bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anode Properties of Si–FeS Films Prepared By Pulsed Laser Deposition in Solid-State Lithium Batteries
Authors: Cervera Rinlee Butch , Suzuki Naoki , Ohnishi Tsuyoshi , Osada Minoru , Mitsuishi Kazutaka , Kambara Takayoshi , Takada Kazunori 
Published: February 2020

Lithium–silicon alloys are one of the most attracting anode materials for next-generation lithium-ion batteries due to the high theoretical capacity, low electrode potential, and the second largest Clark number. However, they have exerted their high performance only in nano-sized form. This study reveals that Si-based anodes fabricated into films exhibit excellent performance even in a bulky state, when they are in a solid electrolyte.
The Si-based films were deposited on stainless steel plates used as current collectors by pulsed laser deposition. Because it is impossible to ablate pure Si by the KrF excimer laser used in this study, 10wt% of FeS, which was reported to be effective in enhancing electrode activity in solid electrolytes [1], was added to Si powder before pressed into a target in order to allow the ablation. Film thickness was varied from 30 nm to 1 µm. Electrode properties of the films were investigated in a solid electrolyte, 70Li2S–30P2S5 glass ceramics, with an In–Li alloy as a counter electrode. The films were galvanostatically lithiated (charged) down to 0.01 V vs. Li+/Li and then delithiated (discharged) up to 2.62 V vs. Li+/Li at various discharge rates.
The Si–FeS films exhibit excellent performance in the solid electrolyte, as shown in the figure. The rate dependence of the discharge capacity clearly indicates that a film with thickness of 30 nm delivers a high capacity approaching the theoretical value at 0.1 C-rate discharge and maintains a high capacity of 2300 mAh g−1 at 100 C. Although such high rate capability may have been reported only for nano-sized Si materials, the film keeps it against increasing thickness. Even a 1-µm-thick film anode delivers a capacity of 3100 mAh g−1 at a discharge rate of 0.1 C, and 2500 mAh g−1is kept at a high rate discharge of 10 C.
It should be emphasized that such high performance is realized in a solid-state cell, which will be free from safety issues. In addition, the use of solid electrolytes is effective in improving cycling performance, which is a great drawback of Si anodes, by preventing detachment of the active material from current collectors. Capacity retention observed for a 400 nm-thick film over 120 cycles exceeds 80% in the solid electrolyte, while it decreases to 38% in an organic liquid electrolyte.
Acknowledgement
This study was partly supported by the Li-EAD project of the New Energy and Industrial Technology Development Organization (NEDO), Japan
Reference
[1] B. T. Hang, T. Ohnishi, M. Osada, X. X. Xu, K. Takada, and T. Sasaki, J. Power Sources 195 (2010) 3323.
Figure. Rate dependence of discharge capacity from the Si−FeS films.
Understanding Structural Changes in NMC Li-Ion Cells by In Situ Neutron Diffraction
Authors: Dolotko Oleksandr , Senyshyn Anatoliy , Mühlbauer Martin , Nikolowski Kristian , Ehrenberg Helmut 
Published: February 2020

A combination of the in-situ high-resolution neutron powder diffraction along with electrochemical analysis was applied to study commercial NMC cells (18650-type) based on a Lix(Ni0.5Mn0.3Co0.2)O2(NMC) cathode and a graphitic anode. The structural changes of the electrode materials during cell charge/discharge have been analyzed using Rietveld refinement and single profile decomposition techniques.
A different behavior of electrochemically-driven lattice distortion was observed for NMC material in comparison to LixCoO2 which influence the overall cell performance. Detailed analysis of the structural changes in the Lix(Ni0.5Mn0.3Co0.2)O2 cathode material revealed reversible Li/Ni cation mixing (5.6(8) %), which is state-of-charge independent below 1600 mAh and disappearing above 1800 mAh (~0.8 Qmax). The cation mixing behavior was traced in detail using the neutron diffraction and it is considered as one of the reasons of the nonlinear change of the cathode material lattice parameters.
A transformation of graphite to LiC12 and LiC6 including the formation of higher ordered lithium intercalated carbons was observed, where the evolution of the anode at higher charge states of the cell is reflected in a change of the phase fractions of LiC6 and LiC12 due to further graphite lithiation.
Can LiMnPO4 Compete with LiFePO4
Authors: Moskon Joze , Pivko Maja , Dominko Robert , Gaberscek Miran 
Published: February 2020

