bluuebunny/crossref_metadata_2025_split huggingface dataset:
In-Situ and First Principles Characterization of Alpha-Manganese Oxide (MnO2)
Authors: Ford Denise , Yang Zhenzhen , Park Joong Sun , Trahey Lynn , Ren Yang , Kim Soojeong , Kim Hacksung , Fister Timothy T , Thackeray Michael M. , Chan Maria K. Y. 
Published: February 2020

Alpha manganese oxide (α-MnO2) is of interest as a cathode material for lithium-ion batteries and as an electrode/electrocatalyst for hybrid Li-ion/Li-O2 systems. It has a tunnel structure with large 2x2 channels that accommodate different species such as Ba2+, K+, NH4
+, or H3O+/H2O. Characterization and modeling of the insertion and removal of Li, oxygen, and H3O+/H2O species under electrochemical cycling and heating is important for understanding how MnO2 acts as a hybrid Li-ion/Li-O2 battery material. In this talk, we will discuss our work in using in-situ synchrotron X-ray diffraction (XRD), X-ray absorption near-edge spectroscopy (XANES), in-situ UV resonance Raman spectroscopy, and density functional theory (DFT) calculations, to unravel the changes in α-MnO2during electrochemical cycling as well as dehydration process. We found evidence of oxygen incorporation and partial removal during electrochemical cycling, as well as two-stage water removal during heating. Both processes involve facile oxygen diffusion through the center of 2x2 tunnels.

Keywords: MnO2, in-situ XRD, DFT

Reference:

Z.-Z. Yang, D. Ford, J.-S. Park, Y. Ren, S. Kim, H. Kim, T. Fister, M. K. Y. Chan,# M. M. Thackeray,# “Probing the release and uptake of water in α-MnO2•xH2O,” Chemistry of Materials 29, 1507–1517 (2017).

Z. Yang, L. Trahey, Y. Ren, M. K. Y. Chan,# C. Lin, J. Okasinski, and M. M. Thackeray, “In-Situ High-Energy Synchrotron X-ray Diffraction Studies and First Principles Modeling of α-MnO2 Electrodes in Li-O2 and Li-ion Coin Cells,” Journal of Materials Chemistry A 3, 7389-7398 (2015).

Acknowledgements:

This work was supported as a part of the Center for Electrochemical Energy Science, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences under award number DE-AC02–06CH11. Use of the Advanced Photon Source, a US DOE Office of Science User Facility operated by Argonne National Laboratory, was supported by DOE under Contract No. DE-AC02-06CH11357. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. 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.

Figure 1
Electrochemical Degradation Processes of Solid Polymer Electrolytes in Li-Ion Batteries: An Online Electrochemical Mass Spectrometry (OEMS) Study
Authors: Sun Bing , Sångeland Christofer , Brandell Daniel , Mindemark Jonas , Berg Erik J. 
Published: February 2020

Li-ion polymer batteries are considered as a promising energy storage solution with respect to battery safety and processing flexibility. Recent advances towards fast Li+ transport and room-temperature ion-conduction in solid polymer electrolytes (SPEs) open up great possibilities promoting their implementations in all-solid-state electronics; amongst the viable candidates functionalized polycarbonates and polyesters have shown their versatility to be applied in all-solid batteries which can operate down to ambient temperatures [1]. Nevertheless, there is a general lack of knowledge about the interfacial chemistry and the electro-/chemical degradation schemes of polymer electrolytes, primarily due to the technical obstacles in sample preparation and reliable in-situ characterization.
In the present study, the gaseous decomposition products from polycarbonate and polyester-based SPEs are traced by online electrochemical mass spectrometry (OEMS). An operando characterization of the evolved gases from poly(trimethylene carbonate) (PTMC)-derived SPEs using high-molecular-weight PTMC and its copolymer as the host materials is performed under both cathodic reduction and anodic oxidation regions at close to ambient temperatures (e.g., 30 °C, 50 °C). Direct correlations between the oxidation and reduction potentials with the gas evolution are observed; the evolutions of CO2 (m/z = 44) and CH4 (m/z = 16) are traced and compared with LiTFSI-containing carbonate liquid electrolyte. Meanwhile, additional gaseous products are detected, such as SO2 (m/z = 64), which could be assigned to LiTFSI decomposition. This was indicated from the detectable salt decomposition residuals in Li-cells using PTMCnLiTFSI-based SPEs by X-ray photoelectron spectroscopy (XPS) [2].
References
[1] B. Sun, J. Mindemark, K. Edström, D. Brandell, Solid State Ionics, 262 (2014) 738-742; J. Mindemark, B. Sun, E. Törmä, D. Brandell, J. Power Sources, 298 (2015) 166-170; Kimura, M. Yajima, Y. Tominga, Electrochem. Comm., 66 (2016) 46-48.
[2] B. Sun, C. Xu, J. Mindemark, T. Gustafsson, K. Edström, D. Brandell, J. Mater. Chem. A, 3 (2015) 13994-14000.
A Combinatorial Model of the Effect of Additives in High-Voltage, NMC Cells
Authors: Bloom Ira , Sahore Ritu , Peebles Cameron , Abraham Daniel P , Gilbert James A 
Published: February 2020

