bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational Examination of Orientation-Dependent Morphological Evolution during the Electrodeposition and Electrodissolution of Magnesium
Authors: DeWitt Stephen , Thornton Katsuyo 
Published: February 2020

Magnesium batteries provide a promising alternative to Li-ion batteries due to their potential for lower cost, higher energy density, and safer, dendrite-free operation. Magnesium is the eighth most abundant element in the earth’s crust, and replacing the relatively rarer lithium could enable reduced battery costs. Furthermore, metallic Mg anodes have a significantly higher theoretical specific volumetric capacity (3833 mAh/cm3) than either Li-graphite anodes (760 mAh/cm3) or metallic Li anodes (2046 mAh/cm3). Finally, metallic Li anodes often form dendrites during cycling that can short the battery, leading to thermal runaway. In contrast, metallic Mg anodes form compact faceted films during cycling with minimal risk of dendrite formation.
Understanding the evolution of the metallic Mg anode is a critical factor in the development of a practical, high-performance Mg-metal battery. In this presentation, we describe a new model for simulating the evolution of the faceted Mg deposits, both during deposition and during dissolution. We apply the standard dilute solution equations to describe the evolution of the concentration and the distribution of the potential in the electrolyte. The evolution of the magnesium deposit is described using a phase-field approach with conserved dynamics and a source term along the deposit surface to account for deposition and dissolution. The deposition/dissolution rate is calculated using Butler-Volmer kinetics. Reaction rate constants that depend on the local orientation of the surface of the deposit allow for the simulation of facet development and evolution. We present two possible models relating the orientation dependence of the forward rate constant to that of the backward rate constant.
We apply this model to a range of experimentally relevant scenarios to improve the understanding of the mechanisms governing the film morphology during cycling. We investigate the effect on the deposit morphology of changing the applied current density during growth, finding that the deposits become narrower and taller as the applied current increases. We present predictions of the characteristic deposit morphology during dissolution for the two orientation-dependent reaction rate models. These predictions provide a diagnostic criterion for future experiments to determine which of the two models is correct. Finally, we present a series of two-deposit simulations to illustrate the types of interactions between deposits and how those interactions influence the film morphology.
Acknowledgement:
This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Effect of Internal Stress and Oxygen Non-Stoichiometry on Phase Transformations in Battery Cathodes
Authors: Sheth Jay , Liu Dawei , Sheldon Brian W. 
Published: February 2020

In battery electrode materials, phase transformations during Li insertion and removal generally lead to volume changes. These can lead to localized stresses that contribute directly to the degradation of the active material. We have employed thin V2O5 films as model cathode materials, to systematically investigate relationships between stress, phase transformations, and degradation. To directly probe the impact of stress, processing conditions were controlled to vary the initial stress state over a wide range (while maintaining similar grain structures). All of these investigations employed precise in situ stress measurements, along with x-ray diffraction and detailed electron microscopy studies. The experimental data was then compared to a thermodynamic model that takes into account the impact of initial and lithiation induced stresses. The experiments and analysis reveal that stress in the electrode can significantly alter the voltage plateaus associated with two phase equillibria.
LiCoPO4 Based High Energy Li-Ion Cathodes
Authors: Allen Jan L. , Allen Joshua L. , Delp Samuel A. , Wolfenstine Jeff , Jow T. Richard 
Published: February 2020

There is an ongoing need for higher energy batteries that operate with the highest abuse tolerance. LiCoPO4 is a 4.8 V cathode material with potentially better abuse tolerance and energy density than the current state of art Li-ion battery chemistries. The intense development of high voltage electrolytes1 and strategies that improve the cycle life2, discharge capacity2 and rate capability3 have increased the interest in this material.
This paper will review our recent efforts on LiCoPO4 electrode development. We will discuss synthesis methods, transport measurements, thermal properties and the improvements in discharge capacity and cycle life that result from substitutions to LiCoPO4.
References
1. J.L Allen, J.L. Allen, S.A. Delp, T.R. Jow, ECS Trans. 27, 63-68 (2014).
2. J. L. Allen, T. R. Jow, J. Wolfenstine, J. Power Sources 196, 8656 (2011).
3. J.L. Allen, T. Thompson, J. Sakamoto, C.R. Becker, T.R. Jow and J. Wolfenstine, J. Power Sources 254, 204 (2014).