In contrast to LiFePO4 (LFP), its chemical and structural analogue, LiMnPO4(LMP), has long been considered a low priority material - not viable for practical applications [1,2]. Despite continuous optimization it has showed relatively low reversible capacities and low rate capability. The interest in this material has grown considerably after demonstration of much improved performance when used in mixtures with LFP [3]. In parallel to that, improvements of the performance of pure LMP have also been occasionally reported.[4]
As indicated in our previous work [5], a precondition for increased performance of LMP is creation of small particle size (on the order of 10-20 nm or smaller) whereby agglomeration of particles needs to be prevented as much as possible. A convenient way to separate particles is their embedment into pyrolytic carbon, as known from many other studies. In addition to the small, well separated particles, the improved performance of our LMP material could partly be due to slightly changed structural features; (in our case the lattice volume was 301.5(6) Å3which is about 0.3-0.5 % smaller than reported for other synthetic procedures)[5].
In the present contribution we analyze carefully the behaviour of LMP and compare it to the performance of LFP. First we show that the capacity of LMP can approach to its theoretical limitation, 170 mAh/g. Secondly, we show that the power performance can also be greatly increased if appropriate charge-discharge conditions are taken into account. At high rates the energy efficiency of LMP may even exceed the efficiency of LFP. We explain in some detail the role of inherent hysteresis of LMP in the light of our recent model [6]. In particular, we show that the rate is decreased due to slow redistribution of charge inside the cathode matrix which leads to relatively high polarization at usual rates. In this context we propose directions for further systematic improvement of the electrochemical behaviour of LMP. Finally, we show for the first time, many hundreds of cycles of LMP without significant loss of capacity (see Fig.). We also perform a post-mortem analysis and analyse the reasons for the failure. We point at the problem of electrolyte degradation (causing problems in the charge step).
References
1. A. Yamada, Y. Kudo, K. Y. Liu, J. Electrochem. Soc.
2001, 148, A747.
2. C. Delacourt, L. Laffont, R. Bouchet, C. Wurm, J.-B. Leriche, M. Morcrette, J.-M. Tarascon, C. Masquelier, J. Electrochem.
Soc.
2005, 152, A913.
3. S. K. Martha, J. Grinblat, O. Haik, E. Zinigrad, T. Drezen, J. H. Miners, I. Exnar, A. Kay, B. Markovsky, D. Aurbach, Angew. Chem. Int. Ed.
2009, 48, 8559.
4. T. Drezen, N.-H. Kwon, P. Bowen, I. Teerlinck, M. Isono, I. Exnar, J. Power Sources
2007,174, 949.
5. M. Pivko, M. Bele, E. Tchernychova, N. Zabukovec Logar, R. Dominko, M. Gaberscek, Chem. Mater.
2012, 24, 1041-1047.
6. W. Dreyer, J. Jamnik, C. Guhlke, R. Huth, J. Moškon, M. Gaberšček, Nat. Mater. 2010, 9, 448.
Nano-Hierarchical Hollow Manganese Oxide Anode Material with High Performance for Lithium-Ion Battery
Authors: Weng Yu-Ting , Lee Rung-Chuan , Wu Nae-Lih 
Published: February 2020

Lithium-ion batteries (LIBs) are expected to continue playing important roles in energy storage for mobile communication and electric vehicle (EV) and renewable energy applications in the foreseeable future. Graphite as a commercial anode material for LIB possesses the advantages of high coulombic efficiency and good cycle stability. However, its theoretical capacity is only 372mAh/g, and this limits the total capacity of the full battery. The demand for higher energy capacity of the energy storage cell has been driving the development of alternative anode materials with higher capacities. Certain nanocrystalline metal oxides have been shown to be able to work as a reversible anode through heterogeneous conversion reaction.
The high theoretical capacity and density give metal oxides the edge over graphite as high energy density anodes for LIB. Nevertheless, due to the high kinetic barrier of the conversion reaction at room temperature, metal oxide anodes typically exhibits large potential hysteresis between lithiation and de-lithiation cycles. The hysteresis reduces the operating voltage window as well as the energy efficiency of the LIB cell. Furthermore, the poor conductivity and large volume expansion arising from lithiation of the metal oxide particles are major shortcomings that may cause poor cycling stability. Compared with other conversion–type metal oxide anodes, manganese oxide (MnOx) shows smaller potential hysteresis and lower operation potential. In addition, MnOxhave the advantages of being environment friendly and abundant.
In this work, we have prepared hierarchical hollow MnO2 by utilizing a SiO2-templating hydrothermal process. The results revealed that the novel hollow nanostructure MnO2 electrode had a specific charge capacity as large as 1364 mAh/g at 0.1 C-rate, and it unprecedentedly demonstrates high rate performance, retaining 878 mAh/g at 2 C-rate and good cycle stability.
Nanostructured Iron Trifluoride from the Fluorination of Iron Silicide
Authors: Guerin Katia , Louvain Nicolas , Hamwi Andre , Laik Barbara , Pereira-Ramos Jean-Pierre , Sougrati moulay-Tahar , Jumas Jean-Claude , Willmann Patrick 
Published: February 2020