Coin cells containing the additives, vinylene carbonate (VC) and tris(trimethylsilyl)phosphite (TMSPi), in the range of 0 to 0.020 wt. fraction, were cycled between 3.0 and 4.4 V. The changes in C/10 and C/1 capacity and cell resistance at 60% SOC were found to follow linear-with-time kinetic rate laws. After aging, the electrodes were characterized by X-ray photoelectron spectroscopy. The concentration of some surface species correlated very strongly with changes in cell performance.
Further, the cell performance data could be modeled using a statistics of mixtures approach. The modeling indicated that there was a strong, synergistic interaction between VC and TMSPi, as expected. The interaction between these additives lessened capacity fade. These results, as well as others, will be discussed.

Acknowledgment

The work at Argonne National Laboratory was performed under the auspices of the U.S. Department of Energy (DOE), Office of Vehicle Technologies, under Contract No.
DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.
Improvement of Li-Garnet Interface and in Situ Neutron Depth Profiling Diagnose
Authors: Wang Chengwei , Gong Yunhui , Xie Hua , Zhang Lei , Liu Boyang , Wang Howard , Wachsman Eric D. , Hu Liangbing 
Published: February 2020

Solid state electrolytes are known for non-flammability, dendrite blocking, and stability over large potential windows. Garnet-based solid state electrolytes have attracted much attention for their high ionic conductivities and stability with lithium metal anodes. However, high interface resistance with lithium anodes hinders their application to lithium metal batteries. Herein, we develop several efficent and effective techniques that exhibit a significantly improved contact and lead to an interface resistance as low as ~ 7 Ω·cm2. We also use neutron depth profiling (NDP), a nondestructive and uniquely Li-sensitive technique, to reveal the interfacial behaviors of garnet SSE in contact of metallic Li through monitoring Li plating-stripping processes in situ. The NDP measurement has demonstrated the predictive capabilities for diagnosing short-circuits in garnet-based solid state batteries. Two types of cells, symmetric lithium/garnet/lithium (LGL) cells and asymmetric lithium/garnet/carbon-nanotubes (LGC) ones have been fabricated to emulate the behavior of Li metal and Li-free Li metal anodes, targeting full-cell applications with Li-free cathode (e.g., sulfur, and oxygen) and Li-containing cathode (e.g., LiCoO2, LiFePO4, etc.), respectively. The NDP data implies the limitation of Li-free Li metal anode in forming reliable interfacial contacts, and strategies of excessive Li and better interfacial engineering need to be investigated.
Modeling Electrolyte Influence on Stability and Interfacial Structure of Functionalized LiMn2O4 Battery Cathodes
Authors: Letchworth-Weaver Kendra , Nicolau Bruno G. , Ghadar Yasaman , Knight Chris , Gewirth Andrew A , Chan Maria K. Y. 
Published: February 2020