Figure 1
In Situ Light Microscopy Observation of Sodium Dissolution/Deposition Reaction in Propylene Carbonate-Based Electrolyte
Authors: Yui Yuhki , Hayashi Masahiko , Hayashi Katsuya , Nakamura Jiro 
Published: February 2020

Sodium-ion batteries (SIBs) are anticipated as promising alternatives to lithium-ion batteries (LIBs), and many studies have been conducted on electrodes for SIBs using half-cells. In general, sodium metals are used for the counter electrode of half-cells. However, there are few reports [1] on sodium dissolution/deposition, knowledge of which an understanding of which is important for advancing the development of SIBs. In this study, we focused on sodium metal and observed morphologies of sodium dissolution/deposition reactions in propylene carbonate-based electrolyte solution using in situlight microscopy.
Morphologies of sodium depositions were observed by using in-situ light microscopy (Lasertec Corp., ECCS B310). The semicircular cell for in-situ light microscopy examination was a stack consisting of a sodium sheet as a counter electrode (0.2 mm thick), an electrolyte solution (1 mol/l NaPF6/PC)-soaked polypropylene separator (19 mm in diameter), and a Cu sheet (0.01 mm thick) or sodium sheet (0.2 mm thick) as a working electrode. Electrochemical measurements were performed by using an automatic galvanostatic discharge-charge system (Hokuto HJ1001SD8) at a constant current of 65 mA/cm2at room temperature.
The sodium deposition reaction on the sodium sheet was observed, and the morphologies were granular and needle-like (not shown here). Figure 1 shows cross-sectional images of sodium deposition on the Cu sheet, separator, and sodium metal. The morphologies of sodium deposition showed no difference from that on sodium sheet. Then, needle-like sodium led to away from the Cu sheet and became “dead sodium”. This suggests that the sodium metal dissolution/deposition efficiency is low.

[1] K. Matsumoto et al., J. Power Sources, 265 (2014) 36.

Figure 1
Fluorinated Alkyl Substituted Sulfones As Electrolytes for High Voltage Lithium-Ion Battery
Authors: Su Chi-Cheung , Hu Libo , Xue Zheng , He Meinan , Xu Kang , Zhang Zhengcheng 
Published: February 2020

