascribed to the reaction [2]: Co3+[Fe3+(CN)6]0.6[Fe2+(CN)6]0.3+ 0.6Na+ → Na0.6Co3+[Fe2+(CN)6]0.9. Plateau III is ascribed to the reaction[2]: Na0.6Co3+[Fe2+(CN)6]0.9 + Na+ → Na1.6Co2+[Fe2+(CN)6]0.9. Thus the plateau II (the plateau III) on the discharge curve means reduction process of Fe3+ (Co3+)[2]. On the other hand, S
EC distributes around 0.4 mV K-1 (1.4 mV K-1) in the plateau II (the plateau III). Therefore, it is suggested that S
EC significantly depend on the redox site. In the presentation, we also report S
EC of NCF71 and NMF83 and discuss the material and redox site dependences of S
EC by using ionic model (point charge model) approach.
[1] T. Shibata, Y. Fukuzumi, W. Kobayashi, Y. Moritomo, submitted.
[2] R. L. Magnússon, W. Kobayashi, M. Takachi Y. Moritomo, AIP adv. 7 045002 (2017).

Figure 1
Yolk-Shell Structured Sb@C Anodes for High Energy Na-Ion Batteries
Authors: Song Junhua , Yan Pengfei , Luo Langli , Wang Chongmin , Lin Yuehe , Li Xiaolin 
Published: February 2020

Na-ion batteries (NIBs), as the analogy to Li-ion batteries, are regarded as one of the most promising technologies to satisfy the request on both performance and cost for grid energy storage. To further boost the specific energy and power of the state-of-the-art NIB, an anode material with comparable capacity and long-term stability to graphite anodes in lithium-ion batteries (LIBs) is highly desired. Antimony (Sb) has a theoretical capacity of 660 mAh g−1 upon full sodiation and hence holds great promises as the good anode candidate for high energy Na-ion batteries.
A low cost and scalable approach of annealing poly-dopamine (PDA) coated Sb2O3 was used to prepare the yolk-shell structured Sb@C nanocomposite for high performance Na-ion battery anodes. Controlled reduction reaction and selective removal of Sb2O3 by acid etching generate the promised void space to accommodate the volume expansion of Sb while carbonization of the PDA forms highly conductive carbon shells. The by-product from the etching, SbCl3, can be reused rendering the approach a scalable and economic one. The yolk-shell Sb@C anode exhibits excellent electrochemical performance in terms of specific capacity, rate capability and cycling stability. The reversible phase transformation of crystalline Sb during charge/discharge was observed by the in-situ XRD for the first time. The designed composite with Sb: C of 70: 30 delivers almost theoretical capacity of ~ 554 mAh g−1. The specific capacity is still ~ 315 mhA g−1 at the current density of 5 A g−1 (10 C rate). The O3-Na0.9[Cu0.22Fe0.30Mn0.48]O2 (cathode)-Sb@C-hard carbon (anode) full-cell shows high specific energy of ~ 130 Wh kg−1 (based on the total weight of cathode and anode) in the voltage range of 2.0–4.0 V in NaClO4 electrolyte with 10 wt% fluoroethylene carbonate (FEC) additive. It is ~ 1.5 times energy of the full-cells with similar design using hard carbon anodes (~ 84 Wh kg−1).

Figure 1
Cycling Performance of Sodium Ion Battery Comprised of Naphthalene Based Polyimide/MWCNT Composite Cathode and Highly Porous Polyvinylidene Fluoride Separator Membrane
Authors: Manuel James , Ramasamy Ramaraja P. 
Published: February 2020

