bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphate-Based Cathode Frameworks for Potassium-Ion Battery
Authors: Masese Titus , Sano Hikaru , Senoh Hiroshi , Shikano Masahiro 
Published: February 2020

Lithium-ion battery has remained as the dominant energy storage system due to its high energy density and electrochemical reversibility for the last few decades, albeit its cost and resource restrictions remain prohibitive for largescale applications. With this imminent concern, a great deal of attention has been devoted recently to the development of lower cost and more abundant alternative chemistries such as potassium-ion battery (PIB) [1].
Intensive research on a number of potentially economical potassium-containing host materials as cathode materials for PIB have been reported recently, but most of the potassium-based materials are still not able to meet industrial standards. This mainly stems from the structural instability posed during the electrochemical extraction of the large potassium ion, and also the electrochemical inactivity of some of the host materials. Therefore, at this juncture, it is necessary to identify potassium-containing host materials that can reversibly (de)insert potassium.
During the course of our investigation, we have identified K-rich phosphate-based cathode frameworks that can facilitate reversible (de)insertion of potassium-ion. In this presentation, we will briefly introduce our current research progresses on phosphate-based polyanion cathode materials (such as K
x
MP2O7 pyrophosphates (some of the phases of which are shown in Fig. 1), K
x
MPO4F fluorophosphates and K
x
MPO4 monophosphates (x=1,2)) and provide preliminary results about their electrochemical activity.

Reference
s
:

[1] A. Eftekhari, J. Power Sources,
126 (2004) 221-228.

Figure 1
Enabling Storage of Divalent Cations in Layered Vanadium Pentoxide through Controlled Interlayer Interactions
Authors: Rhodes Christopher , Niu Sibo , Cox Peyton 
Published: February 2020

Cathode materials that store divalent cations (Mg2+, Zn2+, Ca2+) can provide batteries with high capacities, lower costs, and improved safety. However obtaining cathode materials that store divalent cations and have high voltages, high capacities, and high reversbilities remains a key challenge due to the high charge densities and polarizabilities of divalent cations which results in strong interactions with the host lattice and low diffusion coefficients. Our group has investigated layered vanadium pentoxide (V2O5) as a model host material for divalent cation charge storage. Recent work by our group has shown that incorporation of poly(ethylene oxide) between the V2O5 layers alters the interlayer structure and dynamics and improves the transport and storage of divalent Mg2+.1 Based on the importance of the characterizing the structure of the interlayer region, we have used changes in Raman-active acoutic phonon modes to probe interaction of solvents and ions with the V2O5 layers. The effects of altering polymer composition within the interlayer and the electrolyte composition on the storage of divalent cations have been recently explored, and results of this work will be presented. The design of layered materials with controlled interlayer compositions provides an approach to significantly improve charge storage and transport of divalent cations.

References

Perera, S.D.; Archer, R.; Damin, C.A.; Mendoza-Cruz, R.; Rhodes, C.P. Controlling interlayer interactions in vanadium pentoxide-poly(ethylene oxide) nanocomposites for enhanced magnesium-ion charge transport and storage, Journal of Power Sources,
2017, 343, 580-591. DOI:10.1016/j.jpowsour.2017.01.052.
Fully Dense Sintering of Li Garnet Materials for All Solid State Li Ion Batteries
Authors: Zhang Lei , Gong Yunhui , Fu Zhezhen , McOwen Dennis W. , Gritton Jack E. , Godbey Griffin L. , Wachsman Eric D. 
Published: February 2020