Metal fluorides are low cost inorganic compounds that have been studied for their industrial applications such as smelting in metallurgy, uranium enrichment processor optical material production. This applied development of the synthesis of inorganic fluorides allowed intense fundamental researches in the 70’s and 80’s as regards their electronic, and more particularly magnetic, properties. In the last decades, research subjects have been shifted toward the nanostructuration of inorganic fluorides, due to potential applications such as in secondary lithium battery. Indeed, nanostructured metal fluoride materials are potential candidate materials as cathodes for lithium-ion batteries through both insertion and conversion reactions and they could improve the theoretical specific capacity of the positive electrode.
Among the MF3 fluorides (M = metal), iron trifluoride, FeF3, is one of the most promising candidate. However, its application as a cathode material for lithium ion battery has been largely hindered by both its low conductivity and its high sensibility to air humidity leading to cyclability rather limited. This work will present some new strategies to develop nanostructured iron fluoride of high chemical stability. They have been prepared through the reactivity of some unusual metal precursors with molecular fluorine gas. In order to favor the nanostructuration of the metal fluoride, the kinetic of fluorination has been followed by in-situ Infra-Red measurements. All the metal fluorides obtained have been then characterized by Scanning Electronic Microscopy, XRD, IR, MOSSBAUER, and Raman spectroscopies. Finally, the electrochemical performances will be presented and correlated with both the fluorination conditions and the physicochemical characteristics of the samples prepared.
Single-Phase Layered Compositions in the Li-Mn-Ni-O System Which Do Not Significantly Oxidize Electrolyte at 4.6 V Versus Li/Li+
Authors: Rowe Aaron W. , Camardese John , McCalla Eric , Dahn Jeff 
Published: February 2020

Detailed phase diagrams of the Li-Mn-Ni-O system have been determined to provide a broader understanding of how synthesis conditions affect the phase composition of Li-Mn-Ni-O positive electrode materials.1,2 Figure 1 shows the positive electrode region of the Li-Mn-Ni-O pseudoternary phase diagram for samples quenched from 900oC. The phase diagram is labeled with various individual compositions, single-phase regions, tie-lines, and multi-phase co-existence regions all elucidated through extensive crystallographic analysis,3 introducing many opportunities for characterization of new positive electrode materials. In order to develop Li-ion batteries with high energy densities and long cycle lives, ideal novel materials would not react with carbonate-based electrolytes at high potentials (≥ 4.6 V vs. Li/Li+).
In this study, three single-phase layered compositions in the Li-Mn-Ni-O system, labeled as A, B and C in Figure 1, were studied by ICP-OES, XRD, and ultra high precision coulometry (UHPC), a technique which uses precise measurement of coulombic efficiency (CE) and charge endpoint capacity slippage to detect electrolyte oxidation. Sample A was determined to be Li[Li0.157Ni0.122Mn0.650□0.071]O2, a Li-deficient, Mn-rich material containing 3.5% metal site vacancies.4 Sample B was Li[Li0.117Ni0.325Mn0.558]O2, an essentially Ni-rich member of the Li-rich oxide solid solution series (dashed orange line in Figure 1), while sample C was determined to be Li[Li0.148Ni0.480Mn0.471]O2, an approximate Li-rich analogue of Li[Ni0.5Mn0.5]O2.
Figure 2 shows the CE, discharge capacity, and normalized charge endpoint capacity for cycle 10 onwards for samples A, B, and C cycled to 4.6 V and 4.8 V, and for Li[Ni1/3Mn1/3Co1/3]O2 cycled to 4.2 V, 4.4 V, and 4.6 V. In general, cycling to 4.6 V yielded better CE and lower slippage of the Li-Mn-Ni-O materials compared to cycling to 4.8 V, which produced more slippage due to electrolyte oxidation. The performance of the Li-deficient Li[Li0.157Ni0.122Mn0.650□0.071]O2 material cycled to 4.6 V was striking, as it maintained a substantially higher CE and a lower charge endpoint capacity slippage per cycle than Li[Li0.117Ni0.325Mn0.558]O2, Li[Li0.148Ni0.480Mn0.471]O2, and industry standard Li[Ni1/3Mn1/3Co1/3]O2 (cycled to only 4.2 V) while maintaining a reversible capacity of 225 mAh/g after 50 cycles. These results highlight the inherent “inertness” of Li[Li0.157Ni0.122Mn0.650□0.071]O2 and its suitability as a thin protective shell in a core-shell particle configuration.