Large scale energy storage is the key to incorporating renewable resources like wind, tidal, and solar into power grid allowing us to use these resources when power is needed. High cost and less availability of lithium metal hampers the usage of the present reigning energy storage champion-lithium ion batteries (LIBs) in large scale applications. Sodium ion batteries (NIBs) could provide an alternative solution for expensive LIBs because sodium is the 4th most abundant metal on earth and has worldwide availability. The energy density is not crucial issue in the field of large scale energy storage systems and therefore low cost of NIBs surpasses the lower gravimetric and volumetric densities of NIBs than LIBs1. Currently electrochemists are involved in the hunting for highly efficient electrode materials for NIBs. Advantages like stability, insolubility in electrolytes, and a high theoretical capacity with its two available anhydride groups attached to the stable aromatic ring makes the polyimide (PI) as a preeminent candidate for cathode active material for NIBs2.
In this work we have synthesized naphthalene tetracarboxylic dianhydride (NTCDA) based polyimide/multi-walled carbon nanotube (PI/MWCNT) composite for use as a cathode active material for high performance NIB. PI/MWCNT composite was synthesized in a two-step process and was characterized using field emission scanning electron microscopy (FE-SEM) and Fourier Transform infrared spectroscopy (FTIR). Three-dimensional network of MWCNT inside and between PI particles enhances the conductivity and thereby electrochemical performance of PI/MWCNT composite electrode. A highly porous polyvinylidene fluoride (PVdF) membrane made by phase inversion method was used as the separator for NIB. The electrochemical performance of cells based on PI/MWCNT composite cathode with PVdF membrane delivered high capacity and cycle capability at different C-rates.

Fig. 1: SEM image of cross section of PVdF membrane.

References:

1. Ong, S. P.; Chevrier, V. L.; Hautier, G.; Jain, A.; Moore, C.; Kim, S.; Ma, X.; Ceder, G., Voltage, stability and diffusion barrier differences between sodium-ion and lithiuim-ion intercalation materials. Energy & Environmental Science
201
1, 4, 3680-3688.
2. Mazur, S.; Lugg, P. S.; Yarnitzky, C., Electrochemistry of aromatic polyimides. Journal of Electrochemistry (1987), 134, 346-353.

Figure 1
Theoretical Understanding and Experimental Suppression of the Capacity Degradation of Ni-Rich Layered Oxide Cathode Materials for Li Ion Battery
Authors: Kong Fantai , Liang Chaoping , Longo Roberto C , Zheng Yongping , Wheeler Virginia D. , Wollmershauser James , Feigelson Boris , Cho Kyeongjae 
Published: February 2020

Ni-rich layered oxides LiNi1-x
M
x
O2 (x = 0.1-0.2, M = Ni, Co, Mn, Al, etc.) have been widely viewed as the next generation cathode materials for Li ion battery, due to their high capacities (>200 Ah/kg), high energy densities (>800 Wh/kg), high ionic diffusivity (10-8 cm2/s) and high electronic conductivity (10-1 S/cm).[1] However, these oxides have faced a big challenge of severe structural instability. Depending on different particle sizes, morphologies and doping/alloying treatments, the materials normally have 40%-80% capacity degradation after ~100 charging/discharging cycles. Based on traditional understanding of layered oxides, three main hypothesis[2-3] have been proposed within battery research community: 1) surface phase transition and interaction, 2) bulk phase transformation, and 3) mechanical degradation involving inter-grain crack formation. However, it is still not clear which mechanism is playing the dominating role during degradation of Ni-rich layered oxides. Unfortunately, due to lack of systematic theoretical study on the thermodynamic and kinetic process of degradation upon delithiation, the fundamental driving forces and the relative kinetics are poorly understood. Therefore, in this work, we report our recent results from atomic scale Density Functional Theory modeling, which carefully simulates the processes relevant to degradation of Ni-rich layered oxides, from which we have delivered significant theoretical understanding of the above mentioned three hypothesis.
Furthermore, based on these theoretical understandings, we have performed experiments to validate the proposed surface modifications through both conventional wet chemistry coating and advanced particle Atomic Layer Deposition (ALD). These computational and experimental combined studies could provide us deeper understanding of degradation of Ni-rich layered oxides, and shed light on the future direction towards stabilized high energy cathode materials.
[1] J. Xu, F. Lin, M. M. Doeff, W. Tong, J. Mater. Chem. A, 2017, 5, 874
[2] M. D. Radin, Y. S. Meng, A. Van der Ven, etc., Adv. Energy Mater. 2017, 1602888
[3] W. Li, B. Song, A. Manthiram, Chem. Soc. Rev., 2017, 46, 3006
Modeling the Effect of Aging on the Performance Decay of a Lithium-Ion Battery during Charge-Discharge Cycling
Authors: Cho Jaeseong , Lee Myoung Kyou , Koo Boram , Shin Chee Burm 
Published: February 2020