Traditional lithium (Li)-ion batteries with liquid electrolytes suffer the problems of poor safety, limited voltage, unstable solid-electrolyte interphase formation and poor cycling performance, all of which can potentially be solved by solid-state lithium batteries (SSLiBs). The widely studied solid-state electrolytes (SSEs) includes LiSICON [1], NASICON-type Li conductors [2], perovskites [3] and garnets [4]. Garnet electrolytes are especially attractive for SSLiBs [4], since it has high total Li-ion conductivity, chemical stability with high voltage Li cathodes, chemical stability with Li anode. Aside from these good electrochemical property, developing an inexpensive and environmentally friendly thin-film preparation methods is critical for its application in SSLiBs. Such a thin film should have very high relative density, in order to prevent Li dendrite growth as well as to further improve total Li conductivity.
Li garnet materials are known to be difficult to sinter, due to Li evaporation at high temperature. Traditional die-pressing and ambient pressure sintering products garnet pellets with low relative density (<96%) and bad grain-grain connection. Currently there are only several papers reporting fully dense garnet (relative density >99%). These works require either high pressure sintering [5] or specially synthesized garnet nano powders [6]. These requirements hinder the cost-effective mass production of garnet thin film. Here in this work, we use a cost-effective tape-casting and sintering method to fabricate fully dense garnet thin films. The thinness of the thin film can be varied from as thin as 20 um to as thick as 1mm. The size of the thin film can be controlled by trimming before or after sintering. Figure 1(insert) shows the transparency of sintered garnet thin wafer. It high relative density is confirmed by SEM in figure 1.
The mechanism behind the fully dense sintering is studied. It is found that a good powder packing in the green tape and garnet particle surface modification by moisture and carbon dioxide during sintering contributes.
Reference:
[1] Xu, X. et al. Chem. Mater. 23, 3798-3804 (2011).
[2] Feng, J. K. et al. Mater. Technol. 28, 276-279 (2013).
[3] Ihlefeld, J. F. et al. Adv. Mater. 23, 5663-5667 (2011).
[4] Thangadurai, V. et al. Chem. Soc. Rev. 43, 4714-4727 (2014).
[5] Sharafi, A. et al. J. of Power Sources 302, 135-139 (2016).
[6] Yi, E. et al. J. of Power Sources 352, 156-164 (2017).
Figure 1: Fully dense garnet thin film has seamless cross section, indicating a very strong grain-grain connection. The insert shows its transparency.

Figure 1
(Invited) Enabling Global Impact of Amperometric Gas Sensors
Authors: Stetter Joseph R , Carter Michael T , Findlay Melvin W 
Published: February 2020

The enabling technology needed to catch the integrated “sensing-computing-communicating” economic engine of the early 21st century is that of environmental sensing. Human exposure to the environment [air, water, food, biologicals] is responsible for a major part of the disease burden of global populations and WHO predicts at least 6M premature deaths this year. A major route of exposure is inhalation and we all breathe the same air, and air pollution sensors that target the EPA priority pollutants of CO, NO2, Ozone, and SO2 are of increasing importance. One must measure something in order to understand and mitigate its effects and gas sensors do this job. Disruptive technologies, i.e. those that bridge the cost-performance gap, are required to field measurement capability globally. The amperometric gas sensor1,2 is an important contributor to environmental measurement capability. Recent advances have used printed electronics and semiconductor fabrication approaches to enable new commercialization opportunities. The ability to develop new sensor designs and to use advanced materials is key to setting up supply chain capability that has led to ever larger deployments of these sensors for breath/health measurements, environmental measurements, and safety. These new sensors exemplify a path to commercialization for high volume low-cost sensing with potential for high global societal impacts.
1] M. T. Carter, J. R. Stetter, M. W. Findlay and V. Patel, “Printed Amperometric Gas Sensors,” ECS Transactions, 50(12), 211-220 (2012). DOI 10.1149/0512.0211ecst.
2] Joseph R. Stetter and Jing Li, in Modern Topics in Chemical Sensing: Chapter 4, “Amperometric Gas Sensors – A Review,” Chemical Reviews, 108 (2), 2008, pp352-366.
Open Your Data
Authors: Morovati Meredith 
Published: February 2020

There has been much talk about the reproducibility and re-use crisis: scientists from various fields are losing faith in the ability to replicate previous research and many have complained of the difficulty of accessing repository data. This is occurring during a time when local, national, and international governments, which develop public policy, should be relying on the outputs of research. Yet, there is increasing noise about what truly comprises these outputs and what the value of the research really is. There is a lot of work to be done to improve the public’s trust in science, to better communicate about science to non-scientists, and to continue to build upon reputable, quality research.
Open access to all outputs of science can improve the relationship between scientists and the public, and provide opportunities for the development of new research. Shoring up published scholarly articles with open data is an essential starting place. Opening your data to publish it alongside your article will increase public confidence in research and allow others to re-use your data to pursue new directions in order to advance science.
At Dryad, we have been encouraged by recent changes in fields previously resistant to open access, which are now implementing open data practices. The Dryad repository has over 18,000 packages of data, with over 56,000 separate data files that link out to over 600 different journals. We encourage researchers from all fields to take advantage of data repositories to help make their data discoverable, freely reusable, and citable.
Soft Materials for the Lithium-Air Battery Electrode
Authors: Gould Emily Margaret , Clegg Paul S 
Published: February 2020

