bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrolytic Nickel Phosphide with One-Dimensional Pore Channels
Authors: Gwon Yong-Guk , Lee Jong-Won , Shin Heon-Cheol 
Published: February 2020

Nickel phosphide has been widely studied in various applications including electrochemical catalyst, electrode for capacitor, electrode for solar cell and electrode for lithium/sodium ion battery. It is synthesized by a variety of methods including hydrothermal/solvothermal/ionothermal method, ball milling, organometallic method, phosphorization, electroplating, etc. Among them, electroplating has many advantages such as relatively simple equipment set up, easy control of electrodeposit’s composition/thickness/structure by changing plating condition, and simplification of process scale-up.
When used as electrochemical functional electrode, porous materials have great kinetic advantages such as decrease in activation overvoltage due to wide surface area and decrease in concentration overvoltage due to open mass transfer path. Well defined porous structure with esp. one-dimensional channels has been usually fabricated using porous template and the process includes at least more than three steps: the application of template, deposition, and removal of template. Apart from the relative complexity of the process, the template might be damaged in the course of experiments and is cost-prohibitive for large scale production.
This work reports nickel phosphide thin films with one-dimensional pore channels, prepared by an electrochemical deposition. In particular, it is synthesized by single step process without porous template. Figure shows typical porous structure of the electrolytic nickel phosphide. Based on plating mechanism and observation of deposit’s growth pattern over time, it is suggested that the porous structure is formed by complex factors such as competitive reaction between deposit formation and gas generation, and island-type deposit growth. It was proved that the porous structure can be well controlled by plating conditions such as current density and pH.
The electrochemical properties of the porous nickel phosphide thin films were investigated as an electrode for functional electrochemical devices (i.e., batteries and capacitors). The redox processes and interfacial resistance along with energy storage characteristics were analyzed through various electrochemical techniques.
In this presentation, the pore formation mechanism of the electrolytic nickel phosphide and the factors governing porous structure will be proposed. In addition, the feasibility of its use as an energy storage materials will be discussed.

Figure 1
Selective Conversion to Formic Acid from CO2 By Electrochemical Reduction over Cuxsny Intermetallic Compounds
Authors: Ochiai Hiroya , Gunji Takao , Matsumoto Futoshi 
Published: February 2020

Electrochemical reduction of CO2 is of high value because it can reduce the amount of greenhouse gas in the atmosphere. However, since CO2 is a very stable compound due to the strength of C=O bonds, it is extremely hard to turn CO2 into other compounds. In addition, potassium bicarbonate, which is commonly used as electrolyte for electrochemical CO2 reduction, decomposes on most catalysts to form hydrogen (H2) by reduction of proton (H+) at the potentials required to reduce CO2. Therefore, it is important to use a catalyst that prevents the H2 evolution reaction.
Widely studied electrocatalysts for electrochemical CO2 reduction are novel metals, such as Pd, Ag and Au, because they can efficiently reduce the CO2 to CO in high selectivity with low overpotentials. Although non-precious metals such as Zn, Sn and/or Bi are promising as the electrocatalysis for the CO2 reduction, using them require high overpotentials and also result in the formation of H2.
Sn electrode is a viable candidate for CO2 reduction catalyst because it shows relatively high selectivity towards formation of formate. However, Sn demonstrates a function towards H2 evolution reaction. In order to overcome this problem, we have attempted alloying of Sn with Cu which can modify the electronic state and crystal structure of active site of Sn. In this study, we successfully prepared CuxSny intermetallic nanoparticles supported on carbon, which not only significantly improved the electrocatalytic activity of CO2 reduction, but also showed a highly selective conversion to formic acid. The structural difference of surface between Sn and SnCu, which corresponds to the high activity and selectivity towards CO2 reduction reaction, is also discussed in this poster session.
Co-Doping Effects of Iron and Copper into Carbon Nanotubes on Oxygen Reduction Reaction Activity
Authors: Fujibayashi Natsuki , Kato Masaru , Yasuda Satoshi , Yagi Ichizo 
Published: February 2020