The lithium-ion battery (LIB) is the primary choice for electric vehicle (EV) applications due to its high energy density, high voltage and low self-discharge rate. The service life of LIB for EV applications is generally limited by aging and the aging of LIB depends strongly on the thermal history during usage. In order to secure the resilience of LIB for the EV applications, it is essential to develop a modelling tool that has a capability to account for the relationship between the aging and thermal history of LIB to design an optimal battery management system.
In this work, a modeling is performed to predict the effect of aging on the performance decay an LIB as well as variation of thermal behaviours during cycling for a long time. The validation of the modeling approach is provided through the comparison of the modeling results for a 14.6Ah LIB cell from LG Chem. with the experimental measurement data obtained from the cycling tests. The cycling tests were performed under the protocol of the constant-current charge and the constant-current discharge.
In Fig. 1, the discharge capacities measured at every thousand cycles for discharge rates of 1C, 3C, and 5C were compared with those calculated from the modeling. The modeling results and the experimental data on the capacity fade of the aged LIB cell are in good agreement in Fig. 1. Fig. 2 shows the temperature distributions from the experimental IR image and the modeling for the LIB at an environmental temperature of 25 ˚C at times of 240, 480, and 636 s during the CC discharge with a rate of 5C after 1000 cycles. Model predictions reasonably reproduce the experimental data.

Figure 1
CVD MoS2 Transistor Circuit for Organic Light-Emitting Diode
Authors: Kwon Hyeokjae , Lee Han Sol , Im Seongil 
Published: February 2020

Like graphene, 2D semiconductors are formed by mechanical exfoliation using scotch tapes in general. Among many nanosheet materials, molybdenum disulfide (MoS2) semiconductor has been the most extensively studied, since it has displayed excellent carrier mobility, high on/off current ratio, and good subthreshold swing in a field-effect transistor (FET) form with n-type conduction. However, fabricating 2D MoS2 by the mechanical exfoliation limits the length scale only to a few micrometers. So, one of the remaining important issues is how to fabricate such 2D MoS2 in a large scale, which would open the gate toward more practical applications enabling photolithographic device/circuit patterning. Several research groups have thus recognized the issue, studying and reporting on the chemical vapor deposition (CVD) of large scale MoS2 2D sheets. Yet, only a few studies of full photolithographic patterning and integration for polygrain 2D MoS2-based devices in large scale on glass have been reported.
We demonstrate CVD-grown large scale polygrain MoS2 nanosheets and related field effect transistor (FET) circuits, which were patterned and integrated by photolithography on glass substrate. CVD MoS2 nanosheet transistors are applied to demonstrate their possibility as switching/driving elements for the pixel of organic light-emitting diode (OLED) display. The maximum mobility of MoS2 FETs either as switch or as driver was ~1 and 7 cm2/Vs at VD=1 V

Figure 1
Polypeptides As Complexing Units
Authors: Solladie Nathalie 
Published: February 2020

One of our research field concerns porphyrin-functionalized a-polypeptides to control the spatial organization of the chromophores and enable exciton migration through the pool of porphyrins to mimic the light harvesting antennae of the photosynthetic system.1

In the photosynthetic system, the solar energy is collected by pigment molecules attached to the light harvesting complexes, in which the chlorophylls are held in a parallel orientation by fairly short a-helical polypeptides. When a photon hits one of the chlorophylls, the absorbed energy spreads extremely rapidly to the others until the reaction center is reached.1 Succeeding in organizing the porphyrins in a similar way as nature does should provide information about the relation existing between the orientation of the chlorophylls and the efficiency of nature in transferring an excited state over a very long distance and with minimal loss of energy.
The right-handed 310 helical conformation adopted by our poly-L-lysine functionalized with eight porphyrins induces an overlap of the chromophores (studies realized in collaboration with Prof. T. Keiderling, University of Chicago, US), which thus present sufficient electronic coupling to promote a good exciton migration within the molecular wire.
The properties of our peptides with pendant porphyrins were studied extensively in collaboration with with Professor S. Fukuzumi (Univeristy of Osaka, Japan) and applications were found as organic photovoltaic cells,2 multiple photosynthetic reaction centers3 and for the successful purification of Single-Walled Carbon Nanotubes.4

Acknowledgements

This work was supported by the CNRS and the French Ministry of Research.