Lithium-air batteries provide a promising high-energy-density alternative to traditional Lithium-ion technologies, particularly for use in electric vehicles. Current Li-air batteries can be recharged, but their usefulness is limited by their short lifetime. The discharge capacity of the battery is dictated by the build-up of reaction products, which choke the cathode by blocking further reactions between the electrolyte and the air [1]. As the breakdown of these reaction products during charging is never fully complete, subsequent charging cycles reduce the discharge capacity until the battery is no longer useful.
We investigate the use of soft materials to create a Li-air cathode that brings the three key components: electrolyte, electrode and air, into close contact with each other, increasing the contact area between the components and thereby reducing the likelihood of the reaction product keeping the electrolyte and air apart from each other. We use high internal phase Pickering emulsions (Pickering HIPE) (Fig. 1) to create a ‘tricontinuous’ structure (Fig. 2), in which the conducting particles on the interface and both liquid phases are all continuous in 3D space [2]. When fully realised, this structure should allow us to create a cathode where the build-up of reaction product over repeated charge cycles has very little effect on the ability of the electrolyte to react with oxygen from the air during discharge.
[1] J. Read, J. Electrochem. Soc. 149 (2002) A1190.
[2] D. Cai, J.H.J. Thijssen, P.S. Clegg, Appl. Mater. Interfaces 6 (2014) 9214 – 9219.

Figure 1
The Design and Investigation Zinc-Air Flow Battery with Automatic Control System
Authors: Si Jingyu , Zheng Dong , Wang Gongwei , Liu Dan , Harris Joshua , Qu Deyang 
Published: February 2020

The zinc-air rechargeable battery are considered as promising candidate for application in electromobility and large-scale stationary energy storage due to its high energy density , inexpensive and safety. However, the traditional battery structure limits the capacity of zinc-air battery due to ZnO generated and slow down the electrochemical reaction after discharge. A zinc-air flow battery with automatic control system is designed and manufactured, in which the flowing KOH electrolyte carries the anode electrode - zinc powder. Experiments investigated that the zinc morphology changes during the charge and discharge.The results show that several factors affect the performance and life of the battery, include the KOH concentration ,viscosity of the fluid，depth of discharge and discharge current.

Figure 1
Effect of Frequency on Structure of Porous Alumina Formed By Indirect Oxidation
Authors: Ishino Mami , Hashimoto Hideki , Asoh Hidetaka 
Published: February 2020

In general, industrial anodization based on direct current or alternating current (AC) electrolysis can be applied to the surface treatment of large-sized and long aluminum products such as building materials. However, conventional anodization is unsuitable for the simultaneous surface treatment of a large number of small components including fine particles because direct conduction between the aluminum anode and the cathode is essential for completing the electrical circuit.
Recently, we proposed new surface treatment method, i.e., indirect oxidation and investigated the influences of electrolysis conditions such as voltage, frequency, reaction time, concentration of electrolyte, and temperature on the growth of porous oxide film [1]. In our previous study, high-purity (99.99 %) aluminum sheets with a working area of 10 cm2 and aluminum particles (99.5 %) of 3 mm diameter were used as processing objects. In the case of AC electrolysis in 8 mmol dm−3 oxalic acid at 20 °C, 60 VM, and 150 Hz, which were the base condition in this study, the current density was approximately 100 A m−2. When AC electrolysis was conducted at higher temperatures and voltages using a high concentration of oxalic acid compared with that in the base condition, a high current density in the 120–200 A m−2range was observed. Frequency had relatively small effect on current density. Even in the indirect oxidation, we observed that the relationship between the film thickness and the AC electrolysis time was approximately linear. We also used aluminum particles as a processed material to demonstrate the versatility of the indirect-oxidation-based surface treatment [1]. After indirect oxidation for 240 min under the base condition, the treated aluminum particles were immersed in dye solution. The dye was absorbed in porous alumina films over the entire surface of the aluminum particles. This result indicates that the porous films were uniformly and simultaneously formed on aluminum particles, i.e., the present technique can accommodate a wide variety of particle shapes and sizes with high throughput and low costs.
In this study, we carry out a preliminary study to investigate the effect of frequency on the structure of porous alumina formed by indirect oxidation. We mainly focus on the difference between the proposed method and conventional AC anodization. The correlation between the cell dimensions and applied voltage will be also discussed.
[1] H. Asoh, M. Ishino, H. Hashimoto, RSC Adv., 6, 90318 (2016).
Development of a Portable Nickel-Based Sensor for Hydroxyl Ion
Authors: Jafari Behnaz , Muthuvel Madhivanan , Botte Gerardine G 
Published: February 2020