Polymer electrolyte fuel cells (PEFCs), which can efficiently convert hydrogen into electricity without using fossil fuels, are a promising energy conversion device. In cathodes of PEFCs, oxygen reduction reaction (ORR) occurs and its low reaction rate limits the performance of PEFCs. Therefore, the electrocatalysts for the ORR are necessary. Currently, platinum-based electrocatalysts for the ORR are mainly used because platinum shows the highest electrocatalytic activity in the metals. Since platinum metal is expensive and rare, to make the fuel cells more widely used, there is a need to develop non-platinum-based electrocatalysts based on iron and/or copper with high ORR activity1,2,3,4).
A cytochrome c oxidase (CcO), which is a metalloenzyme and contains iron and copper metal ions, catalyzes the ORR efficiently to produce ATP in mitochondria5) and its activity is higher than that of artificial platinum-based electrocatalysts6). Metalloenzymes are not practical because of their stability and difficulty in isolation and purification.
In this study, we developed iron-copper co-doped carbon electrocatalysts (Fe/Cu/CNT) synthesized from the mixtures of Fe and/or Cu complexes and carbon nanotubes in heat treatment inspired by the CcO’s active center. Synthetic conditions of Fe : Cu metal ratios and heating temperatures were optimized. The ORR activity was evaluated by hydrodynamic voltammetry using a rotating ring disk electrode in 0.05 M sulfuric acid aqueous solution saturated with oxygen. The activity of Fe/Cu/CNT electrocatalyst was compared with two electrocatalysts: iron-doped carbon electrocatalyst (Fe/CNT) and copper-doped carbon electrocatalyst (Cu/CNT). The Fe/Cu/CNT catalyst showed more positive onset potential for the ORR than Fe/CNT and Cu/CNT, indicating that Fe/Cu/CNT is more active and the coexistence of iron and copper in CNTs contributes to the improvement of ORR activity.
References

Kato et al., Chem. Lett., 45, 1213–1215 (2016).

Kato et al., Appl. Energy Mater., 1, 2358–2364 (2018).

Chung et al., Science,
357, 479–484 (2017).

Yasuda et al., Adv. Funct. Mater., 26, 738–744 (2016).

Sakamoto et al., PNAS, 108, 12271–12276 (2011).

Kjaergaard et al., Inorg. Chem. 49, 3567–3572 (2010).
In-situ EIS to Investigate Influence of Conductive Additive Addition Rate on Charge Transfer Resistance of Lithium Ion Batteries
Authors: Kojima Fumiya , Hoshi Yoshinao , Shitanda Isao , Itagaki Masayuki 
Published: February 2020

In order to develop the lithium ion batteries (LIBs) with higher capacity, it is important to select the suitable compositions of conductive additives for the reduction of the internal resistance of the positive and negative electrodes of LIBs1). In the present study, the influence of the conductive additive addition rate on the internal resistance of the positive electrode was investigated by in-situ EIS 2). This method enables us to measure impedance spectra of the positive electrode, negative electrode and cell of LIBs simultaneously without stopping the measurement of charge/discharge curve.
The positive electrode was fabricated by screen printing. The mixture of the slurry containing LiCoO2 powder, carbon nanowire (CNW), polyvinylidene fluoride and N-methylpyrrolidone were screen-printed on the aluminum foil. In this case, the compositions of CNW were 8 to 30 wt % as the conductive additive. In order to investigate the effect of CNW on electrochemical properties of LIB, an acetylene black (AB) was used as the conductive additives instead of the CNW. The spherical natural graphite on cupper foil was used as the negative electrode and a lithium wire was used as the reference electrode (RE). All measurements were carried out by the three-electrode cell (Toyo system co. ltd.) at room temperature (25℃) in an argon atmosphere.
In the impedance spectrum of the positive electrode measured by the in-situ EIS, three loops were observed on the Nyquist plane. Since the diameter of the loop in the low frequency range was decreased with the increase of the states of charge (SOC), it is considered that this loop is related to the time constant of charge transfer resistance R
ct and electric double layer capacitance 2). The values of R
ct of the positive electrode estimated from the diameter of the loop in the low frequency range were decreased with increasing with the addition rate of the conductive additive. The effect of the addition rate of the conductive additive of the positive electrode on the values of R
ct at each SOC were discussed.
References:
1) F.Y. Su, C. H. You, Y. B. He, W. Lv, W. Cui, F. M. Jin, B. H. Li, Q. H. Yang and F.Y. Kang, J. Mater. Chem., 20, 9644-9650 (2010).
2) M. Itagaki, K. Honda, Y. Hoshi, I. Shitanda, J. Electroanal.
Chem., 737, 78­-84 (2015).
Development of Highly Ion-Conductive Layered Double Hydroxide As Electrolyte for Solid-State Alkaline Fuel Cells
Authors: Taniguchi Yusuke , Yamada Hirohisa , Maeda Kazuki , Sakai Chikako , Katakura Katsumi 
Published: February 2020

