bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Direct Forming of Ternary Metal Fluoride Thin Film Electrode By Pulsed Laser Deposition
Authors: Zhao Yu , Liu Xiaojiang , Wei Kaiyuan , Wang Jiali , Chen Hong , Cui Yanhua 
Published: February 2020

The rechargeable Li-ion batteries are the preferred the energy storage devices for electric vehicles and portable electronics. The potential probability of leakage and combustion caused by liquid electrolyte is being the current challenge. In recent years, the concept of all-solid-state thin film batteries has been mentioned due to the requirement of safety and flexibility. However, the conventional cathodes with low special capacity (140-170 mAh g-1) limit the improvement when used the next-generation anodes Sn and Si. Specifically, the fluoride-based materials have been the interests once again due to the higher theoretical capacities (3 to 4.2 times to the commercial cathodes).[1] More recently, a new insight into the mechanisms involved in ternary metal fluorides, which is designed the possibility of solid-solution Cu0.5Fe0.5F2 to figure out the poor electronic conductivity, large polarization and cyclic instability in the binary transition-metal fluoride.[2]
In this work, we have been increasingly interested in the direct synthesis of the electro-active Cu0.5Fe0.5F2 thin films electrodes by Pulsed Laser Deposition approaches. Thin film depositions were performed from high purity LiF, Fe and Cu mixed targets (mol ratio 4:1:1) at room temperature. The initial electrochemical oxidation occurs at the first charge to form solid-solution Cu0.5Fe0.5F2 shown in the CV curve. During the delithiation process, the oxidation of Fe (Fe0 to Fe2+) occurs at 3.0 V, and further oxidation to higher valence state at 3.3 V. In the higher voltage region, the oxidation peak at 3.8 V indicated the conversion from Cu0 to Cu2+ and the forming of solid-solution Cu0.5Fe0.5F2. The lithiation process is quite different from the charge process. The CV curve clearly indicated the reduction of Fe and Cu presented overlap range from 3.7 V to 3.2 V, which may promoted the conversion to forma disordered rutile-like Cu–Fe–F phase. The final results may weaken the low hysteresis of Fe and the dissolution of Cu. The novel ternary metal fluoride is appealing for use in all-solid-state thin film Li-ion batteries.
Fig.1 The cyclic voltammetry curve of Cu0.5Fe0.5F2 at scan rate 0.1 mV/s.
Reference
[1] Donato E. Conte, Nicola Pinna, A review on the application of iron(III) fluorides as positive electrodes for secondary cells, Mater Renew Sustain Energy (2014) 3:37.
[2] Feng Wang, Sung-Wook Kim, Jason Graetz, et al. Ternary metal fluorides as high-energy cathodes with low cycling hysteresis, NATURE COMMUNICATIONS (2015) 6:6668.

Figure 1
Novel Cathode Materials for Na-Ion Batteries Composed of Nano-Rod Primary Particles in Spherical Secondary Particles
Authors: Hwang Jang-Yeon , Myung Seung-Taek , Yoon Chong seung , Kim Sung-Soo , Aurbach Doron , Sun Yang-Kook 
Published: February 2020