Creating an artificial cathode-electrolyte interface (CEI) from self-assembled monolayers of phosphonic acids offers a promising avenue to prevent capacity loss in Li-ion batteries due to metal dissolution from the cathode. A complete theoretical description of the complex and inherently multi-scale interface between the battery electrode surface and an organic electrolyte can enable rational design of such functionalized cathode coatings. We first present a microscopically informed continuum model for organic electrolyte [1,2] which reproduces key solvation phenomena relevant to battery operation. We go on to predict how the structure and energetics of the metal oxide cathode in Li-ion batteries change due to the presence of liquid electrolyte. We find that compared to vacuum calculations [3], the voltage stability window of the Li-terminated (001) and (111) surfaces of the spinel LiMn2O4 (LMO) cathode in solution is enhanced. Furthermore, we demonstrate that our solvation model, in combination with density-functional theory and classical molecular dynamics, simultaneously captures both the formation of a stable artificial CEI on the LMO surface and the interaction of the CEI molecules with the electrolyte. Our theoretical description captures the experimentally observed trends in solubility and cyclic voltammetry of the coated LMO surface, demonstrating how adjusting the length and functionalization of the phosphonates can balance the competing needs of maximizing Li-ion conductivity but minimizing cathode dissolution.

Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

[1] K. Letchworth-Weaver and T.A. Arias, Phys. Rev. B. 86, 075140 (2012).
[2] D. Gunceler et al, Modelling Simul. Mater. Sci. Eng. 21,074005 (2013).
[3] R. Warburton et al, ACS Applied Materials and Interfaces, 8 (17), 11108–11121 (2016).
Synthesis of Li4Ti5O12 Microspheres and Their Electrochemical Performance As Anode Materials for Li-Ion Batteries
Authors: Park In-Su , Hong Hye-Jin , Kim Jiwoong , Ryu Taegong 
Published: February 2020

Lithium titanate, Li4Ti5O12 (LTO) has drawn significant attention in the lithium ion battery because it shows some interesting features such as a low toxicity and low volume change (2-3%) on both lithium insertion and de-insertion, along with an excellent cycling life. Especially, the mesoporous LTO microspheres are considered as an ideal anode material because of their good rate performance, morphological properties, and a large tap density. However, it is very challenging to synthesize monodispersed LTO microspheres with desirable structural characteristics and electrochemical performances. In this study, LTO microspheres were synthesized using a facile process and cheap Ti-source (TiOSO4). The round shaped secondary particles (μm scale) were consisted of LTO primary particles (< 100 nm). The structural properties and electrochemical performances of Li4Ti5O12 microspheres will be discussed in the Meeting.
References
[1] Goriparti, S.; Miele, E.; De Angelis, F.; Di Fabrizio, E.; Proietti Zaccaria, R.; Capiglia, C. J. Power Sources,
2014, 257, 421.
[2] Lin, C.; Fan, X.; Xin, Y.; Cheng, F.; Lai, M.O.; Zhou, H.; Lu, L. Nanoscale, 2014, 6, 6651.

Figure 1. FE-SEM images of the synthesized microspheres.

Figure 1
In-Operando EDXRD of Graphite and Silicon-Graphite Electrodes in Lithium-Ion Cells
Authors: Yao Koffi P.C. , Kalaga Kaushik , Okasinski John , Almer Jon , Abraham Daniel P 
Published: February 2020

Improvements in the energy density of lithium-ion batteries (LIBs), through the adoption of novel high capacity anodes as alternatives to graphite, are being widely pursued. Silicon, with a theoretical capacity of 3579 mAh g-1, lithiation voltage comparable to that of graphite, and high abundance, is considered the most appropriate alternative. The advantages of high energy density are countered by severe capacity fade, limiting the cycle life of Si-containing cells. Fundamental mechanistic understanding of lithiation and de-lithiation processes in Si-electrodes is essential to identify causes of capacity loss. Several in-situ and ex-situ microscopy and spectroscopy techniques have provided information on structural, chemical, and morphological changes of electrodes at specific states of charge and during calendar/cycle life ageing.
We adopted Energy Dispersive X-ray diffraction (EDXRD) to track structural changes in all components of pure Graphite (Gr) and Silicon/Graphite (Si/Gr = 15/73 w/w) based lithium-ion cells. Beamline 6 A-B at the Argonne Photon Source (APS), equipped with a fixed 3º angle single element Ge detector and incident white X-ray beam was used to obtain in operando EDXRD spectra from CR2032-type coin cells. The coin cells were assembled with a Li metal counter electrode, and 1.2 M LiPF6 in EC/EMC (3:7 w/w) + 10 wt% FEC as the electrolyte, and underwent electrochemical cycling at a ~C/8 rate. Lattice parameters corresponding to the spectral peaks were derived from the energy of the diffracted X-rays. Variations in the average Gr layer spacing during lithiation of the pure Gr half-cell was used to calibrate an “average layer spacing vs. state of lithiation” in the Gr-component. The lattice parameters of different phases formed upon lithiation and delithiation of Si and graphite were estimated which can, thus, be used to obtain the extent of lithiation in Si and in graphite quantitatively at every state-of-charge. The consequences of this lithiation-delithiation behavior will be highlighted during our presentation.

