bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Aluminium–Air Secondary Battery with Long-Term Stability
Authors: Mori Ryohei 
Published: February 2020

A metal-air secondary cell with the abundant metal aluminium has been assembled by placing the aluminium ion conductor Al2(WO4)3 both on top of the aluminium anode and underneath the air cathode. It was possible to enhance the cell capacity and suppress the yield of by-products, by modifying the cell structure. When aqueous NaCl was used as an electrolyte, byproducts such as Al(OH)3 or Al2O3were not detected. We suggested that this is one of the reasons for obtaining secondary battery with Aluminium -Air cell. When the condition was optimized, the battery functioned for approximately one month. We found that the impedance was increased after 1 week of charge-discharge reaction. Moreover, by combining the air cathode active material and the solid electrolyte, we were able to achieve a higher cell capacity. This provides a snapshot of future Al-air secondary batteries.
Figure A Schematic Figure of Aluminium-Air Secondary Battery
Nitrogen-Doped Mesoporous Carbon Promoted Chemical Adsorption of Sulfur and Fabrication of High-Areal-Capacity Sulfur Cathode with Exceptional Cycling Stability for Lithium-Sulfur Batteries
Authors: Song Jiangxuan , Xu Terrence , Gordin Mikhail L , Wang Donghai 
Published: February 2020

Lithium-sulfur batteries have attracted increasing attention as next-generation energy storage devices for plug-in hybrid and all-electric vehicles, owing to the extremely high theoretical specific capacity (1672 mA h/g) and energy density (2600 Wh/kg) of sulfur. In addition, sulfur is low-cost, abundantly available, and eco-friendly, making Li-S batteries even more attractive.1-3

As one important component of sulfur cathodes, the carbon host plays a key role in the electrochemical performance of lithium-sulfur batteries. In this talk, mesoporous nitrogen-doped carbon (MPNC)-sulfur nanocomposite is reported as a novel cathode for advanced Li-S batteries. The nitrogen doping in the MPNC material can effectively promote chemical adsorption between sulfur atoms and oxygen functional groups on the carbon, as verified by X-ray absorption near edge structure spectroscopy, and the mechanism by which nitrogen enables this behavior is further revealed by density functional theory calculations. Based on the advantages of the porous structure and nitrogen doping, the MPNC-sulfur cathodes show excellent cycling stability (95% retention within 100 cycles) at a high current density of 0.7 mAh/cm2 with a high sulfur loading (4.2 mg S/cm2) and a sulfur content (70 wt.%). A high areal capacity (~3.3 mAh/cm2) has been demonstrated by using this novel cathode, which is crucial for the practical application of Li-S batteries. We believe that the important role of nitrogen doping promoted chemical adsorption can be extended for development of other high performance carbon-sulfur composite cathodes for Li-S batteries.

Acknowledgements

This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy under Contract No. DE-EE0005475.

References

[1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J.-M. Tarascon, Nat. Mater.
2012, 11, 19.
[2] X. Ji, L. F. Nazar, J. Mater. Chem.
2010, 20, 9821.
[3] A. Manthiram, Y. Fu, Y.-S. Su, Acc. Chem. Res.
2013, 46, 1145.
Enhanced Electrochemical Performance of Li1.17Ni0.25Mn0.58O2 Cathode Material for Lithium-Ion Battery Via Fluorine Doping and LiCrMnO4 Coating
Authors: Fan Li-Zhen , Li Hongxiao 
Published: February 2020

The layered lithium-enriched and manganese metal oxides are considered to be an attractive cathode with a high capacity of 250 mAh g-1 when charged above 4.5 V [1]. However, the irreversible loss of oxygen and undesirable dissolution of transition metal ions during charge/discharge process cause the poor cycling performance and unsatisfactory thermal stability [2]. Many strategies are applied to overcome the large irreversible capacity loss during the first cycle and the following-up capacity fading. Substitutions and surface coatings are considered to be effective ways to solve these problems [3,4].
In this study, in order to improve the electrochemical performance of Li1.17Ni0.25Mn0.58O2 cathode material, fluorine doping and LiCrMnO4 coating were applied. F- is more electronegative thus fluorine substitution may change the energy bond between the transition metal ions and the anion. The spinel LiCrMnO4 with three-dimensional Li+ diffusion channels exhibits high electronic conductivity and the Cr3+ can be oxidated to Cr6+, which provides a higher capacity. Therefore, we synthesized the fluorine doping materials by the co-precipitation method followed by a high-temperature solid-state reaction. And the LiCrMnO4 coated Li1.17Ni0.25Mn0.58O2 was prepared by a chemical deposition method followed by a high-temperature calcination.
The result reveals that irreversible loss of oxygen was reduced during the first charge and cycling performance was enhanced dramatically by fluorine doping and LiCrMnO4 coating. For fluorine substitution materials, the improvement in cycling performance was more visible at high temperature. For LiCrMnO4 coating materials, the rate capability was largely improved. The modified cathode materials exhibit excellent cycling stability.