Layered Double Hydroxides (LDHs) have been studied by many researchers for their interesting properties such as ion exchangers, adsorbents, polymer stabilizer, catalyst, and so on. LDHs are well known as anionic clays include anion species and water molecules in the interlayer which consist of positively charged metal hydroxide layers. It was reported that some types of LDHs prepared by co-precipitated method have high OH- conductivity and high performance as electrolyte for Alkaline Fuel Cells (AFCs)1). On the other hand, it is necessary to develop a newly industrial LDH synthesis method which enables to synthesize the particle and the composition uniformly. Homogeneous precipitation method with Urea is one of the general and promising LDH synthesis method to prepare the uniform LDH, in which pH controlled by hydrolysis of Urea. However only CO3
2- type LDHs are formed by the method. Therefore, we developed the new type synthesis named “decarboxylation method” that enables to synthesize LDH with high crystallinity and selective anion species in inner layer from precursor compounds in one pot.
Prepared samples were measured by ICP and XRD to determine the compositions and structures, respectively, and observed by FE-SEM. Several intercalated anion (CO3
2-, SO4
2-, NO3
-, and Cl-) type M(II) (Zn2+, Co2+, and Ni2+)-Al(III)LDHs were successfully prepared by the decarboxylation method with highly crystallinity and uniform particle size distribution. The ionic conductivities on prepared LDHs were measured by the AC impedance method. Each NO3
- type LDH has remarkably higher ionic conductivity than another type LDHs. The NO3
- type Zn-Al LDH has highest conductivity than another cation type LDHs, and its conductivity is via 16 mS/cm at 80 oC under R.H.80%.
1) Y. Furukawa, K. Tadanaga, A. Hayashi, and M. Tatsumisago, Solid State Ionics,
192, 185-187 (2011).
A Tale of Two Environments: Being the Only Woman in the Room Doesn’t Have to be a Negative Experience
Authors: Ayers Katherine E. 
Published: February 2020

While there is increasing focus on issues of diversity and discrimination in universities, it can be harder to get data from industry. In this talk, I will relate some of my personal experiences and observations over my career in industry, ranging from environments that were not optimal for women to thrive in, to being part of an inclusive environment with strong and supportive mentors. Blatant discrimination has become much less common, but subtle biases can still impede women’s progress, and impact their own sense of self-worth, such that they can hold themselves back as well. Typical examples include women speaking up in meetings and not being acknowledged, then having a male peer say the same thing and be rewarded, or supervisors always looking to a male employee for answers, even when his female peer is an expert. It can be easy to doubt yourself when this happens over and over, and question whether changing jobs will make any difference. As a result, studies show that a much higher percentage of women than men leave STEM fields entirely. However, being willing to take the risk and try again can pay huge dividends.
In many panels I have participated in on women in science, men have also asked how they can help support women. Suggestions include: Be cognizant of how women are being engaged in meetings and work environments and point out unequal treatment. When a female co-worker excels at something or brings up a great idea, be the one to point out that she did. When an opportunity comes up that a female co-worker would be really good at, encourage her to apply. While I have been the only woman at many senior level meetings, I don’t feel isolated when I have peers that value my input and work collaboratively.
An Odyssey through Lithium-Ion Battery Development, the Two Body Problem and Surviving Academia in a Foreign Language
Authors: Schougaard Steen Brian 
Published: February 2020