References

W. Kühlbrandt, Nature
1995, 374, 497-498.

T. Hasobe, K. Saito, P. V. Kamat, V. Troiani, H. Qiu, N. Solladié, K. S. Kim, J. K. Park, D. Kim, F. D'Souza, S. Fukuzumi, J. Mater.
Chem.
2007, 39, 4160-4170.

S. Fukuzumi, K. Saito, K. Ohkubo, V. Troiani, H. Qiu, S. Gadde, F. D’Souza and N. Solladié, Phys.
Chem. Chem. Phys.
2011, 13, 17019-17022.

Kenji Saito, Vincent Troiani, Hongjin Qiu, Nathalie Solladié, Takao Sakata, Hirotaro Mori, Mitsuo Ohama, Shunichi Fukuzumi, J. Phys. Chem. C
2007, 111, 1194-1199.

Figure 1
Fabrication of SU-8 Based Three-Dimensional Carbon Microelectrodes Array As Anode Material for Lithium Ion Batteries
Authors: Suresh Mamidi , Kakunuri Manohar , Sharma Chandra Shekhar 
Published: February 2020

Introduction

The development of three-dimensional (3D) microelectrodes is essential not only to achieve high energy and power density Li-ion batteries but also to minimize the ohmic losses and therefore achieve better performance. In this work, we used SU-8, an epoxy based negative photoresist which yields hard carbon upon pyrolysis for fabricating 3D micro-post arrays as electrodes1. The SU-8 derived 3D carbon microelectrodes on Silicon (Si) wafer has been reported earlier in literature, however the capacity values were quite moderate2. This is due to the high resistance offered by Si wafer used as a collector. Our group reported recently that the gravimetric reversible capacity value may be almost doubled when SU-8 derived carbon film was prepared on stainless steel (SS) wafer as compared to Si wafer. This inspires us further to fabricate 3D carbon microelectrodes array on SS wafer and to test their electrochemical performance.
Experimental
SU-8 2100 was spin coated on cleaned SS wafer. Prebaking, UV exposure and post-exposure baking conditions were optimized to prepare SU-8 based 3D micropillars with an aspect ratio of 2 (50µm height and 25µm diameter), and 35µm spacing using photolithography. As-obtained micropillars were then pyrolysed under the controlled N2 atmosphere in a tubular furnace at 900ºC to obtain 3D carbon microelectrode arrays. As-fabricated, 3D carbon microelectrode array on SS wafer was used as working electrode while lithium foil as the counter electrode in Swagelok half-cell assembly to test their electrochemical performance using potentiostat/galvanostat.

Results and discussions

Figure 1a shows the optical profiler image of SU-8 derived 3D carbon microelectrode array. It was observed that the 3D cylindrical morphology was retained after carbonization however there was nearly 50% shrinkage. As-obtained 3D carbon microelectrode arrays were found to have 26µm height, 16µm diameter, and 40µm spacing. Galvanostatic charge-discharge experiments were carried out at 37.2 mA/g current density. These 3D carbon microelectrode arrays have shown a high discharge capacity (~600 mAh/g) even after 165 continuous charge/discharge cycles (Figure 1b). This is significantly higher than the reported values for 3D carbon micropillars on Si wafer2. A comparison of volumetric capacity was also made. Further detailed characterization of these carbon microelectrodes and their electrochemical performance with cyclic voltammetry results will be presented during the conference.

References:

Kakunuri, M. & Sharma, C. S. Photoresist Derived Carbon Films as High Capacity Anodes for Lithium Ion Battery. ECS Trans.
61, 37–43 (2014).

Teixidor, G. T., Zaouk, R. B., Park, B. Y. & Madou, M. J. Fabrication and characterization of three-dimensional carbon electrodes for lithium-ion batteries. J. Power Sources
183, 730–740 (2008).