References

[1] C.S. Johnson, N. Li; C.Lefief, M.M. Thackeray, Electrochemistry Communications, 9, 787 (2007).
[2] T.A. Arunkumar, Y. Wu, A. Manthiram, Chemistry of Materials, 19, 3067 (2007).
[3] H.X. Li, L.Z. Fan, Electrochimica Acta, 113, 407 (2013).
[4] Y.K. Sun, M.J. Lee, C.S. Yoon, J. Hassoun, K. Amine, Advanced Materials, 24, 1192 (2012).
Interactions Between LiFePO4 and Binders in Water-Based Electrode Slurries
Authors: Li Chia-Chen , Tsai Feng-Yen , Hsieh Han-Wei , Tung Chih-An 
Published: February 2020

Since 1997, lithium iron phosphate (LiFePO4) has been well-known as a potential cathode-active material for a lithium-ion battery because of its advantages of having large theoretical capacity, good cycle-life performance and better safety. Nevertheless, LiFePO4 has other disadvantages, such as its poor electrical conductivity and low diffusion for lithium ions (Li+), and thus it is common for the commercial LiFePO4 to have surface coating of conductive materials, which carbon is the most popular one, to enhance the electrical conductivity and the Li+ diffusivity.
On the other hand, for considerations of environmental consistency and low cost, the technique of fabricating electrodes based on a water-based process by using water as the mixing solvent and water compatible polymer as the binder is gaining favor and has attracted significant interest. In this investigation, the interactions between the cathode active powder, LiFePO4, and the water soluble binder, SBR and CMC binder blend, in the water-based electrode slurries were discussed. The experimental results showed that the factor of the quality of the surface carbon coating on LiFePO4 dominated the interactions between LiFePO4 and the binder. When the surface carbon coating on the active powder was less completed and showing more exposure of the inner LiFePO4, the active powder gelled with the binder significantly and caused the as-prepared water-based electrode slurry to exhibit poorer dispersion property and higher elastic flow behavior. The poorer dispersion of slurry resulted in a less-uniform distribution of compositions in the dried electrode sheets and harmed the electrochemical performance. In addition, the initial mechanism for the gelation of LiFePO4 with the binder blend had also been proposed, which was highly probable due to the chemical chelation between the exposed iron from the inner LiFePO4 and the hydroxyl group of CMC.
Soft Chemical Approach to Surface Modification of Olivine-Type LiFePO4 nanoplatelets and Their Electrochemical Properties
Authors: George Chandramohan , Paolella Andrea 
Published: February 2020

Abstract:Olivine phosphate (LiFePO4) is a remarkable cathode material1-4 for lithium ion (Li-ion) batteries due to its high theoretical capacity (Q= 170 mA h g-1), exceptional cycling stability, low cost, environmental compatibility and safety. Conventionally, on this material a carbon coating5 has widely been attempted for better Li ions kinetics and cycling (charge/discharge). Here, we report a colloidal synthesis route to prepare platelet-shaped (~10 nm thick) LiFePO4 nanocrystals (NCs). We then explore soft chemical strategies for the surface preparation of phospho-olivine platelet NCs by a treatment with either lithium fluoride (LiF) or lithium hexafluorophosphate (LiPF6). The NCs were given, for instance, a coating of LiF to yield core-shell type structures (LiFePO4 core and LiF shell) as shown in Figure.1a-b. The core-shell NCs were extensively characterized with the aid of several structural and compositional techniques (via X-ray diffraction, high-resolution electron microscopy, and electron energy loss spectroscopy), highlighting their morphological/structural features relevant for high-rate capable electrodes. We then illustrate the electrochemical properties (via cyclic voltammetry, galvanostatic charge/discharge, and impedance spectroscopy) of core-shell NCs in Li metal half-cells by comparing their carbon coated NC counter parts.