In part due to the two body problem originating from a two Ph.D. couple desiring academic careers, this talk will cover the trials and trepidations related to a (successful) career in a foreign – not English speaking institution. Issues related to funding, career building, laboratory dynamics and the science of developing next generation lithium-ion batteries will be highlighted.
The target audience is young researchers that desire the extra challenge of “making it” in a foreign environment, while remaining in a relationship and staying relatively sane, as well as anyone who is committed to improving diversity in electrochemistry.
Advanced Semiconductor-Electrocatalyst Systems for Photoelectrochemical Hydrogen Production in Microgravity Environments
Authors: Brinkert Katharina 
Published: February 2020

Efficient artificial photosynthesis systems follow the concept of the Z-scheme of natural photosynthesis. They are realized as catalyst- and surface-functionalized photovoltaic tandem devices [1,2] enabling photoelectrochemical water oxidation while simultaneously recycling CO2 and generating hydrogen as a solar fuel for storable renewable energy. The successful implementation of an efficient photoelectrochemical (PEC) water splitting cell is not only a highly desirable approach to solving the energy challenge on earth: an effective air revitalization system generating a constant flux of O2 while simultaneously recycling CO2 and providing a sustainable fuel supply is also essential for the International Space Station and long-term space missions, where a regular resupply from earth is not possible.
We demonstrate in a series of drop tower experiments that efficient direct hydrogen production can be realized photoelectrochemically in microgravity environment, providing an alternative route to existing life support technologies for space travel [3]. The photoelectrochemical cell consists of an integrated catalyst-functionalized semiconductor system that generates hydrogen with current densities >15mAcm-2 in the absence of buoyancy. Conditions are described adverting the resulting formation of ion transport blocking froth layers on the photoelectrodes. The current limiting factors were overcome by controlling the micro- and nanotopography of the electrocatalyst using shadow nanosphere lithography [4]. We show that shadow nanosphere lithography can be used as a prosperous tool to obtain desired catalyst nanostructures of high fidelity on a light-absorbing semiconductor surface with tunable optical properties showing significant advantages for photoelectrochemical hydrogen production in microgravity and terrestrial applications [5].

References

[1] Young J. L., Steiner M. A., Döscher H., France R. M., Turner J. A., Deutsch T. G. (2017). “Direct solar-to-hydrogen conversion via inverted metamorphic multi-junction semiconductor architectures”, Nat. Energ.
2. (17028).
[2] Cheng W. H., Richter M. H., May M. M., Ohlmann J., Lackner D., Dimroth F., Hannappel T., Atwater H. A., Lewerenz H. J (2018). “Monolithic Photoelectrochemical Device for 19% Direct Water Splitting”, ACS Energy Lett.
3, 8, 1795-1800.
[3] Brinkert K., Richter M. H., Akay Ö., Liedtke J., Gierisig M., Fountaine K. T., Lewerenz H. J. (2018). Efficient Solar Hydrogen Production in Microgravity Environment. Nat. Commun.
9 (2527).
[4] Patoka P., Giersig M. (2011). “Self-assembly of latex particles for the creation of nanostructures with tunable plasmonic properties”, J. Mater.
Chem.
21, 16783-16796.
[5] Brinkert K., Richter M. H., Akay Ö., Giersig M., Fountaine K. T., Lewerenz H.-J. (2018). “Advancing semiconductor-electrocatalyst systems: application of surface transformation films and nanosphere lithography”, Faraday Discuss. 208, 523-535.
A High-Energy-Density and Long-Life Chalcogenide-Iodide Redox Flow Battery
Authors: Li Zhejun , Lu Yi-Chun 
Published: February 2020