Acknowledgement:

The authors acknowledge colleagues at Argonne, especially S. Trask, B. Polzin, A. Jansen, and D. Dees. The electrodes and electrolytes are from Argonne’s Cell Analysis, Modeling and Prototyping (CAMP) Facility, which is supported within the core funding of the Applied Battery Research (ABR) for Transportation Program. Support from the U.S. Department of Energy’s Vehicle Technologies Program (DOE-VTP), specifically from Peter Faguy, is gratefully acknowledged. This document has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.
High Safety Electrode Additive for Preventing Internal Short Circuit Problem in Lithium Ion Battery
Authors: Yeh Nan-Hung , Wang Fu-Ming 
Published: February 2020

In January 2017, Samsung announced the reason why the Note 7 explodes and losses of more than 5 billion US dollar. According to their explanations, it was caused by the internal short circuit problem in the lithium ion battery. Currently, there is no effectively solution for eliminating the internal short circuit problem owing to the sudden accident.
In this research, a new technology has been developed, which can be used to terminate the thermal runaway and promise the safety performance of lithium ion battery. High voltage layer-type cathode material LLNNO (Li1.2Ni0.2Mn0.6O2) is employed and combined with this safety electrode additive for investigation. In terms of the results, Fig. 1 shows that the electrode additive significantly enhances the cycle performance at 60oC. In addition, the first charge and discharge curve shows in Fig. 2 that the power density is increased by the safety additive, indicating the Li+ diffusion pathway is well established on the electrode’s surface. This electrode additive not only provides high thermal stability on electrochemical reaction, but the columbic efficiency of charge-discharge is also enhanced.

Figure 1
Surface Modification of 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2 with SnO2 Cathode Material for Lithium Ion Batteries
Authors: Luo Hongze , Fikeni Lusanda , Manquthu Sinethemba Patricia , Seteni Bonani , Rapulenyane Nomasonto , Mathe Mkhulu K. , Wen Lei 
Published: February 2020

Lithium and manganese-rich xLi2MnO3·(1−x)LiMO2 (M=Ni, Co, Mn) composite cathode materials are one of the most investigated cathode materials due to their ability to provide high discharge capacity. However, xLi2MnO3·(1−x)LiMO2cathode materials suffer from high initial irreversible capacity and poor cycling stability. The development of this type composite cathode materials for lithium ion battery is still the challenge for meeting current and future energy storage requirements.
The surface modification of the materials is an effective way to overcome those disadvantages according to many work have been reported. In this work, we report that the discharge capacity and cycle performance of 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2 was significantly improved though SnO2 surface modification. The X-ray diffraction study confirms that the material has layered LiMn0.5Ni0.5O2 structure along with the formation of the superlattice ordering of Li2MnO3 without any major change in the crystal structure with SnO2 surface modification. The lower resistance to charge transfer in the SnO2 modified sample is responsible for its better performance.
Lithium Molybdenum Oxyfluorides As High-Capacity Positive Electrodes for Rechargeable Lithium Batteries
Authors: Takeda Nanami , Hoshino Satoshi , Ikeuchi Issei , Natsui Ryuichi , Nakura Kensuke , Yabuuchi Naoaki 
Published: February 2020