NIBs have attracted significant interest during the last decade due to their cost-effectiveness compared to LIBs since sodium is the 6th most abundant element in the earth’s crust to a depth of 16 km.[1-3] Additionally, NIBs undergo reactions that are similar to those of LIBs in terms of ion intercalation and solid-state diffusion, phase transitions, surface film formation, and interfacial charge transfer processes, thereby facilitating the R&D process. The development of high-energy and high-power density sodium-ion batteries is a great challenge for modern electrochemistry. The main hurdle to wide acceptance of sodium-ion batteries lies in identifying and developing suitable new electrode materials. This study presents a composition-graded cathode with average composition Na[Ni0.61Co0.12Mn0.27]O2, which exhibits excellent performance and stability. In addition to the concentration gradients of the transition metal ions, the cathode is composed of spoke-like nanorods assembled into a spherical superstructure. Individual nanorods particles also possess strong crystallographic texture with respect to the center of the spherical particle. Such morphology allows the spoke-like nanorods to assemble into a compact structure that minimizes its porosity and maximizes its mechanical strength while facilitating Na+-ion transport into the particle interior. Microcompression tests have explicitly verified the mechanical robustness of the composition-graded cathode and single particle electrochemical measurements have demonstrated the electrochemical stability during Na+-ion insertion and extraction at high rates. These structural and morphological features contribute to the delivery of high discharge capacities of 160 mAh (g oxide)-1 at 15 mA g-1 (0.1 C rate) and 130 mAh g-1 at 1500 mA g-1 (10 C rate). The work is a pronounced step forward in the development of new Na ion insertion cathodes with a concentration gradient.
References
[1] B. Scrosati, J. Hassoun, Y. K. Sun, Energy Environ. Sci. 2011, 4, 3287.
[2] V. Etacheri, R. Marom, R. Elazari, G. Salitra, D. Aurbach, Energy Environ. Sci. 2011, 4, 3243.
[3] J. Emsley, Nature’s Building Blocks, Oxford University Press, Oxford, UK 2011.
The Impact of Dead Li on Mass Transport, Voltage Profiles, Capacity, and Failure of Lithium Metal Anodes
Authors: Chen Kuan-Hung , Wood Kevin N. , Kazyak Eric , LePage William S. , Davis Andrew L. , Sanchez Adrian J. , Dasgupta Neil P. 
Published: February 2020

Currently, Li metal anode development is restricted by low Coulombic efficiency, poor cycle life, and safety concerns. Each of these challenges stem from the extreme reactivity of Li metal and the resulting undesirable interactions at the electrode/electrolyte interface. Dendrites grow during electrodeposition, consuming electrolyte, leading to dead Li formation and capacity fade, and eventually causing short circuiting. The limited knowledge of the dynamically evolving Li metal surface during extended cycling has prevented rational design of methods to mitigate these undesirable behaviors. Our recent work elucidated the correlation of galvanostatic voltage traces with morphology evolution on Li metal anodes during early cycles, providing a “window” into cells which traditionally are difficult to monitor with operando techniques [1]. The present work builds on that understanding by studying the evolution of the voltage trace shape and the dead Li layer over extended cycling in both Li-Li symmetric and full cells containing Li metal anodes (Figure 1).
In this work [2], we focus on understanding: 1) the evolution of the voltage trace from the peaking shape seen in Figure 1a to the arcing seen in Figure 1b during extended cycling in both half and full cells, 2) how the accumulation of a dead Li layer impacts mass transport, and 3) why dead Li causes capacity fade and failure of full cells containing Li metal anodes. Continuous accumulation of dead Li on the anode surface leads to the formation of a tortuous porous interphase. This layer creates larger interfacial concentration gradients which lead to large overpotentials. Based on experimental results and modeling, we provide a detailed understanding of the effects that mass transport through complex interphases has on capacity fade, voltage traces, and failure of Li metal anodes in half and full cell configurations. We demonstrate that these effects at the anode have significant impacts on full cell performance, in many cases driving failure. This result underscores the importance of understanding the dynamic morphology evolution on anode surfaces and shows that Li-Li symmetric cells are a powerful tool to study the underlying physical phenomena occurring during cycling. This study enables evaluation of methods of reducing dead Li formation and rational design of solutions for improved performance in Li-metal batteries, an important step towards making Li metal rechargeable batteries a commercial reality.

References

1. K. N. Wood, E. Kazyak, A. F. Chadwick, K.-H. Chen, J.-G. Zhang, K. Thornton, N. P. Dasgupta, ACS Cent. Sci. 2, 790 (2016).
2. K.-H. Chen, K. N. Wood, E. Kazyak, W. S. LePage, A. L. Davis, A. J. Sanchez, N. P. Dasgupta, Submitted.