Redox flow batteries (RFBs) are promising technologies for application in both grid-scale power station and electric vehicles owing to their flexible architecture decoupling power and energy1, 2. The development of aqueous RFBs has been strongly hindered by low energy density, limited cell voltage and rapid capacity fading, which largely can be attributed to the poor solubility of electroactive species, small voltage window of water and limited ion selectivity capability of membrane1. Chalcogenide has been reported to have high solubility in nonaqueous environment with high charge/discharge reversibility, which makes it a promising anolyte candidate for aqueous RFBs3-5. However, it is found that these sulfur-based RFBs have been challenged by their poor cycle life and rate capability, owing to the strong shuttle phenomenon and slow kinetics of polysulfide reaction3, 5. It is critical to manipulate the competition between diffusion/crossover and the rate of electrochemical reaction of soluble active species in order to improve cycle life of RFBs.
In this work, we exploited a composite-based ion-exchange membrane for chalcogenide-iodide RFBs. We evaluated the effectiveness of various membrane compositions and will discuss the role of each component in the membrane toward long-life operation. We applied UV-vis spectroscopy to probe the active reaction species involved in the RFB operation. In addition, we will discuss the use of complexing agent for polysulfide species to increase the energy density (molar electron number per molecule) and energy efficiency (higher reaction kinetics) of the chalcogenide-iodide RFBs.
Acknowledgement:
This work was fully supported by a grant from the Research Grant Council of the Hong Kong Special Administrative Region, China under NSFC/RGC Joint Research Scheme 2018/19 Project No. N_CUHK435/18.
Reference:

W. Wang, Q. Luo, B. Li, X. Wei, L. Li and Z. Yang, Adv. Funct. Mater., 23, 970-986 (2013).

F. Pan and Q. Wang, Molecules, 20, 20499-20517 (2015).

S. Yun, S. H. Park, J. S. Yeon, J. Park, M. Jana, J. Suk and H. S. Park, Adv. Funct. Mater., 1707593 (2018).

N. Li, Z. Weng, Y. Wang, F. Li, H.-M. Cheng and H. Zhou, Energy Environ. Sci., 7, 3307-3312 (2014).

Z. Li, G. Weng, Q. Zou, G. Cong and Y.-C. Lu, Nano energy, 30, 283-292 (2016).
Aging Study of the Lithium Metal Batteries Using Nickel-Rich Cathode Materials
Authors: Badillo Jimenez Juan Pablo , Börner Markus , Beuse Thomas , Schappacher Falko , Winter Martin 
Published: February 2020

The lithium ion battery (LIB) is the most important energy storage device since the last decade, which is due to the excellent characteristics of operating voltage, cycle life and its low self-discharge rate. [1]. Nevertheless lithium ion batteries are gradually reaching their theoretical limits, in terms of energy density, power density as wells as durability and cost [2, 3]. Because electronic portables devices as wells as electric vehicles demand high energy density batteries, the development of next generation batteries has strongly increased during the recent years. To achieve high energy densities in these systems, lithium is used as anode due to its outstanding properties regarding the theoretical specific capacity (3860 mAh g-1) and the negative electrochemical potential (-3.04V vs. standard hydrogen electrode). However, the rapid degradation as well as safety issues related to the morphological transformation from dense to porous lithium metal affect the cell performance [4-7].
In this work, we studied the influence of the test conditions on the morphological changes on the lithium anode and cycle life of the lithium metal battery (LMB). For this, we carried out ex-situ measurements for a better understanding of the morphological changes of the anode material. Depending on the applied conditions, the cycle life of the system was improved with lower capacity fading and at the same time the morphological changes of the lithium anode were suppressed.
In the second part, the investigation is focused into the degradation of different nickel-rich cathode materials. Most of the studies on lithium metal batteries are based on the degradation of the lithium anode, however, here; it could be shown that aging of the cathode material is an important part for the development of the LMB. The results showed a good cycle performance over 300 cycles with relative low capacity fading of the LMB with all the implemented cathodes. The electrochemical data analysis showed the degradation of the cathode material, controlling at the same time the morphological changes of the lithium anode.

Literature

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Figure 1