The detection and measurement of hydroxyl ion (OH-) in a solution is important in many applications, namely treatments of natural water and wastewater. The quantification of OH- is normally carried out by titration method, but this method is time consuming and needs several reagents for precise analysis. Additionally, titration method cannot detect low concentration of OH- ions in solution. Alternatively, the hydroxyl ion concentration in any solution could be estimated using pH sensors. Commercial pH probes sense the proton concentration in a solution and the concentration of OH- is determined by use of the following equation.
pH= 14+log [OH-] (1)
However, these pH sensors, which are made of glass electrodes, show acidic and alkaline errors at low and high pH values, respectively [1]. Moreover, these pH meters exhibit a sluggish response, especially in alkaline media. Some reported an optical pH sensing for high pH values, but they were not portable [2].
The focus of this investigation is to develop an electrochemical sensor to detect and measure OH ion in a solution. The presence of hydroxyl ion in a solution will be detected using the electrochemical oxidation of nickel hydroxide to oxyhydroxide (eq. 2). Considering this, a simple, low-cost, easy-to-miniaturize nickel- based electrochemical sensor was designed to examine the possibility of on line electrochemical sensing of OH-. The sensor signal is based on the current produced by the following reaction that happens between the nickel electrode and the hydroxyl ions present in solution;

Ni(OH)2(s)+OH−

⇄
NiOOH(s)+H2O(l)+e−

(2)

According to this mechanism, the nickel electrode can selectively measure OH- concentration.
The analysis of the oxidation reaction was evaluated by cyclic voltammetry. Furthermore, the oxidation current at different concentrations of OH- obtained by chronoamperometry revealed a linear correlation between oxidation current and concentration in alkali range within a short response time (Figure 1). This finding suggests that the sensor can be used for OH- electrochemical quantification. However, the presence of other species in solution might affect this correlation. For instance, urea, which is widely used in fertilizers and can be found in wastewater, might affect sensor signal. It was observed when urea exists in media, urea oxidation happens and produces current which interferes with hydroxyl ion sensing.
The purpose of this work is finding of mathematical correlation between oxidation current and OH- concentration in the presence of urea.

References

Safavi, A. and H. Abdollahi (1998). "Optical sensor for high pH values." Analytica chimica acta 367(1): 167-173.

Safavi, A. and M. Bagheri (2003). "Novel optical pH sensor for high and low pH values." Sensors and Actuators B: Chemical 90(1): 143-150.

Figure 1
Field-Driven Splitting of Pure Water Based on Deep-Sub-Debye-Length Nanogap Cells
Authors: Wang Yifei , Narayanan S. R. , Wu Wei 
Published: February 2020