In an effort to enhance the energy and power density of Li-ion battery technology to facilitate the commercialization of electric vehicles, material researchers have developed new cathode materials with improved specific capacity [1] and operating voltage (5 V vs. Li+/Li).[2] However, the state-of-the-art electrolyte containing 1.2 M lithium hexafluorophosophate (LiPF6) in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC)/ethyl methyl carbonate (EMC) decomposes at above 4.5 V vs. Li+/Li which prevents the extensive use for the high voltage cathode materials. [3] Thus, the exploration of new electrolytes with elevated voltage stability has been actively pursued. [2]
In this paper, we present a novel electrolyte candidate of fluorinated sulfones for high voltage Li-ion battery. Aided by DFT computation, fluorinated sulfones with various chemical structures (trifluoromethyl)sulfonylethane (FMES), 1-(trifluoromethyl)sulfonylpropane (FMPS) and 2-(trifluoromethyl)sulfonylpropane (FMIS) were designed, synthesized and characterized with analytical methods including NMR, GC-MS and FT-IR and their oxidation stability were examined by a floating method using LiNi0.5Mn1.5O4/Li cell. Sulfone with trifluoromethyl (-CF3) substitution at alpha position possesses enhanced oxidative stability and reduced viscosity as compared to their non-fluorinated counterparts. The alpha-substituted fluorinated sulfones also showed improved wetting ability with PE/PP separators. A facile method for the synthesis of 1,1,1-trifluoro-3-(methylsulfonyl)propane (FPMS), which enabled us to produce adequate amount of FPMS for electrolyte testing, was also developed. Unlike alpha-substituted fluorinated sulfones, the gamma-substituted fluorinated sulfones resemble the properties of their non-fluorinated ones.
References:
[1] (a) Nyten, A.; Abouimrance, A.; Armand, M.; Gustafsson, T.; Thomas, J. O. Electrochem. Commun., 2005, 7, 156-160. (b) Ellis, B. L.; Makahnoul, R. M.; Makimura, Y.; Toghill, K.; Nazar, L. F. Nat. Mater., 2007, 6, 749-753.
[2] (a) Zhang, Z.; Hu, L.; Wu, H.; Weng, W.; Koh, M.; Redfern, P. C.; Curtiss, L. A.; Amine, K. Energy Environ. Sci., 2013, 6, 1806-1810. (b) Hu, M.; Pang, X.; Zhou, Z. J. Power Sources, 2013, 237, 229-242. (c) Xu, M.; Zhou, L.; Done, Y.; Chen, Y.; Garsuch, A.; Lucht, B. L. J Electrochem. Soc.
2013, 160, A2005-A2013. (d) Von Cresce, A.; Xu, K. ECS Trans., 2012, 41, 17-22. (e) Santhanam, R.; Rambabu, B. J. Power Sources, 2010, 195, 5442-5451.
[3] a) Kunduraciz, M.; Amatucci, G.G. J Electrochem. Soc.
2006, 153, A1345-A1352. (b) Wolfenstine, J.; Aleen, J. J. Power Sources, 2005, 142, 389-390.

Figure 1
Mechanically Robust Sandwich-Structured C@Si@C Nanotube-Based Li-Ion Battery Anodes
Authors: Liu Jinyun , Goodman Matthew D. , Zhang Hui Gang , Epstein Eric S. , Huang Bo , Pan Zeng , Kim Jinwoo , Choi Junhee , Huang Xingjiu , Liu Jinhuai , Li Nan , Hsia K. Jimmy , Dillon Shen J. , Braun Paul V 
Published: February 2020

Advanced secondary (rechargeable) batteries require high energy density and high structural stability anodes and cathodes. High volumetric energy density is particularly desirable for micro-electronic devices and portable applications, however it can impact almost any application. In current commercial lithium-ion batteries, carbon-based anodes are dominant; however, their capacity and structural stability are not ideal due to the low theoretical capacity (372 mAh g‒1) and intrinsically fragile structure of carbon. Silicon is a very attractive anode material because of its huge theoretical capacity (~4,200 mAh g‒1). Nevertheless, the solid electrolyte interphase (SEI) formation on Si surface is generally unstable due to the large volume change during lithiation-delithiation (400%), which leads to substantial capacity decay with cycling.
Here we present an anode design consisting of closed-end Si nanotubes coated with carbon on both sides (C@Si@C). This sandwich-like structure with double-sided carbon coatings provides both good electrical conductivity and effective protection of electrochemically active Si, leading to a stable SEI. Because the C@Si@C nanotube array was fabricated onto a three-dimensional (3D) scaffold, the anode exhibits a considerable energy density.
Our results show this nanotube array exhibits a capacity of about 2,200 mAh g-1, and a nearly constant Coulombic efficiency of about 98% over 60 cycles. Correspondingly, the volumetric energy density (~750 mAh cm–3) considerably exceeds the volumetric energy density of commercial graphite anodes (~300 mAh cm–3). Through a series of control experiments, we find the C@Si@C nanotube array gives much better capacity and structure stability compared to the Si nanotubes without carbon coatings, the ZnO@C@Si@C nanorods, a Si thin film on Ni foam, and C@Si and Si@C nanotubes. In-situ SEM observations on lithiation-delithiation shows a stable structure evolution of the sandwich nanotube. Through stress and plastic strain modeling, while the plastic strain in the nanotubes increases gently, the one in the nanorods increases dramatically. Since the plastic strain amplitude in the nanorods is significantly higher than that in the nanotubes, in terms of a low-cycle fatigue mechanism of Si during lithiation-delithiation, it is expected that the nanorods would fail with significantly fewer lithiation-delithiation cycles compared to the nanotubes. Our findings show this design of sandwich-structured nanotube array is effective for fabricating anodes with both stable structure retention and high energy density. We believe this strategy is quite general can find application for a large variety of other anode and cathode designs.
Characterization of Thin and Uniform Carbon Coated Overlithiated Layer Oxide Cathode Material for Lithium Ion Batteries
Authors: Park Kwangjin , Yoon Jaegu , Park Jun-ho , Hong Suk-Gi , Doo Seokgwang , Park Jin-Hwan 
Published: February 2020