References

1. E. McCalla, A. W. Rowe, R. Shunmugasundaram, and J. R. Dahn, Chem. Mater., 25, 989–999 (2013).
2. E. McCalla, A. W. Rowe, C. R. Brown, L. R. P. Hacquebard, and J. R. Dahn, J. Electrochem. Soc., 160, A1134–A1138 (2013).
3. E. McCalla and J. R. Dahn, Solid State Ion., 242, 1–9 (2013).
4. E. McCalla, A. W. Rowe, J. Camardese, and J. R. Dahn, Chem. Mater., 25, 2716–2721 (2013).
Binder-Free Metal Fibril–Supported Fe2O3 Anode for High-Performance Lithium-Ion Batteries
Authors: Choi Jaecheol , Jeong Jiseon , Ryou Mhyung-Hyun , Kim Chang-Hyeon , Lee Yong Min 
Published: February 2020

Metal oxides have been extensively investigated as anode materials for lithium-ion batteries (LIBs) owing to their higher theoretical capacity compared to graphitic carbon (372 mAh g−1), which has been widely used as a commercial anode material1,2. Among the established metal oxide anode materials, Fe2O3 is considered a promising anode candidate because of its numerous advantages including high theoretical capacity (1007 mAh g−1), abundance, relatively low cost, and environmental friendliness. However, a large volume of expansion (six Li+ per formula unit) and electrode destruction upon electrochemical cycling results in severe capacity fading. Moreover, due to the insulating properties of the discharge product, Li2O (Fe2O3 + 6Li+ ↔ 2Fe + 3Li2O), Fe2O3 suffers from sluggish reaction kinetics, especially at a high current rate3.
To solve these problems, we report a simple fabrication process for a stainless steel metal fibril–supported Fe2O3 (Fe2O3/SF) material as a lithium battery anode. Utilizing the well-developed 3D structure of Fe2O3/SF, the material shows not only a superior rate capability but also extremely long cycle life (2000 cycles), even at a high current density.

References

[1] A. S. Aricò, P. Bruce, B. Scrosati, J. M. Tarascon and W. Van Schalkwijk, Nat. Mater., 4, 2005, 366-377.
[2] Z. Wang, L. Zhou and X. W. Lou, Adv. Mater., 24, 2012, 1903-1911
[3] Q. Su, D. Xie, J. Zhang, G. Du and B. Xu, ACS Nano, 7, 2013, 9115-9121.
Electrochemical Two-Step Delithiation/Re-Lithiation of LiCoPO4 Observed By In Situ XRD, In Situ XAS, and Ex Situ 7-Li/31-P NMR Spectroscopy
Authors: Indris Sylvio , Kaus Maximilian , Issac Ibrahim , Heinzmann Ralf , Ehrenberg Helmut 
Published: February 2020

LiCoPO4 was synthesized by solid-state and supercritical-solvothermal routes. Electrochemical tests were performed by galvanostatic cycling against Li metal at different rates and cyclic voltammetry. The electrochemical delithiation/re-lithiation mechanism was investigated by in situ x-ray diffraction (XRD), in situ x-ray absorption spectroscopy (XAS), and ex situ
7Li/31P nuclear magnetic resonance (NMR) spectroscopy. In situ XRD experiments reveal a two-step reaction with two subsequent two-phase steps and an intermediate phase of approximate composition Li0.7CoPO4 [1]. In order to gain insight into the oxidation/reduction process of Co2+/3+ during cycling in situ XAS measurements were performed which indicate a highly reversible process. 7Li and 31P NMR spectra of samples with different Li contents obtained during delithiation and re-lithiation again reveal a highly reversible two-step mechanisms with an intermediate phase. For this intermediate phase, two non-equivalent Li environments (peak ratio of 1:1) and two non-equivalent P environments (2:1) could be evidenced. These results are discussed in terms of arrangement of Li ions, Li vacancies, and Co2+/Co3+ and they hint at an intermediate phase of composition Li2/3CoPO4.
[1] N. N. Bramnik, K. Nikolowski, C. Baehtz, K. G. Bramnik, H. Ehrenberg, Chem. Mater.
19 (2007), 908.
Investigating the Phase Transitions of Graphite By In Situ Neutron Diffraction
Authors: Heß Michael , Villevieille Claire , Nesper Reinhard , Novák Petr 
Published: February 2020