The demand for the increase in energy density of rechargeable lithium batteries are still growing. Recently, the use of two-electron redox of vanadium ions coupled with a high electronegativity anion in the crystal lattice is proposed as an effective strategy to enhance the energy density of positive electrode materials.[1] Theoretical capacities of lithium insertion materials depend on both total extractable lithium ions and electron numbers in the structure of positive electrodes. Therefore, in addition to the lithium-enrichment in the structure, the use of multi-electron redox processes for transition metals is expected to be an important strategy to further increase energy density of positive electrode materials. We have recently proposed a new lithium-excess oxide, Li9/7Nb2/7Mo3/7O2, which delivers a large reversible capacity of ca. 290 mAh g-1 based on highly reversible three-electron redox of Mo3+/Mo6+.[2] Three-electron redox of molybdenum ions is expected to be a promising system to further increase energy density of positive electrode materials with less transition metal ions. Nevertheless, redox potential of Mo3+/Mo6+in the oxide framework structure is relatively low for positive electrodes.
In this study, to increase in the redox potential of three-electron redox reaction of Mo3+/Mo6+, a mixed anion system, oxyfluorides, is targeted. Crystal structures and electrode performance of a new series of xLiF–LiMoO2 binary system, Li1+x
MoO2F
x
, as oxyfluoride positive electrodes are systematically examined. The highest theoretical capacity based on Mo3+/Mo6+ is expected for x = 2 (Li3MoO2F2) in this binary system. Li3MoO2F2 was prepared by mechanical milling from LiMoO2 and LiF. A mixture of LiMoO2 and LiF was mechanically milled with a ZrO2 container and balls. Li3MoO2F2 is found to crystallize into an anion-/cation-disordered rocksalt structure with low crystallinity. Electrochemical properties of Li3MoO2F2 before and after mechanical milling are compared in Figure 1. The sample after mechanical milling delivers a large reversible capacity of ca. 280 mAh g-1, which nearly corresponds to that of theoretical capacity based on the two-electron redox reaction of Mo3+/Mo5+. However, higher average voltage for the molybdenum oxyfluoride is evidenced compared with those of oxides.[2]
From these results together with structural and electrochemical data of Li1+x
MoO2F
x
(x= 0.5, 1, and 1.5), we will discuss the feasibility of molybdenum oxyfluoride materials with multi-electron redox reactions as positive electrode materials for rechargeable lithium batteries.

References

[1] R. Chen et al., Adv. Energy Mater.,
5, 1401814 (2015).
[2] S. Hoshino, et al., and N. Yabuuchi, ACS Energy Letters, 2, 733 (2017).

Figure 1
Surface-Modified Li4Ti5O12 for High Stability and Rate Performance Anode Materials
Authors: Yang Guijun , Kang Ji Hoon , Kang Jin Kyeong , Park Jong Won , Jung Yongju 
Published: February 2020

Lithium titanium oxides have attracted great attention worldwide for use in long-life applications such as electric vehicles and energy storage systems. Because Li4Ti5O12 (LTO) operates at a higher voltage range (~1.5 V vs. Li/Li+) and experiences little volume change, excellent structural stability and safety are ensured during cycling without the formation of Li dendrites. However, it is well known that LTO materials have a drawback in rate property due to their poor electric conductivity, which has limited their practical applications to long-life lithium batteries until now [1].
So far, various approaches have been presented to overcome this issue, including different metal ion doping [2], surface treatment with conductive materials [3], synthesis of nanomaterials [4], and partial reduction of surface Ti4+ to Ti3+ by hydrogen [5]. However, most of methods are considered complicated and expensive processes in the aspect of a large scale production.
In this work, we fabricate various Li4Ti5O12 materials with different Ti3+ content through a carbothermal reduction process and intensively investigate the effect of Ti3+ on their electrochemical performances. In addition, we suggest an optimal surface composition of Li4Ti5O12 materials enabling high current operation as well as high capacity.
References
1. T. Ohzuku, A. Ueda, N. Yamamoto, J. Electrochem. Soc., 142, 1431 (1995).
2. D. Dambournet, I. Belharouak, J.W. Ma, K. Aminev, J. Power sources, 196, 2871 (2011).
3. G.N. Zhu, H.J. Liu, J.H. Zhuang, C.X. Wang, Y.G. Wang, Y.Y. Xia, Energ environ sci., 4, 4016 (2011).
4. Y.G. Wang, H.Q. Li, P. He, E. Hosono, H.S. Zhou, Nanoscale, 2, 1294 (2010).
5. J.X. Qiu, C. Lai, E. Gray, S. Li, S.Y. Qiu, E. Strounina, C.H. Sun, H.J. Zhao, A.Q. Zhang, J. Mater. Chem. A, 2, 6353 (2014).