Figure 1
Passivated Lithium Metal As Anode Materials for Advanced Battery Applications
Authors: Cha Eunho , Choi Wonbong 
Published: February 2020

Lithium (Li) metal electrodes are widely regarded as the promising anodes since their energy densities far exceed those of lithium-intercalated carbon anode materials. However, Li metal anodes are plagued with dendrite formation and electrolyte incompatibility that limits their lifespan and stability within any battery systems that employ them. A promising way to resolve those limitations involves the use of passivating layers to protect the surface of Li metal. This study will explore the mechanism behind the formation of Li dendrite and the passivation of the Li metal surface; it will also discover how coating Li metal with Li ion-conducting layers would effectively protect it from attacks by solvents, contamination, and active species in the electrolyte. Here, we demonstrate the facile method to protect the surface of Li metal with precise structural control. Utilizing symmetric Li-Li cell configuration, the protected Li exhibited stable cycling with minimal polarization at current density of 10 mA cm-2; it also demonstrated over 300% longer cycle life than unprotected Li metal. In addition, a full-cell system using sulfur cathode confirmed an improved capacity retention with our protected Li metal over the cell with bare Li metal for over 300 cycles. The improvement in cycle life and the suppression of lithium dendrite growths through the passivation of Li metal electrodes reveal a new direction for the advancement of Li metal anode in rechargeable batteries.
Ordered Nickel Nanomesh-Based Electrodes for High Capacity Thin-Film Lithium Ion Batteries
Authors: Zankowski Stanislaw Piotr , Vereecken Philippe M. 
Published: February 2020

The growing market of small consumer electronics, such as cell phones, smartwatches or electronic eyewear requires development of small power sources that allow for both satisfactory usage time and fast charging. Lithium-ion batteries (LIBs) are currently the systems of choice thanks to their high energy and power density. However, downscalling these batteries for small device applications still possess a big challenge. Thin-film Li-ion micro-batteries with high (dis)charging rate capability are currently available on the market, but are limited to niche applications such as chip backup power as the total output energy are still far too low for consumer device applications. Also, the manufacturing of thin film batteries requires sophisticated PVD/CVD deposition techniques. To overcome these issues, 3D architecturing of the current collector can be employed [1, 2]. This can provide a system where very thin active materials are stacked over enormously large surface area of a 3D current collector to yield a cell with both high power density (due to reduced materials thickness) and high energy density (thanks to large total volume of the active materials). To minimize the dead volume, it is imperative that the current collectors are both small and have controlled spacing. Herein, we report on the fabrication of ordered nickel nano-mesh (Fig. 1a). The nanostructured cathode is prepared by cost effective electrodeposition method, using anodized aluminum oxide (AAO) as a template for 3D interconnected nanowires. A nickel nanowire mesh with 30 nm-wide nanowires and 80 nm spacing is shown in Fig. 1a. Further, we demonstrate an accurate method to determine the effective surface area based on the electrochemical passivation of nickel. In this example, the current collector contains 71% of empty volume and has the total surface area enhancement reaching up to 97x for the 2.7 μm-long 3D nanoscaffold in Fig. 1a. Next, 25 nm of manganese dioxide was electroplated on the Ni nano-mesh current collector (Fig. 1b). The thin film cathode layer showed 82x higher current and 66x higher charge for lithium extraction in Li+/PC electrolyte as compared to 65nm planar MnO2 electrode (Fig. 1c). Additionally to electrochemical performance, we will discuss the methods we used to mitigate material incompatibility between the current collector and active material during thermal processing, needed for good crystallization of the electroactive layers. Backed with simulation and grazing-incidence XRD data, we will stress the importance of appropriate interface engineering for fabrication of reliable nickel-based nanostructured electrodes.
1. J. F. M. Oudenhoven, L. Bagetto, P. H. L. Notten, Adv. Energy Mater., 2011, 1, p. 10-33.
2. J.Vanpaemel, A. M. Abd-Elnaiem, S. De Gendt, P. Vereecken, J. Phys. Chem. C, 2015, 119 (4), pp 2105-2112

Figure 1
Transformation of Bulk Alloys to Oxide Nanowires and Their Use in a Li-ion Battery Separator
Authors: Yushin Gleb , Lei Danni , Benson James , Magasinksi Alexandre 
Published: February 2020