Reference:

(1) Padhi, A. K.; Nanjundaswamy, K. S.; Masquelier, C.; Okada, S.; Goodenough, J. B. J. Electrochem. Soc.
1997, 144, 1609-1613.
(2) Kang, B.; Ceder, G. Nature
2009, 458, 190-193.
(3) Gibot, P.; Casas-Cabanas, M.; Laffont, L.; Levasseur, S.; Carlach, P.; Hamelet, S.; Tarascon, J.-M.; Masquelier, C. Nat.Mat
2008, 7, 741-747.
(4) Nishimura, S.-i.; Kobayashi, G.; Ohoyama, K.; Kanno, R.; Yashima, M.; Yamada, A. Nat.Mat
2008, 7, 707-711.
(5) Wang, J.; Sun, X. Energy & Environmental Science
2012, 5, 5163-5185.

Figure.1 a) Transmission electron microscopy (TEM) image of LiFePO4NC samples a) pristine; b) after a treatment with lithium fluoride (LiF)
Probing Active Particle Assembly in Lithium-Ion Battery Electrode Processing
Authors: Liu Zhixiao , Mukherjee Partha P. 
Published: February 2020

Lithium-ion batteries (LIB) are currently considered as the primary choice for electric drive vehicles. The electrode microstructure and composition play an important role in determining the performance of the LIB. To this end, the processing of the multi-phase slurry consisting of active nanoparticles, conductive additives, binder and solvent determines the electrochemical properties and performance of the electrode. Morphology and the size of the active nanoparticles affect the LIB performance due to large active surface area, short diffusion length and fast kinetics. On the contrary, the aggregation of the active nanoparticles might have a detrimental effect. Therefore, fundamental understanding of the aggregation behavior of the active particles in the slurry is of paramount importance.
In this regard, the evaporation dynamics of the slurry is a key factor which determines the microstructural heterogeneity of the electrode. The morphology of the aggregated particles is governed by a variety of physicochemical factors such as interaction between nanoparticles, diffusion rate of the nanoparticles and evaporation rate of the solvent. In this work, we present a mesoscale modeling approach in order to investigate the influence of evaporation on active particle assembly in LIB electrode processing. Our mesoscale model is based on a coarse-grain formalism combining lattice gas and kinetic Monte Carlo methodologies. We will present a comprehensive study of the active particle aggregation behavior and resultant influence due to the (1) evaporation rate of the solvent, (2) active particle and binder interaction, and (3) active particle morphology. Figure 1 shows representative aggregation characteristics of different active particle morphology.

Reference

J. Li, B. L. Armstrong, J. Kiggans, C. Daniel and D. L. Wood, Langmuir, 28, 3783-3790 (2012).

J. Li, C. Daniel and D. L. Wood, Journal of Power Sources, 196, 2452-2460 (2011).

H. Zheng, R. Yang, G. Liu, X. Song and V. S. Battaglia, Journal of Physical Chemestry C, 116, 4875-4882 (2012).

E. Rabani, D. R. Reichman, P. L. Geissler and L.ha E. Brus, Nature, 426, 271-274 (2003).
Dynamic Behaviour of Pt Microelectrode Arrays during the Galvanostatic Oxidation of CO
Authors: Bonnefont Antoine , Crespo-Yapur Alfonso , Bozdech Sébastien , Schuster Rolf , Krischer Katharina , Savinova Elena R. 
Published: February 2020

The electroxidation of carbon monoxide has been used as a prototype reaction in fundamental electrocatalysis1. On Pt electrodes, the CO bulk electroxidation is a typical example of a bistable electrochemical system2. The bistable kinetics of the reaction stems from the interplay between the competitive Langmuir-Hinshelwood mechanism and the controlled mass transport of CO toward the electrode. On macroscopic Pt electrodes, different kinds of spatio-temporal instabilities may occur during the CO oxidation depending on the nature and the strength of coupling existing between different parts of the electrochemical system3,4.
In this presentation we will discuss the influence of the size, the interelectrode distance and the supporting electrolyte concentration on the dynamic behaviour of a Pt microelectrode array in the electrooxidation of saturated CO solutions. A custom built galvanostat allows the individual currents flowing through each of the microelectrodes to be measured. Three different kinds of cooperative behaviour could be evidenced for the first time and explained with the help of mathematical modelling. When the applied reaction current value is linearly increased, sequential activation of the microelectrodes was observed (cf. Fig.), while a complex dynamical switching regime was obtained when the current was kept constant5. At low supporting electrolyte concentration, spontaneous oscillations of the potential emerged through the coupling of individual electrodes.