Thin and uniform carbon coated overlithiated layer oxide (OLO) using 2,3-dihydroxynaphthalene (DN) is prepared. The pristine and DN coated samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). An amorphous nanolayer coating of carbon is obtained on the surface of layered pristine material. The coating layer was confirmed by TEM analysis. The thickness of coating layer was approximately 5 nm, when the content of DN coating was 0.2 wt.%. For optimization of coating condition, the coating weight and the temperature of heat treatment was changed. The 0.1wt% DN coated OLO which was heated at 500oC exhibits the improved electrochemical performance. The initial discharge capacity of 202 mAh·g−1 is obtained at 1C. This capacity is larger of 2% than that of bare OLO. The capacity retention (93.9% at 50th cycle) is also maintained compared to bare OLO (92.3% at 50th cycle). The average voltage drop of coated OLO showed 20mV lower than that of bare sample after 50th cycle. The thin and uniform carbon layer leads to improvement of kinetic and protection of direct contact between cathode and electrolyte.

References

1. N. Yabuuchi, K. Yoshii, S. Myung, I Nakai, S. Komaba, J. Am. Chem. Soc. 2011, 133, 4404-4419
2. T. Kwon, H. Nishihara, Y. Fukura, K. Inde, N. Setoyama, Y. Fukushima, T. Kyotani,

Figure 1
The Transition from Planar to Curved and Flexible Batteries
Authors: McNulty David , Buckley D. Noel , O'Dwyer Colm 
Published: February 2020

There is currently an enormous drive in research, development, production and marketing of Li-ion batteries for smartphone, tablets, portable electronics and of course hybrid and full electric vehicles (1-3). The design of the portable electronics is currently being limited by the requirement to accommodate rigid planar batteries. Capacities can of course be increased, but this increases the bulk design, size and weight of the battery. For future portable devices, particularly wearable technology devices, there will be a need to transition from traditional planar cells to curved and flexible cells (4-6). One approach towards the development of curved and flexible cells is through the development of a sprayable battery process (7-9).
In this work we detail the preparation of sprayable paints using the most commonly used commercial cathode and anode materials, LiCoO2 and graphite respectively as well as a sprayable separator. Initially the component paints were sprayed on to rigid current collectors. The resulting layered cells were tested in split cells to confirm their successful operation. The paints were then applied to curved current collectors leading the transition from a rigid planar cell to a flexible cell. Through detailed electrochemical investigations we compare the electrochemical performance of the layered cells in split cells, and in pouch cells on curved and flexible current collectors. Our approach initially uses commercial cathode and anode materials to confirm the successful operation of non-planar cells. We also investigate the use of a promising alternative cathode material in the form of V2O5 polycrystalline nanorods (poly-NRs) (10). Through galvanostatic cycling and cyclic voltammetry the electrochemical performance of poly-NRs in a full Li-ion cell in both planar and non-planar arrangements is demonstrated.