One dimensional (1D) nanostructures offer prospects for enhancing electrical, thermal and mechanical properties of a broad range of functional materials and composites, but their synthesis methods, such as catalyst-assisted vapor deposition, physical vapor deposition, hydrothermal synthesis, the use of sacrificial templates and others, are relatively expensive and difficult to scale. Here we demonstrate direct transformation of bulk materials into nanowires at room temperature and ambient pressure without use of catalysts, corrosive or toxic chemicals, or any external stimuli [1]. The nanowire formation proceeds via a minimization of the strain energy at the boundary of chemical transformation reaction front. We show transformation of multi-micron particles of Al alloy and Mg alloy into alkoxide nanowires of tunable dimensions, which are converted into oxide nanowires upon simple heating in air. The reported approach provides opportunities for ultra-low cost large-scale synthesis of 1D materials and membranes.
Conventional polymer separators for Li-ion batteries (LIBs) suffer from limited mechanical strength and low thermal stability, which may lead to thermal runaway and cell explosion. We produced flexible, binder-free, nonwoven fabric composed of gamma-Al2O3 nanowires, using a simple tape casting technique followed by a heat treatment in air. The overall morphology of the produced fabric is somewhat similar to that of a paper, where the cellulose fibers are replaced with stronger and stiffer Al2O3 nanowires. Owing to the fibrous nature of thus-produced free-standing films and the small diameter of the Al2O3 nanowires, they exhibit good flexibility. This is in contrast to anodized Al2O3 membranes of comparable thickness that are known to be extremely brittle and difficult to handle. Results of electrolyte wetting tests revealed significantly superior performance of Al2O3 paper compared to commonly used commercial olefin (polypropylene) separator or a cellulose fiber separator. The wetting rate of the Al2O3 separator is significantly higher owing to its polar nature, as determined by both the final wetting area and the speed of etting. Thermal stability tests demonstrate the advantage of having a flexible porous ceramic separator with operating temperatures above 800°C, which is important because of rapid heating to high temperatures that may occur in failing LIBs. In contrast, the most commonly used olefin separators typically start melting at around 120°C and oxidize at around 300°C. Finally, the strength of ceramic fibers is known to exceed that of the olefins, which should allow formation of thinner separators in automotive LIBs without sacrifice of their mechanical properties.
[1]. D Lei, J Benson, A Magasinski, G Berdichevsky, G Yushin, Transformation of bulk alloys to oxide nanowires, Science 2017, 355 (6322), 267-271.
Electrochemical Characteristics of Carbon Based Cathode Material with Molybdenum Sulfide Catalyst for Lithium Air Batteries
Authors: Kim Jiyeon , Choi Yusong , Griep Mark H. , Jang Yoonhee , Cho Janghyeon , Yoo Hyeryun 
Published: February 2020

Lithium air batteries have been recognized as one of expected next-generation military power sources, supplying power for a long time even in independent extreme environment. For the commercialization of lithium air batteries, it is essential to search for a cathode material capable of stable and efficient on electrochemical reaction at the interface with the electrolyte. Among the numerous cathode materials, such as carbon nanostructures, expensive noble material, and metal oxides, carbon-based materials are intensively researched as candidate oxygen electrode for lithium air batteries thanks to the engineering pore size and the competitive cost. However, they suffer from degradation of the carbon structure due to the formation of side products limiting the benefit of theirs oxygen reduction reaction characteristic. Recently, molybdenum sulfide(MoS2) has been received the attention as a promising catalyst to maximize oxygen reduction and evolution reactionon the carbon-based cathode. In this study, various shaped MoS2 were grown on activated carbon felt, and their electrochemical properties were compared and analyzed in order to attain a way to maximize the electrochemical reaction in electrode. We also investigated the structure and microstructure of the electrodes before and after discharge test to understand the relation between the performance of cathode materials under various synthesis condition of the catalyst for lithium air batteries.
Electrochemical Investigations on Arylsilicon and Aryltin Hydrides and Their Resulting Polymers
Authors: Biedermann Judith , Zeppek Cathrin , Torvisco Gomez Ana , Hanzu Ilie , Uhlig Frank 
Published: February 2020