Acknowledgements: Financial support from the International Center for Frontier Research in Chemistry (University of Strasbourg) and of the Labex “Chemistry of Complex Systems” is gratefully acknowledged

F. Maillard, G.Q. Lu, A. Wieckowski, U. Stimming, J. Phys. Chem. B
109, 16230, 2005

M.T.M. Koper, T.J. Schmidt, N.M. Markovic, P.N. Ross, J. Phys. Chem. B
105, 8381, 2001

R. Morschl, J. Bolten, A. Bonnefont, K. Krischer, J. Phys. Chem. C,
112, 9548, 2008

P. Bauer, A. Bonnefont, K. Krischer, ChemPhysChem, 11, 3002, 2010

D. A. Crespo-Yapur, A. Bonnefont, R. Schuster, K. Krischer, E.R. Savinova, ChemPhysChem, 14, 1117, 2013
Thin Layer Sonoelectrochemistry
Authors: Duda Chester G , Null Emily M , Leddy Johna 
Published: February 2020

Ultrasound irradiation of electrodes in a thin electrolyte layer improves heterogeneous electron transfer kinetics.1,2

A bulk fluid irradiated with ultrasonic energy of sufficient intensity generates bubbles by compression and rarefaction. On bubble collapse, extremes of temperature (T ≳ 5000 K) and pressure (P ≳ 10³ atm) are generated at the narrow interface between the fluid and bubble void3. In bulk fluids, ultrasound enhances transport and impacts homogeneous reactions, but the energy attenuates. In prior sonoelectrochemical studies (first by Coury), bulk electrolyte was irradiated with sufficient ultrasonic intensity to generate cavitation. Cavitation increased homogeneous reaction rates, transport, and turbulence. No effects on heterogeneous electron transfer were found.
In a thin layer sonoelectrochemical system (Figure 1), heterogeneous electron transfer rates increase. Thin layers have two advantages for harvesting sound energy2. Sound waves reflect back into the thin layer | air interface to retain energy. Losses from attenuation are less within thin layers. No frank cavitation is observed in thin layers.
Electrolyte fills the well to form a meniscus. Cyclic voltammograms are recorded for each Ru(bpy)3
2+ and Fe3+ with and without sonication (Figure 2). Sonication intensity can be varied. Sonication has no impact on the voltammetry for Ru(bpy)3
2+ for which electron transfer rates are rapid compared to the scan rate. Sonication does not impact transport. Rates of Fe3+ reduction increases with sonication intensity, as shown by the more rapid rise in current on sonication. Peak potentials shift because the reference is shifting. Where rates are slow, sonication increases heterogeneous electron transfer rates without significantly impact on diffusional transport1.

References and Acknowledgments: Support of the National Science Foundation and the University of Iowa is gratefully acknowledged. With thanks to Andrej Wieckowski for his explorations and contributions to understanding electrocatalysis.
[1] Chester G. Duda, Ph.D. dissertation, University of Iowa, 2012.
[2] J. Leddy, C.G. Duda, and W.J. Leddy III, Provisional U.S. Patent application, 2013.
[3] K.S. Suslick, Y. Didenko, M.M. Fang, T. Hyeon, K.J. Kolbeck, M.M. Mdleleni, and M. Wong, Acoustic Cavitation, Phil. Trans. Royal Soc. A 1999.
Electrocatalysts for Oxidating of Polyhydric and Monohydric Alcohols to Carbon Dioxide on Platinum Alloy Nanoparticles Dispersed on Noble Metal Oxides
Authors: Miecznikowski Krzysztof , Murawska Magdalena , Cox James A. 
Published: February 2020