Acknowledgements

This research was supported through a Science Foundation Ireland Technology Innovation and Development Award under contract no 13/TIDA/E2761.

References

1. N. Liu, H. Wu, M. T. McDowell, Y. Yao, C. Wang and Y. Cui, Nano Lett, 12, 3315 (2012).
2. D. McNulty, D. N. Buckley and C. O'Dwyer, J. Power Sources, 267, 831 (2014).
3. V. Etacheri, R. Marom, R. Elazari, G. Salitra and D. Aurbach, Energy & Environ Sci, 4, 3243 (2011).
4. M. Osiak, H. Geaney, E. Armstrong and C. O'Dwyer, J. Mater. Chem. A, 2, 9433 (2014).
5. J. Ren, Y. Zhang, W. Bai, X. Chen, Z. Zhang, X. Fang, W. Weng, Y. Wang and H. Peng, Angew. Chem. Int. Edit., 53, 7864 (2014).
6. C. O'Dwyer, NPG Asia Mater, 6, e139 (2014).
7. Y. Hu and X. Sun, J. Mater. Chem. A, 2, 10712 (2014).
8. H. Gwon, J. Hong, H. Kim, D.-H. Seo, S. Jeon and K. Kang, Energy & Environ Sci, 7, 538 (2014).
9. N. Singh, C. Galande, A. Miranda, A. Mathkar, W. Gao, A. L. M. Reddy, A. Vlad and P. M. Ajayan, Sci. Rep., 2, 481 (2012).
10. D. McNulty, D. Buckley and C. O’Dwyer, J. Electrochem. Soc., 161, A1321 (2014).
A Study on Rate Capacity and Safety of Ionic Liquid-Based Lithium Ion Battery
Authors: Nishimura Takuya , Kojima Katsunori 
Published: February 2020

Lithium ion battery (LIB) is expected to be applied to large-format energy storage system and the cell performance with higher safety along with high energy density and high power density is demanded in industry applications. In order to improve the safety performance of LIB, much attention has been paid to an ionic liquid, instead of an organic solvent, as an electrolyte. LIB with the ionic liquid-based electrolyte, however, shows relatively poor rate capability compared to LIB with the organic solvent. Recently, several papers have revealed that LIB with bis(fluorosulfonyl)imide (FSI) anion-based ionic electrolyte shows good rate capability1,2). The reason is because of the reduction of charge transfer resistance between FSI anion-based ionic liquid electrolyte and electrode. The point of further development of the LIB using the ionic liquid-based electrolyte is to achieve both the improvement in the rate capability and safety by optimizing cell design including electrode, separator and others.
In this study, influence of the electrode design and the nonwoven fabric separator on rate capability of a LIB with N-methyl-N-propylpyrrolidinium (Py13)/FSI-based ionic liquid electrolyte was investigated. The safety behavior of the LIB using Py13/FSI-based ionic liquid electrolyte was also evaluated by the overcharging test and nail penetrating test, comparing with the LIB using organic electrolyte. The rate capability of the LIB using Py13/FSI-based ionic liquid electrolyte was improved by optimizing the electrode design with higher porosity and thinner thickness and by using the nonwoven separator with more than 80 % of porosity. It is suggested that the enhancement of lithium ion mobility in both the porous electrode and the porous separator filled with the ionic liquid electrolyte is more effective to improve the rate capability, comparing the organic electrolyte. As a result of evaluation of the safety behavior, LiNi0.5Mn1.5O4/Li4Ti5O12cell using Py13/FSI-based ionic liquid electrolyte, as compared with the organic electrolyte, exhibited a superior safety performance in the nail penetrating test. The heat generation was also drastically suppressed by the high thermal stability ionic liquid electrolyte. The heat generation was drastically suppressed in comparison with the organic electrolyte due to high thermal stability of the ionic liquid electrolyte.
References
1) H. Matsumoto, H. Sakaebe, K. Tatsumi, M. Kikuta, E. Ishiko, M. Kono , J. Power Sources., 160, 1308 (2006)
2) T. Sugimoto, M. Kikuta, E. Ishiko, M. Kono, M. Ishikawa, J. Power Sources., 183, 436 (2008)
Improving the Electrochemical Performance of Nanostructured Sn Film Anodes By a Catalytic Top Coat
Authors: Polat Deniz Billur , Bilici Burcin , Keles Ozgul 
Published: February 2020