Silicon and tin are interesting candidates for anode materials in Lithium ion batteries as they have some of the highest theoretical specific capacities (4200 mAh g-1 for silicon and 991 mAh g-1for tin).[1] This advantage is counteracted by a major volume expansion with subsequent contraction during lithiation and delithiation. This expansion is causing the electrode to pulverize, lose electrical contact and thus leading to a quick fade in capacity. Pulverization may be avoided when nanoparticles or nano-sized polymers are used as they are small enough to allow “active material breathing” and thus to evade a breakdown of the electrode.[2]
Organosilicon and organotin hydrides have been studied as precursors in the formation of nano-sized polymeric materials which consist of a backbone of covalently bonded metal atoms.[3] These materials feature an increased degree of electron delocalization and may therefore be interesting for the use in charge-transfer devices and Li-ion batteries.[4] We focused on the synthesis, characterization and possible application of differently substituted arylsilicon and aryltin hydrides and their respective nanoparticles and nano-sized polymers.[5]
Moreover we synthesized aryl-substituted silicon and tin hydrides of the types R3EH, R2EH2 and REH3 (R = phenyl, 1-naphthyl; E = Si, Sn) as precursor materials and characterized them using cyclic voltammetry. The precursors were then pyrolysed or polymerized, respectively, and the resulting nanoparticles were incorporated within anodes of Li-ion batteries.
Herein we report first electrochemical characterization of differently aryl-substituted silicon and tin hydrides using cyclic voltammetry methods. Additionally, these precursor materials as well as their respective nanoparticles were tested as anode materials in Li-ion half-cells.

References:

[1] a) C.K. Chan et al., Nat. Nanotechnol., 2008, 3, 31-35. b) B. Veeraraghavan, A. et al., J. Electrochem. Soc., 2002, 6, A675-A681.
[2] X. Xiao et al., Adv.
Funct. Mater., 2015, 25, 1426-1433.
[3] a) F. Choffat, P. Smith, W. Caseri, J. Mater.
Chem., 2005, 15, 1789-1792. b) K. Schittelkopf, R.C. Fischer, S. Meyer, P. Wilfling, F. Uhlig, Appl. Organomet. Chem., 2010, 24, 897-901.
[4] a) S. Adams, M. Dräger, Main Group Met. Chem., 1988, 11(3), 151-180. b) F. Choffat, P. Smith, W. Caseri, Adv. Mater, 2008, 20, 2225-2229.
[5] a) C. Zeppek, Dissertation, 2015, University of Technology Graz. b) C. Zeppek, et al., J. Organomet. Chem., 2013, 740, 41-49. c) C. Zeppek, et al. in preparation.
A Hydrocarbon Cathode for Dual-Ion Batteries
Authors: Rodríguez Pérez Ismael Antonio , Jian Zelang , Waldenmaier Pieter K. , Palmisano Joseph W. , Chandrabose Raghu Subash , Wang Xingfeng , Lerner Michael M. , Carter Rich G. , Ji Xiulei 
Published: February 2020

The paradigm of battery research has begun to shift to exploring electrode materials that are completely renewable, where such electrode materials ideally do not contain any metallic elements. We have demonstrated, for the first time, a polycyclic aromatic hydrocarbon (PAH) - crystalline and readily available coronene - exhibiting highly reversible anion-storage properties. Conventional graphite anion insertion electrodes operate at potentials > 5.0 V vs Li+/Li, requiring additives and the use of ionic liquids. The coronene electrode shows flat plateaus at 4.2 V (charge) and 4.0 V (discharge) in a standard alkyl carbonate electrolyte and delivers a reversible discharge capacity of ~ 40 mA h g-1. Ex situ characterization reveals that coronene retains its crystalline structure and chemical bonding upon PF6
- incorporation. Coronene-PF6 electrodes show impressive cycling stability: 93% capacity retention after 1600 cycles. The discovery of the reversible anion-storage properties of coronene may open new avenues toward dual-ion batteries based on PAHs as electrodes.