Figure 1
Enhanced Bioelectrocatalytic Reduction of O2 By Laccase Using an Ethanol-Induced Immobilization on Nitrogen-Rich Carbon Nanofibers
Authors: Cho EunByul , Holmberg Sunshine , Ghazinejad Maziar , Rostro Magdalena , Parra Roberto , Madou Marc J 
Published: February 2020

The use of carbon nanomaterials as potential alternative materials suitable for energy storage and for applications in metal-free catalytical fuel cells have been studied significantly. This has led to the development of various enzymatic catalysts for bioelectrocatalytic oxygen reduction reaction (ORR) on carbon nanomaterials to enhance their electrochemical properties. The selection of catalytic enzymes and electrodes, and immobilization of enzymes to allow direct electron transfer (DET) are highly desirable for achieving effective enzymatic biofuel cells (BFCs).
Laccases, multicopper oxidoreductases, are suitable for such needs in biofuel cells due to its thermostability, substrates-versatility, and high redox potential that can employ direct electron transfer, thus, improving bioelectrocatalytic reactions. Recent studies have revealed that electrocatalysis with laccase can be enhanced by selectively orienting laccase active sites near the electrode, promoting fast and direct electron transfer to allow high current density reached at high redox potential.
Here, we present a simple technique of immobilizing laccase on our nitrogen-rich graphitic carbon nanofibers by regulating the enzyme orientation with ethanol treatment. The effect of ethanol on laccase for electrocatalysis has been investigated electrochemically on nitrogen-rich graphitic carbon nanofibers synthesized via a stress-induced pyrolysis. Its performance is also compared to that of glass-like carbon nanofibers, glassy carbon and Toray carbon papers. Our findings show a cost-effective and time-efficient fabrication approach for enhancing bioelectrocatalytic oxygen reduction of laccase using ethanol treatment and the incorporated electrocatalytic effect of graphitic and pyridinic nitrogen groups in pyrolytic carbon nanofibers.
The Effect of Grain Size on the Corrosion Behavior of Mg-RE Alloy ZE10A
Authors: Shrestha Nikunja , Kersten Bethany R , Zillinger James , Utgikar Vivek , Raja Krishnan S. 
Published: February 2020

Mg-RE alloy Electron717 (ZE10A, UNS M11600) has a nominal composition of 1.2wt % Zn, 0.25wt% Zr, <0.5%Zr, 0.007wt%Mn, 0.004wt %Fe,0.001wt%Ni and balanced Mg. Zirconium addition acts as a grain refiner, so it helps increase castability, mechanical properties and provide better corrosion resistance.1
ZE10A alloy may have better corrosion resistance than unalloyed Mg. Even though formation of Zn2Zr3 type precipitates has been suggested in this type of alloy, heat treatment in the temperature range of 200 – 300 ºC for different time periods did not show significant increase in the hardness. Therefore, this alloy is considered not age hardenable. Brady et.al showed that ZE10A alloy forms a dual layered passive film with inner layer rich in MgO and outer layer of Mg(OH)2.2 The formation of two layers make it more resistant to corrosion. This presentation will focus on the corrosion behavior of the ZE10A alloy as a function of grain size, and the hydrogen evolution behavior in different electrolytes.
The alloy was investigated in three different heat-treated condition such as (1) As received (grain size of 7.90 µm), (2) Solution treated at 525oC for 8 hours (grain size of 26.24 µm) and (3) Solution treated at 525oC for 24 hours (grain size of 41.37 µm). Anodic and cathodic polarizations were carried out in three different electrolytes (pH unadjusted) such as:
1) 0.6M NaCl
2) 0.5M NaNO3

3) 0.1 M Na2SO4

Table 1.0 Summary of anodic and cathodic polarization results of ZE10A alloy in different heat-treated conditions and in three different solutions.
Table 1 summarizes the polarization results. The polarization resistance decreased with increase in the grain size in all the electrolytes, in general. The corrosion current density increased with the grain size. Higher corrosion current densities were observed in the Na2SO4 solution than that in the other two electrolytes. The anodic Tafel slopes are found to be higher in the Na2SO4 solution than in NaCl and NaNO3, whereas, cathodic Tafel slopes did not reveal a clear trend of variation either with the grain size or type of electrolyte. The presentation will focus on how the microstructures in terms of grain size, and secondary phase distribution influence the corrosion behavior of the ZE10A alloy based on the experimental results and literature review.
[1] N.T. Kirkland et.al JOM, 2011, 63(6)28-40
[2] M.P.Brady et. al Scripta Met. 106(2015) 38-41

Figure 1