To improve the electrochemical performance of Sn anode, a Cu film with high surface area is used as substrate material. To improve the electrochemical performance of this nanostructured Sn anode, a catalytic material is applied as top coat on the Sn film. The bare and the coated Sn films are tested galvanostatically in half cells with C/12 rate in voltage ranges of 0.2-1.2V. To understand differentiation in their performances, cyclic voltammetry and electrochemical impedance spectroscopy are applied on these samples. The results show that the combination of high surface area and catalytic top coating point to a new approach to improve the long term cycleability and high capacity performance of LIB anodes.
Keywords: Lithium ion battery, Sn anode, CV, EIS, electrolytic coating.
Oxides As Cathode Materials for Mg-Ion Batteries
Authors: Barile Elizabeth C. , Gewirth Andrew A. 
Published: February 2020

Magnesium (Mg) batteries have the potential to revolutionize energy storage. Theoretically these batteries far outperform current Li-ion batteries in both volumetric and gravimetric capacities.
[1]
Additionally, Mg is a more earth abundant (13.9% Mg in earth’s crust compared to 7x10-4 % Li) and less expensive alternative ($2700/ton Mg and $64000/ton Li), ideal for automobile electrification and thus transforming society.
[2]

Despite these attractive properties, implementation of Mg-ion batteries has been hindered by several challenges. Most significantly, 1) electrolytes which allow for reversible Mg deposition have limited stability, and 2) reversible intercalation of Mg2+in cathode materials is kinetically slow and often irreversible. Thus, future Mg-ion batteries must incorporate stable high voltage and capacity cathode materials with fast and reversible Mg intercalation kinetics.
Mg battery prototypes have used Chevrel phase cathodes, Mo6S8, and its derivatives.
[3]
These cathodes incorporate a delocalized framework to accommodate the charge and diffusion of hard Mg2+ ions. The multiple Mo ions allow for a diffuse charge network to accommodate intercalated Mg2+ ions. However, Chevrel phase cathodes suffer from low voltages (~1.1 V vs Mg/Mg2+) and only partial reversibility, where the total capacity drops by ~40% after the first discharge cycle.
[4]
For Mg batteries to be realized commercially, the cathode’s voltage and reversibility must be improved.
In this talk we discuss our efforts using transition-metal oxides with open and delocalized structures as cathode materials for Mg-ion batteries. We investigate various bronzes and polyoxometalates, which have known magnesiated forms and high redox potentials. We find that these oxides exhibit reversible electrochemical behavior in various non-aqueous electrolytes and report on our efforts at confining these materials to electrode surfaces.

[1] Yoo, H.; Shterenberg, I.; Gofer, Y.; Gershinsky, G.; Pour, N.; Aurbach D. Energy Environ. Sci.
2013, 6, 2265.
[2] Saha, P.; Jampani, P.; Datta, M.; Okoli, C.; Manivannan, A.; Kumta, P. J. Electrochem.Soc.
2014, 161, A593.
[3] Aurbach, D.; Lu, Z.; Schechter, A.; Gofer, Y.; Gizbar, H.; Turgeman R.; Cohen, Y.; Moshkovich, M.; Levi, E. Nature, 2000, 407, 724.
[4] Saha, P.; Datta, M.; Velikokhatnyi, O.; Manivanna, A.; Alman, D.; Kumta P. Prog. Mater. Sci.
2014, 66, 1.