The most important tasks in the previous century are to develop fuel cells as alternative electrochemical devices for efficient generation of energy. The low-temperature acid-type systems, such as hydrogen-oxygen polymer electrolyte membrane fuel cells and direct alcohol fuel cells are, at present, the most commonly studied devices in many laboratories world-wide [1-8]. Among organic compound fuels for anodic reactions in fuel cells, methanol has been historically most extensively studied and, more recently, alternative liquid fuels like a short chain alcohol (such as ethanol, ethylene glycol) becomes essential. It is well established that Pt is rated as the most active material for oxidation of small organic molecules in acidic media but the easily poisoning by intermediate byproduct – CO adsorb species the binary or ternary platinum-based alloys with Ru, Sn, Rh, Pb, Ir, W or Mo were proposed to enhance the electrooxidation activity towards alcohols[1-8]. The splitting of the C–C bonds is particularly difficult at ambient (low) temperatures, and the surface of catalytic platinum readily undergoes poisoning with intermediates of the ethylene glycol or ethanol oxidation. This problem may be partially solved by applying bifunctional electrocatalysts. Metals, like ruthenium, tin or rod may activate molecules of water and supply strong oxidizing agents: –OH groups and thus remove adsorbed species from platinum surface.
In order to increase the overall kinetic of electrooxidation of ethylene glycol or ethanol, we propose modification of bifunctional, metallic catalyst with metal oxide. Our concept involves adsorption onto the surface of commercial available Pt alloys nanoparticles ultra-thin layers of tungsten oxide, molybdenum oxide, zirconium oxide or iridium oxide. Presence of metals oxide (WO3, MoO3, ZrO2, IrO2) on nanoparticle have led not only to the specific interactions but also increased the catalytic surface. Introduction of noble metals oxide to Pt-based alloy nanoparticles lead to the increase of the catalytic current under voltammetric and chronoamperometric conditions.

References:
[1] M. Li, D.A. Cullen, K. Sasaki, N.S. Marinkovic, K. More, R.R. Adzic, J. Am. Chem. Soc. 135 (2013) 132
[2] H. Wang, Z. Jusys, R.J. Behm, Electrochim Acta 54 (2009) 6484
[3] R. Ojani, J.-B. Raoof, S. Fathi, Electrochimi. Acta 54 (2009) 2190
[4] A. Kowal, M.Li, M. Shao, K. Sasaki, M.B. Vukmirovic, J. Zhang, N.S. Marinkovic, P. Liu,A.I. Frenkel, R.R. Adzie, Nature Mater. 8 (2009) 325
[5] D.M. dos Anjos, F. Hahn, J.-M. Leger, K.B.Kokoh, G.Tremiliosi-Filho, J. Braz. Chem. Soc. 19 (2008) 795
[6] P. J. Barczuk, A. Lewera, K. Miecznikowski, P. J. Kulesza, J. Power Sources 195 (2010) 2507
[7] K. Miecznikowski, P.J. Kulesza, J. Power Sources 196 (2011) 2595
[8] K. Miecznikowski, J. Solid State Electrochem. 16 (2012) 2723.
TaOx-Capped Pt Nanoparticles As Active and Durable Electrocatalysts for Oxygen Reduction
Authors: Awaludin Zaenal , Moo James Guo Sheng , Okajima Takeyoshi , Ohsaka Takeo 
Published: February 2020

Here we demonstrate the formation of unique structure of TaOx-capped Pt nanoparticles on a Pt/TaOx/GC electrocatalyst (Fig. 1), where at first tantalum oxide (TaOx)and next Pt nanoparticles were electrodeposited on the glassy carbon (GC) substrate, for an oxygen reduction. The surface characterizations show that the nanoparticles of TaOx deposit homogeneously on the GC surface, forming a thin layer and surprisingly, the Pt nanoparticles do not exactly deposit on the top layer of the TaOx, i.e., Ta2O5 but inside their framework and consequently a unique assembly of the TaOx-capped Pt particles is fabricated. The analyses using XPS spectra indicate electronic interactions of TaOxwith the GC, as well as with the Pt nanoparticles. The electrochemical measurements conducted by cyclic voltammetry and rotating ring-disk electrode voltammetry reveal that the novel electrocatalyst possesses an enhanced activity for an oxygen reduction reaction, without any loss of performance even after 250,000 cycles (1,111 h) of a durability test. The plausible reasons for the remarkable activity and durability of this electrocatalyst are proposed.

Fig. 1 Schematic illustrations of (a) Pt deposited on a TaOx-modified GC surface with a TaOx framework, (b) O2 adsorption on Pt-TaOxinterface and (c) bonding formation of Ta with GC and Pt.

Acknowledgement

The present research was financially supported by Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.

References

1) Z. Awaludin, M. Suzuki, J. Masud, T. Okajima and T. Ohsaka, J. Phys. Chem. C, 115, 25557 (2011).
2) Z. Awaludin, J.-M. Sheng Moo, T. Okajima and T. Ohsaka, J. Mater. Chem. A, 1, 14754 (2013).