Hydrogen is a clean and renewable energy resource. Today, more than 90% of the industrially-produced hydrogen comes from steam reforming of natural gas, which are non-renewable and generate greenhouse gases as by-products. Water electrolysis can be a solution for a sustainable energy supply. However, only 4% of the industrial hydrogen production comes from water electrolysis, basically due to the low conversion efficiency. In this paper, we have demonstrated a novel method to achieve efficient pure water splitting based on our deep-sub-Debye-length nanogap cells, with efficiency that can be even better than 1 mol/L NaOH solution. This is the first time that even pure water can be efficiently electrolyzed.
For traditional water electrolysis in macro-system, electric field has been screened into double layer region due to high-concentration electrolyte added to increase water conductivity. The weak electric field inside bulk solution leads to slow ion transport and thus slow reaction rate. In our nanogap cells with pure water, double layer regions of cathode and anode are overlapped so that huge electric field can exist in the entire electrode gap. When the gap is small enough (Figure 1), the migration rate can be even larger than electron-transfer rate (a.k.a. chemical reaction), leading to much higher efficiency than traditional method. The high electric field enhances water ionization and ion transport. From a microscopic perspective, the conductivity of water has been enhanced “equivalently”. We have named this process “virtual breakdown mechanism”.
Figure 2 shows the schematic diagram and fabrication result of our metal-dielectric-metal sandwiched-like nanogap cells, achieved by common photolithography and low DC-bias nitride etching. The gap distance (or nitride thickness) has been down to 37 nm. I-V curve measurements based on our nanogap cells with pure DI water are shown in Figure 3. When gap distance shrank, the electrolysis current became larger due to higher electric field between two electrodes (Figure 3(a)). The threshold voltage around 1.5 V suggests that the energy efficiency is very close to 100% based on a thermoneutral potential of 1.48 V. Figure 3(b) shows currents saturated at fixed voltages when the gap distance became smaller, indicating electron-transfer limited reactions. The electrolysis of pure water and 1 mol/L NaOH solution were compared in Figure 4, both based on our nanogap cells. The different data dispersion indicates the different reaction locations for pure water and NaOH solution (Figure 4(b)). The electrolysis current from pure water was comparable to that from 1 mol/L sodium hydroxide solution, indicates more than 105-fold enhancement of equivalent conductivity of pure water.

Figure 1
Fabrication of Superhydrophobic Aluminum Surfaces By Pyrophosphoric Acid Anodizing and SAM Modification
Authors: Nakajima Daiki , Kikuchi Tatsuya , Natsui Shungo , Suzuki Ryosuke O. 
Published: February 2020

Anodizing is one of the most important surface finishing techniques for aluminum and its alloys in various industrial applications. Recently, we reported a novel anodic aluminum oxide formed via anodizing in a new electrolyte, pyrophosphoric acid solution (H4P2O7). Pyrophosphoric acid anodizing leads to the formation of numerous alumina nanofibers measuring less than 10 nm in diameter on the aluminum substrate. In the present investigation, we report the fabrication of a superhydrophobic aluminum surface modified by anodic alumina nanofibers and self-assembled monolayers (SAMs).
High-purity aluminum specimens (4N, 400 µm thick) were ultrasonically degreased and electropolished. The specimens were immersed in a concentrated pyrophosphoric acid solution (74.0 wt%, T = 273–293 K), and then were anodized at a constant voltage of 10 to 75 V to form anodic alumina nanofibers. After anodizing, the specimens were immersed in 5 mM n-alkylphosphonic acid / ethanol solutions (Ti= 293–313 K) for up to 48 h to form SAMs on the anodic alumina nanofibers. Seven types of n-alkylphosphonic acid with different chain lengths were used for SAM-modifications. The surface nanomorphology of the anodized specimens was examined by field emission scanning electron microscopy (FE-SEM). The water contact angles on the specimens were measured by an optical contact angle meter. Distilled water droplets (2–3 µL volume) were placed on the specimens, and the contact angles of the droplets were measured by a charge-coupled device (CCD) camera.
Figure 1 shows the appearances of water droplets on the a) electropolished aluminum surface and b) nanofiber-covered aluminum surface after TDPA-SAM modifications (Ti = 313 K, ti= 24 h). The contact angle greatly increased from approximately 110° to 160° by pyrophosphoric acid anodizing. Because the pyramidal alumina bundles were formed on the aluminum specimen by pyrophosphoric acid anodizing (Figure 2), the water droplet was supported by the top of the pyramidal alumina bundles with TDPA-SAMs, and a large amount of air was trapped in the spaces between the alumina bundles.
As the aluminum specimens were anodized at the low temperature of 273 K, the contact angle increased with anodizing time, and the aluminum surface exhibited a superhydrophobic behavior after anodizing for 4 h. However, the contact angle gradually decreased after that time, and the superhydrophobic angles above 150° no longer appeared after the excess anodizing process. High-aspect-ratio anodic alumina nanofibers then bent under their own weight, and the aluminum surface was completely covered by the long alumina nanofibers. The contact angle decreases by long-term anodizing at low temperature because of the loss of the air trapping space caused by the excess growth of the alumina nanofibers.

Figure 1