Graphite is one of the most common negative electrode materials in today’s lithium-ion batteries [1]. Intensive research has revealed most of its thermodynamic properties [2-5] and modeling of its free energy was able to determine some of these properties like the phase diagram and the staging phenomena to some extent [6, 7]. However, these tools were partially insufficient to describe the open-circuit potential and phase transitions in the low state-of-charge regime of the Li-graphite system.
The phase transitions during the intercalation of lithium in graphite were therefore investigated using in situ neutron diffraction. In situ neutron diffraction data have been collected to determine the transitions of the lithium-graphite intercalation compound in the range of 7-30 % of the state-of-charge (100 % = LiC6). Only this limited SOC range has been investigated in detail since previous findings by Billaud and Dahn already describe the range from 0-7 % and 30-100 % very precisely [3,5]. This new set of data suggests a continuous lithium intercalation in a certain solid-solution regime for each pure phase (stage) at room temperature. This result is found to be consistent with the phase diagram of Woo et al. [4] and is able to extract the in-plane density of lithium in each stage.
References:
1. M. Winter, J. O. Besenhard, M. E. Spahr, P. Novák, Adv Materials 10, (1998), 725-763
2. D. Guerard, A. Herold, Carbon 13, (1975), 337-345
3. D. Billaud, F. X. Henry, M. Lelaurain, P. Willmann, J. Phys. Chem. Solids 57, (1996), 775-781
4. K. C. Woo, W. A. Kamitakahara, D. P. DiVincenzo, D. S. Robinson, H. Mertwoy, D. J. Milliken, J. E. Fischer, Phys. Rev. Lett. 50, (1983), 182-185
5. J. R. Dahn, Phys. Rev. B 44, (1991), 9170-1977
6. S. E. Millman, G. Kirczenow, Phys. Rev. B 26, (1982), 2310-2313
7. P. Hawrylak, K. R. Subbaswamy, Phys. Rev. Lett. 53, (1984), 2098-2101
Redox Active Oligomers Synthesized from Anthraquinone for Use in Rechargeable Lithium Batteries
Authors: Yao Masaru , Ando Hisanori , Kiyobayashi Tetsu 
Published: February 2020

Using redox active organic materials, that contain no scarce metal resources, as a positive-electrode active material instead of conventionally used rare-metal oxides can be a solution to the resource problem of the current rechargeable lithium batteries. Several types of organic positive-electrode materials have been proposed. Among them, low-molecular-weight crystalline organic compounds have been drawing attentions recently, since these compounds tend to show high utilization ratios during the charge/discharge processes. 9,10-Anthraquinone (AQ) (Fig. 1a), one of those low-molecular-weight crystalline organic compounds, also shows a capacity close to its theoretical value [1,2]; however, the electrode using AQ tends to seriously degrade upon cycling because of the dissolution of the redox-related molecules into the electrolyte solution during cycling.
To suppress the dissolution and to improve their cycle stability, we focused our attention on the oligomerization technique. In this study, an anthraquinone dimer and a trimer connected by the -C≡C- bonds (Figs. 1b and 1c) were newly synthesized using the Sonogashira cross-coupling reaction; and their performances as positive-electrode active materials were compared with the AQ-monomer. The positive electrodes using the dimer and trimer as active materials showed initial discharge capacities of about 200 mAh/g, with the average voltages of 2.2-2.3 V vs. Li+/Li. These values are close to those of the AQ monomer, suggesting the two-electron redox reaction per AQ unit. Fig. 2 compares the cycle-life performances of the electrode using the AQ-monomer, dimer, and trimer. While the capacity of the AQ-monomer electrode rapidly decreased, the synthesized dimer and trimer showed better cycle stabilities. In particular, the trimer retained almost a constant capacity during 50 cycles without drastic decay. The oligomerization of the AQ units effectively reduces the solubility. The present study revealed that oligomerization of the redox active molecular units was an effective way to extend the cycle-life without losing the discharge capacity.
References
[1] Z. Song, H. Zhan, Y. Zhou, Chem. Commun., 4 (2009) 448.
[2] M. Yao, S. Yamazaki, H. Senoh, T. Sakai, T. Kiyobayashi, Mater. Sci. Eng. B, 177 (2012) 483.